Introduction to Anatomy PDF

Introduction of Anatomy Lecturer Fatih KARAMUS  Ways to Become a Successful Student in Anatomy Believing that you will succeed first Determining your working method Studying regularly for classes Prepare and attend theoretical and practical lessons in advance Take advantage of d...

Introduction of Anatomy Lecturer Fatih KARAMUS  Ways to Become a Successful Student in Anatomy Believing that you will succeed first Determining your working method Studying regularly for classes Prepare and attend theoretical and practical lessons in advance Take advantage of different sources Solving question examples Making time for medical English Anatomy Study Methods at Altınbas University Theoretical Lesson Practical Lesson Model Slide Anatomical Models Cadaver Applications Inspection Palpation Which books can you prefer? You are free to choose any kind of anatomy books… Our university has a Complete Anatomy 2024 subscription. You can access via your INSTITUTIONAL e-mail. History of Anatomy It is accepted that the history of anatomy began with anatomical pictures found in finds from ancient times. In these paintings, it is understood that people drew the animals they hunted and their organs on the cave walls. In the findings obtained later in different parts of the world, it is seen that the first dissection was performed on dead animals and the first anatomy information was obtained.  In Egypt, this information was conveyed through papyri. Mesopotamians valued the liver very much, In India, anatomy was accepted as the basic education in medicine, Written information about the first history of anatomy can be found in the Edwin Smith papyrus [B.C. 1600], the first written records about anatomy date back to Hippocrates, who was born on the island of Kos [B.C. 469-399]. Hippocrates (Hippokrates of Kos) KOS ISLAND  Hippocrates made judgments that were truly surprising for that period, and made significant contributions to anatomy, for example, by making the correct definition of the skull bones. Hippocrates' famous saying "Primum nihil nocere" (first do no harm). Secundum cavere! Tertium sanare! Hippocrates; Because of these contributions to medicine, he is considered the Father of Medicine.  Aristotle [B.C. 384-322] used the word "Anatomy" for the first time in his works and gave information about systems. Students of Hippocrates, B.C. In the 4th century, they described the valves of the heart, and some thought that after death, blood accumulates in the veins and air circulates in the arteries because the arteries appear empty. Herophilus [B.C. 335-280]; He was born in Kadıköy and is the person who initiated the real dissection in anatomy. Therefore, he is considered the first anatomist. In addition to cadaver dissections, he also performed live dissections on many prisoners…  Claudius Galenus=Galen (AD 129-201) He studied animal anatomy to learn human anatomy and tried to see the connection between morphology and function. He wrote the work "Anatomical Procedure" about Osteology, Myology, Arthrology and Angiology. This work was used until the late Middle Ages.  Later, the studies of Turkish, Arabic and other scientists made great contributions to anatomy and medicine. Ibn-i Sina [A.D. 980-1037] He was known to Europeans as Avicenna, and in his book "el-Kanun fi't-Tıbb" (The Law of Medicine), he placed anatomical descriptions among the texts in books describing diseases. This book was used as a textbook in the West for 400 years. Hippocrates held the liver responsible for blood circulation and regarded the heart as a vasodilator. Ibn Nefis [A.D. 1210-1288] contributed greatly to the development of anatomy dissection techniques with the autopsies he performed. In 1242, he was the first person to accurately describe circulation in humans. History of Anatomy Leonardo da Vinci [A.D. 1452-1519]; He made great visual contributions to anatomy by drawing pictures of bones, muscles and organs. Andreas Vesalius [A.D. 1514-1564]; It played an important role in the establishment of modern anatomy and anatomy became an independent branch of science. Vesalius examined many cadavers. In addition to many of Vesalius's works, his work "De Humani Corporis Fabrica" (Mechanics and structure of the human body), published in 1543, is one of the important works and was taught as an anatomy textbook in European countries for many years. For this reason, Vesalius is considered the "Father of Anatomy". Here the dead teach the living  Gabriele Falloppio [A.D. 1523-1562] is one of the important anatomists. He made many anatomical discoveries and named them (Fallopian tube) and published the book "Observationes Anatomicae". Hieronymous Fabricius [A.D. 1537-1619]; He named Falloppio the valves in the veins. Fabricius William Harvey [A.D. 1578-1657] announced that he discovered the human circulatory system in 1628 after some experiments, and the book he wrote on this subject (Exercitatio anatomica de motu cordis et sanguinis in animalibus) broke new ground in anatomy and physiology. Gray Sobotta With his drawings on anatomy, English anatomist and surgeon Henry Gray [M.S. 1827-1861] with his book "Gray's Anatomy", German anatomist Johannes Sobotta [1869-1945] Netter and American medical doctor and medical illustrator Frank H. Netter [1906-1991] made great contributions to anatomy with their atlases.  Marcello Malpighi, an Italian biologist, and physician, pioneered microscopic anatomy and studied the histological structure of human tissues using a microscope. Falloppio Fabricius Eighteenth Century In England and Scotland, medical colleges used formalin to preserve cadavers for anatomy studies. John Hunter and William Hunter, surgeons, and anatomists, established anatomy museums in London and Glasgow. Sobotta Gray Karl Ernst von Baer (1792-1876), a Baltic German scientist, focused on human organ development and is regarded as the father of modern embryology. Netter  Nineteenth Century The dissection of human cadavers for medical school anatomy studies became mandatory in London and Scotland. Physicist Wilhelm Conrad Roentgen (1845-1923) was the first to notice X-rays, marking the beginning of radiological anatomy in 1895. In Türkiye, Physician Şanizade Mehmet Ataullah Efendi [1771-1826] contributed greatly to anatomy education by writing the book titled Teşrih = Anatomy [Mirat-ül Ebdan fi Teşrih-i Aza-ül İnsan]. This book is considered to be the first printed medical work in our country, and the book contains detailed dissection information as well as general medical information. The founder of modern anatomy in Turkey is Mazhar Pasha [1845-1920], one of the Turkish anatomists. Throughout this history, in addition to the development of anatomy, the problem of cadavers, which is the most important educational tool, has always continued.  In England, the anatomy law was passed by the parliament in 1832, and with this law, it became legal for medical schools to use unclaimed and posthumously donated corpses for anatomical studies. The first dissection on a cadaver in Türkiye was made in 1841 with the decree of Abdulmecid I. Today, abandoned and donated corpses are used for anatomy courses in medical schools. Procedures regarding cadaver importation still continues. In addition to cadavers, plastic models and plastinated cadavers began to be used in many faculties. Starting from the 19th century until today, many valuable anatomists have been trained in our country. These scientists also trained very valuable anatomists, carried out a lot of research and left many written and visual works. Plastination: Gunter von Hagen PRINCIPLES OF PARTICIPATION IN ANATOMY LABORATORY 1.Each student must participate in practical lessons in their assigned group, at their designated table. Changes to groups or tables are NOT permitted, regardless of the reason. 2.Attendance for the practical lesson will be recorded at the end of the session. Each group's attendance will be taken at their own desks. Signatures of students attending the wrong group will be considered invalid. Only signatures given during their own group's session will be accepted. 3.Students must arrive at the laboratory on time for their course. Those not present at the exact start time will NOT be permitted entry, nor will they be allowed to leave the laboratory early, except in cases of special need. Students arriving late will not be able to join other groups for the practical course. 4.Anatomy laboratory courses are organized and finalized into four groups by the academic staff responsible for the course. 5.Students must attend the laboratory with all educational materials related to the course and should review their notes in advance. 6.Students who do not wear white coats will not be allowed to enter the laboratory for any reason. DAMAGE TO THE MODELS WILL NOT BE ALLOWED, IT IS PROHIBITED What is Anatomy? Terminology? Anatomy; It is the branch of science that studies the normal structure of the human body, its organs, the location of these organs and the relationship between them. Cells constitute the basic building blocks of the human body. Among these cells, those with the same purpose come together to form tissues, tissues come together to form organs, and organs come together to form systems. What is Anatomy? Terminology? Gross Anatomy (Systems/Regions) Microscopic Anatomy (also known as histology) Clinical Anatomy Neuro Anatomy Radiological Anatomy Functional Anatomy Developmental Anatomy (also known as embryology) Most universities in Türkiye only use Latin terminology as Terminologia Anatomica.  Please note that our lesson is medical terminology, not Latine or English. L: Sulcus tendinis musculi flexoris hallucis longi dexter E: Groove for tendon of flexor hallucis longus muscle of right talus Terminology? It is a branch of science that deals with terms. As in every field of science, there are words that have a special meaning and have a certain meaning in the Department of Anatomy, and these words are called "terms". Medical terms have gradually taken shape until today. The terms were first dominated by the Egyptian language, then by Greek, and then by Latin. Many terms continue to be used in both Latin and Greek. A special medical language consisting of approximately 10,000 words is used in the field of health, which is called "Medical Terminology" (there are 125,000 medical terms in the Dorland Medical Dictionary). Terminology? Learning anatomical terminology is similar to learning a new language. Anatomical language is a fundamental medical terminology that facilitates communication among various health professionals. Mastering the anatomical alphabet is essential for progressing in anatomy, as it serves as the foundation for further medical knowledge. For example, when describing the terms "front" or "behind" in anatomy, it is necessary to use anatomical terminology: "anterior" for front and "posterior" for behind.  Lingua Latina (Latine Language) It is a language spoken by immigrants who migrated to Italy from northwestern Europe and settled in the region called Latium near Rome. This language, which was later used by the Romans, began to be widely used over time. Foreign terms, especially from Greek, entered Latin from the societies they were in contact with, and Latin was enriched with these added terms. Although Latin is widely used in medical education, it is not a living language today.  If there was no common language, the terms would change according to each country as follows. Meanings of liver in different languages Karaciğer - Turkish Hepar - Grek Liver – English Qaraciyər – Azerbaijani Turkish ‫ اﻟﻛﺑد‬- Arabic Higado - Spanish Le foie - French Fegato - Italian Die Leber - German Figado - Portuguese De lever - Dutch Maksan – Finnish Leveren – Danish  ANATOMY TERMINOLOGY [Terminologia Anatomica] Anatomy was the first branch of science to define its terms in terminology. For the first time, at a meeting in Basel, Switzerland, in 1895, it was determined how the terms would be used and written (BNA = Basel Nomina Anatomica). Later, the book called "Nomina Anatomica", which determined the international use of anatomy terms, was published. In the following years, world anatomists gathered at regular intervals and determined new terms or terms to be changed and published them. Most recently, a study called Terminologia Anatomica (TA) was conducted and published in 1998. But new terminology studies continue. in front of at the back, behind placed internally, inside outside below above below located between something extreme, far above around around inside outside layer in front after, behind low, below above normal, above normal overgrowth big, gross small related with hot someting, fire fake, not optimal half half one one two two three three four, four time more four, four time more multiple multiple  This table shows some usage of medical prefixes. G: Greek L: Latine The Anatomical Position 1. The anatomical position is the standard reference position of the body used to describe the location of structures. 2. The body is in the anatomical position when standing upright with feet together, hands by the side and face looking forward. 3. The mouth is closed and the facial expression is neutral. 4. The rim of bone under the eyes is in the same horizontal (also called as transverse or axial) plane as the top of the opening to the ear, and the eyes are open and focused on something in the distance. 5. The palms of the hands face forward with the fingers straight and together and with the pad of the thumb turned 90° to the pads of the fingers. The toes point forward.  Positions The supine position is when a person rests on their back with their face upward. In a supine posture, the patient lies face-up, with their head supported by a pad or pillow and their neck in a neutral position. The prone position is when a person is lying on their stomach and their face facing downwards. In a prone posture, the patient's body is flat, with the chest down and the back up. In terms of anatomical positioning, the dorsal side is up, and the ventral side is down.  Positions The lateral position is when a person lies on one side of their body, either the right or left lateral side. In the lateral position, pillows are strategically placed along the patient's back and possibly buttocks. A pad is placed between the patient's contracted legs to prevent hip adduction and internal rotation. The lithotomy position is when a person lies supine with their hip joints flexed and abducted and their knee joints partially flexed. In the lithotomy position, the patient is on their back with hips and knees flexed and their thighs apart. This position is commonly used in vaginal examinations and childbirth. Anatomical Planes In the anatomical position, there are four imaginary flat surfaces or planes that traverse the body. These planes are the median, sagittal, coronal (frontal), and horizontal (transverse) planes. These imaginary planes intersect the body, resulting in various cuts or slices of various organs and systems. mid Anatomical Planes The median plane, also known as the mid-sagittal plane, is a specific type of sagittal plane that passes through the body's center, longitudinally dividing it into equal right and left halves. This plane aids in the study of symmetry and bilateral structures. The right and left description of the body is done in this plane. The sagittal plane is a plane situated on one or the other side of the median plane and parallel to it, termed the paramedian or sagittal plane. It runs parallel to the body's midline. A structure located closer to the median plane of the body compared to another structure is described as medial to the other. Likewise, a structure positioned farther away from the median plane than another structure is defined as lateral mid to the other. Anatomical Planes The frontal (coronal) plane is a vertical plane that intersects the body at a right angle to the sagittal plane, dividing it into anterior (front) and posterior (back) sections. It is commonly employed for examining structures from a front-to-back viewpoint. The terms anterior and posterior are used to indicate the front and back of the body, respectively. When describing the relationship between two structures, one is considered anterior or posterior to the other based on its proximity to the anterior or posterior body surface. The transverse (axial) plane is a horizontal plane that divides the body into superior (upper) and inferior (lower) sections. mid  Terms to describe location Anterior (or ventral) and posterior (or dorsal) describe the position of structures relative to the " front" and " back" of the body. Medial and lateral describe the position of structures relative to the median sagittal plane and the sides of the body. Superior and inferior describe structures in reference to the vertical axis of the body. Descriptions of the directional terminology and relationships are given below. Anterior: Front Posterior: Behind or back Ventral: Towards the body's front Dorsal: Towards the body's back Proximal: Closer to the trunk or the location of the body part's origin Distal: Away from the trunk or the location of the body part's origin Superior: Towards the head's top Inferior: Towards the feet Cranial: Towards the head Caudal: Towards the tail Descriptions of the directional terminology and relationships are given below. Median: Midline of the body Medial: Towards the median Lateral: Away from median External: Towards the superficial surface Internal: Away from the deep surface Superficial: Nearer to the surface Deep: Away from the surface Palmar: Anterior hand or palm of hand (palmar) Dorsal (of hand): Posterior surface of hand (dorsum) Plantar: Inferior surface of the foot (sole) Dorsal (of foot): Superior surface of the foot (dorsum)  The Anatomical Terms of Movements Movements in the body generally occur at joints, which are connections between two or more bones. These movements are supported by body muscles. Examples of joints include the shoulder and knee. Additionally, specific structures like the lips, tongue, and eyelids have individual movement capabilities. These movements can occur in various directions and degrees of motion and are classified into different types. To define movements at joints, two aspects are considered: the axis or fulcrum around which the body part moves and the plane of the movement. It can be challenging to understand these movements without observing them in action. Flexion: Decreasing the angle formed by two structures. Extension: Increasing the angle formed by two structures. Plantar flexion: Flexion of the plantar (bottom) surface of the foot. Dorsiflexion: Flexion of the foot's dorsum (top) portion. Abduction: Moving away from the midline Adduction: Moving towards the midline. Protrusion: Straight forwards or forward movement (movements of tongue and mandible). Retraction: Moving backward and medially simultaneously. Depression: Moving downward. Elevation: Moving upwards. Medial (internal) rotation: Spiral movement towards the midline. Lateral (external) rotation: Spiral movement away from the midline. Inversion: The plantar side of the foot is rotated in the direction of the median plane. Eversion: The foot is rotated away from the median plane on the plantar side. Protraction: Moving forwards and laterally simultaneously. Retrusion: Moving backward (movement of tongue and mandible). Flexion (trunk): Side (lateral flexion) or forward (anterior flexion) bending. Extension (trunk): Bending backward. Pronation: The radius is rotated medially, causing the palm to face posteriorly (if in anatomical position) or inferiorly (if the elbow is bent). Supination: Lateral rotation of the radius, resulting in the palm facing anteriorly (if the elbow is in an anatomical position) or superiorly (if the elbow is flexed). Circumduction: A coordinated movement that begins with flexion and progresses through abduction, extension, and adduction. Deviation: The wrist joint can move in either direction (radial deviation or ulnar deviation). Opposition: Using the thumb of the same hand to touch the pad of any of your fingers. Reposition: Separating any of your fingers' pads from the thumb of the same hand. Rotation (trunk): Twisting motion towards or away from the midline (left or right). The Anatomical Terms of Movements Surface Landmarks The names of surface areas on the body have been assigned in various ways. For instance, the bones comprising the skull are named according to regions such as the frontal, temporal, and occipital areas. The surface landmark of pectoral regions Clavicle Jugular notch Manubrium of sternum Sternal angle (2nd costal cartilage) Body of sternum Xiphoid process of sternum Nipple (4th intercostal space) Ribs of the pectoral region Surface Landmarks These landmarks, can be palpated regardless of an individual's size or body shape. They are distinct structures that can be felt or seen directly and remain consistent across individuals, unless there are unique anatomical variations. Surface landmarks can also be identified in areas such as the abdomen or thorax, including foramina for neurovascular bundles, suture intersections, and bony structures. Surface Anatomy Surface anatomy refers to the study of the external aspects of the body. It is crucial in evaluating normal anatomy in medical imaging and describing the location, appearance, and relationships of observable anatomical structures. Anatomical landmarks are specific locations on the body that can be clearly defined and accurately located. These landmarks include foramina for neurovascular bundles, intersections of sutures, and bony processes. Surface anatomy also involves understanding the human body's shape, proportions, and surface landmarks, which correspond to deeper structures that are not directly visible, both in static and dynamic positions. Anatomical Regions Anatomical Regions All anatomical regions are identified by accurate landmarks, resulting in universally accepted terms that healthcare professionals immediately recognize and understand These landmarks are provided by easily tangible or visible structures, referred to as surface anatomy. Regions of the Head and Neck The head and neck have various regions that are named based on the anatomical components they include. These regions are not defined by precise planes. Some of these regions include the frontal, orbital, infraorbital, nasal, oral, mental, sternocleidomastoid, lateral cervical, posterocervical, buccal, parotideomasseteric, infratemporal, zygomatic, temporal, occipital, and parietal regions. There are regions such as the submandibular, submental, carotid, and muscular triangles and the supraclavicular, jugular, and retromandibular fossae.  Anatomical Regions Regions of the Lower Extremity The lower extremity consists of the hip, gluteal, thigh, knee, leg, ankle, and foot. The regions of the lower limb include the femoral triangle, gluteal, femoral (anterior, posterior), genicular (anterior, posterior), popliteal, crural (anterior, posterior), lateral retromalleolar, dorsal, plantar, and calcaneal regions. Anatomical Lines Anatomical lines are imaginary lines drawn vertically or horizontally across an upright. One important line is the line of symmetry, which is the imaginary line along which body can be folded to create a perfect match between its two halves. For example, human face exhibits symmetry, with only one line of symmetry. Surface Anatomical Lines Several lines and surface landmarks can be identified on the trunk (thorax and abdomen These include the sternal line, parasternal line, midclavicular line, anterior/middle and posterior axillary lines, paravertebral line, scapular line, ribs, sternum, vertebral spine processes, clavicle, and pectoral muscles. These landmarks provide reference points locating and describing specific regions on the surface of the body. Anatomical Lines Various Body Regions The body regions consist of distinct zones or regions formed by connecting imagine lines at various points. These regions include the presternal region, infraclavicular fossa: clavipectoral triangle, deltoid region, axillary region, pectoral region, inframammary region, vertebral region, suprascapular region, scapular region, interscapular regio lateral pectoral region, infrascapular region, lumbar triangle, sacral region, gluteal regio and anal region. These regions provide a framework for identifying and describing special areas of the body. Anatomical Lines Abdominopelvic Regions In the study of human anatomy, the abdomen is divided into four quadrants using a cross centered in the umbilicus. These quadrants provide a systematic way of describing and locating specific regions within the abdominal cavity. The right upper quadrant (RUQ) is in the upper right portion, while the left upper quadrant (LUQ) is in the upper left portion. The right lower quadrant (RLQ.) is situated in the lower right portion, and the left lower quadrant (LLQ) is in the lower left portion. Each quadrant contains various organs and structures, such as the liver, gallbladder, stomach, spleen, intestines, and appendix.  Anatomical Lines Abdominopelvic Regions In human anatomy, the abdomen is further divided into nine regions, forming a grid pattern created by two horizontal and two vertical lines. The two vertical lines pass through the middle of the clavicles and the middle of the inguinal ligaments, while the two horizontal lines divide the abdomen. One horizontal line crosses the subcostal space directly, and the other goes through the iliac tubercles. These four lines divide the anterior abdomen into nine distinct regions: the right hypochondriac region, epigastric region, left hypochondriac region, right lumbar region, umbilical region, left lumbar region, right iliac region, hypogastric region, and left iliac region. These regions provide a standardized anatomical reference or describing the location and orientation of structures within the abdomen. Anatomical Lines Cavities of the Body Most anatomical structures are found within cavities, which are fluid-filled areas. Membranes and other structures divide these bodily cavities, providing protection, lubrication, and reducing friction during organ movement. Each cavity contains unique neurovascular structures and organs specific to its location. For example, the skull protects the brain, while the vertebral column safeguards the spinal cord. The thorax contains the heart and lungs, the abdomen has the internal organs, and the pelvis contains the reproductive organs. Anatomical Lines There are two major body cavities: the ventral or anterior cavity (including the thorax, abdomen and pelvis) and the dorsal or posterior cavity (comprising the cranial and spinal cavities). The Anterior cavity is further divided into smaller cavities, namely the thoracic and abdominopelvic cavities. The thoracic cavity is subdivided into the superior, anterior, middle, and posterior mediastinal cavities and the two pleural cavities. The abdominopelvic cavity encompasses the abdominal and pelvic cavities, separated by the diaphragm. On the other hand, the Dorsal or Posterior cavity consists of the cranial and vertebral cavities. These cavities play a crucial role in housing and protecting vital organs and structures within the body. Introduction of Osteology Lecturer Fatih KARAMUS General Informations about Bones CHARACTERISTICS OF BONE Bone is a living tissue that supports the body's skeleton. It is a complex, rigid, inflexible, hard, vascular, and dynamic connective tissue. Bones are composed of cells and intercellular matrix substances. A fibrous membrane surrounds the bone called the periosteum (fibrovascular osteogenic membrane). Bone growth occurs through surface accretions, also known as appositional growth.  There are three types of bone cells: osteoblasts, osteocytes, and osteoclasts. Characteristics Of Bone Osteoprogenitor or osteogenic cells are bone stem cells that play an essential role in bone healing and growth. Osteogenic cells transform into osteoblasts, which are responsible for bone formation. Osteoclasts are bone-resorbing cells, and osteocytes are mature bone cells. The intercellular matrix of bone contains 15- 20% water, 30-40% collagen protein with a minimum of proteoglycans, and 50-60% inorganic mineral salts such as calcium, phosphorus, sodium, and others. The presence of calcium in bone causes radiograph pictures to appear opaque. Characteristics Of Bone The bone matrix consists of inorganic matter (calcium hydroxyapatite) and organic matter (which provides flexibility to the bone). Dense bundles of collagen fibers are embedded in an amorphous ground substance made of protein polysaccharides and hyaluronic acid, forming the organic matter. Osteoblasts secrete all these components. The most abundant protein in bone is collagen, which creates a soft framework. Calcium phosphate is a mineral that adds strength and hardens the bone structure. The combination of collagen and calcium makes the bone strong and flexible enough to tolerate stress. Bone Function Bones serve several vital functions in the body, including: Providing the skeletal frame and body architecture. Preventing the collapse of the body. Protecting internal organs from impact- related injuries. Facilitating the movement of body parts. Supporting blood formation and the generation of red and white blood cells. Participating in the buildup and release of substances and minerals. Bone Vascularization Blood enters the endosteal cavity through periosteal vessels, then flows through marrow sinusoids before exiting via numerous small vessels close to the articular surfaces. Nutrient arteries pass obliquely through the cortex before dividing into longitudinally directed branches. Reductions and disruptions in bone vascular supply are primarily linked to bone loss and dysfunction. Bone Innervation A dense network of sensory and sympathetic nerve fibers exists in bone tissue and plays critical roles in bone modeling, remodeling, metabolism, and adaptability. The sympathetic nerve supply of bone originates in the appropriate ganglion region. For example, in the case of tibial diaphysis innervation, it descends through the sciatic nerve and primarily through the medial popliteal nerve, entering the bone alongside the nutrient artery. Bone Innervation Haversian canals typically run parallel to the bone's surface and along its long axis, containing one or two capillaries and nerve fibers. Volkmann's canals are blood and nerve supply channels that connect the periosteum to the Haversian canals.  Several anatomical features have specific technical terms that are used to describe them. Familiarize yourself with the list provided below. Diaphysis: Shaft of a bone Meatus: Outlet Epiphysis Ends or extremities of a bone, where Trochanter: A large prominence for attachment of growth takes place rotator muscles Metaphysis: Line of junction between the diaphysis Sulcus: A groove and epiphysis Sinus: A cavity in bone lined with mucous membrane Tuberosity: A rounded eminence or bulging of the Lip: Margin of a groove, crest or line bone Head: A rounded, smooth eminence for articulation Process: Marked projection, articulating bone projection Fossa: A furrow or depression Spine: Slender or pointed projection Ramus: A branch of bone Tubercle: Small nodule Symphysis: An almost immovable joint; the line of junction between bones Linea: A slight ridge of bone Suture: Seam, line of union in an immovable Condyle: An enlargement bearing an articular surface articulation Foramen: Short perforation Crest: Prominent ridge Canal: Long perforation Aperture: Opening on surface or space within a bone Bone Ossification There are two varieties of bone ossification: Intramembranous Ossifications Intramembranous ossification directly replaces the membrane with bone without intervening cartilage stages. It is found in the skull vault and several facial bones.  Bone Ossification Endochondral or Intracartilaginous Ossifications Endochondral ossification occurs in the long and short bones of the skeleton, where a model of the bone is first laid down in hyaline cartilage derived from connective tissues in the embryo. The earliest evidence of ossification is the formation of columns of cartilage cells, or chondrocytes, in specific zones: Zone of dormant cartilage cells Zone of proliferating cartilage cells Zone of hypertrophied maturing cartilage cells (The cells increase in size and secrete alkaline phosphatase). Zone of calcification (Calcium salts are deposited in the cartilage matrix). Zone of ossification (Blood vessels grow into the region from the periosteum, bringing with them osteoblasts and osteoclasts). Skeletal bones divide into two groups: Axial Skeleton (80 bones) - Cranium (29 bones: 8 neurocranium, 14 viscerocranium, 6 middle ear, 1 hyoid bone) - Vertebral column & Thorax (51 bones: 26 vertebrae, 24 ribs, 1 sternum) Appendicular Skeleton (126 bones) - Upper extremity bones (64 bones) - Lower extremity bones (62 bones) Bones’ Types and Classification There are two types of bone, compact and spongy (trabecular or cancellous). Compact bone is dense bone that forms the outer shell of all bones and surrounds spongy bone. Spongy bone consists of spicules of bone enclosing cavities containing blood- forming cells (marrow). Bones’ Types and Classification Long bones are tubular. Short bones are cuboidal. Flat bones consist of two compact bone plates separated by spongy bone. Irregular bones are bones with various shapes. Sesamoid bones are round or oval bones that develop in tendons.  Bone Classification Based on the Anatomical Shape Bones can be categorized into groups based on their overall shape, including long, short, flat, irregular, and sesamoid bones. Long bone: Long bones, such as the humerus and the metacarpals in the fingers, are longer than wide. They function to support the weight of the body and enable movement. Short bone: Short bones are roughly cube-shaped and consist mainly of spongy bone. They have a thin layer of compact bone on the exterior surface. Short bones are found in the hands and feet.  Bone Classification Based on the Anatomical Shape Flat bones: Flat bones are composed of a spongy bone sandwiched between two thin layers of compact bone. They have a flat shape and lack a bone marrow cavity. Examples of flat bones include the skull and rib bones.  Bone Classification Based on the Anatomical Shape Irregular bones: Irregular bones have unique and varied shapes. Their surfaces may be short, flat, notched, or ridged. Examples of irregular bones include the vertebrae, hip, and skull bones.  Bone Classification Based on the Anatomical Shape Sesamoid bones: Sesamoid bones are small, flat bones that resemble sesame seeds. They are embedded within tendons to provide reinforcement and reduce stress. Sesamoid bones are commonly found in the knee, thumb, and big toe, with smaller ones in the hands and feet.  Bones of Upper Limb Lecturer Fatih KARAMUS Bones of Upper Limb The bones of the upper limb consist of a total of 64 bones. They can be divided into two parts: the bones of the pectoral girdle and the bones of the free upper limb. The pectoral girdle is composed of the clavicle and scapula. These bones connect the free upper limb bones to the trunk. The scapulae are not connected posteriorly, and each is attached to the rib cage by muscles. The clavicles are rigidly attached anteriorly to the manubrium of sternum on both sides. The scapula and clavicle articulate with each other. Bones of Upper Limb Right Left Right Left Clavicle Clavicle has approximately 15-17 cm long and 2-3 cm wide, extending in the shape of a horizontal letter "S" on the front of the shoulder and thorax. It articulates with the sternum on the inside and the scapula on the outside. It connects the upper Sternal manubrium extremity to the trunk. Clavicula level indicates the border between the neck and the body. Clavicle This bone can be felt under the skin upper and lower two sides of a body (superior surface, inferior surface), two edges, front and back (anterior border, posterior border), It has two ends as (sternal end, acromial end) internal and external. Clavicle The acromial end of the clavicle features a small oval acromial facet for articulation with the scapula, which, in turn, has a corresponding facet on its sternal articular surface (sternal facet). Clavicle The inferior surface of the lateral third of the clavicle features a prominent tubercle (conoid tubercle), along with a line of roughening called the trapezoid tubercle (line), serving as attachment sites for the important coracoclavicular ligament. RIGHT SIDE Clavicle The inferior surface of the medial third of the clavicle features an impression for costoclavicular ligament. costoclavicular ligament Clavicle It is easily palpable and visible in individuals with less fat in that area, Moreover, the clavicle is the most commonly fractured bone at birth, susceptible to fractures from impacts on the shoulder due to falls with outstretched arms or direct hits. To protect these structures during clavicle fractures, the subclavius muscle, situated in the groove for subclavius on the lower surface of the bone, provides cushioning. Clavicle Clavicular fractures commonly result from falls onto the shoulder, direct trauma, or an outstretched arm. The middle section of the clavice is frequently affected by these fractures. The most common associated injuries include injuries to the surrounding soft tissues, such as the subclavian vessels, nerves, and adjacent musculature. Complications may include brachial plexus injuries, subclavian artery or vein compression, and pneumothorax (collapsed lung) in severe cases. SCAPULA SCAPULA At the back of the body Between 2-7 ribs, It has 2 faces, 3 edges, 3 angles. Articulates with humerus and clavicle Scapulae The scapula is a fat, triangular bone located at the 2nd to 7th levels of the ribs, connecting the clavicle to the humerus. It has two faces: the costal surface (anterior) and the posterior surface. Additionally, it features three borders: the superior, medial, and lateral borders, along with three angles: the superior, inferior, and lateral angles.  Scapulae The posterior surface of the scapula is convex and features a protrusion called the spine of scapula. The medial end of the spine has a triangular shape. This spine divides into two concave surfaces: the supraspinous fossa (filled by the supraspinatus muscle) and the infraspinous fossa filled by the infraspinatus muscle). Both the deltoid and trapezius muscles attach to the spine of the scapula. Costal face (Anterior face) Subscapular fossa Muscular line Subscapular muscle Scapulae The superior border of the scapula is the shortest and thinnest, displaying a slight concave shape. It includes a suprascapular notch, which is converted into a hole by the superior transverse scapular ligament. Through this opening, the suprascapular nerve passes, while the suprascapular artery and vein pass over the ligament. The lateral border of the scapula is strong and thick, situated closest to the axilla. On the other hand, the medial border is the long, medial edge of the scapula closest to the vertebral column. The superior angle is formed by the junction of the superior and medial borders, while the inferior angle is formed by the junction of the medial and lateral borders. Scapulae Furthermore, the lateral angle is formed by the junction of the superior and lateral borders and contains the head and neck of scapula. On the lateral margin of the scapula's head, there is a shallow pit called the glenoid cavity, which forms the glenohumeral joint with the head of the humerus. Above the glenoid cavity, a small riage called the supraglenoid tubercle is present, where the long head of the biceps brachii muscle attaches. Below the glenoid cavity, there is a roughened area known as the infraglenoid tubercle, where the long head of the triceps brachii muscle attaches. Scapulae The acromion is the broad, straight lateral extension of the spine of scapula. It can be easily felt outside the shoulder and articulates with the clavicle at the acroioclavicular joint. The lateral margin of the acromion is continuous with the lower edge of the spine of scapula and the acromial angle. Scapulae The coracoid process is a thick, beak- like structure that projects anterolaterally from the lateral end of the scapula. It can be palpated beneath the lateral muscle of the clavicle with deep pressure from the anterior deltoid region. Scapulae Spina scapula expands towards the medial side in a triangle shape, which is called trigonum spinae. The imaginary line connecting the two sides of the trigonum spinae is called the interspinous line. This line passes at the level of the 4th thoracal vertebra corpus or the tip of the spinal process of the 3rd thoracal vertebra. The superior and inferior mediastinum are separated by the plane corresponding to this imaginary line. It is also the level of the tracheal bifurcation, where the trachea divides into two.  Muscles’ origin and insertion points Anterior aspect Posterior aspect HUMERUS Humerus The humerus is the longest bone in the upper limb, located in the arm (brachium). It articulates with the scapula, radius, and ulna. It can be divided into three main regions: the proximal extremity, the body, and the distal extremity. Proximal Extremity: The proximal end of the humerus consists of several structures, including the head, anatomical neck, greater and lesser tubercles, surgical neck, and the upper half of the body. Humerus The head of humerus is rounded and articulates with the glenoid cavity. The lesser tubercle is a small, jagged ridge below the head, situated at the anterior proximal end of the humerus, and medial to the greater tubercle. The intertubercular groove (bicipital groove) lies between the tubercles and contains the tendon of the long head of the biceps brachii. Humerus Anatomical neck The anatomical neck is a slightly narrowed area surrounding the articular Surgical neck surface grace of the head, and surgical neck is narrowed area located just below the greater and lesser tubercles. Surgical neck is the weakest part of the bone and can be susceptible to fractures, which may damage the axillary nerve, circumflex humeral artery, and vein. The crest of intertubercular groove is a sharp edge where the pectoralis major muscle inserts, while the crest of lesser tubercle is another sharp edge where the teres major inserts.  Humerus Body Shaft: The humeral body, also known as the body of the humerus, is the middle portion of the bone. It features deltoid tuberosity, a rough of area on the lateral side of the body where the deltoid attaches. The posterior edge of the tuberosity forms a groove (sulcus) for radial nerve. This groove is most prominent between the deltoid tuberosity and the upper end of the lateral supracondylar ridge. Humerus Inside the sulcus, the radial nerve courses together with the profunda brachii artery (deep artery of the arm), and these structures can be vulnerable to injury in cases of humerus fractures. The medial supracondylar ridge and lateral supracondylar ridge are sharp edges where the fascia and muscles attach. They extend to the medial epicondyle and lateral epicondyle at the distal end. Humerus Distal Extremity: The distal end of the humerus is known as the condyle. On the lateral side is the spherical capitulum, which articulates with the head of radius. The lateral epicondyle is a small, On the medial side, there is jagged prominence on the distal, the roller-shaped trochlea, lateral side of the humerus, which articulates with the proximal to the capitulum. ulna. It is easily palpable and is the tendon of origin for several superficial forearm extensor muscles.  Humerus The medial epicondyle is a large, knob-like prominence located on the distal, medial side of the humerus, proximal to the trochlea. It is also easily palpable and forms an important surface landmark on the arm. Behind the medial epicondyle is a groove for ulnar nerve, through which the nerve passes. The ulnar nerve can be palpated and rolled toward the epicondyle. It can be susceptible to injury in medial epicondyle fractures. Humerus On the anterior side, there are two surfaces: the anteromedial surface and the anterolateral surface, which face the anterior- internal and anterior-lateral sides, respectively. The lateral margin on the outer side starts from the This sharp section is called the greater tubercle and lateral supracondylar ridge. extends downward, On the medial side, the medial gradually transforming into supracondylar ridge starts from the medial margin of the lesser a sharp edge that merges tubercle. with the lateral epicondyle. Humerus The upper half of this edge is not as pronounced, but it becomes a sharp edge as it descends, eventually merging with the medial epicondyle. These two edges form three surfaces in the lower part of the humeral body. On the posterior surface, there is a significant depression called the olecranon fossa near the lower end. Humerus The projection of the ulna, known as the olecranon, fits into this cavity. There is the radial fossa on the anterior-superior side of the capitulum, while the coronoid fossa is located The four muscles that attach to anteriorly to the trochlea. the greater and lesser tubercles are the rotator cuff muscles The radial fossa and (supraspinatus, infraspinatus, coronoid fossa provide a teres major, and subscapularis greater range of motion to muscles). the forearm. Humerus Clinical Correlation: Fractures of the humerus: A surgical neck fracture of the humerus can lead to direct injury or compression of the axillary nerve. Injuries to the axillary nerve can result in functional impairment of the shoulder joint, specifically affecting abduction and external rotation. Shaft fractures of the humerus can result in direct trauma or compression of the radial nerve. Medial epicondyle fracture ulnar nerve injuries  Medial epikondilitis (golfer’s elbow):. Lateral epikondilitis (tennis elbow): Humerus Clinical Correlation: Fractures of the humerus: Injuries to the radial nerve can lead to functional impairment of the forearm and hand, specifically affecting extension at the elbow and wrist joints. Distal part fractures of the humerus are seen rarely. But they can result in direct trauma or compression of the median and ulnar nerves and the brachial artery. Bones of the Forearm Radius The radius is the bone located on the lateral side of the forearm (antebrachium). It is responsible for pronation and supination movements. The radius articulates with the humerus, radius, scaphoid, and lunate bones. Bones of the Forearm Radius The most prominent structure at the upper end (proximal extremity) is the head, which articulates proximally with both the humeral capitulum and the radial notch of the ulna at the elbow joint. The head rests on the radial notch of the ulna and is surrounded by a circular flat articular surface known as the articular circumference. Radius The upper part of the disc- shaped head contains a shallow pit called the articular facet, covered with articular cartilage, which articulates with the capitulum of humerus. The lower part of the radial head is the neck, which narrows as it extends downwards. A noticeable protrusion in the lower-medial part of the neck is called the radial tuberosity, serving as the insertion point for the biceps brachii. Radius The body (shaft) of the radius is the elongated middle section. It has three surfaces: the anterior, posterior, and lateral surfaces, as well as three borders: the anterior, posterior, and interosseous borders. The medial border of the shaft forms a sharp crest called the interosseous border, which provides attachment for the radius and the interosseous membrane that connects to the ulna.  anterior posterior interosseus border border border anterior posterior lateral face face face Radius The lower end of the radius, known as the distal extremity, is wider chan the other parts. On the posterior face, there is a raised area called the dorsal tubercle, where the tendons of the muscles that extend to the fingers sit. On the outer side of the lower end is a projection called the radial styloid process, which extends downward. A crescent-shaped articular surface called the ulnar notch is observed on the inner side. This surface articulates with the articular circumference of the ulna. Radius Clinical Correlation: Colles fracture is a common type of fracture involving the distal end of the radius. It typically occurs as a result of a fall onto an outstretched hand, with the force transmitted up the radius to its distal end. The fracture involves a break in the radius near the wrist joint, specifically at the distal metaphysis or just above it. The fracture line is usually transverse or oblique, with the distal fragment displaced dorsally, resulting in a characteristic dinner fork deformity. Ulna The ulna is located on the medial side of the forearm. It articulates with the radius and humerus. It does not have direct contact with the wrist bones; instead, there is a disc between them. It is located on the medial and parallel to the radius in the anatomical position. Ulna The upper end of the ulna, the proximal extremity, is the thickest and strongest part. On the posterosuperior side is an elbow protrusion called the olecranon, which forms the uppermost part of the ulna and can be easily palpated. It serves as the insertion site for the triceps brachii. Ulna The anterior surface of the olecranon is somewhat concave and forms the upper part of the notch, known as the trochlear notch. The projection that limits the trochlear notch from below and extends anteriorly is called the coronoid process. Just below the coronoid process is a rough surface known as the tuberosity of ulna, to which the brachialis muscle attaches. Ulna The body (shaft) of the ulna is the elongated middle section. It tapers from top to bottom and has three borders: the anterior, posterior, and interosseous borders. It also has three surfaces: the anterior, posterior, and medial surfaces. The interosseous border is the sharp edge to which the interosseous membrane of forearm attaches. Ulna The lower end of the ulna, known as the distal extremity, contains the head. The head has an articular surface on the medial side called the articular circumference, which articulates with the ulnar notch of the radius. Below the articular surface, the articular disc is located. On the posteromedial side of the lower end, there is a projection called the ulnar styloid process. Bones of the Hand The hand skeleton consists of 27 bones and can be divided into three groups: Carpal bones (8) Metacarpals (5) Phalanges (14) Carpal Bones The carpal bones are eight small bones that form the wrist. They are arranged in two rows, with four bones in each row: proximal and distal. The scaphoid, lunate, Right Hand triquetrum, and pisiform are in the proximal row, from lateral to medial. In the distal row, again from lateral to medial, there are the trapezium, trapezoid, capitate, and hamate. Left Hand Bones of Proximal Row Scaphoid: It is the largest bone in the proximal row and most frequently fractured. The ridge on the palmar surface is called the tubercle. It articulates with the radius proximally, the trapezium and trapezoid distally, and the lunate and capitate medially. Lunate: It is a crescent-shaped bone Right Hand in the proximal row. Dislocation of the lunate often occurs, and the median nerve may be damaged in such cases. It articulates with five bones: the radius proximally, the capitate and hamate distally, the scaphoid laterally, and the triquetrum Left Hand medially. Bones of Proximal Row Triquetrum: Located on the ulnar side of the proximal row, and is adjacent to the flexor carpi ulnaris. It articulates with the ulna through the lunate laterally, the pisiform anteriorly, the hamate distally, and the articular disc proximally. Right Hand There is no direct contact with the ulna. Pisiform: It is the smallest of the carpal bones and is located in front of the other bones. The flexor retinaculum, flexor carpi ulnaris and abductor digiti minimi tendons attach to the pisiform. It articulates with the Left Hand triquetrum dorsally. Bones of Distal Row Trapezium: Located on the radial side of the wrist, between the scaphoid and the first metacarpal bone. It has a tubercle known as the tubercle. It articulates with the scaphoid proximally, the first metacarpal distally, and the trapezoid and second Right Hand metacarpal bones medially. Trapezoid: It is the smallest bone in the distal row. It articulates with four bones: the scaphoid proximally, the second metacarpal distally, the trapezium laterally, and the Left Hand capitate medially. Bones of Distal Row Capitate: It is the largest of the carpal bones, located in the center of the wrist. It articulates with the lunate and scaphoid proximally, the second, third, and fourth metacarpal bones distally, the trapezoid laterally, and the hamate medially. Right Hand Hamate: Located on the inferomedial part of the wrist, it has a hook-shaped projection called the hook on the palmar side. It articulates with the lunate proximally, the fourth and fifth metacarpal bones distally, the triquetrum medially, and the Left Hand capitate laterally. Bones of Distal Row Clinical Correlation: Fracture of the lunate bone, also known as lunate fracture, is a relatively rare but significant injury that can occur in the carpal bones of the wrist. Fractures of the lunate typically occur such as a fall on an outstretched hand or a direct impact to the wrist. Metacarpalis (I-V) There are five metacarpal bones in each hand. Each metacarpal bone has a head, body, and base from proximal to distal. The bones are identified by numbers 1 to 5, starting with the most lateral unit. The third metacarpal bone is stable, while the others are movable. Metacarpal I: It is the shortest and thickest metacarpal bone. Its base articulates with the trapezium (carpometacarpal joint). The head is less convex than the heads of other metacarpal bones and articulates with two sesamoid bones on the palmar side. The first metacarpal bone articulates with the trapezium. Metacarpal Il: It is the longest and largest metacarpal bone. The second metacarpal bone articulates with the trapezium, trapezoid, capitate, and the third metacarpal bone. Metacarpalis (I-V) Metacarpal III: Slightly shorter than the longest second metacarpal bone. The third metacarpal bone has a protuberance called the styloid process of third metacarpal. The third metacarpal bone articulates with the capitate and the second and fourth metacarpal bones. Metacarpal IV: It is shorter and thinner than the third metacarpal bone. The fourth metacarpal bone articulates with the capitate, hamate, and the third and fifth metacarpal bones. Metacarpal V: The fifth metacarpal bone articulates with the hamate and the fourth metacarpal bone. Phalanges There are 14 phalanges in each hand, with two in the thumb and three in the other fingers. They are called the proximal, middle, and distal phalanges from proximal to distal. Like the metacarpals, each phalanx has a base, body (shaft), and head. The distal ends of the first and second phalanges and the trochlea of phalanges are spool-shaped. The phalanges articulate with one another.  Bones of Lower Limb Lecturer Fatih KARAMUS Lower Extremity Bones The lower limb consists of several groups of bones, each playing a crucial role in providing support, mobility, and stability to the lower extremities. There are 62 bones in both extremities consisting of the pelvic bones (2 bones) and the bones of free part of lower limb (60 bones). The pelvic bones are composed of two coxal bones, or hip bones, which articulate with the sacrum at the sacroiliac joints. Each coxal bone consists of three fused bones: the ilium, ischium, and pubis. Lower Extremity Bones The bones of free part of lower limb consist of the femur, the longest and strongest bone in the body. The knee joint connects the thigh to the leg, where two bones contribute to its structure: the tibia, commonly known as the shinbone, and the smaller fibula, which lies parallel to it. There is the biggest sesamoid bone in front of the knee joint, the patella. Lower Extremity Bones Within the foot, the tarsal bones provide a stable platform, with seven bones in total, including the calcaneus, talus, navicular, cuboid, and three cuneiform bones. The metatarsals form the framework of the midfoot, consisting of five bones. The phalanges consist of 14 bones, with each toe possessing three phalanges, except for the hallux, or big toe, which has two phalanges. Bones Of Pelvic Girdle The pelvic bones consist of two coxal bones or hip bones. They articulate with the sacrum at the sacroiliac joints to form the pelvic girdle. Additionally, the coccyx articulates with the inferior tip of the sacrum. Therefore, the pelvic girdle consists of the coxal bones, the sacrum, and the coccyx. It serves as the connection between the axial skeleton and the lower limb bones. Each coxal bone is formed by the fusion of the ilium, ischium, and pubis. The coxal bones articulate with the pubic symphysis anteriorly and the sacrum posteriorly. The connection between the coxal bones and the sacrum is made through the sacroiliac joint. Hip (Coxal) Bone The pelvis is a pair of bones formed by the union of three bones called pubis, ilium, and ischium, which connect the lower extremity to the trunk. These bones play a vital role in transferring body weight to the lower extremity. Ossification of the pelvis begins with the ilium, which undergoes endochondral ossification at 9.5 weeks. The development of trabecular bone in the ilium is evident from about 22 weeks of gestation. Ossification occurs from three main centers, separate for the ilium, ischium, and pubis. Hip (Coxal) Bone The ossification center of the ilium appears above the great sciatic notch around the ninth week before birth, the ossification center of the ischium emerges in the body of the bone by the fourth month, and the ossification center of the pubis appears in the superior pubic ramus between the fourth and fith months, At birth, the iliac crest, the base of the acetabulum, and the lower rims are cartilaginous. The ossification of the three parts of the acetabulum causes the formation of a Y-shaped epiphyseal cartilage between the ilium, ischium, and pubis. In the seventh or eighth year, the ossified ischium and pubis fuse to form the ischiopubic ramus. Lower Extremity Bones There are two ossification centers for the iliac crest and a single ossification center for the ischial tuberosity, anterior inferior iliac spine, and the symphysial surface of the pubis. The secondary ossification center of the acetabulum starts to fuse at 15- 17 years and becomes a single bone at 20-25 years of age (synostosis). The round cavity that articulates with the head of femur is called the acetabulum. Before the ossification process, the lines of the three fused bones form the Y-shaped epiphyseal cartilage, which can be seen in the acetabulum. Ilium The ilium is one of the three bones that make up the hip or coxal bones. It is the largest and most superiorly positioned component, consisting of the body of ilium and ala of ilium (wing of ilium) parts. The border between the ala of ilium and the body of ilium forms the upper edge of the acetabulum laterally and the arcuate line medially. It contributes to the formation of the acetabulum, occupying less than 2/5 of the body. There are sacropelvic surfaces where the auricular surface articulates with the sacrum, and it has a gluteal surface where the attachment lines of the gluteal muscles are located. It also has an iliac surface, and the iliacus muscle attaches to the iliac fossa. Ilium The gluteal surface is limited to the iliac crest above and the acetabular margin below. The anterior gluteal line is the longest gluteal line, followed by the posterior gluteal line. The inferior gluteal line is the last gluteal line, and the groove between the inferior gluteal line and the acetabulum is the supra-acetabular groove. The rectus femoris muscle has a reflected head attached to this groove. The sacropelvic surface is formed by the rough area called the iliac tuberosity, and the ear-shaped articular surface that articulates with the sacrum is called the auricular surface. The auricular surface has an anterior groove called the preauricular groove. Ilium The free thick upper edge of the ilium is called the iliac crest. The highest point of the iliac crest lies at the level of the L3-4 intervertebral disc. There are three prominent projections on the iliac crest where the anterolateral abdominal muscles attach. The outer lip is called the outer lip, the middle is the intermediate zone, and the inner is the inner lip. A projection called the tuberculum of iliac crest is present on the outer lip. The anterior superior iliac spine (ASIS) is located at the anterior end of the iliac crest, with the anterior inferior iliac spine (AllS) just below it. The posterior superior iliac spine (PSIS) is found at the posterior end of the iliac crest, and the posterior inferior iliac spine (PIIS) is located just inferior to it. Lower Extremity Bones The inguinal ligament, sartorius, and tensor fasciae latae muscles attach to the ASIS, while the rectus femoris muscle and iliofemoral ligament attach to the AllS. The anterior superior iliac spine and the anterosuperior part of the pubis lie in the same vertical plane. The iliopubic ramus is the raised area at the junction of the ilium and pubis. The arcuate line is continuous anteriorly with the pecten pubis (pectineal line) at the sharp upper edge of the pubis. Ischium The ischium forms the inferoposterior part of the coxal bone. It is the thickest and strongest component of the coxal bone, consisting of two parts: the body and the ramus of ischium. The most protruding rough part on the lower back of the ischium is known as the ischial tuberosity, which is the portion of the bone that contacts the ground when sitting. The sacrotuberous ligament and hamstring muscles attach to the ischial tuberosity. A little more than 2/5 of the ischium's body contributes to the formation of the acetabulum. The posterior border of the ischium is divided by two notches called the greater sciatic notch and lesser sciatic notch. The ischial spine lies between these notches and serves as the attachment site for the sacrospinous ligament. Ischium Additionally, the ischial spine is an important anatomical landmark used for anesthesia of the pudendal nerve, and it lies in the same horizontal plane as the upper end of the pubic symphysis. The greater and lesser sciatic notches are perforated by two ligaments (sacrotuberous and sacrospinous ligaments) to form the greater sciatic foramen and lesser sciatic foramen. The ramus of ischium fuses with the inferior pubic ramus to form the ischiopubic ramus. In males, the anterolateral edge of the ischiopubic ramus is referred to as the phallic crest (crista phallica), and it is attached to the cavernous bodies of the penis. Pubis The pubis forms the anterior part of the coxal bone and contributes approximately 1/5 of the acetabular body. It consists of three parts: the body, superior pubic ramus, and inferior pubic ramus. The inner side of the pubis contains the symphysial surface, which forms the pubic symphysis. The pubic tubercle is an anterior projection of the pubis. The sharp edge extending from the pubic tubercle towards the inner surface is known as the pubic crest, to which the rectus abdominis and pyramidalis muscles attach. Pubis The upper edge of the superior pubic ramus is referred to as the pecten pubis (pectineal line). The anterior obturator crest is located in front of the lower edge, and the posterior obturator crest lies behind it. The obturator groove is situated between the anterior and posterior obturator crests. The inferior pubic ramus extends downward from the body and joins with the ramus of ischium to form the ischiopubic ramus. Pubis The obturator foramen is located on the anteroinferior side of the acetabulum. It is covered by the obturator membrane and is bound by the ischium and pubis. Superiorly, it is bounded by the superior pubic ramus, medially by the body of the pubis, inferiorly by the inferior pubic ramus, and laterally by the body of the ischium. The obturator membrane incompletely closes the groove, forming the obturator canal, through which the obturator vessels pass. The obturator externus muscle is attached to the outer side of the obturator membrane, while the internal obturator muscle is attached to the inner side of the obturator membrane. Acetabulum The coxal bone is located laterally. The ilium forms the superior 2/5 of the acetabulum, the pubis forms the anterosuperior 1/5 portion, and the ischium forms the posteroinferior 2/5 part of the acetabulum. The formation of the acetabulum depends on the ossification centers of the coxal bone. There are three primary ossification centers in the acetabular cartilage between the ages of 8-9. The largest ossification center is located on the anterior wall of the acetabulum and fuses with the pubis. The second ossification center is situated above the cartilage and fuses with the ilium. The third ossification center is positioned in the more posterior aspect and fuses with the ischium. The fusion between these three bones occurs at 16-18 within the acetabulum. Acetabulum The acetabulum articulates with the head of femur to form the hip joint. The part that articulates with the head of femur is known as the lunate surface, which is covered by articular cartilage. The portion of the acetabulum that does not participate in the hip joint and is filled with adipose tissue is called the acetabular fossa. The border of the acetabulum is referred to as the acetabular margin (limbus acetabuli), and the notch under this edge is called the acetabular notch. The ligament of head of femur is attached to the acetabular notch. Damage to the ligament of head of femur and the acetabular branch of obturator artery due to hip joint fracture can lead to avascular necrosis in the hip joint. Skeleton Of The Pelvis The pelvis is formed by the articulation of two coxal bones, the sacrum and the coccyx (1st-5th coccygeal vertebrae). The upper part above the pelvic inlet (entrance) is called the greater pelvis (false pelvis, while the lower part between the pelvic inlet and pelvic outlet is called the lesser pelvis (true pelvis). The space enclosed by this bony framework is known as the pelvic cavity. The linea terminalis, which forms the border between the greater pelvis and the lesser pelvis, is defined by the promontory posteriorly, the anterior edge of the ala of the sacrum, the arcuate line, and pecten pubis laterally, and the posterior edge of the pubic crest and the upper border of the pubic symphysis anteriorly. Skeleton Of The Pelvis The anterior upper edge of the first sacral vertebra forms the promontory. The promontory, along with the lateral part of the sacrum, forms the posterior borders of the greater pelvis skeleton. In contrast, the iliac fossa forms the lateral border, and the upper border of the pubic symphysis forms the anterior border. The greater pelvis contains the cecum, ilium, and sigmoid colon. In comparison, the lesser pelvis accommodates the lower parts of the urinary system, organs of the gastrointestinal system, and the internal genital system. Skeleton Of The Pelvis The axis of the pelvis conforms to the curvature of the sacrum, with its opening facing forward and connecting The pelvic outlet the middle parts of the pelvic inlet and outlet. has a rhomboid shape. The arch formed by the ischiopubic ramus on both sides is called the pubic arch, and the angle between them is called the subpubic angle. The angle of 50°-60° between the plane passing through the pelvic in et and the transverse axis is known as the pelvic inclination, while the plane passing through the pelvic outiet forms an average inclination angle of 15° with the horizontal plane. Skeleton Of The Pelvis The size of the pelvis is not dependent on sex or length. However, there are some differences between genders in terms of pelvic characteristics. The female pelvis is lighter and thinner compared to males, and the attachment sites of muscles and ligaments are less prominent. However, overall pelvic diameters are wider in females. The ala of ilium is more inclined laterally, and the distance between the anterior superior iliac spine is greater in females than in males. The pelvic inlet is broad, round, or oval in females but narrow, heart-shaped, or kidney-shaped in males. The greater pelvis is shallower and wider in females, while the lesser pelvis is shorter in height compared to males. Skeleton Of The Pelvis The distance between the ischial tuberosity is greater in females than in males, and the ischial tuberosities are oriented outward in females whereas inward in males. The distance between both acetabulums is greater in females. The subpubic angle is greater in females than in males. The greater and lesser sciatic notches are shallower in females, and the ischial spine is less prominent compared to males. The phallic crest is visible in the ischiopubic ramus of the male pelvis. The sacroiliac joints and articular surfaces are smaller in females than in males. The preauricular groove is more prominent in females than in males. Skeleton Of The Pelvis The sacrum in females is short, broad, less concave, and more inclined posteriorly, whereas in males it is long, narrow, and more concave. The angle of the promontory is wider in females. The obturator foramen is small and triangular in females, while it is large, round, or quadrangular in males. The pelvic outlet is wider in females, and the coccyx is more mobile. The acetabulum is smaller and located closer to the anterior side. Types of the Pelvis There are four types of pelvis based on the shape of the pelvic inlet: gynecoid, android, anthropoid, and platypelloid. Gynecoid Pelvis The pelvic inlet is broad and circular, and the subpubic angle is wide. This type of pelvis is the most common and suitable for standard delivery, typically found in females. Android Pelvis The pelvic in et is heart-shaped, and the subpubic angle is narrow. The interspinous distance (interspinous diameter) is small. It resembles a male-shaped pelvis, and vaginal delivery is difficult for females with this type of pelvis. Types of the Pelvis Anthropoid Pelvis The anteroposterior diameter is more prominent than the transverse diameter. It is a long narrow, and oval-shaped pelvis. The pelvic inlet is oval, and the sacrum is long. The subpubic angle is narrow, and it has a deep pelvic cavity. Platypelloid Pelvis The transverse diameter of the pelvic inlet is larger than the anteroposterior diameter. The subpubic angle is broad, and this type of pelvis is unsuitable for standard delivery. Diameters of the Skeleton of the Pelvis The pelvis is a complex bony structure crucial for supporting the body's weight, facilitating movement, and protecting vital organs. It has significant relevance in various medical disciplines, including obstetrics, orthopedics, and radiology. The diameters of the pelvis can be categorized into two groups: the inlet and the outlet diameters. Diameters of the Skeleton of the Pelvis The pelvic inlet, also known as the pelvic brim, is an important anatomical landmark that separates the pelvic cavity from the abdominal cavity and marks the entrance to the true pelvis. Understanding the diameters of the pelvic inlet is essential in obstetrics, particularly for assessing the passage of the fetal head during childbirth.  Diameters of the Skeleton of the Pelvis The pelvic inlet has several critical diameters that are clinically significant. The anteroposterior diameter, also called the conjugate diameter, is the distance between the pubic symphysis and the sacral promontory. It represents the narrowest measurement of the pelvic inlet and is crucial for determining the adequacy of the pelvis for childbirth. Another important diameter is the transverse diameter, which measures the widest distance across the pelvic inlet, extending between the lateral walls of the pelvis.  Diameters of the Skeleton of the Pelvis Similarly, the diameters of the pelvic outlet are vital in obstetrics. The anteroposterior diameter of the outlet, also known as the AP diameter, extends from the lower border of the pubic symphysis to the tip of the coccyx. It is essential for determining the fetus's ability to pass through the birth canal during delivery. The transverse diameter of the outlet represents the distance between the ischial tuberosities, the bony prominences on each side of the pelvis known as the "sitting bones." This measurement is relevant for evaluating the width of the pelvic outlet and its impact on the passage of the fetus. Diameters of the Skeleton of the Pelvis These diameters are particularly important in obstetrics as they determine the ease or difficuity of vaginal delivery. Insufficient or abnormally shaped diameters of the pelvic inlet can lead to complications during childbirth, such as obstructed labor. Obstetricians and midwives carefully assess these diameters during antenatal care to ensure the pelvis is adequate for safe vaginal delivery. For further details, please refer to the table below. Bones Of Free Part Of Lower Limb The lower extremity is divided into three regions: the thigh, leg, and foot, each consisting of specific bones. Thigh Region The femur forms the skeletal structure of the thigh. Also known as the thigh bone, it is the longest and strongest bone in the body, connecting the hip bone to the knee joint. The patella, commonly referred to as the kneecap, is a sesamoid bone located within the tendon of the quadriceps muscle and serves to protect the knee joint. Femur (Thighbone) The femur is the single bone in the thigh region. It is the longest, thickest, strongest, and heaviest bone in the human body, comprising approximately 25% of the entire body length. The vertical axis of the femur runs obliquely from top to bottom. The femur ossifies from five centers, including the head of the femur, body of the femur, greater trochanter, lesser trochanter, and distal end. Femur (Thighbone) It is the first long bone to ossify after the clavicle, with ossification beginning in the middle of the body during the seventh week before birth. Secondary ossification centers appear in the distal end at the ninth month, in the head within the first six months after birth, in the greater trochanter during the fourth year, and in the lesser trochanter between 12-14 years of age. Consequently, the head of the femur in a baby is entirely covered by cartilage and cannot be seen on plain radiographs. Femur The head of femur joins the body with the neck of femur. The angle between the longitudinal axes of the neck and body is called the colladiaphyseal angle (caput-collum- diaphyseal angle), which is nearly 150° in newborns and 126° in adults. This angle is larger in children and narrows due to the increase in accumulated load with age, eventually assuming its normal state. The widening of this angle is called coxa valga, while the narrowing of the angle is called coxa vara. In the normal position, the neck of femur is directed upward, inward, and slightly anteriorly, with an angle of 12-14° known as the anteversion angle. Femur (Thighbone) The femur has three parts: the proximal end, body, and distal end. The head of femur articulates with the coxal bone at the proximal end, forming the hip joint and connecting the lower extremity with the trunk. The head of femur is covered by articular cartilage and contains a fovea for ligament of head of femur. The ligament of head of femur attaches to the head of femur via this fovea. The greater trochanter extends from the superolateral side of the proximal end, and the lesser trochanter lies on the inferolateral side. Femur The line connecting the anterior superior iliac spine and the ischial tuberosity, passing through the top of the greater trochanter, is called the Roser-Nelaton line. The highest point of the greater trochanter should align with this line, but in cases such as hip dislocation, the greater trochanter remains above the line. This line forms the Bryant triangle from the anterior superior iliac spine to the apex of the greater trochanter, which is used to detect fractures of the neck. Femur The intertrochanteric crest is the sharp posterior ridge extending between the greater and lesser trochanters, while the anterior ridge is known as the intertrochanteric line. On, the posterior surface of the body, a line called the linea aspera runs from top to bottom, comprising three divisions: the medial lip, intermediate lip, and lateral lip. The lateral lip continues superiorly, forming the gluteal tuberosity (attachment site of the gluteus maximus muscle), while the intermediate lip continues as the pectineal line (or spiral line) and merges with the lesser trochanter, forming the attachment site of the pectineus muscle. Femur The medial lip fuses with the intertrochanteric line and continues inferiorly to the medial supracondylar line, while the lateral lip continues with the lateral supracondylar line. The parts of the distal end include the medial condyle, lateral condyle, and the intercondylar fossa located between the two condyles. The medial condyle is lower than the lateral condyle, while the lateral condyle is wider than the medial condyle. The intercondylar line lies just above the intercondylar fossa between the two condyles. The ridges above the outer surfaces of the medial condyle are called the medial epicondyle. Femur In contrast, the ridges above the outer surfaces of the lateral condyle are called the lateral epicondyle. The lateral collateral ligament of the fibula and the medial collateral ligament of the tibia attach to the lateral and medial epicondyles, respectively. In the superior part of the medial epicondyle, there is a projection called the adductor tubercle, which serves as the attachment site for the adductor magnus muscle. Femur Clinical Correlation: Femur fractures: Femur fractures can vary in their location, pattern, and severity, leading to different types of fractures. Femoral neck fracture: This type of fracture occurs in the femoral neck, which connects the femoral head to the shaft of the femur. In elderly individuals, femoral neck fractures are commonly associated with osteoporosis. These fractures can disrupt the blood supply to the femoral head, leading to avascular necrosis. Intertrochanteric fracture: This fracture involves the region between the greater and lesser trochanters. It commonly occurs due to high-energy trauma and is more prevalent in older individuals. In addition to the fractured bone, structures such as the hip joint capsule and surrounding muscles may be injured. Shaft fractures: This type of fracture runs straight across the shaft of the femur. It is ommonly caused by direct trauma or high-energy injuries. Adjacent structures, sciatic erve, and arteries of the thigh may sustain injury. Supracondylar fracture: This fracture occurs just above the condyles of the femur, near to knee joint. It is commonly caused by high-energy trauma or falls. Patella The patella is the largest sesamoid bone in the body, located within the tendon of the quadriceps femoris muscle. Several ossification centers appear in the patella between the ages of 3 and 6. The body of the bone fuses with the accessory marginal ossification centers. In some cases, ossification may extend from the lateral edge of the patella to the tendon of the vastus lateralis muscle. The patella has two surfaces: the anterior and articular (posterior) surfaces. It articulates with the patellar surface of the femur. The posterior surface is divided into two parts by an articular crest, with the larger half facing the lateral side of the body. The base of patella lies above the body, while the apex of patella lies below it. The tendon of quadriceps femoris muscle attaches to the patella, increasing the power of the muscle by increasing the insertion angle of the quadriceps femoris muscle. Tibia & Fibula There are two bones in the leg, the tibia medially and the fibula lateraliy, The tibia articulates with the femur and joins the knee joint, while the fibula does not participate in the knee joint. The tibia is thicker and stronger than the fibula because it transters body weight from the femur. The space between the two bones is called the interosseus space, which is covered by the interosseous membrane of the leg. Tibia & Fibula Tibia It is the second-largest bone in the body and is located on the anteromedial side of the leg. After the femur, it is the longest, thickest, and heaviest bone in the human body. The tibia has three surfaces (medial, lateral, and posterior surfaces) and three borders (anterior, medial, and interosseous borders). The medial surface is only covered by skin, making it easily felt from the outside and susceptible to direct trauma. It consists of a proximal end, body, and distal end. Tibia The proximal end of the tibia is thicker. It contains the medial condyle and lateral condyle on the sides, with the intercondylar eminence located in the middle on the superior surface. The superior articular surface is a concave upper surface that articulates with the distal end of the femur. The medial articular surface is larger than the lateral articular surface and articulates with the medial condyle of the femur. The intercondylar eminence contains two projections: the lateral intercondylar tubercle and medial intercondylar tubercle. Tibia Surrounding the intercondylar eminence are the anterior intercondylar area and posterior intercondylar area, which are attached by the cruciate ligaments (anterior cruciate ligament and posterior cruciate ligament) and the ends of the meniscus. The fibular articular facet is located posterolaterally to the lateral condyle and articulates with the head of the fibula. There is a tibial tuberosity present. On the posterior side of the proximal end, there is a soleal line that provides an attachment site for the soleus muscle, forming an arch. Tibia The medial malleolus is located at the distal end, and there is a malleolar groove on its posterior surface where the tendon of the tibialis posterior muscle passes behind it. The fibular notch articulates externally with the head of fibula, and the articular surface in this area is called the articular facet. The inferior articular surfaces of the tibia and fibula, specifically the medial malleolus and lateral malleolus via articular facets, articulate with the talus bone. The malleolar groove is found on the posterior surface of the medial malleolus, through which tendons pass. A fracture of the medial malleolus is referred to as a pilon fracture. Fibula (Calf Bone) The fibula is a thin, long bone that does not directly carry body weight and is not involved in the knee joint. It lies lateral to the tibia and serves as an attachment site for muscles. The flat end of the fibula comes inferiorly, and the articular surface at this end is located on the medial aspect. It has three borders (anterior, posterior, and interosseous borders) and three surfaces (lateral, medial, and posterior surfaces). The interosseous membrane of the leg taches to the inner margin, known as the interosseous border. The fibula consists of a proximal end, body (shaft), and distal end. The fibula ossifies from three centers, located in the proximal, body, and distal ends. Fibula (Calf Bone) The medial side of the proximal end of the fibula has an articular surface that articulates with the tibia. It includes a small neck of fibula, an enlarged head of fibula, and an apex of head. The articular surface medial to the head of fibula is called the articular facet. The ligament of fibular head and collateral fibular ligament attach to the apex, while the biceps femoris muscle is attached to the head. Fibula (Calf Bone) The lateral protuberance of the distal end is known as the lateral malleolus and is covered by the articular facet. Behind this facet is the malleolar fossa, and on the back of the lateral malleolus, there is a malleolar groove. The surface that articulates with the talus is called the inferior articular surface. The fibula can be used as a bone graft. Pott's fracture refers to a joint fracture involving the meial and lateral malleoli. Tibia & Fibula Clinical Correlation: Pott fracture: It also known as a bimalleolar ankle fracture, is a common injury involving fractures of both the medial malleolus and lateral malleolus of the ankle joint. It is typically caused by rotational forces or direct trauma to the ankle, resulting in severe pain, swelling, and deformity. Fractures of these malleoli can disrupt the stability of the ankle joint and lead to associated injuries of the surrounding ligaments, tendons, nerves, and blood vessels. Bones of the Foot The skeleton of the foot provides a platform to support body weight and plays an essential role in movement. Foot bones are classified into three parts based on their anatomy and function: tarsal bones (tarsus, ankle bones), metatarsal bones (metatarsus, metatarsals), and phalanges (toe bones). The foot skeleton consists of a total of 26 bones, including seven tarsal bones, five metatarsal bones, and fourteen phalanges. Bones of the Foot Tarsal Bones (Tarsus, Ankle Bones) There are seven ankle bones, which are classified as short bones. They are organized into two rows: the proximal row and the distal row. The proximal row consists of the calcaneus and talus. The distal row is formed by the medial cuneiform, intermediate (middle) cuneiform, lateral cuneiform, and cuboid bone from medial to lateral. The navicular bone is located between the proximal and distal rows. Bones of the Foot Calcaneus (Heel Bone) The calcaneus is the largest, longest, thickest, and strongest tarsal bone. It is commonly known as the heel bone due to its role in forming the heel protrusion. Located below the talus, the calcaneus transfers body weight from the talus to the ground. The calcaneus articulates with the cuboid bone on its anterior surface and the talus on its superior surface. Bones of the Foot The anterior surface of the calcaneus contains an articular surface called the articular surface of cuboid, which interacts with the cuboid bone. Additionally, the calcaneus features a prominent inward projection known as the sustentaculum tali (talar shelf), which supports the head of the talus. The Achilles tendon (calcaneal tendon) attaches to the calcaneal tuberosity of the calcaneus. On the lateral side of the calcaneus, there are two projections: the lateral process of calcaneal tuberosity and the medial process of calcaneal tuberosity. Bones of the Foot The calcaneus has three articular surfaces that articulate with the talus: the posterior talar articular surface, the middle talar articular surface, and the anterior talar articular surface. These surfaces are separated by a groove called the calcaneal sulcus, which, combined with the talar sulcus on the inferior surface of the talus, forms the tarsal sinus. Calcaneal fractures are most frequently observed in this bone. Bones of the Foot Talus (Ankle Bone) Talus is the highest tarsal bone and plays a crucial role in the foot's arch. It is the second-arsal bone, following the calcaneus. The transfer of body weight to the talus occurs e tibia. Positioned above the calcaneus, the talus supports and distributes body. It articulates with the tibia superiorly, medial malleolus medially, lateral malleolus laterally, calcaneus inferiorly, and navicular bone anteriorly. The talus consists of three parts: the head of talus, the neck of talus, and the body of talus. Bones of the Foot The superior surface of the talus body is pulley-shaped and referred to as the trochlea of talus. This portion articulates with the leg bones (tibia and fibula) and is covered with articular cartilage. The lower part of the talus body contains an articular surface known as the inferior articular surface, which articulates with the superior articular surface of the calcaneus. The head of talus articulates anteriorly with the navicular bone. Unlike other tarsal bones, the talus does not have muscle or tendon attachments, although it articulates with the tibia and fibula. Bones of the Foot Clinical Correlation: Fracture of the talus: Fracture of the talus is a rare but significant injury that can lead to various complications, with aseptic necrosis being one of the most concerning. Aseptic necrosis, also known as avascular necrosis or osteonecrosis, is the result of compromised blood supply to the talus following a fracture. The fracture disrupts the blood vessels that supply the bone, leading to ischemia and subsequent death of the bone tissue. Bones of the Foot Navicular Bone The navicular bone is situated between the proximal and distal rows of tarsal bones. It articulates with all tarsal bones except for the calcaneus. The superior surface of the navicular bone is convex and rough, while the inferior surface is irregular. Ossification of the navicular bone begins around the third year. Avascular necrosis can sometimes affect the navicular bone between the ages of 4 to 7 years, leading to a rare condition known as Kohler's disease. Bones of the Foot Cuneiform Bones There are three types of cuneiform bones: medial, intermediate, and lateral cuneiform bones from medial to lateral. The largest is the medial cuneiform, and the smallest is the intermediate cuneiform. Cuneiform bones posteriorly articulate with the navicular bone and anteriorly articulate with metatarsals I-III. They also articulate with each other and participate in forming the transverse arch of the foot. Bones of the Foot Medial Cuneiform It is the largest cuneiform bone, located on the medial side of the foot between the navicular bone and the first metatarsal bone. It has a thin and sharp ridge on the dorsal side of the foot and a wider side on the plantar side. Bones of the Foot Intermediate (Middle) Cuneiform It is the smallest cuneiform bone, located between the medial and lateral cuneiform bones. The triangular anterior surface articulates with metatarsal Il, and posteriorly it articulates with the navicular bone. It has a thin and sharp ridge on the plantar side of the foot and a wide square surface on the dorsal side. Bones of the Foot Lateral Cuneiform It articulates with the third metatarsal bone anteriorly, the navicular bone posteriorly, the intermediate cuneiform medially, and the cuboid bone distally. It has a thin and sharp edge on the plantar side of the foot and a broad, rectangular face on the dorsal aspect. Bones of the Foot Metatarsals There are five metatarsal bones, which are thin and long. All metatarsal bones consist of a base, body (shaft) proximally, and head distally. An avulsion fracture may occur in fifth bone. Additionally, a transverse fracture of the base is called a Jones fracture. The ossification of the body begins in the tenth week before birth, and the ossification of the head begins between the third and fourth years. Bones of the Foot Clinical Correlation: Fractures of the metatarsal bones: The long bones in the forefoot are common injuries that can occur due to various mechanisms, such as direct trauma, twisting forces, or repetitive stress. A