Introduction to Anatomy for Para-Medical Students PDF

Introduction to anatomy for para-medical students ANATOMICAL TERMS Anatomical Positions 1. Erect anatomical position: This is standard position used to describe the anatomy of the human body. ▪ Human body is standing erect. ▪ Eyes & face are lookin...

Introduction to anatomy for para-medical students ANATOMICAL TERMS Anatomical Positions 1. Erect anatomical position: This is standard position used to describe the anatomy of the human body. ▪ Human body is standing erect. ▪ Eyes & face are looking forwards. ▪ Upper limbs are hanging by the sides of the body. ▪ Palms are facing forwards. ▪ Thumbs are directed laterally. ▪ The lower limbs are close together to the middle line. Erect anatomical position 1 Introduction to anatomy for para-medical students 2. Supine position: The body lies on its back. 3. Prone position: The body lies on its face. 4. Lateral decubitus position: The body lies on its side (right or left). 5. Lithotomy position: The body lies on its back with flexion of hip and knee and abduction of hip joints. Supine position Prone position Lithotomy position 2 Introduction to anatomy for para-medical students Anatomical Planes 1. Median (Sagittal) plane: It is the vertical plane which passes in the middle line of the body dividing it longitudinally into equal right and left halves. 2. Paramedian plane: It is a vertical plane parallel to and nearby the median plane. It may be right or left. It divides the body into 2 vertical unequal parts. 3. Coronal (Frontal) plane: It is a vertical plane which divides the body vertically into an anterior part towards the front of the body and a posterior part towards the back. 4. Horizontal plane: It is the transverse plane which runs horizontally dividing the body into an upper and lower parts at any level of the body. Planes of the Body 3 Introduction to anatomy for para-medical students Anatomical Planes 4 Introduction to anatomy for para-medical students Terms of Position Term Meaning Anterior In front or nearer to the front of the body. Posterior Behind or nearer to the back of the body. Superior Near to the upper end of body. Inferior Near to the lower end of body. Median Exactly in the middle line Medial Nearer to the median plane. Lateral Away from the median plane. Proximal Nearer to the root of the limb. Distal Away from the root of the limb. Superficial Towards the skin or body surface. External = Outer Nearer or on the surface of the body. Deep Away from the skin or body surface. 5 Introduction to anatomy for para-medical students Terms of Position TERMS OF NUMBER Uni- = Mono- One Bi- = Di- Two Tri- Three Quadri- Four Multi- = Poly- Many Oligo- Little 6 Introduction to anatomy for para-medical students Example for Terms of Position 7 Introduction to anatomy for para-medical students Example for Terms of Number Monocytes Biceps Triceps Quadriceps Multifidus 8 Introduction to anatomy for para-medical students FASCIA ⁕ It is a type of connective tissue which have the following features: ▪ It lies deep to the skin. ▪ It covers the body wall and limbs. ▪ It binds and connects different body structures together. ▪ It is divided into superficial, deep and internal fasciae. 9 Introduction to anatomy for para-medical students A- Superficial Fascia: A layer of loose connective tissue lies immediately deep to the skin. It connects the skin to the underlying structures. The superficial fascia contains a variable quantity of fat which is more in females than in males. Functions of the superficial fascia: 1. It prevents heat loss from the body, so it acts as thermal insulator and allows storage of energy (due to the presence of fat). 2. It acts as a medium conducting the cutaneous nerves, blood vessels and lymphatics which supply the skin. 3. It contains subcutaneous muscles, as in face (muscles of expression), in the neck (platysma) and in the scrotum (dartos muscle). Muscles of expression Platysma Dartos muscle Palmaris brevis 10 Introduction to anatomy for para-medical students 4. It contains special types of glands , as mammary glands, sweat glands, and superficial lymph nodes. 5. It softens and smoothens the surface of the body. 6. It facilitates the movement of skin over the underlying structures. 7. It gives size & contour of certain parts of the body e.g. breast. B- Deep Fascia: A membrane composed of compact collagen fibers. It is inelastic. It is well defined in the limbs. It is absent in the face and in the anterior wall of abdomen. Parts and Functions: 1. Formation of broad sheets: ▪ They surround the muscles and the different structures of the upper and lower limbs. ▪ They keep the underlying structures in position. 11 Introduction to anatomy for para-medical students They separate different groups of muscles which have different actions and nerve supply. 2. Formation of retinacula: They are localized transverse thickened bands of deep fascia present at wrist and ankle joints. They keep the tendons in position during movements of joints. 3. Formation of palmar aponeurosis (in palm) and plantar aponeurosis (in sole): They are very thick, strong and protective layers of deep fascia. They protect blood vessels, nerves and tendons. 4. Formation of sheaths around big blood vessels: e.g. ▪ Femoral sheath around the femoral blood vessels in lower limb. ▪ Carotid sheath around the carotid arteries and internal jugular vein in the neck. Broad sheet of deep fascia Intermuscular septa 12 Introduction to anatomy for para-medical students sheaths around big blood vessels Interosseous membrane Carotid sheath Palmar aponeurosis Plantar aponeurosis & ankle retinacula 13 Introduction to anatomy for para-medical students CARTILAGE ⁕ Properties: 1. It is a rubbery type of connective tissue, it is tough and resilient. 2. It has no blood vessels, nerves or lymphatics. 3. Gets its nutrition by diffusion from the blood vessels of perichondrium. 4. It consists of mature cartilage cells (chondrocytes), fibers and matrix. 5. Resists compression forces and friction. 6. It has great capacity of growth by multiplication of the chondroblasts (immature cartilage cells). ⁕ Types of Cartilage: I) Hyaline Cartilage: (Glass-like) Characters: Commonest type of cartilage in human body. Matrix: Translucent. Ossification by age: Occurs in certain sites e.g. in epiphyseal cartilages. Sites: 1) In the developing bones in the fetus. 2) In the epiphyseal plates of the long bones. 3) The articular cartilage in joints. 4) The costal cartilage and xiphoid process. 5) Nasal cartilages. 6) The larynx (except the epiglottis) and tracheal rings. 14 Introduction to anatomy for para-medical students 15 Introduction to anatomy for para-medical students II) White fibrocartilage: Characters: a) Matrix: Opaque because it is rich in collagen bundles. Sites: Intervertebral discs. Ossification in old age: Does not occur. III) Yellow elastic fibrocartilage: Characters: a) Matrix: Yellow in appearance because it is rich in yellow elastic fibers. Sites: 1. Auricle of the ear. 16 Introduction to anatomy for para-medical students 2. Epiglottis of the larynx. Ossification in old age: Does not occur. 17 Introduction to anatomy for para-medical students BONES ⁕ Definition & properties: ▪ It is a special type of hard connective tissue which forms the skeleton. ⁕ Functions of Skeleton: 1-Gives the specific shape to the body. 2-Provides the central axis of the body and the skeleton of both upper and lower limbs. 3-Protects the vital organs: the skull protects the brain, and thoracic cage protects the heart and lungs. 4-Provides surface area for muscular attachment. 5- Acts as levers for muscle contraction & movements. 6-Transmits and supports the body weight e.g. vertebral column transmits the weight of the head and trunk to the bony pelvis then through the bones of lower limbs to the feet and lastly to the ground. 7- Forms the joints to make an important part of the locomotor system. 8- Forms the blood elements in the red bone marrow. 9-Stores calcium & phosphorus salts. ⁕ Classification of Skeleton: I) According to the position in the body: 1- Axial skeleton: Skull, mandible, hyoid, sternum, ribs and vertebral column ( i.e bones of head , neck & trunk ). 2- Appendicular (peripheral) skeleton: in upper and lower limbs 18 Introduction to anatomy for para-medical students III) According to structure of bones : 1- Compact ( hard or ivory )bones : ▪ It is the outer hard mass covering the surface of all bones. 2- Cancellous ( spongy ) bones : ▪ It is a network of trabeculae lying inside compact bones. ▪ In between these trabeculae there are many spaces filled with bone marrow. IV) According to the shape of bones: 1- Long bones Site: Present in upper and lower limbs. 19 Introduction to anatomy for para-medical students Structure: two ends (epiphyses) and a shaft (diaphysis) in between. N.B : Physis means growth plate. a) Epiphysis:  It is the expanded upper and lower ends of the long bone.  It is used for articulation and its articular surface is covered with a layer of articular hyaline cartilage. b) Diaphysis (Shaft):  A tube of compact bone (cortex) with a central medullary cavity lined with endosteum and is filled with bone marrow (soft vascular tissue). This meullary cavity doesn’t extend to the epiphysis or the metaphysis.  The shaft is covered with sheath called periosteum which formed of : Superficial layer formed of fibrous tissue. Deep layer formed of fibrous tissues , osteoblast ( bone forming cells ) , sensory nerve fibers and blood vessels ( supply the underlying bone).  The long bones increase in diameter from periosteum.  In the growing long bones, the epiphysis and the diaphysis are separated by a disc of hyaline cartilage called epiphyseal cartilage which is responsible for the growth in length. c) Metaphysis:  It lies in the upper and lower parts of the long bone just close to the epiphyseal cartilage. 20 Introduction to anatomy for para-medical students  It is the most active part of long bone and contains the newly formed bone , formed by the epiphyseal cartilage , which gradually migrate towards the diaphysis. Structure of long bones 2) Short Bones: Site: e.g. carpal bones (in hand) and tarsal bones (in foot). 21 Introduction to anatomy for para-medical students Structure: consist of spongy bone covered with thin layer of compact bone 22 Introduction to anatomy for para-medical students 3) Flat Bones: Site: e.g. bones forming skull cap, scapula , sternum and ribs. Structure: consist of two thin plates of compact bone with middle layer of spongy bone. Function: 1- Protection. 2- Muscular attachment 23 Introduction to anatomy for para-medical students 4) Pneumatic Bones: Bones containing air Site: Skull bones mainly those surrounding the nose (e.g. maxillary and frontal bones) and contain air cavities called paranasal sinuses. Structure: It is formed of compact bone which may contain one air cavity (maxillary sinus) or multiple small air cells (mastoid air cells). Functions: 1. They decrease the weight of skull. 2. They lead to resonance of voice. 3. They have a highly vascular mucosa to warm the inspired air. 5- Irregular Bones: Shape and Site: Bones of irregular shape with projecting processes e.g. vertebrae. Structure: They are similar in structure to the short bones. Vertebra 24 Introduction to anatomy for para-medical students 6- Sesamoid Bones: Structure: small nodules of bones. Site: embedded in some muscle tendons e.g. patella (largest sesamoid bone, embedded in the tendon of quadriceps femoris in front of knee joint). Function: They diminish friction between tendons and underlying bones. 7- Sutural bones : Small bones embedded in the sutures of the skull. ❖ N.B: All bones formed of 2 layers of compact bone with a layer of spongy bone in between except diaphysis of long bones and neumatic bones. 25 Introduction to anatomy for para-medical students ⁕ Growth of bones: ▪ The long bones increase in length from the epiphyseal cartilages by proliferation of its cells.  When the bone becomes mature, the cells of the epiphysial plate stops division and ossifies resulting in fusion between epiphysis and diaphysis.  The epiphyseal plate at one end of the shaft of long bone ossifies earlier than that at the other end, which continues adding bone to the shaft for another 2 to 3 years before it undergoes ossification as well. This end is called the growing end.  Fusion of the epiphysis and diaphysis is under hormonal control.  It occurs in females earlier than males by about 2 years. ▪ The long bones increase in width from osteoblasts in the periosteum around the external bone surface. At the same time, osteoclasts in the endosteum break down bone on the internal bone surface, around the medullary cavity. 26 Introduction to anatomy for para-medical students ⁕ Sex Differences in Bones : 1- Characters of bones: Male bones are heavy and thick while female bones are light and thin. 2- Muscle attachment: Tubercles, tuberosities and ridges are more prominent in male bones and less prominent in female bones. 3- The bony pelvis: The cavity of the pelvis is wider and shorter in female than male to adapt pregnancy and delivery. I) Bone of Upper Limb 27 Introduction to anatomy for para-medical students 28 Introduction to anatomy for para-medical students 29 Introduction to anatomy for para-medical students 30 Introduction to anatomy for para-medical students Bones of lower limb Hip Bone Femur and Patella 31 Introduction to anatomy for para-medical students Tibia and Fibula 32 Introduction to anatomy for para-medical students Bones of the foot 33 Introduction to anatomy for para-medical students Vertebral column Ribs and Sternum 34