Radiographic Anatomy & Physiology for BSRT PDF

p RADIOGRAPHIC ANATOMY & PHYSIOLOGY for BACHELOR OF SCIENCE IN RADIOLOGIC TECHNOLOGY (BSRT) Compiled by: PRIMO B. MONTANA, RXT, RRT, RSO, M.A.Ed. Dean, College of Radiologic Technology Holy Infa...

p RADIOGRAPHIC ANATOMY & PHYSIOLOGY for BACHELOR OF SCIENCE IN RADIOLOGIC TECHNOLOGY (BSRT) Compiled by: PRIMO B. MONTANA, RXT, RRT, RSO, M.A.Ed. Dean, College of Radiologic Technology Holy Infant College RADIOGRAPHIC ANATOMY & PHYSIOLOGY 1  RADIOGRAPHIC ANATOMY & PHYSIOLOGY ANATOMY – is the science dealing with the structure of the body and the relationship of its part. PHYSIOLOGY – is the study of the functions of the organ of the body. RADIOGRAPHIC ANATOMY & PHYSIOLOGY - is the study of the structures of the body both anatomy & tissues based on their visualization on x-ray films. Every part of the body, whether muscle, bone, cartilage, fat, skin, nerve or blood is composed of cells. Each cell has its own function; Example: Bone - for support Muscles - contraction/movement Nerves - carrying messages 2  I. CELL  Is usually a microscopic plant or animal structure containing nucleus and cytoplasmic material enclosed by a membrane.  Is the basic unit or building block of all living things. Each cell breathes and absorbs or takes up the products of digestion: Amino acids from digested proteins, simple sugars from starches and sugar, fatty acids and glycerin from fats, as well as salts, vitamin and etc. Each cell excretes its waste products and has its own function: it maybe for support as in bone, contraction and movement as in muscle, carrying messages as in nerves or transportation of oxygen as in the case of red blood cells. 3  Cell Structures 1. Cell /Nuclear Membrane – is the outer covering that surrounds each cell. This separates cell contents from the surrounding environment. Its main structural building blocks are phospholipids (fats) and globular protein molecules. Besides providing a protective barrier for the cell, the nuclear membrane plays an active role in determining which substances may enter or leave the cell and in what quantity. Because of its molecular composition, the nuclear membrane is selective about what passes through it. It allows nutrients to enter the cell but keeps out undesirable substances. 2. Nucleus – is the centrally placed rounded part of each cell which is separated from the rest of the cell by a covering membrane--- nuclear membrane. - is composed of a semi-liquid substance containing many minute fibrils, linins and granules called Chromatin. - is the center of activity of each cell or the control center of the cell, and its destruction will cause death of the whole cell. The nucleus contains the genetic material, Deoxyribonucleic acid (DNA), secretions of which are called genes. The nucleus also contains one or more small round bodies, called nucleoli which is composed primarily of proteins and Ribonucleic acid (RNA). The nucleoli are assembly sites for ribosomal particles that are particularly abundant in the cytoplasm. Ribosomes are the actual protein-synthesizing factories. 3. Cytoplasm – is that part of the cell outside the nucleus. It is the major site of most activities carried out by the cell. Suspended in the cytosol, the fluid cytoplasmic material, are many small structures called organelles (literally, small organs). The organelles are the metabolic machinery of the cell, and they are highly organized to carry out specific functions for the cell as a whole. The organelles include the ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, mitochondria, cytoskeletal elements and centrioles. A. Ribosomes are densely staining roughly spherical bodies composed of Ribonucleic acid (RNA) and protein. They are the actual sites of protein synthesis. B. The Endoplasmic Reticulum is a highly folded system of membranous tubules and cisterns (sacs) that extends throughout the cytoplasm. The endoplasmic reticulum is continuous with the nuclear envelope, forming a system of channels for the transport of cellular substances (primarily protein) from one part of the cell to another. 4  C. The Golgi apparatus is a stack of flattened sacs with bulbous ends and associated membranous vesicles that is generally found close to the nucleus. D. Lysosomes, which appear in various sizes, are membrane bound sacs containing an array of powerful digestive enzymes. A product of the packaging activities of the Golgi apparatus, the lysosomes contain acid hydrolases, enzymes capable of digesting worn-out cell structures and foreign substances that enter the cell via vesicle formation through phagocytosis or endocytosis. Because they have the capacity of total cell destruction, the lysosomes are often referred to as the “suicide sacs” of the cell. E. Peroxisomes, like lysosomes, are enzyme-containing sacs. However, their oxidases have a different task. Using oxygen, they detoxify a number of harmful substances, most importantly free radicals. Peroxisomes are particularly abundant in kidney and liver cells, cells that are actively involved in detoxification. F. Mitochondria are generally rod-shaped bodies with a double-membrane wall; the inner membrane is thrown into folds, or cristae. Oxidative enzymes on or within the mitochondria catalyze the reactions of the Krebs cycle and the electron transport chain, in which end products of food digestion are broken down to produce energy. G. Cytoskeletal elements ramify throughout the cytoplasm, forming an internal scaffolding called the “cytoskeleton” that supports and moves substances within the cell. H. The paired Centrioles lie close to the nucleus within the centrosome in cells capable of reproducing themselves. They are rod-shaped bodies that lie at right angles to each other. They form the cell projections called cilia and flagella, and in that role are called basal bodies. 4. Centrosome – small granule in the cytoplasm lying close to the nucleus and is concerned with cell division. 5. Processes – are fibers spreading out from the cytoplasm like branches of a tree. 6. Cell Body – is that part of the cell membrane that includes the nucleus and the surrounding cytoplasm. CELL DIVISION: Mitosis and Cytokinesis Growth and sometimes repair of body tissues takes place by the division of existing cells into two daughter cells. Cell division in all cells other than bacteria consists of two events called Mitosis and Cytokinesis. Mitosis is the division of the copied DNA of the mother cell to two daughter cells. Cytokinesis is the division of the cytoplasm, which begins when mitosis is nearly complete. 5  Before cell division, the nuclear membrane disappears. The chromatin granules within the nucleus unite to form a thread or skein. This thread then divides into several pieces called Chromosomes. While this is taking place, the Centrosome, which lies outside the nucleus, divides into two parts, one part migrating to each end of the nucleus. A spindle of new fibers is then formed between the new centrosomes, these fibers passing through the nucleus. A single chromosome becomes attached to each fiber of this spindle. Each chromosome then divides longitudinally. Each half of the divided chromosome is then drawn to one of the centrosomes. At this time the cell membrane constricts in the middle like an hour glass. It finally pinches off at the center dividing the spindle into two parts. Each part has a centrosome and divided chromosome. The chromosome becomes granules. A nuclear membrane is formed about them so a new nucleus is formed. The phases of Mitosis include prophase, metaphase, anaphase and telophase. Prophase is the first phase of mitosis. In early prophase the chromatin condenses, forming bark-like chromosomes. Each duplicated chromosomes consists of two identical threads, called sister chromatids, held together at the centromere. Metaphase is the second phase of mitosis wherein the two centrosomes are at opposite poles of the cell. The chromosomes cluster at the midline of the cell, with their centromeres precisely aligned at the equator of the spindle. This imaginary plane midway between the poles is called the metaphase plate. Anaphase is the third phase and the shortest phase of mitosis that begins abruptly as the centromeres of the centrosomes split simultaneously. Each chromatid now becomes a chromosome in each own right. Telophase is the final phase of mitosis that begins as soon as chromosomal movement stops. The final phase is like prophase in reverse. The identical sets of chromosomes at the opposite poles of the cell uncoil and resume their threadlike chromatin form. A new nuclear envelope forms around each chromatin mass, nucleoli reappear within the nuclei, and the spindle breaks down and disappear. Mitosis is now ended. The cell for just a brief period is binucleate (has two nuclei) and each new nucleus is identical to the original mother nucleus. 6 CYTOKINESIS: Begins during late anaphase and continues through and beyond telophase. A contractile ring of actin microfilaments forms the cleavage furrow and pinches the cell apart. Cell division is extremely important during the body’s growth period. Most cells divide until puberty, when normal body size is achieved and overall body growth ceases. After this time in life, only certain cells carry out cell division routinely – for example, cells subjected to abrasion. Other cell populations – such as liver cells – stop dividing but retain this ability should some of them be removed or damaged. Skeletal muscle, cardiac muscle, and most mature neurons almost completely lose this ability to divide and thus are severely handicapped by injury. Throughout life, the body retains its ability to repair cuts and wounds and to replace some of its aged cells. II. TISSUES: Tissue is a group of cells similar in structure and function. Four Basic Types of Tissue: This four primary tissue types have distinctive structures, patterns and functions, and are further divided into subcategories. A). Epithelial tissue or Epithelium is a sheet of cells that covers a body surface or lines a body cavity. It occurs in the body as (1) covering and lining epithelium and (2) glandular epithelium. Epithelial functions include protection, absorption, filtration, excretion, secretion and sensory reception. For example, the epithelium covering the body surface protects against bacterial invasion and chemical damage; that lining the respiratory tract is ciliated to sweep dust and other foreign particles away from the lungs. Epithelium specialized to absorb substances lines the stomach and small intestine. In the kidney tubules, the epithelium absorbs, secretes and filters. Kinds of Epithelial Tissues: 1. Endothelium – is a word used in connection with the epithelium forming the lining membrane of the heart and blood vessels. 2. Mesothelium – lining membrane of the body cavities. 3. Mucous Membrane – has this name because they secrete fluid, a sticky, stringy fluid. 7  4. Serous Membrane – they secrete a thin watery fluid and they form the pleura of the chest, peritoneum of the abdomen and pericardium of the heart. 5. Synovial Membrane – they lines the joint cavities and secrete fluid to lubricate a joint. B.) Connective or Areolar Tissues is the most abundant and widely distributed of the tissue types. Connective tissues perform a variety of functions, but they primarily protect, support, and bind together other tissues of the body. For example, bones are composed of connective tissue, and they protect and support other body tissues and organs. The ligaments and tendons (dense connective tissue) bind the bones together or bind skeletal muscles to bones. Types of Connective Tissue: 1. Adipose/Fat Tissue – is a modified connective tissues that lies under the skin. It provides insulation for the body tissues and a source of stored foods. 2. Cartilage or Gristle Tissue – consists of oval shaped cells with a cement substance between and holding them together. 3. Bone or Osseous Tissue – composed of cells having many processes extending out from the cell body like legs of a spider. C.) Muscular Tissue is highly specialized to contract and produces most types of body movement. Muscle cells tend to be elongated, providing a long axis for contraction. Three Basic Types of Muscle Tissue 1. Skeletal, Voluntary or Striated Muscle – is the “meat” or flesh of the body and is found attached to bones and ligaments. This muscle will contract in response to messages along the motor nerves from the brain, that is why it is called, “Voluntary”. 2. Visceral, Involuntary or Smooth Muscle – is found mainly in the walls of hollow organs (digestive and urinary tract organs, uterus, and blood vessels). Typically it has two layers that run at right angles to each other; consequently its contraction can constrict or dilate the lumen (cavity) of an organ and propel substances along predetermined pathways. 3. Cardiac Muscle – a special type of striated muscle which is found only in the heart. As it contracts, the heart act as a pump, propelling the blood into the blood vessels. Cardiac muscle is under involuntary control, which means that we cannot voluntarily or consciously control the operation of the heart. 8 D.) Nervous Tissue is tissues which make up the substance of nerves and nerve centers which is made up of two major cell populations. The neuroglia are special supporting cells that protect, support and insulate the more delicate neurons. The neurons are highly specialized to receive stimuli (excitability) and to generate electrical signals that may be sent to all parts of the body. They are the cells that are most often associated with nervous system functioning. III. ORGAN: Organ is a structure composed of two or more tissue types that performs a specific function for the body. For example, the small intestine, which digest and absorbs nutrients, is made up of all four tissue types. IV. ORGAN SYSTEM: Organ System is a group of organs that act together to perform a particular body function. For example, the organs of the digestive system work together to break down foods and absorb the end products into the bloodstream to provide nutrients and fuel for all body’s cells. 11 Systems of the Body: 1. Circulatory or Cardio-Vascular System – include the heart, blood vessels and blood that functions primarily as a transport system that carries blood containing oxygen, carbon dioxide, nutrients, wastes, ions, hormones and other substances to and from the tissue cells where exchanges are made; blood is propelled through the blood vessels by the pumping action of the heart. 2. Digestive System or Alimentary Tract – is concerned with ingestion, digestion and absorption of food or nutrition. It includes the mouth, throat, esophagus, stomach, small bowel and colon as well as the accessory organs of digestion like the liver, gall bladder and pancreas. The digestive system breaks down ingested foods to minute particles, which can be absorbed into the blood for delivery to the body cells. 3. Endocrine System – includes the Pituitary gland, pineal gland, thyroid and parathyroid glands, thymus, adrenal glands as well as parts of the testis, ovaries and pancreas. Endocrine system helps maintain body homeostasis, 9  promotes growth and development; produces chemical messengers called hormones that travel in the blood to exert their effect/s on various target organs of the body. 4. Muscular System – includes all the skeletal or voluntary muscles. The primary function is to contract or shorten; in doing so, skeletal muscles allow locomotion (running, walking, etc.), grasping and manipulation of the environment and facial expression. 5. Nervous System – includes the brain, spinal cord, peripheral nerves and the autonomic nervous system, which includes the sympathetic and parasympathetic. Nervous system allows body to detect changes in its internal and external environment and to respond to such information by activating appropriate muscles or glands. It also helps maintain homeostasis of the body via rapid transmission of electrical signals. 6. Reproductive System- includes the female and male organs of reproduction. It provides germ cells called sperm and it provides also germ cells called eggs. 7. Respiratory System- includes all the air passages and the lungs. The function is to keep the blood continuously supplied with oxygen while removing carbon dioxide. 8. Skeletal or Osseous System – includes the bones, cartilages, tendons, ligaments and joints. Function to support the body and protect internal organs. It also provides levers for muscular action. 9. Urinary System – includes the kidneys, ureters, urinary bladder and urethra. The function is it rids the body of nitrogen-containing wastes including urea, uric acid and ammonia, which result from the breakdown of proteins and nucleic acids. It also maintains water, electrolyte and acid-base balance of blood. 10  10. Lymphatic/Immunity System – includes the lymphatic vessels, lymph nodes, spleen, thymus, tonsils, and scattered collection of lymph nodes. Their function is to pick up fluid leaked from the blood vessels and return it to the blood. It cleanses blood of pathogens and other debris. 11. Integumentary System – includes the epidermal and dermal regions, cutaneous sense organs and glands. It protect deeper organs from mechanical, chemical and bacterial injury. It also excretes salts and urea and it aids in regulation of body temperature. THE BODY CAVITIES: Body cavity lies in front of the vertebral column and is divided into: A. Chest/Thoracic cavity B. Abdominal cavity C. Pelvic cavity A. Chest/Thoracic cavity – occupies the upper part of the body and is enclosed by the chest wall. Diaphragm is a dome-shaped muscular partition between the thoracic and abdominal cavity. B. Abdomen or Abdominal cavity – extends from the under surface of the diaphragm to the pelvic bones. C. Pelvis/Pelvic Cavity – is encircled by the bones of the pelvis and extends from the pelvic inlet to the floor of the pelvis. 11  DIRECTIONAL TERM/TERMS TO DESCRIBE OPPOSITES: 1. Medial – part of a structure or organ that lies nearest to the median line of the body. Lateral – part of a structure or organ which lies farthest away from the median line of the body. 2. Anterior – refers to the front or in the front part of the body, structure or organ. Posterior – towards the back or in the back part of the body, structure or organ. 3. Ventral – it refers to the front. Dorsal – refers to the back like posterior. 4. Superior – refers to the upper, or part nearer to the head end. Inferior – refers to the lower part or part farther from the head end. 5. Internal – refers to the inside of the body or of a part. External – on the outer side of the body. 6. Proximal – part of a structure close to the source or origin. Distal/Terminal – part farther away from the source or origin. 7. Visceral – relates to an organ itself. e.g. visceral pleura. Parietal – relates to a wall of a structure. 8. Intrinsic– part of an organ or structure itself, e.g. An intrinsic growth of the Stomach. Extrinsic – originating outside of an organ, e.g. a pressure on the stomach by an extrinsic mass. 9. Cephalic (adj.)– refers to the head, e.g. cephalic presentation of a fetus. * Cephalad – towards the head end. * Caudal (adj.)– refers to the tail end. * Caudad – towards the tail end. 10. Palmar – refers to the front or palm of the hand. Plantar – refers to the sole of the foot. *Volar – refers to the palm of the hand and sole of the foot. 11. Supine – position assumed when lying on the back with face up, or refers to the hand with palms up. Prone – position assumed when lying on the abdomen/ventral surface, or with palms down. 12 12. Longitudinal - along the long axis of the body. Transverse – across or at right angle to the long axis of the body. 13. Vertical – perpendicular to the horizon. Horizontal – parallel to the horizon. 14. Greater or Major – the larger, e.g. greater trochanter of the femur. Lesser/Minor – the smaller, e.g. lesser tubercle of the humerus, or lesser trochanter. ANTERIOR BODY LANDMARKS Abdominal: Anterior body trunk region inferior to the ribs Acromial: Point of the shoulder Antebrachial: Forearm Antecubital: Anterior surface of the elbow Axillary: Armpit Brachial: Arm Carpal: Wrist Cephalic: Head Cervical: Neck region Coxal: Hip Digital: Fingers and toes Femoral: Thigh Fibular: Side of the leg Frontal: Forehead Hallux: Great toe/Big toe Inguinal: Groin area Mammary: Breast region Manus: Hand Mental: Chin Nasal: Nose Oral: Mouth Orbital: Bony eye socket Palmar: Palm of the hand Patellar: Anterior knee region (knee cap) Pedal: Foot Pelvic: Pelvis region Pollex: Thumb Pubic: Genital region Sternal: Region of the breast bone Tarsal: Ankle Thoracic: Chest Umbilical: Navel 13  The ANATOMICAL POSITION: When anatomists or doctors refer to specific areas of the human body, the picture they keep in mind is a universally accepted standard position called the Anatomical Position. It is essential to understand this position because much of the body terminology used in this manual refers to this body positioning, regardless of the position the body happens to be in. In the anatomical position, the human body is in upright or erect position, with the feet only slightly apart, head and toes pointed forward and arms hanging at the sides with palms facing forward. The MEDIAN LINE OF THE BODY: A line drawn perpendicularly through the center of the forehead, nose, chin, chest, abdomen and pelvis, dividing the body into two equal halves. THE BODY PLANES: Plane – is a real or imaginary flat surface, such as might be made by taking a saw and cutting through the body or part of it, then turning this so as to view it from the cut or flat surface. Body Planes and Sections The body is three-dimensional, and in order to observe its internal structures, it is often helpful and necessary to make use of a section, or cut. When the section is made through the body wall or through an organ, it is made along an imaginary surface or line called a plane. Anatomists commonly refer to three planes or sections that lies at right angles to one another. 14 1. Median or Mid-Sagittal Plane – a plane through the median line of the body by cutting from front to back through the sagittal suture of the skull and continuous down through the body in the same direction, dividing it into two equal parts, the (R) and the (L). 2. Sagittal Plane – is any plane parallel to, or in the same direction as the MSP and to one or other side of the median line. 3. Coronal Plane/Frontal Plane – is a plane made by cutting across the body from side to side and therefore parallel to the coronal suture of the skull. 4. Transverse or Horizontal/Axial Plane – a plane made by cutting across the body or part of it at right angles to the long axis of the body. When organs are sectioned along the transverse plane, the sections are commonly called cross sections. 15 The Skeleton, the body’s framework, is constructed of two of the most supportive tissues found in the human body – cartilage and bone. In embryos, the skeleton is predominantly made up of hyaline cartilage, but in adult, most of the cartilage is replaced by more rigid bone. Cartilage persists only in such isolated areas as the external ear, bridge of the nose, larynx, trachea, joints and parts of the rib cage. Besides supporting and protecting the body as an internal framework, the skeleton provides a system of levers with which the skeletal muscles work to move the body. The skeleton is made up of bones that are connected at joints or articulations. The skeleton is subdivided into two divisions: the axial skeleton (those bones that lie around the body’s center of gravity), and the appendicular skeleton (bones of the limbs or appendages). CARTILAGES OF THE SKELETON Cartilaginous regions of the skeleton have a fairly limited distribution in adults. The most important of these skeletal cartilages are (1) articular cartilages, which covers the bone ends at movable joints; (2) costal cartilages, found connecting the ribs to the sternum; (3) laryngeal cartilages, which largely construct the larynx or voice box; (4) tracheal and bronchial cartilages, which reinforce other passageways of the respiratory system; (5) nasal cartilages, which support the external nose; (6) intervertebral discs, which separate and cushion bones of the spine; and (7) the cartilage supporting the external ear. The skeletal cartilages consist of some variety of cartilage tissue, which typically consists primarily of water and is fairly resilient. Cartilage tissue are also distinguished by the fact that they contain no nerves and very few blood vessels. 16  Like bones, each cartilage is surrounded by a covering of dense connective tissue, called a perichondrium (rather than periosteum), which acts to resists distortion of the cartilage when it is subjected to pressure and plays a role in cartilage growth and repair. The skeletal cartilages have representatives from each of the three cartilage tissue types—hyaline, elastic and fibrocartilage.  Hyaline cartilage provides sturdy support with some resilience or “give”. Most skeletal cartilages are composed of hyaline cartilage.  Elastic cartilage is much more flexible than hyaline cartilage, and it tolerates repeated better. Only the cartilages of the external ear and the epiglottis (flops over and covers the larynx when we swallow) are elastic cartilage.  Fibrocartilage consist of rows of chondrocytes alternating with rows of thick collagen fibers. Fibrocartilage, which has a great tensile strength and can withstand heavy compression, is used to construct the intervertebral discs and cartilages within the knee joint. CLASSIFICATION OF BONES The 206 bones of the adult skeleton are composed of two basic kinds of osseous tissue that differ in their texture. Compact bone looks smooth and homogenous; spongy or cancellous bone is composed of small trabeculae (bars) of bone and lots of open space. Bones may be classified further on the basis of their relative gross anatomy into four groups; long, short, flat and irregular. 1. Long Bones are much longer and generally consisting of a shaft with heads at either end. They are composed predominantly of compact bone. Examples: Humerus, Radius & Ulna, Femur, Tibia & Fibula 2. Short Bones are typically cubed-shaped, and they contain more spongy bone than compact bone. Examples: Metacarpals and Metatarsals. 3. Flat Bones are generally thin with two wafer-like layers of compact bone sandwiching a layer of spongy bone between them. Examples: Scapula, Bones of the Skull, Pelvic bones 4. Irregular Bones are bones that do not fall into one of the preceding categories. Examples: Vertebral bodies, Carpal bones, Tarsal Bones. Some anatomists also recognize two other subcategories of bones. Sesamoid bones are special types of short bones formed in tendons. The patella (knee cap) is the biggest sesamoid bone in the body. Sutural bones are tiny bones between the cranial bones. Except for the patella’s and sutural bones are not included in the bone count of 206 because they vary in number and location in different individuals. 17  GROSS ANATOMY OF THE TYPICAL LONG BONE Bone is one of the hardest materials in the body. Although relative light, bone has a remarkable ability to resist tension and shear forces that continually act on it. 1. Periosteum – is an outer layer of thin bone covering the entire bone, except the ends which help to form a joint. - Assist in the healing of bones following fractures or infection. 2. Cortex – is a layer of dense, compact bone under the periosteum and is usually present in the shafts of long bones. 3. Cancellous Bone – is porous (full of pores), loosely constructed bone like sponge with many spaces, which is formed under the cortex. 4. Medulla – is a central cavity in the shafts of long bones which is lined by the endosteum. 5. Bone Marrow – is the tissue occupying the medulla of long bones and those spaces in the loosely knitted cancellous bone. TWO TYPES OF BONE MARROW: A. Red Bone Marrow – is found in the bones of infants and children. While in adult, it is found in cancellous bone at the end of long bones as well as the body of the sternum, vertebrae, ribs, etc. B. Yellow Bone Marrow – replaces the Red Bone Marrow in the long bones of adults and it contains much fat. 18  6. Nutrient Foramen - is a small canal that contains blood vessels passing through the Periosteum and other layers of bone to reach the Medulla. @@ The bones of the Skull have a construction different to other bones. It has an “Outer Table” which is a layer of compact bone under the Periosteum. The “Inner Table” is a similar layer of compact bone. A “Diploe” which is a layer of cancellous bone between the Outer and Inner Tables. THE SKULL The skull or bony skeleton of the head rests on the superior end of the vertebral column and is divided into two main sets of bones: Cranium which enclose and protect the fragile brain tissue; Facial bones which support the eyes and position them anteriorly. They also provide attachment sites for facial muscles which make it possible for us to present our feelings to the world. The function of the Cerebral Cranium is to protect the brain from injury. 19 I. CEREBRAL CRANIUM - Part of the skull that encloses the brain. It is also referred to as the “Calvarium/Calvaria” or Brain case or Cranial vault. There are eight bones that construct the Cranium. 1. (1) Frontal Bone 2. (2) Parietal Bones 3. (1) Occipital Bone 4. (2) Temporal Bones 5. (1) Sphenoid Bone 6. (1) Ethmoid Bone II. VISCERAL CRANIUM (FACIAL SKELETON) This includes the 14 bones of the face that forms the bony cavities for the protection of the eyes, nasal passages, and mouth. THE 14 FACIAL BONES/VISCERAL CRANIUM 1. (2) Maxillary Bones 2. (2) Zygomatic Bones 3. (2) Nasal Bones 4. (2) Lacrimal Bones 5. (2) Palatine Bones 6. (2) Inferior Conchae or Turbinates 7. (1) Vomer 8. (1) Mandible 20 Sutures – are special interlocking joints between the various bones of the Cerebral Cranium. 4 Most Important Sutures of the Skull: 1. One CORONAL SUTURE 2. One SAGITTAL SUTURE 3. One LAMBDOIDAL SUTURE 4. Two SQUAMOSAL SUTURES CEREBRAL CRANIUM: I. FRONTAL BONE This single bone forms the forehead and part of the roof of the skull. It’s smooth part forms the forehead; It’s orbital parts form the roof of the orbits; And nasal parts help to form the nasal cavities. PARTS OF THE FRONTAL BONE A. SUPRA ORBITAL BORDERS/SUPRA ORBITAL MARGINS Are the ridges forming the upper margins of the circular openings of the orbits. B. GLABELLA Is a smooth, rounded bony prominence above the nose. It lies between the supra-orbital borders of the frontal bone. 21  C. FRONTAL SINUSES (2) Are paired cavities in the squamous or forehead part of the frontal bone, one on each side. They communicate with the nose and vary in size and/or maybe absent. D. NASION Is the middle point of the Fronto-Nasal suture. E. SUPRA-ORBITAL NOTCH/SUPRA ORBITAL FORAMEN. Lies towards the medial end of each supra-orbital border allowing blood vessels and nerves to pass. 2. PARIETAL BONES (2) Are paired bones, one on each side of the Cerebral Cranium. Forms the lateral wall and part of the roof of the skull. Meet in the midline of the roof to form the “Sagittal Suture”. Their anterior borders meet the frontal bone to form the “Coronal Suture”. Parietal Eminence – is a bony prominence on the outer surface of each parietal bone which is the greatest transverse diameter of the skull. 6. OCCIPITAL BONE Is a single bone which forms the posterior part as well as the part of the base or floor of the cerebral cranium. The Upper posterior border, along with the posterior border of the two parietal bones form the “Lambdoidal Suture”. 22  PARTS OF THE OCCIPITAL BONE A. Squamous Part – is the flat posterior part of the occipital bone. B. Foramen Magnum – is an opening in the lower part of the occipital bone through which the Medulla of the brain leaves the skull, which is formed entirely by the occipital bone. C. Lateral Parts of the Occipital Bone – lie on each side of the Foramen Magnum. D. Occipital Condyles – are two oval prominences on the under surface of the lateral parts of the foramen magnum - form the joints with the superior articular surfaces of the first cervical vertebra or Atlas. E. Base of the Occipital Bone – part in front of the Foramen Magnum which unite with the Sphenoid bone in front and forms part of the floor of the skull. F. External Occipital Protuberance/Inion – is the bony prominence on the outer surface of the squamous part of the occipital bone which is readily palpable. 23 4. TEMPORAL BONES (2) Forms part of the lateral walls and base of the skull. Each temporal bone consist of a flat or squamous part above the ear, mastoid portion behind the ear and a petrous part that forms part of the base of the skull. PARTS OF THE TEMPORAL BONES A. Zygomatic Process – is a slender bony process that extends forward from the squamous part to meet a similar process of the Zygomatic bone forming the “Zygomatic Arch” B. Mastoid Process – is a large rounded bony prominence extending down behind the ear. C. Mastoid Air Cells – are small cavities in the mastoid process and adjacent part that communicate with the middle ear. # Infection in the middle ear may spread into these cells--- Mastoiditis. D. Petrous Part – is shaped like a pyramid that extends from the ear medially and forward in the base of the skull. Its inner end is pointed and contains the organ of hearing. E. Styloid Process – is a sharp pointed process that extends down from the base of the petrous part which is seen in lateral view of the skull outlined behind the mandible. It is an attachment point for muscles and ligaments of the neck 24  F. External Auditory Meatus – a tube-like passage extending into the petrous part of the temporal bone. G. Internal Auditory Meatus – lies in the middle or inner part of the petrous, medial to the middle ear. It allows the passage of cranial nerves VII and VIII. H. Internal Ear – lies in the petrous part and is the organ of hearing. I. Mandibular or Articular Fossa – a depression on the temporal bone in front of the EAM. # With the capitulum of the mandible, it forms the Temporo-mandibular joint. J. Jugular Foramen – is an opening medial to the styloid process through which the internal jugular vein and cranial nerves IX, X and XI pass. K. Carotid canal – is an opening medial to the styloid process through which the internal carotid artery passes into the cranial cavity. L. Stylomastoid foramen – is a tiny opening between the mastoid and Styloid processes through which cranial nerve VII leaves the cranium. M. Foramen Lacerum – is an opening between the petrous temporal bone and the sphenoid providing passage for a number of small nerves and for the internal carotid artery to enter the middle cranial fossa. 5. SPHENOID BONE A single bone that help to form a small part of the lateral wall of the skull on each side as well as part of the base of the skull. It is compared to a Bat with two pairs of wings extended. 25  PARTS OF THE SPHENOID BONE A. Body – is the central part that lies in the midline of the floor of the skull, in front of the occipital bone. B. Wings – extended laterally from the body. There are two pairs; the Greater wings and Lesser wings. C. Pterygoid Processes/Plates – extend down from the undersurface of the body. D. Sphenoid Sinuses – are two cavities within the body of the bone, one on each side of the midline that lie behind the nasal fossae and open into them. E. Optic Foramen – is an opening at the front on each side of the body of the sphenoid. The optic nerve (nerve of sight) leave the cranial cavity by these openings to enter the orbits. F. Sella Turcica – is a depression hallowed out on the upper surface of the body which is shaped like a saddle wherein the Pituitary gland/ Hypophysis lies in this depression. 26 G. Dorsum Sella (Back of Saddle) - Is the posterior wall of the Sella Turcica where it curve upward like the back of a saddle. H. Posterior Clinoid Processes – are two small rounded bony processes that extend up and forward from the top of the Dorsum Sella. I. Anterior Clinoid Processes – are two similar processes that extends back from the lesser wings of the sphenoid over the Sella Turcica. 6. ETHMOID BONE Lies in the anterior part of the base of the skull between orbits. Like the Sphenoid bone, this bone is only partly visible because of the adjacent bones. PARTS OF THE ETHMOID BONE A. Cribriform Plate – it fills in a small gap between the orbital parts of the frontal bone. It contains several small openings for the exit of the Olfactory nerves (nerves of smell) from the cranial cavity to the nasal cavities. B. Crista Galli – is a sharp flat pointed process that extends up from the cribriform plate in the midline wherein the Falx Cerebri is attached to it. C. Perpendicular Plate – is a thin, flat, downward extension from the cribriform plate that forms a part of the nasal septum. 27 D. Ethmoid Sinuses – are many small cavities in the labyrinth on each side. They lie between the medial border of the orbits and nasal cavities. THE VISCERAL CRANIUM or FACIAL BONES: Visceral Cranium or Facial Skeleton – is made up of fourteen bones. Of the 14 bones composing the face, 12 are paired. Only the mandible and vomer are single bones. An additional bone, the hyoid bone, although not a facial bone, is considered here because of its location. 28  I. MAXILLA or UPPER JAW Forms the floor of the orbits, the medial parts of the infra-orbital borders, lateral wall of the nasal fossae, the floor of the nasal cavities, part of the roof of the mouth and most of the cheeks. PARTS OF THE MAXILLA A. Body of the Maxilla – is large that forms part of the cheek and lies laterally to the nose. B. Maxillary Sinuses (Antra of Highmore) – is a large cavity in the body of each maxilla. Each open into the nose and contains air. C. Zygomatic Process – extends laterally from the body to meet the maxillary process of the Zygomatic bone. D. Alveolar Process – extends down from the body to accommodate the upper teeth. E. Palatine Process – is a flat plate that extends medially above the mouth and form the anterior part of the Hard Palate. F. Infra-orbital Border – is a ridge of bone forming the inner part of the lower border of the opening of the orbit. 29  G. Infra-Orbital Foramen – is an opening in the body of the maxilla just below the infra-orbital margin of each orbit. H. Anterior Nasal Spine / Acanthion– is a small pointed projection in the midline at the base of the nasal septum. I. Maxillary Tuberosity – a small bony prominence behind the last upper molar. 2. ZYGOMATIC BONE or MALAR BONE Forms the prominent part of the upper cheek and can be felt immediately below the orbit. The upper border is concave and forms the outer part of the infra- orbital border. It also form the lateral wall of the orbit and part of the floor. Its slender temporal process joins the Zygomatic process of the temporal bone forming the “Zygomatic Arch”. 3. NASAL BONES (2) Forms the bridge of the nose which are thin plates of bone that articulate with the frontal bone and extend down to end the nasal cartilage. The two nasal bones meets in the midline and extend laterally to join the maxillary bones. The Nasal Septum lies under the junction of the two nasal bones and the movable part of the nose is composed of cartilages. 30  4. LACRIMAL BONES Maybe difficult to identify but they are small four- sided flat bones that lie on the medial borders of the orbits close to the front. Each Lacrimal bone has a groove for the tear duct which carries tears to the nasal cavities. 5. PALATINE BONES Are small “L” shaped structure lying behind the nasal cavity. Its vertical part helps to form the lateral wall of the nasal cavity behind. ## The two palatine processes of the maxillae and the two horizontal palatine parts form the Hard Palate. 6. INFERIOR CONCHAE or TURBINATES (2) Is a thin curve bone extending medially from the lateral wall of the nasal cavity. The inner or medial border is free, so that this bone forms an incomplete shelf within the nostril and are divided into an Upper and Lower Conchae. 31  7. VOMER Is flat and shaped like a “Ploughshare” that lies vertically and helps to form the Nasal Septum where its lower border rests upon the upper surface of the Hard Palate. 8. MANDIBLE Is shaped like a Horseshoe with its posterior ends turned up on each side to articulate with the Temporal bone forming the “Temporo-Mandibular Joint” (TMJ). PARTS OF THE MANDIBLE 1. Angle of the Mandible / Gonion – is the prominent rounded part where the horizontal parts turns up to become the vertical part. 2. Body – is the horizontal part extending from the angle on one side and back to the angle on the other side. 3. Rami (Sing- Ramus) – are flattened parts extending from the angles up to the joints with the Temporal bone. # Each Ramus has a Coronoid process, Mandibular notch and a Condyloid process. 4. Symphysis Mentis/Mandibular symphysis – is a faint ridge running vertically in the midline where the two halves of the mandible fused to form one bone. 32 5. Mental Protuberance – is the prominence at the lower border of the Symphysis Mentis and is called the “Chin”. 6. Mental Foramen – a small opening on the outer surface of the body below the Second premolar tooth on each side wherein the mandibular nerve passes out to the face. 7. Alveolar Process – is the upper part of the body with cavities for the roots of the lower teeth. 8. Coronoid Process – is a thin, flattened pointed process extending up from the front of the Ramus. 9. Condyloid Process – is the posterior part of each ramus extending up from the angle to the joint. 10. Capitulum – is the slightly expanded upper end of the condyloid process that articulate with the Temporal bone at the “Temporo-Mandibular Joint”. 11. Neck – is the constricted part between the Capitulum and the remainder of the condyloid process. 12. Mandibular Notch – is a half-moon shaped notch between the Coronoid and Condyloid processes. 33 13. Mandibular Foramen – is an opening on the inner side of each ramus which lead into the mandibular canal for the mandibular nerve. This nerve supplies a branch to each lower tooth. PARANASAL SINUSES Paranasal Sinuses – are paired cavities within some of the cranial and facial bones which have an openings into the nasal cavities and filled with air. Their lining membranes are continuous with those of the nasal cavities. And because of their air content, PNS are seen as dark (translucent) shadows in films. PARANASAL SINUSES 1. Frontal Sinuses – are cavities within the frontal bone that extend up into the squamous part forming the forehead. This may be absent or small or quite large or maybe larger than the other. 2. Maxillary Sinuses (Antra of Highmore) – are large cavities in each maxilla that lie behind the soft tissue of the cheek and lateral to the nasal cavities. 3. Ethmoid Sinuses – are groups of small cavities lying in the lateral wall of the nasal cavities on each side. In films, they appear as multiple translucencies between the nasal fossae and orbits. 34  4. Sphenoid Sinuses – are two cavities on each side in the body of the Sphenoid bone. They lie under the Sella Turcica behind the nasal fossae and are visible on Open mouth view. SUTURES OF THE SKULL Sutures of the Skull – are special interlocking immovable joints between the cranial bones that looks like a saw teeth of one bone which fit into small indentations of the adjacent bones. 1. Sagittal Suture – is the joint between the upper adjacent borders of the two parietal bones that extends from front to back along the midline of the vertex of the skull. 2. Coronal Suture – is the joint between the posterior border of the frontal bone and the anterior borders of the parietal bones. They crosses the roof/vertex of the skull transversely and meet the sagittal suture at right angle. 3. Lambdoidal Suture – is the joint between the posterior borders of the two parietal bones and upper border of the occipital bone. This form a curved line on the posterior surface of the skull and meets the posterior end of the sagittal suture in the midline. 35  4. Squamosal Suture – forms the joint between the lateral borders of the parietal bone and the upper border of the temporal bone on each side. This lies on the lateral wall of the skull above and behind the ear. FONTANELS Fontanels or Fontanelles – are gaps in the skull of infants between the angles formed at the junctions of the parietal, frontal and occipital bones. 1. Anterior or Frontal Fontanel – lies at the junction of the two parietal bones with the frontal bone at the midline of the vertex. This is the junction of the coronal and sagittal suture called “Bregma”. 2. Posterior or Occipital Fontanel – is the small gap on the posterior surface of the skull at the junction of the two parietal bones with the occipital bone. It is the point where the sagittal suture meets the lambdoidal suture and becomes filled in with bone at about 6 months and is called “Lambda”. LAYERS OF THE CEREBRAL CRANIUM 1. Outer Table/ Outer Compact Layer – is the outer covering of the brain. 2. Diploe – is the spongy layer and is most bloody. 3. Inner Compact Layer – is the inner layer covering of the brain. 36 THE NECK: The neck occupies the region between the skull and the thorax. Its upper limit being defined by an imaginary line extending from the inferior border of the symphysis mentis to the external occipital protuberance. While it’s lower limit being defined by a line extending from the supra-sternal notch to the superior border of the T1. For radiographic purposes, the neck is divided into posterior and anterior portions. The portion of the neck lying in front of the vertebrae is composed largely of soft tissues, the upper parts of the respiratory and digestive system, the thyroid and para-thyroid glands and submandibular gland. THYROID GLAND Thyroid Gland – consist of two lateral lobes connected together at the lower third by a narrow median portion called the “isthmus”. The lobes are approximately 2 inches (5cm) long, 1 ¼ (3cm) inches wide and ¾ inch (2cm) thick and weighs between 20 and 30 grams. The thyroid gland develops as a tubular invagination from the root of the tongue called the foramen cecum. It grows downward in front of the trachea and thyroid cartilage to reach the position it will occupy as the adult gland. The distal end of this structure proliferates to form the adult gland, while the remainder degenerates and disappears, usually by the fifth to sixth week of fetal development. The Thyroid hormone (TH) is actually two physiologically active hormones known as T4 (Thyroxine) and T3 (Triiodothyronine). Because its primary function is to control the rate of body metabolism and cellular oxidation, TH affects virtually every cell in the body. Hyposecretion of thyroid hormone leads to a condition of mental and physical sluggishness, which is called “Hypothyroidism or Myxedema”. Hypersecretion of TH causes elevated metabolic rate, nervousness, weight loss, sweating and irregular heartbeat and is called “Hyperthyroidism or Grave’s disease”. 37  Parathyroid Glands – are found embedded in the posterior surface of the thyroid gland. Typically there are two small oval glands on each lobe. They secrete parathyroid hormone (PTH), the most important regulator of calcium balance of the blood. When blood calcium levels decrease below a certain critical level, the parathyroids release PTH, which causes release of calcium from bone matrix and push the kidney to reabsorb more calcium and less phosphate from the filtrate. PTH also stimulates the kidneys to convert vitamin D to its active D3 form, calcitriol, which is required for the absorption of calcium from food. Pharynx/Throat – serves as the passage of both air and food and is common to the respiratory and digestive systems. It is a musculo-membranous, tubular structure situated in front of the vertebrae and behind the nose, the mouth and larynx. It is approximately 5 inches (13cm) in length and extends from the undersurface of the body of the sphenoid bone inferiorly to the level of the disk between the 6th and 7th cervical vertebrae where it becomes continuous with the esophagus. The walls of the pharynx consist largely of two layers of skeletal muscles: an inner layer of longitudinal muscle and an outer layer of circular constrictor muscles. Together these initiate wavelike contractions that propel the food inferiorly into the esophagus. The mucosa of the oropharynx and laryngopharynx, like that of the oral cavity, contains a friction-resistant stratified squamous epithelium. Pharyngeal cavity is subdivided into: 1. Nasopharynx 2. Oropharynx 3. Laryngopharynx/Laryngeal part 38  LARYNX – is the organ of voice. It serves also as the air passage between the pharynx and the trachea. It is a movable tubular structure approximately 1 ½ inches (4cm) in length. It is suspended from the hyoid bone and extends from the level of the superior margin of the fourth cervical vertebra to its junction with the trachea. Larynx is composed of 9 Cartilages: 3 Single 3 Paired 1. Epiglottis 1. Arytenoid 2. Thyroid cartilage 2. Corniculate 3. Cricoid cartilage 3. Cuneiform The two most prominent are the large shield-shaped thyroid cartilage, whose anterior medial laryngeal prominence is commonly referred to as Adam’s apple, and the inferiorly located, ring-shaped cricoid cartilage, whose widest dimension faces posteriorly. All the laryngeal cartilages are composed of hyaline cartilage except the flap-like epiglottis, a flexible elastic cartilage located superior to the opening of the larynx. The epiglottis sometimes referred to as the “guardian of the airways”, forms a lid over the larynx when we swallow. This closes off the respiratory passageways to incoming food or drink, which is routed into the posterior esophagus. The mucous membrane of the larynx is thrown into two pairs of folds – the upper vestibular folds, also called the false vocal cords, and the lower vocal folds, or true vocal cords, which vibrate with expelled air for speech. The vocal cords are attached posterolaterally to the small triangular arytenoid cartilages by the vocal ligaments. The vocal folds and the slit-like passageway between them is called the glottis. **These cartilages are connected together with ligaments and are moved by muscles and clothed in a mucous membrane. Epiglottis – is a flat leaf-like plate of cartilage with free upper border that projects back from the anterior wall of the pharynx below the root of the tongue. Thyroid Cartilage – is the largest of its group which forms the laryngeal prominence or the “Adams apple” at the level of C5. Cricoid Cartilage – is the second largest of the group and is connected to the first ring of the trachea. 39  THE THORAX/THORACIC CAGE The Thoracic cage is formed in the midline behind the twelve thoracic vertebrae, by a sternum in front. 12 pairs of ribs and 12 pairs of costal cartilages complete the framework behind, laterally and in front. Its cone-shaped cage-like structure protects the organs of the thoracic cavity including the critically important heart and lungs. Bones of the Thorax are composed primarily of: 1. Sternum or Breast bone 2. 12 Thoracic vertebrae 3. 12 pairs of ribs. THE STERNUM/BREAST BONE: Sternum- is a typical flat bone, is a result of the fusion of three bones—the manubrium, body and xiphoid process. It is attached to the 1st seven pairs of ribs. The superior most manubrium looks like the knot of a tie; it articulates with the clavicle laterally while the body forms the bulk of the sternum. The xiphoid process constructs the inferior end of the sternum and lies at the level of the fifth intercostal space. PARTS OF THE STERNUM: 1. Manubrium – is the upper segment which in early life is separated from the body by cartilage but later it fuses with the body. 2. Body of the Sternum/ Gladiolus – is that part that extend from the manubrium to the Xiphoid process. 3. Xiphoid / Ensiform Process – is the lower pointed end below the body at the level of T10. 4. Supra-Sternal / Jugular Notch – is the concave upper border of the manubrium at the level of T3. 5. Clavicular Notches – are depressions found at each lateral border of the supra- sternal notch. * Clavicular notch and the medial end of the clavicle form the Sterno-Clavicular joint. 6. Costal Notches – are depressions on each lateral margin of the sternum which articulate with the costal cartilages. 7. Sternal Angle / Angle of Lewis – is the prominent transverse ridge at the junction of the manubrium and the body of the sternum at the level of T4-T5. 40  THE RIBS: There are 12 pairs of ribs. They are named from above downwards as the first, second, third, etc. Ribs – are flat curved bones that form part of the posterior wall, the entire lateral wall and part of the anterior wall of the thorax. The Upper seven (7) pairs have separate costal cartilages which articulate with the costal notches on each side of the sternum and are called “True Ribs”. The Lower five (5) pairs are called “False Ribs”. The eighth, ninth and tenth have costal cartilage which are joined together at their anterior ends and join with the seventh costal cartilage above. The eleventh and twelfth ribs have short costal cartilages which are unattached at their anterior ends and so they are called “Floating Ribs” that falls at the approximate level of L3. PARTS OF A RIB: 1. Head – is the slightly expanded posterior end which articulate with the pits on the adjacent border of the vertebra. 2. Neck – is the slightly constricted part lateral to the head. 3. Tubercle – is a small prominence lateral to the neck. It forms a joint with the anterior surface of the adjacent transverse process of a vertebra. 4. Articular Facet – are two pits on the head of the rib that articulate with a facet on a single vertebral body. 5. Shaft – is a long flat, curved part that passes from the neck around the chest wall. 6. Anterior or Sternal End – part that articulate with the costal cartilage.  Costal Cartilages – are 12 pairs of cartilaginous flat plates on the anterior chest wall. 41  Congenital Anomalies on the Bones of the Thorax 1. Cervical Rib – is an extra rib present on one or both sides above the normal first rib. 2. Lumbar Rib – is a short extra rib present below the 12th rib, arising from the first lumbar body. 3. Absence of a rib – one or more ribs maybe absent on one or both sides. 4. Forked Rib – an anomaly wherein the anterior end of a rib maybe forked. 5. Fused Rib – an anomaly wherein the anterior end of the adjacent rib are one. 6. Pectus Excavatum – an anomaly wherein the sternum maybe depressed and thus decreases the antero-posterior diameter of the chest. 7. Pectus Carinatum/ Pigeon’s Chest – anomaly wherein there is protrusion of the sternum. THE ABDOMEN: The abdomen extends from the undersurface of the diaphragm to the pelvic brim. The Pelvic cavity reaches from the pelvic inlet to the floor of the pelvis. Since there is no separation between the abdomen and the pelvic cavity, part of the organ may lie in the abdomen and the remainder maybe in the pelvis. The position of an organ in the abdomen may vary with respiration, with position (upright or horizontal) and with condition (full or empty). 42  The Radiologic Technologist must realize: 1. That the diaphragm extends well up under the costal margins because it is dome- shaped. 2. That broad stocky individuals will have their organs at higher levels than long lanky individuals. 3. That the abdominal organs descend with inspiration. QUADRANTS OF THE ABDOMEN: As a Guide to the Radiologic Technologists for localizing the position of different structures in the abdomen, the division into four Quadrants is most rational. A line is drawn transversely around the abdomen at the level of the umbilicus (navel). A further line is drawn perpendicularly through the umbilicus – median line. These lines divide the Abdomen into FOUR QUADRANTS: 1. Right Upper Quadrant (RUQ) 2. Left Upper Quadrant (LUQ) 3. Right Lower Quadrant (RLQ) 4. Left Lower Quadrant (LLQ) NINE REGIONS OF THE ABDOMEN: One line is drawn transversely around the body at the level of the ninth costal cartilage. A second line is drawn transversely around the body at the level of the iliac crest. Two perpendicular lines are drawn, one on each side of the abdomen, at points midway between that anterior superior iliac spine and the symphysis pubis upwards towards the chest. 43  These four lines divide the abdomen into 9 parts or regions. They are named from right to left as: UPPER: Right Hypochondriac region Epigastric region Left Hypochondriac region MIDDLE: Right Lumbar Umbilical region Left Lumbar LOWER: Right Iliac region Hypogastric region Left Iliac region Definition of Terms: 1. Lumen – is the cavity in any hollow organ. 2. Peritoneum – is a thin layer of epithelium which lines the abdominal and pelvic cavities and is reflected over the surface of most abdominal organs. Two Layers of Peritoneum: 1. Outer or Parietal Layer – closely adheres to the abdominal and greater pelvic walls and to the undersurface of the diaphragm. 2. Inner or Visceral Layer – is reflected over or around the contained organs and form folds called the “mesentery” and “omentum” which serves to support the viscera in position. The narrow space between the two layers of peritoneum is called “Peritoneal cavity”. 3. Mesentery – is a double layer of peritoneum that extends from the posterior abdominal wall to some of the abdominal organs. 4. Omentum – term used to describe a fold of peritoneum between various abdominal organs. 5. Peristalsis – is a wave or alternating contraction and dilatation that occur in the walls of hollow organs. This helps to push the contents along the lumen towards the exit. 44  THE PELVIS Pelvis/Hip Bone/Os Coxae/Os Innominatum/ Innominate Bone – is a hollow, bent cylinder with bony walls located at the lower end of the vertebral column and is consist of 3 parts: 1. Ilium 2. Ischium 3. Pubis * In early life, the ilium, ischium and pubis are three distinct separate bones which meet at the acetabulum. By the eighteen or twentieth year of life, they will be united and the cartilage will be replaced. MAJOR PARTS OF THE PELVIS: 1. Acetabulum – is a cup-shaped cavity or socket on the outer surface of the Innominate bone at the junction of its three parts that accommodate the femoral head and forming the hip joint. 2. Obturator Foramen – is a large opening in the lower part of the Innominate bone where its margins are formed by the rami of the ischium and of the pubis. Is the largest foramen in the human skeletal system. 3. Three Fused Bones – ILIUM, ISCHIUM & PUBIS. A. ILIUM / FLANK BONE – forms the upper 2/5 of the acetabulum and all the Innominate bone above this socket. NOTE: The name of this bone must not be confused with that of the small intestine, the “ILEUM”. 45  Parts of the Ilium: 1. Body of the Ilium – is the thickened part, close to and above the acetabulum 2. Ala or Wing – is a thin, upper, flat curved part above the body. 3. Iliac Fossa – is the curved depression formed by the inner surface of the wing. 4. Crest of Ilium/Iliac Crest – is the upper curved border of the wing at approximate level of L4. This can be felt through its entire length through the lateral wall of the abdomen. 5. Anterior Superior Iliac Spine (ASIS) – is the prominent anterior end of the iliac crest and can readily be palpated through the skin. 6. Anterior Inferior Iliac Spine – lies on the front or anterior border about 1 inch below the ASIS. B. ISCHIUM – forms the lower posterior 2/5 of the acetabulum and part of the Innominate bone. Parts of the Ischium: 1. Body of Ischium – is the thickened part immediately below and behind the acetabulum. 2. Superior or Descending Ramus – part that extends down from the body. 3. Inferior or Ascending Ramus – part that passes forward and medially from the lower end of the superior ramus. 4. Tuberosity of Ischium or Ischial Tuberosity – is the large rounded prominence on the back of the superior ramus. It supports the weight of the body when the subject is sitting. 5. Ischial Spine / Spine of Ischium – is a pointed process that extends back and medially from the posterior part of the body of the ischium. Ischial spine is important in childbirth since the fetal head must pass through. 46 C. PUBIS or PUBIC BONE – forms the anterior 1/5 of the acetabulum and the lower anterior part of the Innominate bone. PARTS OF THE PUBIC BONE: 1. Body of the Pubis – is the flat medial or inner part adjacent to the symphysis pubis or pubic joint. 2. Superior or Ascending Ramus – part extending up, back and out from the body to the acetabulum. 3. Inferior or Descending Ramus – part that passes down and back from the lower part of the body to meet the inferior ramus of the ischium. 4. Symphysis Pubis / Pubic Symphysis– is the joint between the bodies of the two pubic bones. Pelvic Divisions: Pelvis Major (False pelvis) - Located between the iliac fossae, superior to the pelvic brim - Actually part of the abdominal cavity Pelvis Minor (True pelvis) - Located inferior to the oblique plane of the pelvic brim - Contains the urinary bladder, rectum, some reproductive organs and bowels. 47 Which of these Pelves belongs to a woman? The plural of Pelvis is Pelves 48  THE SHOULDER GIRDLE and UPPER EXTREMITY The Upper extremity is called the “Upper Limb” that includes: 1. The Shoulder 2. Arm/Humerus/Brachium 3. Forearm/ Antebrachium 4. Wrist 5. Hand The Shoulder has two bones forming the Shoulder Girdle: 1. Scapula 2. Clavicle SCAPULA or SHOULDER BLADE – is a flat triangular bone lying against the upper, lateral, posterior chest wall. Parts of the Scapula: 1. Body of the Scapula – is flat and triangular which has Three Borders: A. Vertebral or Medial Border – the inner border that lies close to the vertebral column. B. Axillary or Lateral Border – is the outer border that lies behind and close to the armpit. C. Upper or Superior Border – is the short upper border which has a depression on the lateral end called “Scapular Notch” D. Two Angles of the Scapula: 1. Medial or Superior Angle – is the inner end at its junction with the vertebral border. 2. Inferior Angle – is the rounded lower end of the body of the scapula. 49 2. Spine of the Scapula/Scapular spine – is a narrow ridge or crest of bone that projects back from the posterior surface of the body. It passes transversely from the medial to the lateral border. This divides the posterior surface of the scapular body into the “Supraspinatus fossa” and “Infraspinatus fossa”. 3. Acromion – is a flat rounded bony prominence continuous with the lateral end of the spine of the scapula. 4. Head of Scapula – is a poorly defined slightly expanded part lateral to the neck. 5. Neck of Scapula – is the thickened, slightly constricted part from the body. 6. Glenoid Cavity – is an oval depression on the outer surface of the head, somewhat cup-shaped. This accommodate the head of the humerus, forming the shoulder joint. 7. Coracoid Process – is a beak-like projection of bone continuous with and projecting forward from the neck of the scapula. CLAVICLE / COLLAR BONE The Clavicle is a long slender bone resembling somewhat an old fashion key. It has a double curve or depression called the “Supra and Infra Clavicular fossa that lies horizontally in front of the upper thorax. Its inner or sternal end articulate with the sternum forming the “Sterno- clavicular joint”. While it’s outer or acromial end articulate with the acromion of the scapula forming the “Acromio-clavicular joint”. 50  BONES OF THE UPPER EXTREMITY A. HUMERUS/ARM/BRACHIUM -is a long cylindrical bone extending from the shoulder to the elbow joint. Parts of the Humerus: 1. Head of the Humerus – is the smooth, expanded, rounded upper end that articulate with the Glenoid cavity of the scapula to form the “Shoulder joint”. 2. Anatomical Neck – is the slightly constricted, obliquely directed part adjacent to the head. 3. Greater Tubercle/Tuberculum Majus – is the large rounded bony prominence on the upper, lateral border just below the anatomical neck. It has a small depression for the insertion of the Spinatus muscle. 4. Lesser Tubercle/Tuberculum Minor – is a small bony prominence on the front of the upper humerus just below the anatomical neck. 5. Surgical Neck – is the constricted part of the upper humerus below the tubercles. It is called surgical neck as fracture may occur in this area especially in elderly. 6. Shaft/Body/Diaphysis – is the long rounded part that becomes flattened from front to back as it approaches the elbow. 7. Deltoid Tubercle/Deltoid Tuberosity – is a rough prominence on the front or anterior surface above the midpoint of the humerus into which the Deltoid muscle inserts. 8. Trochlea/Pulley – is that part on the distal end of the humerus that articulate with the semi-lunar notch of the ulna. 9. Capitulum/Capitellum – is a small rounded prominence also on the lower end of the humerus that lies on the outer or lateral side of the trochlea. 10. Coronoid Fossa – is a depression on the front of the humerus immediately above the trochlea. * The Coronoid process of the ulna fits into this fossa when the forearm is flexed. 51  11. Olecranon Fossa – is a depression on the back or posterior surface of the humerus above the trochlea into which the olecranon fits when the forearm is extended. 12. Medial Epicondyle – is a knuckle- like rounded bony prominence on the medial border of the lower humerus above the trochlea. 13. Lateral Epicondyle – is a similar bony prominence on the outer border of the lower humerus. B.FOREARM/ANTEBRACHIUM Has two long bones, the Radius and Ulna which extend from the elbow to the wrist. When the Upper Limb is in the anatomical position with the palm of the hand in front, these two bones lie parallel to each other. The RADIUS is on the LATERAL side, while the ULNA on the MEDIAL side. Parts of the RADIUS: 1. Head – is the upper expanded disc-like end that articulate with the capitulum of the humerus. 2. Neck – is the constricted part immediately below the head. 3. Radial Tuberosity – is a prominence below the neck on the antero-medial border. 4. Shaft/Body/Diaphysis – become gradually larger as it approaches the wrist joint. 5. Styloid Process – is a large bony prominence on the outer or lateral border and distal end of the radius. 6. Ulnar Notch – is a depression on the inner border of the lower radius just above its lower end. The outer border of the head of the ulna fits into this notch. 7. Lower Articular Surface – is large and forms the wrist joint along with the proximal carpal bones. 52  Parts of the ULNA: 1. Olecranon – is the blunt rounded upper end of the ulna that lies behind the elbow joint and forms the tip of the elbow. * Tip of the Olecranon fits into the olecranon fossa of the humerus when the forearm is extended. 2. Coronoid Process - forms a beak-like projection from the anterior surface of the ulna below and in front of the olecranon. * Coronoid process fits into the coronoid fossa of the humerus when the forearm is flexed. 3. Semi-lunar Notch/Trochlear Notch – is a small half-moon-shaped, concave hollow on the front of the upper ulna. This accommodate the trochlea of the humerus. 4. Radial Notch – is a small hollow or concavity on the outer or lateral border of the semi-lunar notch of the ulna. * The inner border of the head of the radius fits into this notch. 5. Shaft of the Ulna – is somewhat rounded and becomes smaller as it approaches the wrist. 6. Head of Ulna – is it’s lower, expanded end and can be felt through the skin. 7. Styloid Process – is a very small bony prominence extending down from the postero-medial border of the head. THE HAND or MANUS: The hand includes the bones of the wrist or carpus, the bones of the palm or metacarpals and the bones of the digits—phalanges. 53  WRIST or CARPUS – have eight carpal bones. Four of them form a proximal row adjacent to the lower end of the radius. The other four form a distal row adjacent to the metacarpal bones. Carpal Bones in the Proximal Row (from thumb side) Navicular/Scaphoid Lunate or Semi-Lunar Triangular or Triquetral/Triquetrum Pisiform Carpal Bones in the Distal Row (from thumb side) Greater Multangular or Trapezium Lesser Multangular or Trapezoid Capitate or Os Magnum/Capitatum Hamate/Unciform Description of some Carpal Bones:  Navicular/Scaphoid – boat-shaped. This is frequently fractured in injuries to the wrist because its blood supply is poor.  Pisiform- pea-shaped bone - lies in front of the triangular bone. It is the smallest among the proximal carpal bones. In x-ray of the wrist (PA), this will show its image superimposed upon that of the triangular bone.  Hamate - has a hook-like process arising from its front or anterior surface---- the “Hamulus”.  Lunate - moon-shaped bone.  Triquetrum – articulate with the small Pisiform Anteriorly and is pyramid is shape. 54  METACARPAL BONES: There are FIVE metacarpal bones which form the bony framework of the palm. They are named from the thumb side as the first, second, third, fourth and fifth metacarpal bones. PHALANGES/PHALANX: There are FOURTEEN phalanges. The thumb has only two phalanges: proximal and distal or terminal phalanx. Each of the other digits or fingers has three phalanges: proximal, middle and distal phalanx. Each metacarpal bone and each phalanx has a base or proximal end, body and head or distal end. The tip of the distal phalanx is called “Tuft”. JOINTS: Joint – is also called articulation or Arthrosis which is the point of contact between two bones, between bone and cartilage or between bone and teeth.  Every man has 360 joint bones. Classifications of Articulation or Joints: 1. Diarthrotic/Diarthrosis/Synovial – is a freely movable joint. Types of Synovial Joints: A. Ball & Socket – Hip & Shoulder B. Condyloid joint- Mandible to Temporal C. Gliding – Wrist, ankle, vertebrae D. Hinge – Elbow & Phalanges E. Pivot – Atlas to Axis/Radius to Ulna F. Saddle – Carpals 55  2. Ampiarthrotic/Ampiarthrosis – partially/slightly movable joint. EXAMPLES OF SLIGHTLY MOVABLE JOINTS A. Synchondrosis – cartilaginous joint in which the connecting material is hyaline cartilage. B. Symphysis – cartilaginous joint in which the end of articulating bones covered with hyaline cartilage, but a broad flat disc of fibrocartilage connects the bone 3. Synarthrotic/Synarthrosis or Fibrous Joint– are immovable joints. Joint in which no movement takes place. Types of Fibrous Joint: 1. Suture of Skull 2. Syndesmoses 3. Gomphosis JOINTS OF THE UPPER EXTREMITY: 1. Sterno-Clavicular joint: a. Clavicular notch of sternum b. Inner end of the clavicle 2. Acromio-Clavicular joint: a. Acromion of scapula b. Outer end of the clavicle 3. Shoulder joint: a. Glenoid cavity of the scapula b. Head of the humerus 4. Elbow joint: a. Trochlea of the humerus b. Capitulum of the humerus c. Semi-lunar notch of the ulna d. Head of the radius 5. Proximal Radio-Ulnar joint: a. Medial border, head of the radius b. Radial notch, on the lateral border of the ulna. 56  6. Distal Radio-Ulnar joint: a. Lateral border, head of ulna. b. Ulnar notch of radius on the medial border 7. Wrist joint: a. Distal articular surface of radius b. Navicular, lunate, triangular bones. 8. Inter-carpal joints: a. Between the adjacent margins of all carpal bones. 9. Carpo-Metacarpal joints: a. Distal row of the carpal bones b. Bases of the five metacarpal bones 10. Proximal Inter-phalangeal joint: a. Heads or distal ends of the proximal phalanges b. Bases of the middle phalanges 11. Distal Inter-phalangeal joint: a. Heads or distal ends of middle phalanges b. Bases of the distal or terminal phalanges CONGENITAL ANOMALIES OF THE UPPER EXTREMITY: 1. Abrachium – one or both upper limbs maybe absent. 2. Supernumerary Digits – extra digits present from the normal five digits. 3. Sprengel’s Deformity – there is elevation and deformity of the scapula. 4. Madelung’s Deformity – there is curvature of the shaft of the radius resulting in its distal articular surface lying obliquely. 57  BONES OF THE LOWER EXTREMITY: The Lower extremity or Lower limb is also called the “Inferior or Distal Extremity” as it is farther away from the head end of the body. Bones of the lower extremity includes; the femur, patella, tibia and fibula and the foot which is made up of the tarsal bones, metatarsal bones and phalanges. Parts of the FEMUR: 1. Head of Femur – is the upper, expanded rounded end that articulate with the acetabulum to form the “hip joint”. 2. Neck of Femur – is the constricted part connecting the head to the rest of the bone. 3. Greater Trochanter – is the large prominence on the outer (lateral) border of the upper femur. 4. Lesser Trochanter – is a much smaller rounded process that lies at a lower level than the greater trochanter extending in medially from the upper border of the shaft. 5. Intertrochanteric Crest – is a ridge of bone that passes obliquely across the back of the upper femur between the two trochanters. 6. Shaft/Body – is a long and rounded bone that becomes larger as it approaches the knee. 7. Medial Condyle – is a rounded knob-like process forming the medial half of the lower end of the femur. 8. Lateral Condyle – is a further rounded prominence on the outer (lateral) half of the lower end of the femur. 9. Intercondyloid Fossa/Notch – is a deep notch between the medial and lateral condyles of the femur. 10. Medial Epicondyle – is a large prominence on the inner (medial) surface of the lower femur just above the medial condyle. 58  11. Lateral Epicondyle – is a small rounded prominence on the outer (lateral) surface of the lower femur above the lateral condyle. 12. Patellar Surface – is the smooth anterior surface on the front of the lower femur above the intercondyloid fossa. THE PATELLA Patella/Knee Cap/Pan – is a sesamoid bone (cartilaginous tissue) within the tendon of the long muscle on the front of the thigh– the quadriceps muscle. Parts of the Patella: 1. Base – is the broad upper border. 2. Apex – is its lower pointed end. The posterior surface of the patella is smooth and glides over the patellar surface of the femur. Fabella – is another sesamoid bone in the lateral head of Gastrocnemius muscle located on the popliteal surface of the femur. 59  THE L E G: The Leg has two bones – the TIBIA and FIBULA, each extending from the knee to the ankle. These bones lie parallel to each other side by side. The TIBIA is much larger and takes the weight of the body. TIBIA: Tibia/Shin Bone – lies on the inner (medial) side of the fibula. Parts of the TIBIA: 1. Medial Condyle – is the medial (inner) half of the enlarged upper end. Its smooth, slightly cupped upper surface articulate with the medial condyle of the femur at the knee joint. 2. Lateral Condyle – is the outer half of its expanded upper end. Its smooth surface articulate with the lateral condyle of the femur to complete the knee joint. 3. Intercondyloid/Intercondylar Eminence – is a small double-pointed prominence on the upper articular surface of the tibia about its midpoint. 4. Tibial Tuberosity – is a rounded prominence on the anterior (front) surface of the upper tibia below the condyles. 5. Articular Facet – is a smooth pit on the outer or lateral surface of the lateral condyle of the tibia where it accommodate the medial border of the head of the fibula, forming the “Proximal Tibio-Fibular” joint. 6. Shaft/Body/Diaphysis – is round in its mid portion, but is flattened and enlarged at its lower end. 7. Medial Malleolus (Little Hammer) – projects down from the medial border of the distal end of the tibia. It forms a large prominence on the medial or inner border of the ankle which is visible and palpable. 8. Distal Articular Surface – is a four-sided (quadrilateral) smooth surface on the lower end of the tibia. It articulate with the trochlear surface of the talus. 9. Fibular Notch – is a small depression on the lateral border of the tibia just above the ankle joint. It articulate with the adjacent lower fibula and helps to form the “Distal Tibio-Fibular” joint. 60  FIBULA: Fibula / Calf Bone - is a long slender bone lying lateral to and parallel with the tibia. This bone does not reach the knee joint but forms a small part of the ankle. Parts of the FIBULA: 1. Head of Fibula – is the upper expanded end and articulate with the articular facet of the tibia to form the “Proximal Tibio-Fibular” joint 2. Shaft/Body – is a long and slender bone. 3. Lateral Malleolus – is the lower expanded end of the fibula. It, along with the medial malleolus of the tibia forms the “Ankle Mortise”. ANKLE/TARSUS/TARSAL BONES: There are 7 Tarsal or Ankle bones compared to 8 Carpal or Wrist bones. They are named from Back to Front as; 1. Calcaneus or Os Calcis 2. Talus or Astragalus 3. Navicular or Scaphoid st nd rd 4. 3 Cuneiforms; 1 , 2 , 3 Cuneiforms 5. Cuboid Bone Calcaneus /Heel Bone/Os Calcis – forms the heel of the foot. It has a body and an expanded posterior end or tuberosity which can be felt as the heel. Talus/Astragalus – helps to form the ankle joint. It bears the body weight and has a body,