Anatomy 1st Week By COMT PDF

01 Introduction to Anatomy Anatomy: means cutting –up for studying the normal structure of organs in living. Types of study: Macroscopic anatomy: Studying normal structure of organs by naked eye. Microscopic anatomy (Histology): studying of normal structure of cells under micr...

01 Introduction to Anatomy Anatomy: means cutting –up for studying the normal structure of organs in living. Types of study: Macroscopic anatomy: Studying normal structure of organs by naked eye. Microscopic anatomy (Histology): studying of normal structure of cells under microscope. Developmental anatomy: Studying of intrauterine life. Applied anatomy: Application of anatomical facts in medicine and surgery. Surface anatomy: Identification of borders of organs on the skin surface. Radiographic anatomy: Studying of anatomy by using imaging techniques: CT, MRI, X-ray ….. Anatomical position & anatomical planes Anatomical position: human is standing erect. Face & eyes are looking forward. Arms are hanged beside the trunk. Palms of the hand are facing forward. Anatomical planes: Sagittal plane: a vertical plane which divides the body into right & left parts. If it is dividing two equal halves, it’s called median plane. Coronal plane: a vertical plane which divides the body into front & back parts. Transverse plane: a horizontal plane which divides the body into upper & lower parts. Anatomical terms Terms of relationship: Terms of comparison: Anterior → in front. Cranial → nearer to the head Posterior → behind. Caudal → nearer to the tail. Superior → above. Proximal → nearer to the trunk. Inferior → below. Distal → away from the trunk. Medial → closer to median plane. Ventral → nearer to the anterior Lateral → away from the median plane. abdominal wall. Dorsal → nearer to the backbone. 1 Terms of movements: Flexion → to bend. Extension → to straighten. Abduction → movement away from the median plane. Adduction →movement towards the median plane. Circumduction → multi-axial movement in a sequence of flexion, abduction, extension & adduction or vice versa. Protraction (protrusion) → movement forward Retraction (retrusion) →movement backward. Dorsiflexion of foot → movement to make toes approximate the front of leg. Planterflexion of foot → the reverse. Rotation → turning movement around a single axis.  Rotation in hand: supination → palm of the hand is facing forward.  Pronation → palm of the hand is facing backward.  Rotation in foot: inversion → sole of the foot is facing inward. Eversion →sole of the foot is facing outward. Body cavities Ventral body cavities Dorsal body cavities Thoracic cavity → containing lungs & heart. Cranial cavity → containing brain. Abdominal & pelvic cavities → containing Vertebral canal → containing spinal abdominal & pelvic viscera. cord. These cavities are lined by serous These cavities are lined by membranes. meninges. General Anatomy & Embryology | edited by CO MT  02 Skin & Fascia Introduction: The skin forms the external surface of the body. The skin consists of two layers:  Epidermis → A superficial epithelial layer.  Dermis → A deeper connective tissue layer. The skin has four appendages that developed from ectoderm: Hairs, nails, sebaceous glands & Sweat glands. Functions of the skin: 1. It protects the underlying soft tissues from mechanical, osmotic & thermal damage. 2. It acts as a barrier against microorganisms. 3. It regulates heat exchange between the body & the external environment (Sweating). 4. The largest sensory organ for touch, pressure, pain & temperature. 5. Absorption of substances (drugs –toxins). 6. Activation of vitamin D by the effect of ultraviolet rays. Epidermis of skin: It is formed of stratified squamous epithelium – keratinized. It is composed of five layers: 1. Stratum coneum → non- nucleated cells, filled with water- retaining keratin protein. About 10- 30 layers. 2. Stratum lucidum →found in thick skin (Palm of hand & sole of foot). Non-nucleated clear cells. 3. Stratum granulosum → with granular cytoplasm containing lipids. 4. Stratum spinosum →polyhedral cells connected tightly by desmosomes. 5. Stratum basale → proliferating basal layer on the basement membrane that give rise to all layers of epidermis. 3 Dermis: It is consisted of connective tissue, in which the following structures are found: 1. Blood vessels. 2. Lymph vessels. 3. Sensory nerve endings. 4. Hair follicles, sweat glands & sebaceous glands. Flexure lines of skin (skin creases): Linear skin furrows lie opposite joints. Site: especially found in palm of hand, front of wrist joint. It is produced by firm attachment of the skin to the underlying deep fascia. Papillary ridges (Finger prints): They are narrow, slightly raised ridges that separated by fine parallel furrows to help perfect hand grip. They are found in the palm of hands, sole of feet as well as tips of fingers & toes. They are specific to the individuals which of medicolegal importance. Blood supply of skin: epidermis is avscular & receives its nourishment from vascular epidermis. Nerve supply: 1. From the skin: sensory receptors for touch, temperature & pain. 2. To the skin: Autonomic sympathetic fibers that supply sweat glands, sebaceous glands & arrector pilorum muscles. Superficial fascia: Definition: A layer of loose areolar connective or adipose tissue that connects the skin to the underlying bones or deep fascia. It is known also by Hypodermis. Site & functions: It is well developed at these sites: trunk wall, abdominal wall, buttocks & face. It is absent in ear pinna, eye lids, penis & scrotum. It is condensed in scalp, palm of hand & sole of foot. Functions: 1. It facilitates skin movement. 2. It forms a soft bed for blood vessels & nerves of skin. 3. It retains body warmth. 4. It gives your body a smooth contour. General Anatomy & Embryology | edited by CO MT  Deep fascia: Definition: A dense connective tissue that is commonly arranged in sheets that form a stocking around the muscles and tendons beneath the superficial fascia. Site & functions: Deep fascia is absent in face, scalp & anterior abdominal wall. Functions: 1. It invests muscles to make a degree of tension to help muscle action. 2. It sends septa between muscles. 3. It invests delicate structures: glands & blood vessels to keep their fixation in place. 4. It is thickened at the palm of hands (Palmar aponeurosis) & sole of feet (Planter aponeurosis) for protection of the underlying soft structures: vessels & nerves. 5. It helps venous return from the lower limbs by forming a closed compartments inside which the skeletal muscles contract to squeeze veins (Muscle Pump). General Anatomy & Embryology | edited by CO MT  03 Bone tissue Bone tissue & functions  Bone tissue: Bones are hard forms of connective tissues. It forms 18% of body weight. The body is formed of 206 bones. Cells:  Osteocytes → mature bone cells.  Osteoblasts → young bone cells.  Osteoclasts → phagocytic cells for bone remodeling. Matrix:  Organic (collagen bundles type-1) 30% of dry bone.  Inorganic salts → calcium carbonate & calcium phosphate, 70%.  Bone functions: 1. Gives body shape. 2. Forms joints for locomotion. 3. Protection of vital organs like brain & heart. 4. Containing bone marrow for blood cells formation. 5. Storage for calcium & phosphorus. Types of bones  Histological classification: two types Compact bone → bony matrix contains tiny spaces with no bone marrow. Example: shaft of long bones. Spongy bone → bony matrix contains large spaces rich in bone marrow. Example: ends of long bones.  Developmental classification: two types Intra-membranous ossification → young bone cells are arranged in membrane like structure as in flat bones. Intra-cartilaginous ossification → young bone cells are developed from cartilaginous model as in long bones.  Morphological classification: 1. Long bones: Present in limbs. They have a shaft & two articular ends. Growth of long bones:  They are developed by intra-cartilaginous ossification.. 6   Primary centers of ossification appear at the shaft (diaphysis) of bones by 8th : 12th week of intra-uterine life.  Secondary centers of ossification appear at the ends (epiphysis) of bone around time of birth.  Epiphysial cartilage plate persists at junction between epiphysis & diaphysis for bone growth till time of 19th -25th years of age. Blood supply of long bones: i. Nutrient artery & vein. ii. Peri-osteal twigs of vessels. iii. Articular vessels near the joint ends. 2. Short bones: They are small cubical bones. Example: carpal & tarsal bones. General Anatomy & Embryology | edited by CO MT 3. Flat bones: They have flat wide surface for protection & muscle attachment. Example: skull cap & scapula. 4. Irregular bones: They are of irregular configuration. Example: vertebrae. 5. Sesamoid bones: Small nodular bones present within muscle tendons to protect them against friction. Example: patella. 6. Pneumatic bones: Only in facial bone. Air spaces replace the bone marrow & communicate with nasal cavity. Example: Para-nasal sinuses. General Anatomy & Embryology | edited by CO MT Skeletal system  Axial skeleton: formed of: Skull & mandible. Vertebral column. Sternum. Ribs.  Appendicular skeleton: formed of: Upper limb: which is formed of:  Shoulder girdle (clavicle & scapula).  Arm bone (Humerus).  Forearm bones (Ulna & radius).  Carpal bones (8 bones).  Metacarpal bones.  Phalanges ( 3 except for thumb, only 2) lower limb: which is formed of:  Pelvic girdle (hip bones).  Thigh bone (Femur).  Leg bones (tibia & fibula).  Tarsal bones (7 bones).  Metatarsal bones.  Phalanges ( 3 except for big toe, only 2) General Anatomy & Embryology | edited by CO MT  04 Joints Types of joints Joints are junction or articulation between two or more bone.  Types: 1. Fibrous joints: bones are connected by an intervening fibrous tissue. Examples: sutures of skull & syndesmosis between lower ends of tibia & fibula. 2. Cartilaginous joints: bones are connected by cartilaginous tissue. A. Primary cartilaginous joint → formed of hyaline cartilage as epiphysial cartilage plate. It allows no movement. B. Secondary cartilaginous joint →formed of fibro-cartilage as intervertebral disc. It allows compression & torsion movement (limited). 3. Synovial joints: Joints are connected by a joint with a cavity which contains synovial fluid & enclosed inside a fibrous capsule. Features: A. Articular cartilage: formed of hyaline cartilage, very smooth surface with no vessels or nerves. B. Fibrous capsule: fibrous sac enclosing the joint. It is perforated by vessels & nerves. C. Synovial membrane: fine delicate membrane secreting synovial fluid. D. Synovial fluid: lubricating egg albumin like fluid to minimize friction between articular surfaces. E. Ligaments: strong fibrous bands connecting bones together. 10  Structures could be found inside the synovial joint:  Articular disc: formed of fibro-cartilage, compressible for shock absorbance & minimize friction. Examples: T/M joint, knee joint & sterno-clavicular joint.  Intra-articular ligaments: ligaments inside the joint cavity. Example: cruciate ligaments inside the knee joint.  Muscle tendons: found in shoulder joint, the tendon of long head of biceps. Classification of synovial joints 1. Plane joints: Flat articular surfaces allow minimal gliding movement. Example: inter carpal joint. 2. Uni-axial joints: Allow two movements around single axis. Hinge joints: with transverse axis. Example: elbow joint. Pivot joints: with longitudinal axis. Example: median Atlanto-axial joint. 3. Bi-axial joints: Allow four movements around two axes. Ellipsoid joint: an oval convexity is introduced into elliptical concavity. Example: Radio-carpal joint. Saddle joint: concavo-convex opposing surfaces of saddle shape. Example: carpo-metacarpal joint of thumb. General Anatomy & Embryology | edited by CO MT 4. Multi-axial joints: Allow free movement. Ball & socket joints. Examples: hip & shoulder joints General Anatomy & Embryology | edited by CO MT