Exam 2 Review Notes PDF

Chapter 5 -- 8 Exam review Structure of skin Consists of three major regions - Epidermis - superficial region - Dermis - middle region - Hypodermis -- deepest region Epidermis - Keratinized stratified squamous epithelium - Sweat glands - Eccrine: forehead, neck, back, palms...

Chapter 5 -- 8 Exam review Structure of skin Consists of three major regions - Epidermis - superficial region - Dermis - middle region - Hypodermis -- deepest region Epidermis - Keratinized stratified squamous epithelium - Sweat glands - Eccrine: forehead, neck, back, palms - Apocrine: axillary regions, groin - Ceruminous: produces earwax for protection - Oil glands - Produce sebum - Waterproofs and softens skin and hair - Hairs and hair follicles - Nails Dermis - Binds epidermis to tissue below - Supplied with blood vessels, nerve fibers, lymphatic vessels - Has two layers - Papillary layer - Reticular layer Skin color Three pigments contribute to skin color - Melanin (yellow to reddish-brown to black, responsible for dark skin colors) - Carotene (yellow to orange, most obvious in the palms and soles) - Hemoglobin (responsible for the pinkish hue of skin) ABCDE Rule for Melanoma A -- Asymmetry; the two sides of the pigmented area do not match B -- Border exhibits indentations C -- Color is black, brown, tan, and sometimes red or blue D -- Diameter is larger than 6mm (size of a pencil eraser) E -- Evolving is any change in elevation, itching, scabbing, or bleeding Three major types of skin cancer - Basal cell carcinoma - Least malignant, most common - Stratum basal cells proliferate and slowly invade the dermis and hypodermis - Cured by surgical excision in 99% of cases - Squamous cell carcinoma - Second most common - Involves keratinocytes of stratum spinosum - Mostly found on scalps, ears, lower lips, and hands - Good prognosis if treated by radiation therapy or removed surgically - Melanoma - Most Dangerous - Involves melanocytes - Highly metastatic and resistant to chemotherapy - Treated by wide surgical excision accompanied by immunotherapy Burns - First degree - Epidermal damage only - Localized redness, edema (swelling), and pain - Second degree - Epidermal and upper dermal damage - Blisters appear - Third degree - Entire thickness of skin damaged - Grey-white, cherry red, or black - No initial edema or pain (nerve endings destroyed) - Skin grafting is usually necessary Types of cartilage - Skeletal Cartilage - Contain no blood vessels or nerves - Dense connective tissue girdle of perichondrium contains blood vessels for nutrient delivery to cartilage Three types of skeletal cartilage - Hyaline cartilages - Provide support, flexibility, and resilience - Most abundant type - Found in the ribcage or at the end of long bones - Elastic cartilages - Similar to hyaline cartilage but contains elastic fibers - Found in the external ear and epiglottis - Fibrocartilages - Collagen fibers that have great tensile strength - Act as shock absorbers - Found in the knees and between vertebrae, and the pubic symphysis Bones of the skeleton have two main groups - Axial skeleton (head, spine, ribs, and sternum) - Appendicular skeleton (Every other bone) Bone shapes - Long bones - Longer than they are wide - Short bones - cube shaped bones (in wrists and ankles) - Sesamoid bones (within tendons, e.g. patella) - Flat bones - Thin, flat, slightly curved - Irregular bones - Complicated shapes Functions of Bones - Support - For the body and soft organs - Protection - For the brain, spinal cord, and vital organs - Movement - Levers for muscle action - Storage - Minerals (calcium and phosphorus) and growth factors - Blood cell formation - Hematopoiesis in marrow cavities - Triglyceride - Energy storage in bone cavities Microscopic Anatomy of Bone Cells of bones - Osteogenic (osteoprogenitor) cells - Stem cells in periosteum and endosteum that give rise to osteoblasts - Osteoblasts - Bone-forming cells - Osteocytes - Mature bone cells - Osteoclasts - Cells that break down (resorb) bone matrix Compact Bone anatomy - Osteon (Haversian system) -- Structural unit - Lamellae - Weight-bearing - Column-like matrix tubes - Central (Haversian) canal - Contains blood vessels, nerves, and lymphatic vessels - Perforating (Volkmann's) canals - At right angles to the central canal - Connects blood vessels and nerves of the periosteum and central canal - Lacunae - Small cavities that contain osteocytes - Canaliculi - Hair-like canals that connect lacunae to each other and the central canal Spongy Bone Anatomy - Trabeculae - Align along lines of stress - No osteons - Contain irregularly arranged lamellae, osteocytes, and canaliculi - Capillaries in endosteum supply nutrients Structures of a long bone - Diaphysis - Shaft - Epiphyses - Expanded ends of bone - Spongy bone interior - Epiphyseal line (remnant of the growth plate) - Articular (hyaline) cartilage on joint surfaces Two types of ossification - Intramembranous ossification - Membrane bone develops from fibrous membrane - Forms flat bones - Clavicles and cranial bones - Endochondral Ossification - Cartilage (endochondral) bone forms by replacing hyaline cartilage - Forms most of the skeleton Intramembranous Ossification process - An ossification center appears in the fibrous connective tissue membrane - Selected centrally located mesenchymal cells cluster and differentiate into osteoblasts, forming an ossification center - Bone matrix (osteoid) is secreted within the fibrous membrane - Osteoblasts begin to secrete osteoid, which is mineralized within a few days - Trapped osteoblasts become osteocytes - Woven bone and periosteum form - Accumulating osteoid is laid down between embryonic blood vessels, which form a random network. The result is a network of trabeculae or spongy bone - Vascularized mesenchyme condenses on the external face of the woven bone and becomes the periosteum - Bone collar of compact bone forms and red marrow appears - Trabeculae just deep to the periosteum thickens, forming a woven bone collar that is later replaced with mature lamellar bone. - Spongy bone consisting of distinct trabeculae, persists internally and its vascular tissue becomes red marrow. Endochondral Ossification process - Bone collar forms around hyaline cartilage model - Cartilage in the center of the diaphysis calcifies and develops cavities - The periosteal bud invades the internal cavities and spongy bone begins to form. - The diaphysis elongates and a medullary cavity forms as ossification continues. Secondary ossification centers appear in the epiphyses in preparation for stage 5. - The epiphyses ossify. When completed, hyaline cartilage remains only in the epiphyseal plates and articular cartilage. Bone fracture types - Comminuted - Bone fragments into three or more pieces - Common in the elderly, whose bones are more fragile - Compression - The bone has been crushed - Common in porous bones subjected to extreme trauma, as in a fall - Spiral - Ragged break occurs when excessive twisting forces are applied to a bone - Common in sports - Epiphyseal - Epiphysis separates from the diaphysis along the epiphyseal plate - Tends to occur where cartilage cells are dying and calcification of the matrix is occurring - Depressed - Broken bone portion is pressed inward - Typically found in the skull - Greenstick - Bone breaks incompletely, much in the way a green twig breaks. Only one side of the shaft breaks; the other side bends. - Common in children, whose bones have relatively more organic matrix and are more flexible than adults. Name and locate each bone Know which bones articulate with which bones Differentiate between the axial skeleton and the appendicular skeleton Be able to differentiate between the different vertebrae Be able to identify bones individually The skull has two sets of bones - Cranium bones (8) - Facial bones (14) Classifications of Joints Functional Classifications - Synarthroses -- Immovable - Amphiarthroses -- Slightly movable - Diarthroses -- freely movable Structural Classifications - Fibrous - Cartilaginous - Synovial Fibrous Joints Bones joined by dense fibrous connective tissue NO joint cavity Most are synarthrosis (immovable) There are three types - Sutures - Syndesmoses - Gomphoses Suture -- Joint held together with very short interconnecting fibers, and bone edges interlock - Fibrous - Synarthroses - Found only in the skull Syndesmosis -- Joint held together by a ligament. Fibrous tissue can vary in length but is longer than is sutures - Fibrous - Synarthroses Gomphosis -- Peg in socket fibrous joint. The periodontal ligament holds teeth in their socket - Fibrous - Synarthroses Cartilaginous Joints Bones united by cartilage No joint cavity Two types - Synchondroses - Symphyses Synchondroses -- Bones used by hyaline cartilage (Epiphyseal plate, sternum, joint between first rib and sternum) - Cartilaginous - Synarthroses Symphyses -- Bones united by fibrocartilage (Pubic symphysis) - Cartilaginous - Amphiarthroses Synovial Joins - All are diarthrotic - Include all limb joints, most joints of the body - Articular cartilage: hyaline cartilage - Joint (synovial) cavity: small potential space - Articular (joint) capsule - Outer fibrous capsule - Inner synovial membrane - Synovial fluid - Viscous slippery filtrate of plasma and hyaluronic acid - Lubricates and nourishes articular cartilage - Three types of reinforcing ligaments - Capsular (intrinsic) -- part of the fibrous capsule - Extracapsular -- outside the capsule - Intracapsular- deep to capsule; covered by synovial membrane - Rich nerve and blood vessel supply - Capillary beds produce filtrate for synovial fluid Synovial Joint types Friction-Reducing Structures - Bursae - Flattened, fibrous sacs lines with synovial membranes - Tendon Sheath - Elongated bursa that wraps completely around a tendon Synovial joint movements - Gliding - One bone surface glides or slips over another similar surface - Hand gliding over the ulna and radius - Angular movement that occurs along the sagittal plane - Flexion- Decreases the angle of the joint - Extension- increases the angle of the joint - Hyperextension- excessive extension beyond the normal range of motion - Angular movement that occurs along the frontal plant - Abduction -- movement away from the midline - Adduction -- movement towards the midline - Circumduction -- flexion + abduction + extension + adduction of a limb so at to describe a cone in space - Rotation - The turning of a bone around its own long axis - Between the c1 and c2 vertebrae - Rotation of the humerus and femur - Special movements - Movement of radius around the ulna - Supination -- turning hand backward (cupping motion) - Pronation -- turning hand forward - Movements of the foot - Dorsiflexion (upward movement) - Plantar flexion (downward movement) - Inversion -- turn of the sole medially - Eversion -- turn of the sole laterally - Movements in a transverse plane - Protraction (anterior movement) - Retraction (posterior movement) - Elevation (lifting a body part superiorly) - Depression ( moving a body part inferiorly) - Opposition of the thumb -- Movement in the saddle joint so that the thumb touches the tips of the other fingers Nonaxial joints (plane joints) - Flat articular surfaces - Short gliding movements Uniaxial joints (hinge joints, pivot joints) - Hinge Joints - Motion along a single plane - Flexion and extension only - Pivot joints - The rounded end of the bone conforms to a "sleeve" or ring of another bone Biaxial Joints (condyloid ((ellipsoidal)) joints, saddle joints) - condyloid ((ellipsoidal)) joints - Both articular surfaces are oval - Permit all angular movements - Saddle Joints - Allow greater freedom of movement than condyloid joints - Each articular surface has both concave and convex areas Multiaxial joints (Ball-and-socket joints) - The most free-moving synovial joints