Skeletal System PDF

Function: 1. Support 2. Movement 3. Storage of minerals and triglyceride 4. Protection 5. Blood cell formation - hematopoiesis through red bone marrow that contains RBC, WBC, and platelets Parts of skeletal system: Bones 206 bones 1. Axial skeleton -80 bones...

Function: 1. Support 2. Movement 3. Storage of minerals and triglyceride 4. Protection 5. Blood cell formation - hematopoiesis through red bone marrow that contains RBC, WBC, and platelets Parts of skeletal system: Bones 206 bones 1. Axial skeleton -80 bones Skull - cranial bones (joined by sutures): Temporal, Parietal, Frontal, Occipital, ethmoid, sphenoid 4 sutures: Sagittal suture - between parietal. Coronal suture - parietal and frontal. Squamous suture - parietal and temporal. Lambdoid suture - parietal and occipital. Facial bones: Mandible, vomer, inferior nasal concha, lacrimal, maxilla, nasal,palatine, zygomatic Fetal skull: fontanels “soft spots” ossify at the age of 2. 4 fontanels: mastoid, posterior, anterior, sphenoidal fontanel. “The growth of the skull must be in harmony with the growth of the brain. As the brain develops, the skull must also grow to accommodate the growth of the brain creating a perfect fit for it.” Paranasal sinuses - hollow portions of bones surrounding the nasal cavity. Function: amplify sounds as we speak, lighten the skull. Vertebral column - spine. Body’s major axial support. Surround and protect the spinal cord. Composed of 24 single bones and 2 bones that are formed by fused vertebrae. Parts: - Cervical (c1 - c7). C1 = atlas, holds head, has transverse foramen (veins and arteries). C2 = axis, rotates head, has a large vertical process called dens/odontoid process that acts as a pivot joint. - Thoracic (t1 - t12) - in the chest, heart shaped, articulate with ribs. - Lumbar (l1-l5) - block like bodies, sturdiest. - Sacrum - 5 fused vertebrae - Coccyx - fusion of 4 small irregularly shaped vertebrae, aka human tailbone. Structure: - Body - round central portion - Vertebral arch - composed of lamina (upper) and pedicle (lower) - Vertebral foramen - space in the middle where the spinal cord passes through - Transverse process (2) - enables muscle movement, located at the lateral sides. - Spinous process (1) - points posteriorly from the arch  - Superior and inferior articular process (2) - enable articulation b/w adjacent vertebrae. Facet - top white part of articular process. Primary curvature - C shaped, newborns Secondary curvature - S shaped, adult Bony thorax - Sternum - breastbone, fusion of 3 bones: manubrium - top part,looks like a tie knot, body - form mostly the sternum, xiphoid process - inferior end. - Ribs - True ribs (pair 1-7) - attached directly to sternum. False ribs (pairs 8-12) - no direct attachment. Floating ribs (pairs 11-12)- no attachment at all. 2. Appendicular skeleton -126 bones Limbs (appendages) - Upper extremities: Humerus - upper limb. Ulna - forearm, pinky. Radius - forearm, thumb. Carpals - (8) Hamate, Capitate, Trapezoid, Trapezium, Pisiform, Triquetrum, Lunate, Scaphoid. Metacarpals (5)- palm. Phalanges - (14) fingers, distal-middle-proximal. - Lower extremities: Femur - thigh. Patella - sesamoid, kneecap. Tibia - larger, inwards. Fibula - small, outward. Tarsals (7) - medial cuneiform, intermediate cuneiform, lateral cuneiform, navicular, cuboid, tallus, calcaneus. Metatarsals - (5) sole of foot. Phalanges - toes Pectoral Girdle - Clavicle - collarbone (long bone) - Scapula - shoulder (flat) Pelvic girdle - two coxal bones + sacrum Pelvis = “” + coccyx - Ilium - top - Ischium - lower - Pubis - middle inwards Joints: - Based on shape 1. Plane joint 2. Hinge joint 3. Condylar joint 4. Pivot joint joint 5. Ball and socket joint 6. Saddle joint Movement at synovial joint: - Flexion - decreases angle - Extension - relaxed position - Hyperextension - angle of 180 - Lateral flexion - flexion toward left or right  - Abduction - away from midline - Adduction - towards midline - Circumduction - combination of all, forms circular movement. - Rotation - twist movement - Medial rotation - Lateral rotation Arms: - Supination - palm upward, ulna and radius are parallel - Pronation - palm downward, radius on top of ulna Foot: - Dorsiflexion - toe points upward - Plantar flexion - toe points downward - Inversion - bottom foot toward midline - Eversion - bottom foot away from midline Mandible: - Protraction - jaw points outward - Retraction - original position - Depression - downward (open mouth) - Elevation - upward Scapula: - Protraction - shoulder forward - Retraction - shoulder inward / kunot likod - Depression - downward shrugging - Elevation - upward shrugging Fingers: - Opposition - thumb is in contact with other fingers - Reposition - normal position Joints (articulation) - where 2 or more bones meet Cartilages: - tissue that covers the surface of a bone at a joint Types of Cartilage: Hyaline - found in ribs, nose larynx and trachea Fibrocartilage - found in intervertebral disc, joint capsules and ligaments Elastic - found in external ear, epiglottis and larynx  Ligaments - tough elastic bands of connective tissue, give support and limit the joint’s movement - BONE to BONE (BB) Tendons - tough connective tissue, surround the joint, MUSCLE to BONE (MB) TWO BASIC TYPES OF BONE TISSUE Compact bone - dense and looks smooth, homogenous Spongy bone - small needle-like pieces of bone, many open spaces CLASSIFICATION OF BONES (on the basis of SHAPE) Flat bone - thin, flattened and usually curved, two thin layers of compact bone surround a layer of spongy bone ex: frontal, lacrimal, nasal, occipital, parietal, vomer, scapula, sternum, rib, hip Long bones- longer than they are wide, shaft with heads situated at both ends - contains mostly compact bone ex: clavicle, upper limbs, and lower limbs except carpals, tarsals, patella Short bones - cube- shaped, wide as they are long, contains mostly spongy bone - ex:Carpals and Tarsals Sesamoid bone - type of short bone that forms within the tendons ex: patella Irregular bone - irregular shape Ex: Mandible, maxilla, temporal, ethmoid, sphenoid, palatine, zygomatic, inferior nasal concha, hyoid, vertebrae, sacrum, coccyx Anatomy of a Long bone: Diaphysis (shaft) - bone’s length, composed of compact bone Epiphysis (ends) - composed of mostly spongy bones enclosed by thin layers of compact bone Articular cartilage - covers the external surface of epiphysis, made of hyaline cartilage, decreases friction at joint surfaces Periosteum - outside covering of the diaphysis, fibrous connective tissue membrane Epiphyseal line - remnant of the epiphyseal plate, ADULT. Epiphyseal plate - flat plate of hyaline cartilage, YOUNG, causes lengthwise growth of a long bone Endosteum - lines the inner surface of the shaft - made of connective tissue Medullary Cavity - cavity inside the shaft, contains yellow marrow (fat) in adults, contains red bone marrow for blood cell formation in infants until the age of 6 or 7 Structure of bone: SPONGY: Trabeculae - needle like ike pieces Open Spaces - filled by marrow blood vessels and nerves COMPACT: Central (Haversian) Canal - located inside and middle of osteon, carries nerves and blood vessels.  Osteon - structural and functional unit of a compact bone, contains central canal and matrix rings. Canaliculi - tiny canals,form of transport system connects all bone cells to a nutrient supply Perforating (Volkmann’s) Canal - perpendicular to central canal, carries blood vessels and nerves Inside osteon: Lamella - circle the haversian Lacunae- houses the osteocytes Bones formation, growth and remodeling: Ossification - process of bone formation, long growth occurs in two main phases: intramembranous and endochondral. Remodeling: osteoclast and osteoblast Osteoprogenitor cell / osteogenic - active stem cell Osteocytes - mature bone cells that maintain the bone matrix. Osteoclast - giant destroying cell, breaks bone. Osteoblast - bone forming cell. Bone Fracture - break in a bone. Types: 1. Open (compound) fracture - penetrates the skin 2. Closed (simple) fracture - doesn’t penetrate the skin Treatment: 1. Closed reduction - doctor manually coaxed into position the bones 2. Open reduction - bone is secured with pins or wires. 4 major event for bone repair: 1. Hematoma Formation - blood filled swelling 2. Fibrocartilage callus formation - trabeculae appears as callus forms 3. Bony callus formation - spongy bone replaces callus 4. Bone remodeling - the spongy bone is replaced by compact bone where the bone is fully remodeled. Common Types of Fracture: Comminuted - bone breaks into three or more fragments Compression - bones crushed Depressed - broken bone portions is pressed inward Impacted - broken bone ends are forced into each other Spiral - ragged break occurs when excessive twisting forces are applied to a bone Greenstick - bone breaks incompletely much in the way a green twig breaks