Anatomy & Physiology Chapter 5
Ischium
"Sitdown bone"
True Ribs
(First 7) Ribs that attach directly to the sternum by costal cartilages
False Ribs
(Following 5) Ribs that attach indirectly to the sternum or are not attached to the sternum at all
Floating Ribs
(Last 2 false ribs) Ribs that lack the sternal attachments.
Healing of a bone fracture (stages)
1. Hematoma formation 2. Fibrocartilage callus formation -- made of cartilage matrix, bony matrix, and collagen fibers; splints the bone 3. Bony callus formation (of spongy bone) 4. Bone remodeling -- response to mechanical stresses placed on it to form strong permanent "patch"
Ossification (Bone formation)
1. Hyaline cartilage model is completely covered with bone matrix by bone forming cells called osteoblasts 2. Enclosed hyaline cartilage model is digested away, opening up a medullary cavity within the newly formed bone. 3. Except articular cartilages (persists for life and reduces friction) and epiphyseal plates (for longitudinal growth)
Bone Remodeling
1. Resorption (osteoclasts eat old bone) 2. Osteoblasts lay down new matrix and become trapped within it. 3. Once they are trapped, they become osteocytes, or mature bone cells.
Functions of the Skeletal System
1. Support- bones form the internal framework that supports and anchors all soft organs. 2.Protection- bones protect soft body organs 3.Movement- skeletal muscles use the bones as levers to move the body and its parts 4.Storage- bones store fat and minerals (such as calcium and phosphorous) 5.Blood Cell Formation- aka hematopoiesis occurs within the marrow cavities of certain bones
Classification of bone (4)
According to shape: long, short, flat and irregular
Synovial joints
Articulating bone ends are separated by joint cavity containing synovial fluid. Really moveable!! (Ex Shoulder joint)
Simple (closed) Fracture
Bone breaks cleanly, but does not penetrate the skin.
Greenstick Fracture
Bone breaks incompletely much in a way a green twig breaks. Common in children, whose bones have relatively more collagen in their matrix and are more flexible than those of adults.
Comminuted Fracture
Bone breaks into many fragments. Common fracture in the aged, whose bones are more brittle.
Closed Reduction
Bone ends are coaxed back into their normal position by the physician's hands
Cartilaginous joint
Bone ends are connected by cartilage. Can be either slightly moveable (ex pubic synthesis) or Immoveable (ex hyaline cartilage epiphyseal plates of growing long bones)
Compression Fracture
Bone is crushed
Why do bone injuries heal much more rapidly than injuries to cartilage?
Bones are much more well vascularized than cartilage so blood cells are able to carry in nutrients and facilitate healing.
Irregular bones
Bones that don't fit any other proceeding categories. (Ex vertebrae and hip bones)
Fibrous joints
Bones united by fibrous tissue. Basically Immoveable. (Ex sutures of skull)
Fracture
Break in a bone
Impacted Fracture
Broken bone ends are forced into each other. Commonly occurs when one falls and attempts to break the fall with outstretched arms; also common in hip fractures.
Depressed Fracture
Broken bone portion is pressed inward (typical of skull fracture)
Compound (open) Fracture
Broken ends of the bone protrude through soft tissues and the skin. More serious than a simple fracture; may result in severe bone infection requiring massive doses of antibiotics.
Major regions of vertebral column (5)
Cervical curvature (7), thoracic curvature (12), lumbar curvature (5), sacrum & coccyx
Rheumatoid arthritis (RA)
Chronic inflammatory disorder, autoimmune disease, begins with inflammation of synovial membrane, which thickens and the joint swells. Cartilage is destroyed, scar tissue forms and ossifies thus fusing the bones and rendering bone ends innoveable
Bones of shoulder (pectoral) girdle
Clavicle and scapula
Function of intervertebral disks
Cushion vertebrae and absorb shocks
Anatomical name for the shaft of a long bone
Diaphysis
Factors that cause bone to become soft or atrophy
Diet poor in calcium and protein, lack of Vitamin D, smoking, insufficient physical activity
Rickets
Disease in children in which the bones fail to calcify
Gouty arthritis (gout)
Disease in which uric acid accumulates in the blood and crystalizes in the soft tissue of joints.
Anatomical name for the ends of a long bone
Epiphyses
Differences between male and female pelvis
Female inlet is larger and more circular, the pelvis as a whole is shallower, and the bones are larger and thinner, female illia flare more laterally and their sacrum is shorter and less curved. Female ischial spines are shorter and farther apart (making the outlet larger) and the pubic arch is more rounded (angle of pubic arch is grater)
Diarthroses
Freely moveable joints
Bones of the cranium (8)
Frontal, occipital, sphenoid, ethmoid & parietal and temporal (which have pairs!)
Short bones
Generally cube shaped, contain mostly spongey bone (ex wrist and ankles)
Function of joints
Hold bones together securely and give the rigid skeleton mobility
Bones that make up the hip bone
Ilium, ischium and pubis
Synartgoses
Immovable joints
Bones connected by the coronal suture
It connects the Frontal & Parietal bones
Bones connected by the sagittal suture
It connects the two Parietal bones
Illium
Large, flaring bone that forms most of the hip bone
Osteoporosis
Loss of bone leading to thin, fragile bones
Bone of skull not joined by suture
Mandible (Attached to skull by freely moveable joint)
Pubis
Most anterior bone of coxal bone
Osteoarthritis (OA)
Most common form of arthritis, chronic degenerative condition that typically affects the age. Aka "wear and tear arthritis"
Arthritis
Over a 100 different inflammatory or degenerative diseases that damage the joints. Symptoms include : pain, stiffness, swelling of joint.
Role of PTH and mechanical forces acting on the skeleton in bone remodeling.
PTH determines when (or if) bone is to be broken down or formed in response to the need for more or fewer calcium ions in the blood, while the stress of muscle pull & gravity acting on the skeleton determine where bone matrix is to be broken down or formed so that the skeleton can remain as strong and vital as possible.
Factors that keep bone healthy
Physical stress, good nutrition & estrogen (for women)
Spiral Fracture
Ragged break occurs when excessive twisting forces are applied to a bone. Common sports fracture.
Reduction
Realignment of broken bone ends
Abnormal spinal curvatures
Scoliosis, kyphosis & lordosis
Amphiarthoses
Slightly moveable joints
Visual difference between spongey and compact bone
Spongey bone is composed of small needlelike pieces while compact bone is dense and looks smooth and homogeneous.
Open Reduction
Surgery is performed and the bone ends are secured together with pins or wires.
Bursae
Synovial membrane
Differences between fetal and adult skull
The infants face is small compared to the size of its cranium, but the skull as a whole is large compared to the infants total body length. (1/4 in infant but 1/8 in adult). The fetal skull also has regions that are yet to be covered by bone (fontanels) - allows the fetal skull to be compressed slightly during birth & allow the infant's brain to grow during the later part of pregnancy and early infancy.
Major parts of Axial Skeleton (3)
The skull, the vertebral column, and the bony thorax
Major components of thorax (3)
The sternum, ribs & thoracic vertebrae
Flat bones
Thin, flattened, and usually curved. (Ex bones of skull, ribs and sternum)
Major function of the pelvic girdle
To bear weight
Major function of the shoulder girdle
To provide flexibility
Long bones
Typically longer than they are wide, have shaft with heads at both ends, mostly compact (ex bones of the limbs)