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)