Anatomy of Human Skeleton Flashcards

Axial and Appendicular

ž 1. Support ¡ Framework & support of the body ž 2. Protection of internal organs ¡ Central nervous system is enclosed by the cranium & vertebrae ¡ Visceral organs are enclosed by the rib cage ¡ Pelvis encloses the lower viscera ž 3. Movement ¡ Site of attachment for skeletal muscles ¡ System of levers and fulcrums allows body parts to move

ž 4. Mineral Storage ¡ Calcium & phosphate is stored in the bones ¡ Adds strength to the bones and is available to the rest of the body ž 5. Storage of blood producing stem cells ¡ Hematopoiesis (blood cell production by stem cells) occurs in the red marrow (found in the spongy bone in the ends of long bones and in flat bones such as the hip, sternum, skull, ribs, vertebrae and scapulae). ž 6. Storage of Energy – Yellow Marrow ¡ Yellow marrow (found in the medullary cavity) contains adipose tissue - an energy source

Long bones
Short bones
Flat bones
Regular bones

ž 1. Long Bones (longer than wide) ¡ Possess a slightly curved, elongated shaft (diaphysis) and two expanded ends (epiphyses). The ends are smooth and articulate with other bones. ¡ Composed of compact bone in the shaft and spongy bone in the ends. ¡ Examples include the tibia, fibula, femur, metacarpals, metatarsals, phalanges, radius, ulna, and humerus.

ž 2. Short Bones (cube-shaped) ¡ Their shape is usually cuboid, cuneiform, trapezoid, or scaphoid. ¡ Composed of mostly spongy bone ¡ Examples include the carpals and tarsals.

ž 3. Flat Bones (flat and thin) ¡ resemble shallow plates and form boundaries of certain body cavities. ¡ Composed of spongy bone sandwiched between layers of compact bone ¡ Examples include the bones of the cranial vault, the ribs, sternum and scapula.

ž 4. Irregular Bones (complex shapes) ¡ Are irregular in shape ¡ Have a variable composition ¡ Examples include the vertebrae, hip bones, and bones in the base of the skull.

Architecture of a Long Bone

ž Both spongy and compact bone are made of hydroxyapatite, a mineral composed of calcium and phosphate. ž As mentioned earlier, bones serve an important function in storing calcium and phosphate and making them readily available for the entire body.

ž Diaphysis ¡ The shaft of a long bone ¡ Walls of the diaphysis consist of a veneer of compact bone ž Medullary Cavity ¡ The center space of the diaphysis of a long bone ¡ Houses yellow marrow (an energy source)

ž Periosteum ¡ Thin veneer of connective tissue on the outside of the diaphysis of long bones ¡ Contains nociceptors (receptors that respond to potentially damaging stimuli) nerve endings (carries nerves) ¡ Carries the blood vessels for the bone ¡ Is attached to bone by strong collagenous fibers (Sharpey's fibers) that extend to the outer circumferential and interstitial lamellae ¡ Site of attachment for tendons and ligaments ¡ Has an underlying layer of osteoblasts that allow for bone growth in width

ž Endosteum ¡ Thin veneer of connective tissue lining the medullary cavity ž Epiphyses ¡ The ends of long bones ¡ There is always a proximal and distal epiphysis (relative to the core of the body) ¡ The epiphyses are composed of spongy bone ¢ spongy bone houses the red marrow (blood producing stem cells are contained in the red marrow) ¡ Spongy bone is always covered with a veneer of compact bone

ž Articular cartilage ¡ the cartilage that covers the areas where bones connect with one another (articulate) ¡ is composed of hyaline cartilage ¡ covers the ends of the epiphyses of bones

Architecture of a Long Bone