Anatomy Ch. 7

Name and describe 4 functions of the skeletal system

Support- bones form the body’s supporting framework, Protection- Our skeletal system protects organs and tissues underneath them, Movement- Muscles are anchored to bones and when they contract and shorten they move the connected bones, Storage- we must maintain a constant level of calcium and phosphorus for bodily functions, which bones store and release as needed.

What are the 5 types of bones

Long, Short, Flat, Irregular, Sesamoid

Diaphysis

the shaft of the bone, a hollow tube of hard bone which makes it strong and light

Medullary Cavity

the central cavity of bone where yellow bone marrow is stored, an inactive, fatty form of marrow

Epiphyses

the ends of the bone, contains red bone marrow

Articular Cartilage

thin layer of cartilage covering each epiphysis, functions as a cushion in the joint

periosteum

fibrous membrane covering a long bone, continuous with ligaments and tendons

compact bone

makes up the wall of the diaphysis

spongy bone

fills the epiphysis to reduce weight of the skeleton, also filled with red bone marrow

osteons

compact bone is made of this, circular and tubelike arrangements of concentric rings of bone, cemented together

central canal

the hollow center of an osteon that contains blood vessels

osteocytes

living bone cells that lie between the layers of the lamella in spaces called lacunae

cancaliculi

materials are transported between the osteocytes by these canals. they are tiny passageways that connect the lacunae with one another and with the central canal

trabeculae

needlelike threads of spongy bone that surround a network of spaces, bones are very active with living tissue

osteoblasts

bone building cells

osteoclasts

bone absorbing cells

endrochondral ossification

process which most bones are formed from cartilage. sculpts bones into adult shape

epiphyseal plate

as long as this cartilage called _______ remains between the epiphyses and diaphysis, growth continues

describe the differences between a male and female skeleton

Male skeleton is bigger and generally longer with a more square jaw line. Female skeleton has a smaller, lighter skull, and a rounder, smaller jaw. Female hips are thinner, pelvic cavity is wider and less funnel shaped, later pelvic inlet and outlet, wider pubic arch and sacrum, and a more movable coccyx

list and describe the three major types of joints

Synarthroses (Fibrous)- no movement, as fibrous connective tissue grows between the joints and holds them close together

Amphiarthroses (cartilaginous)- slight movement, cartilage connects the articulating bones

Diarthroses (synovial)- joints with free movement

What is the structure of a joint

Joint capsule- made of fibrous connective tissue, lined with synovial membrane, attached to shaft of bone

Ligaments- cords made of fibrous connective tissue, grows out of periosteum, lashes two bones together

Articular cartilage- over joint ends of bones, absorbs jolts

Synovial membrane- secretes lubricating fluid, allows easier movement with less friction

Tell me about freely moving joints

Ball and Socket (shoulder)- widest range of motion, ball shaped head fits into concave socket of another bone

Hinge (knee)- movement in two directions, flexation, extention

Pivot (neck)- small projections of bone pivots in an arch of another bone

Saddle- found only in thumbs, great mobility

Gliding- least movable diarthotic joints, flat surfaces allow limited gliding- movement

condyloid (radius and carpal bones)- oval projection fits into and elliptical socket

Atlas

Vertebrae #1

Axis

Vertebrae #2

flextion

bending at a joint so the angle decrease and parts move closer together

extension

straightening parts at a joint so the angle increase and parts move farther apart

dorsiflexion

ankle movement that brings ankle closer to the shin

plantar flexion

ankle movement that brings the ankle farther from the shin

hyperextension

extension at a joint beyond anatomical position abnormal extension resulting in injury

abduction

moving a part away from the midline

adduction

moving a part toward the midline

pronation

hand movement so palm is downward pf facing posteriorly

supination

hand movement so palm is upward pf facing anteriorly