Skeletal System A&P

ligament

flexible band of connective tissue that connects bone to bone

cartilage

tough, flexible tissue that covers the ends of bones and decreases friction

bone marrow

soft connective tissue within the medullary cavities of bones which produces blood cells

medullary cavity

cavity within the shaft of the long bones filled with bone marrow

axial skeleton

bones of skull, vertebral column, and rib cage

appendicular skeleton

forms the extremities and is composed of the shoulder girdle, arm bones, pelvic girdle, and leg bones

compact bone

hard, dense bone tissue, usually found around the outer portion of bones

spongy bone

located toward the end of long bone; contains small open spaces which lightens bone

innervated

contains nerve fibers

vascular

contains blood vessels

osteocyte

mature bone cell

osteoblast

cells that make bone

osteoclast

cell that breaks down bone

chondrocyte

mature cartilage cell

osteon

unit of compact bone; made up of concentric circles called Haversian canals

epiphyseal plate

growth plate, made of cartilage found near the ends of long bones; gradually turns to bone as skeleton matures

bone remodeling

ongoing replacement of old bone tissue by new bone tissue

parathyroid hormone

hormone that stimulates calcium release from bones

calcitonin

hormone that increases the deposition of calcium into the bones

closed fracture

broken bone with no break in the skin

open fracture

broken ends of the bone protrude through the skin

comminuted fracture

bone breaks into many fragments

greenstick fracture

only one side of the bone shaft is broken, and the other is bent; most often seen in children

transverse fracture

break is perpendicular to the long axis of the bone

compression fracture

fracture in which the bone collapses especially in short bones such as vertebrae

stress fracture

small crack in the bone that often develops from chronic, excessive impact

spiral fracture

ragged break occurs when excessive twisting forces are applied to a bone

hematoma

localized swelling filled with blood

bony callus

osteoblasts produce a mass of spongy bone and convert the fibrocartilage to a bony callus as a fracture heals

bony landmark

unique mark or protrusion on bone that provides a site for muscle or ligament attachment or nerve or blood vessel passage

cervical

vertebrae of the neck

thoracic

vertebrae of the chest or thorax

lumbar

vertebrae of the lower back

sacrum

wedge-shaped bone consisting of five fused vertebrae connecting the two pelvic bones

coccyx

tail-bone

suture

immovable joint that connects the bones of the skull

mandible

lower jaw bone

maxilla

upper jaw bone

frontal bone

forms the forehead

parietal bones

two bones on the side and top of the skull

temporal bone

two bones that form the lateral aspects and floor of the skull

occipital bone

bone found at the back and base of the skull

foramen magnum

large opening at the base of the skull through which the spinal cord passes

intervertebral discs

fibrous cartilage between vertebrae which provide shock absorption and flexibility

costal cartilage

cartilage that connects the sternum and the ends of the ribs

pectoral girdle

clavicle and scapula; anchors the upper limb

pelvic girdle

pelvis; anchors the lower limb

sternum

breast bone; between the ribs

clavicle

collar bone; links the scapula and sternum

scapula

shoulder blade

humerus

upper arm bone

radius

forearm bone on the thumb side

ulna

forearm bone on the pinkie finger side

carpals

wrist bones

metacarpals

bones of the palm of the hand

phalanges

fingers or toes

coxal bone

hip or pelvic bone; consists of ilium, ischium, and pubis

femur

thigh bone

tibia

medial, thicker bone of the lower leg; shin

fibula

lateral, thinner bone of the lower leg

medial malleolus

medial projection of distal end of the tibia

lateral malleolus

lateral projection of distal end of the fibula

patella

knee cap

tarsals

ankle bones

metatarsals

bones forming the arch of the foot

synovial joint

freely movable joint containing a cavity filled with synovial fluid

hinge joint

a joint allowing movement in one plane only, ex. elbow

pivot joint

freely moving joint in which movement is limited to rotation, ex. atlas-axis of the neck

ball and socket joint

joint that allows limb to move freely in a circle; found in shoulders and hips

osteoarthritis

progressive, degenerative joint disease characterized by loss of articular cartilage

bursa

fluid-filled fibrous sac between certain tendons and bones

tendon

band of fibrous tissue that connects muscle to bone

fontanelle

soft membranous spot between the skull bones of an infant

synarthroses

immovable joints

amphiarthroses

slightly movable joints

diarthroses

freely movable joints

zygomatic

cheekbone