Skeletal system I lab

axial skeletal system

portion of the skeleton that is located along the midline of the body

includes the unilateral skull, hyoid, vertebrae, sacrum, coccyx, bilateral ear ossicles, and ribs

appendicular skeletal system

bilateral portion of the skeleton that includes the shoulder girdle and upper limbs, and pelvic girdle and lower limbs

what are the three main components of the axial skeleton

skull, vertebral column, thoracic cage

how can bones be classified?

by shape or bony landmarks

flat bones

broad bones that provide protection or muscle attachment

composed of two thin layers of compact bone surrounding a layer of cancellous (spongy) bone

long bones

grow primarily by elongation of the diaphysis (central shaft) with an epiphysis at each end of the growing bone

short bones

about as wide as they are long, these bones provide support with less movement

irregular bones

named for their complex shapes, these bones typically have a thin cortical layer with more cancellous bone in their tissue

sesamoid bones

small, round bones that are shaped like a sesame seed

form in tendons where a great deal of pressure is generated in a joint

protect tendons by helping them overcome compressive forces (classified as short bones)

osteoblast main function

bone growth

osteocyte main function

maintains the bone matrix

osteoclast main function

breaks down bone tissue

compact (cortical) bone

makes up about 80% of a person’s total bone mass

forms the dense, outer layer of a bone

provides strength, protection, movement to the body

plays a role in storing and releasing calcium into the bloodstream

canaliculi function

allows osteocytes to communicate with each other and the haversian canal via cytoplasmic processes

lacuna function

hosts an osteocyte in a small, fluid-filled space

haversian canal function

provides a pathway for nerves, lymphatic, and blood vessels

osteon function

resists mechanical stress and strengthens bone

osteon function

responds to mechanical stimuli, communicates with osteoblasts and osteoclasts, regulates the bone matrix

tubercle

a bumpy area of bone where muscle tendons and ligaments attach

trochanter

similar to a tubercle, but they are only found on the femur bone

tendons and ligaments attach to the greater and lesser trochanter of the femur

condyle

smooth, convex articular (joint) surface

an example of a process formed where joints occur between adjacent bones

fossa

hollow or depressed area

foramen

channel in the bone that allows other structures (like nerves and blood vessels) to pass through the bone

fissure

deep furrow, cleft, or slit

process

projection or bump

spine

pointed process

ramus

extension of a bone that forms an angle with the rest of the structure

example of irregular bone

vertebrae

example of short bones

carpal bones

example of flat bones

parietal bone

example of long bones

humerus

example of sesamoid bone

patella

sinus

chamber within a bone, normally filled with air

meatus

passage or channel, especially the opening of a canal

canal

duct or channel

crest

prominent ridge

line

low ridge

tuberosity

rough projection

sulcus

narrow groove

processes formed where joints (articulations) occur between adjacent bones

head, neck, facet, condyle, trochlea

head

expanded articular end of an epiphysis, often separated from the shaft by a narrower neck

neck

narrow connection between the epiphysis and diaphysis

facet

small, flat articular surface

trochlea

smooth, grooved articular process shaped like a pulley