bones and muscles

function of skeletal system

to protect internal organs and support the body by giving it structure and strength

function of skull

protects the brain

clavicle

connects arm to body

scapula

attachment for arm muscles

sternum

protects heart and lungs

ribs

protects heart and lungs

vertebrae

protects spinal cord, supports body

humerus

upper arm bone

radis & ulna

forearm bones

pelvis

supports lower body, protects organs

femur

thigh bone, strongest in body

patella

protects knee joint

tibia & fibula

lower leg bones

carpals/metacarpels/phalanges

hand bones

tarsals/metatarsels/phalanges

feet bones

axial skeleton

part of skeleton that forms the central axis of the body. skull, vertebrae rib cage. provides support, protection, attachment for muscles

appendicular skeleton

part of the skeleton that forms the limbs and girdles attached to the axial skeleton. clavicle, scapula, hands, legs. provides movement allowing the transfer muscles to move the limbs. supports weight of body

joints

location in the body where 2 or more bones meet

types of joints

fibrous joint, cartillagious joint, synovial joint

fibrous joint

bones are joined by dense fibrous connective tissue fixed with no joint cavity. no movement. skull

cartillagious joint

bones are joined by cartillage. no joint cavity present. limited movement. vertebrae

synovial joint

bones are separated by fluid-filled joint cavity enclosed within a capsule and lined with a synovial membrane. freely moveable. shoulder, knee

features of synovial joints

articular cartilage, synovial membrane, synovial fluid, bones 1 & 2, ligaments, articular capsule

articular cartilage

smooth, slippery layer covering the ends of bones, reducing friction and shock during movement

synovial membrane

lines the joint capsule that produces synovial fluid to lubricate the joint

synovial fluid

thick, slippery fluid inside the joint capsule lubricating and nourishing the cartilage

bone 1 & 2

two bones that form the joint

ligament

tough elastic connective tissues that connect bone to bone. stabilizes the joint and prevents excessive movement.

articular capsule

tough fibrous outer layer that enters the joint. holds the bones together and protects the joint

joint type

hinge, ball and socket, condyloid, pivot, gliding, saddle

hinge

joint that allows movement in one direction. allows flexion and extension. elbow and knee

ball and socket

spherical head fits into a round socket. flexion, extension, abduction, adduction, allows movement in full rotation. shoulder, hip

condyloid

oval-shaped bone end fits into a similarly shaped hollow. flexion, extension, abduction, adduction, circumduction. allows movement in two directions. wrist

pivot

ring of bone rotates around a process fo another bone. rotates only. neck, forearm

gliding

flat bone surfaces slide over each other. small gliding movements in all directions. carpals, tarsals

saddle

both bone surfaces are concave and convex like a saddle. flexion, extension, abduction, adduction, cricumduction. allows movement in two directions. thumb

tendon

connects muscle to bone

ligament

connects bone to bone

types of muscles

skeletal, cardiac, smooth

skeletal

voluntary, striated, attached to bones

cardiac

involuntary, striated, heart walls

smooth

involuntary, not striated, wall of internal organs.