The Skeletal System Flashcards
axial skeleton
skull
vertebral column (backbone)
ribs (12 pairs)
sternum (breastbone)
appendicular skeleton
pectoral and pelvic girdles
and their attached limbs (arms and legs)
joint
where two bones meet
synovial joint
a freely movable joint composed of synovial fluid and cartilage
antagonistic pairs
pairs of muscles that pull against each other
have opposite effects
osteoblasts
bone producing cells
osteoclasts
located in bone marrow in medullary cavity
bone digesting cells
break down bone in the cavity and release calcium into bloodstream, controlled by parathormone
catabolic cells as they break down bone
osteoblasts then form bone to replace digested bone
produce collagen that is covered by parathormone
ligament
strong fibrous tissue that connects bone to bone
tendon
strong inelastic fibre that connects muscle to bone
functions of skeleton
protection of internal organs eg skull
movement: muscles and bone
support: holds the body upright
manufacture of blood cells
long bones
femur tibia fibula humerus radius ulna
skull
cranium
fused bones
ribs
12 pairs
true ribs: 7 attached to sternum
false ribs: 3 attached to cartilage
floating ribs: 2 attached to spine
vertebral column
made of 33 vertebrae
discs of cartilage in between
cartilage
located at end of epiphysis
reduce friction
acts as shock absorber
pectoral girdle
clavicle and scapula
attached limb - arm
metacarpals
fingers (phalanges)
pelvic girdle
hip joined to sacrum
attached limb - leg
metatarsals
toes (phalanges)
types of joint
immovable
slightly movable
movable
immovable joint
bones are fused
eg skull, pelvis
slightly movable joint
bones slide over each other
eg discs of cartilage between vertebrae of spine (protects nerves)
movable joint
synovial
comprised of synovial membrane, synovial fluid and cartilage
eg
hinge - knee elbow, movement in one direction up and down
ball and socket - shoulder, hip, movement in all directions
synovial joint functions
synovial membrane - secretes synovial fluid
synovial fluid - lubricates joint
cartilage - reduces friction by preventing bones rubbing against each other
ligament - holds bones together
disorder of skeletal system
arthritis
arthritis
inflammation in joints, resulting in swelling, warmth, pain and restricted movement
cause-
wear and tear, injury, old age, cartilage in synovial joints wears down
prevention-
care in selection of footwear for walking/running
avoid frequent weight bearing exercise
treatment-
physiotherapy
anti-inflammatory medication
severe cases, replacement of artificial joint
muscles
types: cardiac smooth (digestive) (tire slowly) skeletal (tire quickly) arranged in pairs that work in opposite directions
how antagonistic pairs work
bicep contracts (tricep relaxed) arm pulled upward bicep relaxes (tricep contracts) arm pulled downward
bone structure
epiphysis (head) diaphysis (shaft) periosteum compact bone spongy bone medullary cavity cartilage
periosteum
tough fibrous membrane that contains osteoblasts, blood vessels and nerves
compact bone
location: diaphysis, end of epiphysis
function: strength, flexibility
composition:
living- bone forming cells, protein (collagen)
non living- calcium salts
contains living cells, nourished by blood supply
spongy bone
location: mainly the epiphysis
composition: a network of thin, bony bars and plates, along with spaces filled with marrow
function: gives strength to bone, red marrow makes blood cells
medullary cavity
location: hollow in the centre of long bone
contains yellow bone marrow
red bone marrow
produces blood cells:
RBCs
WBCs
platelets
yellow bone marrow
stores fat
bone growth
occurs at 8th week of embryonic development
growth plate
what: disc of cartilage found at junction between epiphysis and the diaphysis of a bone
function: causes an increase in bone length by producing cartilage
stops functioning when adult is fully grown
ossification
cartilage formed and turned into bone
osteoblasts function
produce collagen which covers the cartilage produced, hardened by calcium and phosphate
protein gives flexibility
osteoblasts and osteoclasts
enlarge medullary cavity and thicken compact bone
factors affecting bone renewal
exercise
hormones
diet
exercise
weight bearing exercise stimulate osteoblasts
new bone formed where it is needed by osteoblasts, bones thicker and stronger
hormones
parathormone
site of production: parathyroid
function: remove calcium from bone, raising calcium levels in blood
significance: calcium needed for nerve and muscle function, and to replace lost calcium in bones
diet
calcium needed in the diet to replace calcium lost in bones
