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