Skeletal System
how many bones are in the thoracic vertebra?
12
the mature skeletal system has how many bones?
206
babies have how many bones?
302
how many bones are in the coccyx?
4 (fused together)
how many bones are in the lumbar vertebra?
5
how many bones are in the sacrum?
5 (fused together)
how many bones are in the cervical vertebra?
7
articular cartilage (long bone anatomy)
thin layer of cartilage covering piphyses of the bone
periosteum (long bone anatomy)
tough, fibrous tissue covering the bone
articulation
two or more bones joined together at a joint
elevation
upward movement of the scapula and shoulder
ossification begins when?
at 8 weeks
consists of bones and cartilage that support and protect the organs of the head, neck, and trunk
axial skeleton
made of hard, compact bone
diaphysis
depression
downward movement of the scapula and shoulder
epiphysis (long bone anatomy)
end portion of bones
contains growth plate, made of spongy bone, contains red marrow, and red and white blood cells (and platelets) are made
epiphyses
bones of the skull, ribs, scapula, sternum, pelvis, cranium
examples of flat bones
spinal column, vertebra, sacrum
examples of irregular bones
patella, big toe, thumb
examples of sesamoid bones
wrist, ankle
examples of short bones
which bones protect internal organs?
flat bones
pronation
forearm turns the hand so the palm is downward
supination
forearm turns the hand so the palm is upward
diarthroses
freely movable joints
ossification
hardening of the bone (lay down minerals to replace cartilage)
synarthrosis
immovable joint
extension
increases the angle between two bones (extend)
which bones protect internal organs?
irregular bones
endosteum (long bone anatomy)
lining of the medullary canal
which bones support weight and facilitate movement?
long bones
osteocytes
mature bone cells
center of shaft, filled with yellow bone marrow that makes and stores fat cells, contains blood vessels, gives bones flexibility
medullary canal
diaphysis (long bone anatomy)
middle portion of the bone
abduction
movement of an extremity away from midline
adduction
movement of an extremity towards midline
eversion
movement of the sole away from the median plane
inversion
movement of the sole towards the median plane
necessary for bone growth and nutrition
periosteum
rotation
pivot motion where a bone moves around a central axis
how many bones are in the appendicular skeleton?
roughly 126 bones
how many bones are in the axial skeleton
roughly 80 bones
which bones are embedded in tendons?
sesamoid bones
which bones provide stability?
short bones
amphiarthroses
slightly movable joints
fontanel
space between bones of the skull from birth to 1 year (soft spot)
where are long bones found?
the arms and legs (humerus and femur)
circumduction
the circular movement of a limb
osteoclast
absorbs bone tissue during growth/healing
osteoblast
bone-forming cell
flexion
brings two bones closer together (bend)
Fluid-filled sac lined by a synovial membrane
bursa
medullary canal (long bone anatomy)
center/inside of the shaft