Ch 6/7 Skeletal System pt 1 Flashcards
axial skeleton
skull, vertebral column, ribs
appendicular skeleton
upper and lower limbs, shoulder and hip girdle
function of bones
support, protection, movement (bones as levers), mineral storage (Ca and P), hematopoiesis
long bones
shaft and two ends (ie humerus, tibia, ulna, phalanges)
short bones
cube shaped (carpals, tarsals)
flat bones
thin, flat, slightly curved (ie ribs, scapula, skullbones, sternum)
irregular bones
complicated shapes (vertebra, coxal bones)
foramen
hole through bone
meatus
canal through bone
fossa
shallow depression in bone
condyle
rounded projection involved in articulation (bone-bone connection)
head
larger bony projection held on a narrow neck
facet
smooth, flattened surface forming articulation
tubercle
small, rounded projection (often rough area)
crest
narrow, prominent ridge of bone
osteocyte
maintain bone tissue
osteoblast
form bone matrix
osteoclast
resorbs bone
osteogenic
stem cells
osteoprogenitor
become osteocytes
chondrocytes
mature cartilage cells
chondroblasts
cartilage forming cells
bone homestasis
1) Resting - ossified, rigid
2) Activation - activates osteoclasts for resorption
3) Resorption - osteoclasts secrete hydrochloric acid to break down P and Ca in osteocytes for blood
4) Reversal - activates osteoblasts for reforming
5) Formation - formation of new osteocytes
6) Mineralization - adding Ca and P back to bone to ossify
bones as mineral storage
when blood levels of Ca are too high, calcitonin is released and osteoblasts add Ca to bone
when blood levels of Ca are too low, PTH (parathyroid hormone) is release and stimulates osteoclast activity
two types of bone development in fetus
starts at 8 weeks
fibrous membranes (intermembranous ossification) bones of skull and clavicle
hyaline cartilage (endochondral ossification) all bones below skull except clavicle, epiphyseal plates form between diaphysis an epiphysis
how are bones formed
longitudinally, from the center out. appositional growth on the inside (center widens and bone expands)