microanatomy, joints, diseases, and development

hyaline cartilage

embryonic skeleton, ribs, synovial joints, trachea, nose

elastic cartilage

ear lobes, epiglottis

fibrocartilage

knee, vertebrae, pubis

endochondral ossification

cartilage is replaced by bone

compact bone

dense and strong

spongy bone

porous and weaker- found in epiphyses

osteon

building blocks of compact bones

dynamic

bone material is _______ it is constantly recycled (7-10 years)

osteoblasts

cells that deposit new bone material (bone builders)

-take calcium from the blood and put into bone

osteoclasts

cells that are responsible for bone resorption

-breaking down bone and putting into bloodstream

blasts and clasts in adults

balance between blasts and clasts

blasts and clasts in juvenile

MORE OSTEOBLASTS than osteoclasts

blasts and clasts in elderly

MORE OSTEOCLASTS than osteoblasts (less dense)

wolff's law

weight bearing exercise stimulates osteoblasts (bones build back stronger/thicker)

sunlight's effect on bones

vitamin D helps absorption of calcium= strong bones

estrogen

what hormone leads to more osteoblast activity?

osteoblasts

bone building cells

growth plate

where the primary growth meets the secondary growth

periosteum

covers the diaphysis part of the bones

calcium

primary mineral found in bones

small intestines

takes calcium into the body through a proper diet and absorbs into the bloodstream

osteogenesis OR deposit

process of bone formation (by osteoblasts)

resorption

process of bone removal (by osteoclasts)

osteoporosis

loss in bone mass, bone tissue breaks down with age

fractures

after menopause, women are at a higher risk for developing what?

Vitamin D

Needed for proper calcium absorption

weight bearing exercises

have been shown to resist osteoporosis because they place stress on the bones that forces them to absorb more bone

estrogen

hormone released by the ovaries that plays important role in bone remodeling

osteoclasts

a lack of estrogen allows _____ to remove more bone than normal

spine, hip, wrist

regions of bone most affected by bone loss in osteoporosis

thyroid gland

gland that deals with elevated blood Ca2+

calcitonin

hormone released by thyroid gland that brings down calcium levels

parathyroid gland

gland that monitors decrease in blood Ca2+

PTH (parathyroid hormone)

hormone released by parathyroid that brings up calcium

not enough PTH, low blood calcium, brittle bones

parathyroid gland stops functioning

density would decrease because of the reduced stress on bones from lack of gravity

what would happen to bone density on the moon?

mitosis

process of cellular division that allows new cells to form and push the bone out longer

slide 7

A- mostly cartilage

B- beginnings of mitosis

C- grown/matured cartilage

D- ossified bone

differentiation

when a stem cell takes on a specific job