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Lecture 13 SQ

Terms in this set (21)

How might the skeleton change with age, lifestyle, or nutritional status?
calcium and phosphate ions in blood lost via urine and must be replaced. bones could become weak with age, poor nutrition, lack exercise
Do bones remodel in the same way that they grow?
no
What is osteoporosis?
a medical condition in which the bones become brittle and fragile from loss of tissue, typically as a result of hormonal changes, or deficiency of calcium or vitamin D.
Are both men and women susceptible to bone loss with age?
Yes
Why are women more susceptible to bone loss with age? Why does this become a problem after a certain age (or lifestage)?
Because of menopause;because of the different sex hormones. after menopause especially
What factors affect how bone remodels? (What are the controls of remodeling?) What cells are involved and how do they act to remodel bone?
calcitriol-promotes calc & phos ion absorption
-growth hormone

thyroxine-
-ovaries&testes

parathyroid hormone
-calcitonin
Why are vitamins D & C important in bone health? Why is calcium important in bone heath? What would happen if you did not have enough vitamin C - what part of the bone matrix would be most affected? What would happen if you did not have enough vitamin D - what part of the bone matrix would be most affected?
D-becomes calcitriol (calc absorb)
C-collegen synthesis
calcium-makes bones strong

lack of c-lack of collegen
lack vit D-lack calc abs and calc taken from bones
and bones would become weak
What hormones are important to growing and maintaining bone?
estrogen and testosterone parathyroid hormone
What is the primary hormone responsible for controlling blood calcium levels in the blood? Where is this hormone produced (in what gland)? Where does this hormone act? How does this hormone function to increase calcium level in the blood (what cells or processes are activated)? How is calcitriol involved? Why is controlling calcium level in the blood important?
parathyroid hormone; parathyroid gland; in bones and blood; calcitriol and pth increases calcium absorption in intestines and pth makes kidneys retain calcium ions and stimulates osteoclasts to release stored calcium; vital for neurons and muscle cells. especially heart cells.
What hormone can lower calcium level in the blood? Where is this hormone produced (in what gland)? How does this hormone function to decrease calcium level in the blood (what cells does it activate)?
calcitonin. produced by thyroid gland. inhibits osteoclast activity. promotes loss in kidneys. these to reduce calcium ion conc in body fluids
What is the primary controller of blood calcium levels in the adult human?
mostly maintain by parathyroid hormone
Describe the steps in fracture repair.
...
How are cartilage cells and bone cells involved in fracture repair? What is a callus?
1.formation of fracture hematoma (red blood cells)
2.fibrocartilaginous callus formation(blast chondroblast)
3. bony callus formation by osteoblast
4. bone remodeling by osteoclast and blast
Does spongy bone or compact bone form first during fracture repair?
too much osteoblast activity due to overstimulation of growth hormone which stimulates osteoblast and synthesis of bone matrix (produced by pituitary gland)
What is the role of phagocytes in fracture repair?
responsible for debridement, resorption of the cartilaginous callus, resorption of the bony callus
In a certain condition (osteopetrosis), too much bone is deposited. What cells do you think are affected here and how are they affected to create this condition?
Osteoclasts; inhibited
Why is supplemental (pharmaceutical) calcitonin sometimes prescribed to patients with osteoporosis?
because it promotes calcium loss at kidneys and inhibits calcium absorption in intestines. basically lowers blood calcium levels
Which is more detrimental to blood calcium homeostasis - loss of the parathyroid gland or thyroid gland (assume each gland is removed by itself, leaving the other)?
parathyroid
How would a tumor of the parathyroid gland affect the skeleton? (Tumor would result in excess PTH release.)
too much osteoclast activity leading to weak bones
Why, in terms of the skeleton, is exercise recommended at all life stages?
to continue to strengthen bones and stimulate remodeling
what 3 factors are shown to affect bone mass?
bone mass, bone density
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