Bones and calcium Flashcards
Draw and label a vertebrae
f
Name the 2 spine curvatures
Lordosis and khyphosis
Draw and label the 2 spine curvatures
c
What spine curvature is the secondary curvature
Lordosis
Where is calcium from our diet absorbed
upper lower intestine
Name the 2 main hormones that control calcium aborption
Parathyroid hormone and 1.25 dihidroxyvitamin (DHCC)
What is the role of 1.25 dihydroxyvitamin
Controls calcium absorption and activates vitamin d
What happens to PTH levels when calcium increases
PTH decreases
What does PTH stimulate
Stimulates renal tubular calcium reorption and peromotes bone resorption, which stimulates DHCC formation
Describe the 2 steps of calcium absorption
- Absorption in small intestine occurs. Controlled by DHCC. 20%-60% of injested calcium is absorbed here. DHCC increaes absorption if dietary intake of calcium drops
- In kidney, calcium is absorbed in thick acending loop and distal convulated tube. Here, pth increases apsorption levels.
Name the cellular marker for osteoclast function
RANK ligand
How does rank ligand work
When present, rank ligand stimulates osteoclasts. Estrogen produces OPG, which when binds to RANK inhibits rank ligand therefore inhibits osteoclast function,
When does hypocalceamia occur
When there is decreased calcium levels in the body
What is the hypercalaemia receptor
chief cells of the parathyroid gland detect decreased calcium
What is the hypercalaemia control centre
Chief cells stimulate PTH release
What is the hypercalaemia effector
- PTH increase osteoclastic activity, releasing calcium
- Calcium resorption in kidney increases
- pth stimulates 1.25 DHCC to absorb calcium in the gut
When does hypercalcaemia occur
When there are increased calcium levels in the body
What i the hypercalcaemia receptor
Parafollicur cells of the thyroid gland that detect increased calcium levels
WHat is the hypercalcaemia control centre
Thyroid gland produces more 1.25 DHCC
What is the hypercalcaemia effector
- 1.25 DHCC stimulates an increase in number/activity of osteoblasts, preventing calcium release
- Calcium resorption in kidneys decreases
What 2 joints do you find between vertebra
intervertebral discs and atricular process
Describe intervertebral discs (structure and function)
concentric layers of fibrocartilage that helps carry weight
Describe articular process joints
interlock at the facet joint and control the direction of movements
What movements do vertebral joints allow
Straightening = extension
turning=rotation
What limits excessive movement by vertebral joints
ligaments
