13. Introduction To Cellular Calcium Homeostasis

Question 1

How is whole body calcium homeostasis regulated?

Answer 1

Intestinal calcium uptake
Calcium reabsorption in kidneys
Bone calcium regulation

Question 2

What controls calcium homeostasis?

Answer 2

Endocrine control:

• calcium sensing receptors in parathyroid gland
• parathyroid hormone
• calcitonin

Question 3

What processes is intracellular [Ca2+] responsible for/regulates?

Answer 3

Muscle contraction
Neurotransmission/stimulus-secretion coupling
Fertilisation
Cell death
Regulation of metabolism
Learning and memory

Question 4

How are calcium concentration gradients set up and maintained?

Answer 4

Relative impermeability of plasma membrane to calcium
Pumps ad transporters that move calcium out of cytoplasm
Calcium buffer proteins

Question 5

What mechanisms increase intracellular [Ca2+]?

Answer 5

Calcium movement across plasma membrane (influx)
Voltage operated calcium channels
Ligand gated ion channels
Calcium movement out of ER
Calcium induced calcium release (CICR)
IP3R