Calcium

Question 1

which mineral tightly regulates levels of calcium

Answer 1

phosphorous

Question 2

how much ECF calcium is biologically active

Answer 2

50%
small amount is complexed and the rest in protein bound

Question 3

what type of crystals are formed by salt precipitation in bone remodelling

Answer 3

hydroxyapatite
mainly calcium phosphate salt

Question 4

what are the physiological functions of calcium

Answer 4

controls membrane excitation
excitation - contraction coupling
haemostasis
stimulus - secretion coupling
second messenger and enzyme activity
maintenance of tight junctions between cells
bone formation

Question 5

why must Ca2+ plasma conc be tightly regulated

Answer 5

potential detrimental effects of free calcium
death due to muscle asphyxiation

Question 6

three main hormones of Ca2+ regulation

Answer 6

parathyroid hormone
vitamin D
calcitonin

Question 7

parathyroid glands anatomy

Answer 7

4 rice-grain sized glands
2 posterior to each lobe of the thyroid

Question 8

what triggers PTH secretion

Answer 8

decrease in free Ca2+ conc in the ECF

Question 9

effect of PTH on kidneys

Answer 9

increases Ca2+ reabsorption
stimulates active Vit D formation
decreases phosphate reabsorption

Question 10

what is the effect of PTH on bone

Answer 10

stimulates active osteoclasts increasing resorption increasing by causing release of hydroxyapatite

Question 11

effect of Vit D on intestine

Answer 11

increases Ca2+ absorption

Question 12

where is calcitonin secreted from
in response to what

Answer 12

parafollicular (C) cells of the thyroid gland
in response to high conc of Ca2+ in the EFC

Question 13

what would happen if PTH had no effect of phosphate levels

Answer 13

it would not be secreted and the increased Ca2+ conc would simply crystalise with the phosphorus

Question 14

effects of calcitonin on the kidneys

Answer 14

decrease phosphate reabsorption
decrease Ca2+ reabsorption

Question 15

effects of calcitonin on bone

Answer 15

oppose action of PTH on osteoclasts
decreases resorption
decreased Ca2+ release

Question 16

what is the active form of vitamin D

Answer 16

D3 calcitriol

Question 17

what are the sources of vitamin D forms

Answer 17

D2 and D3 come from diet
D3 is the only one synthesised in the skin using UV radiation

Question 18

where is inactive vitamin D stored

Answer 18

liver

Question 19

where is active vitamin D created

Answer 19

kidney

Question 20

effects of vitamin D on kidneys

Answer 20

increased phosphate reabsorption
increased Ca2+ reabsorption

Question 21

effect of calcitonin on the intestine

Answer 21

none

Question 22

effect of vitamin D on the intestine

Answer 22

increased phosphate reabsorption
increased Ca2+ reabsorption

Question 23

effect of vitamin D on bone

Answer 23

promotes PTH action on osteoclasts
increased resorption
increased release of Ca2+ into plasma

Question 24

where does reabsorption, absorption, and resorption occur

Answer 24

reabsorption - kidney absorption - intestine resorption - bone

Question 25

effects of PTH hypersecretion

Answer 25

hypercalcemia and hypophosphatemia moans (depressions and anxiety - lmao) bones (bone pain - osteoporosis) stones (de la kidney) groans (abdominal pain, nausea and vomiting)

Question 26

where is pain caused by kidney stones

Answer 26

sides and back below ribs

Question 27

treatment options of kidney stones

Answer 27

small: drink water, pain relievers, relaxation of ureter large: sound waves to break up stones, surgery, parathyroid gland surgery

Question 28

what bone disorder results from not enough calcium

Answer 28

osteoporosis

Question 29

effects of PTH hyposecretion

Answer 29

hypocalcemia and hyperphosphatemia muscle cramps and twitches from motor nerves, respiratory muscles go into hypercalcaemic spasm death.

Question 30

what is the treatment for hypocalcaemia

Answer 30

synthetic PTH (doesn't exist) active Vit D and high calcium diet and supplements

Question 31

what happens in vitamin D deficiency

Answer 31

impaired intestinal absorption of Ca2+ leading to PTH secretion to maintain Ca2+ conc at the expense of bones bone becomes some and deformed due to pressures of weight bearing rickets - children osteomalacia - adults