E-learnnig Parathyroid

Question 1

calcium ions are important for?

Answer 1

growth 
skeletal system 
neurotransmitters 
muscle contraction 
hormone secretion 
clotting 
Ca signally 
apoptosis 
bone and tooth formation 
cell division and growth 
neuronal activity 
secretory activity of glands

Question 2

what 2 hormones regulate calcium balance, excretion and storage?

Answer 2

calcitonin

parathyroid hormone

Question 3

the bone accounts for ____ of stored Ca

Answer 3

> 1kg

Question 4

kidneys excrete around ____ Ca per day

Answer 4

200mg

Question 5

what synthesises new bone tissue?

Answer 5

osteoblast

Question 6

diseases of Ca 2+ homeostasis

Answer 6

primary and secondary hyperparathyroidism
osteoporosis
rickets
receptor mutations

Question 7

what’s rickets

Answer 7

a Vitamin D deficiency or mutation effecting vit D synthesis

Question 8

what produces calcitonin

Answer 8

the thyroid glands non follicular cells

C cells

Question 9

TF: Ccells are in higher number than follicular cells

Answer 9

no

Question 10

were these non follicular (parafollicular) C cells found

Answer 10

between the follicles

Question 11

size of calcitonin?

Answer 11

32AAs

Question 12

half life of calcitonin?

Answer 12

5 minutes

Question 13

calcitonin main function?

Answer 13

reduce blood calcium ion concentration

Question 14

calcitonin effects against parathyroid hormone

Answer 14

calcitonin opposes PTH effects which is made by cellist the parathyroid gland

Question 15

how many parathyroid glands?

where are they located?

Answer 15

4

on the posterior surface of the thyroid gland

Question 16

___% of the population have fewer than 4 parathyroid glands

Answer 16

5

Question 17

2 types of cells in the parathyroid glands?

Answer 17

chief cells

oxyphil cells

Question 18

function of chief cells?
structure?

Answer 18

reduce parathyroid hormone (PTH)

small helical protein hormone of 84 AA

Question 19

oxyphil cells function?

Answer 19

unknown function

Question 20

function of Parathyroid hormone?

Answer 20

increase blood calcium ion concentration when it gets too low

Question 21

what detects low blood calcium ion concentration?

Answer 21

GPCRs that sense Ca2+

Question 22

how does PTH increase Ca concentrations?

Answer 22

by indirectly stimulating osteoclasts to release more CA from the bone- resorption

INCREASING renal Ca REABSORPTION- reducing excretion via filtration

increasing production of vitamin D, which stimulates the uptake of Ca from the intestine as well as increasing bone resorption and renal Ca reabsorption

Question 23

PTH has an ______ effect to calcitonin

Answer 23

opposite

Question 24

explain negative feedback of Ca concentrations?

Answer 24

increase in blood calcium decreases PTH secretion

increase in blood Ca also increases bone formation

Question 25

how does calcitonin reduce blood calcium concentrations?

Answer 25

reducing osteoclast activity to reduce bone resorption and allows rapid bone deposition by osteoblasts