Parathyroid gland

Question 1

whats the role of the parathyroid glands

Answer 1

regulate calcium

secrete PTH

Question 2

where is calcium found in the body?

Answer 2

calcium pools

• bone
• extracellular fluid
• gut from the diet

Question 3

what is PTH

Answer 3

parathyroid hormone
peptide
made as pre-pro hormone

Question 4

actions of PTH

Answer 4

regulation of calcium

stimulates Vit D production

Question 5

where are the 3 points of reguation for calcium

Answer 5

gut
bones
kidney

Question 6

hormones used in calcium homeostasis

Answer 6

PTH
calcitonin
vit D

Question 7

what part of the parathyroid secrete PTH

Answer 7

chief cells

Question 8

properties of PTH

Answer 8

peptide hormone
short half life
extracellular receptor

Question 9

hypercalcaemia

Answer 9

high Ca

supressed secretion of PTH

Question 10

hypocalcaemia

Answer 10

low Ca

stimulated secretion of PTH

Question 11

actions of PTH

Answer 11

regulates concentration of calcium in the blood by regulating absorption and resorption of ca in the bones

• stimulates bone breakdown
• stimulates renal resorption of kidney

Question 12

what is calcitonin?

Answer 12

made in thyroid
stimulated by high calcium
leads to a decrease in PTH so calcium is lost not retained

Question 13

actions of calcitonin

Answer 13

lowers blood calcium in response to hypercalcaemia

inhibits bone brakdown

Question 14

how is ca released from bones

Answer 14

osteoblasts are stimulated by PTH to mae osteoclast activating factors
osteoclasts then break down the bone releasing calcium
GPCR in bone allows PTh to bind and signalling intaacellulary

Question 15

vitamin D

Answer 15

used to increase the calcium in the gut

Question 16

how does Vit D work

Answer 16

binds to nucear receptors and positively regulates expression of calcium binding protein which is needed for the transport of calcium across the gut wall

Question 17

how is vit D made?

Answer 17

made in the skin with UV

• skin exposed to UV light
• UV reacts with enzyme dehydrocolesterole
• the reaction makes pre- Vit D
• strucutral chnges make active Vit D: D3, cholecalciferol

Question 18

high blood calcuim stimulates…

Answer 18

calcitonin

Question 19

too much PTH

Answer 19

hyperparathyroidism
hypercalcaemia too much Ca
due to primary tumour of parathyroid

Question 20

symptoms of too much PTH

Answer 20

reabsorption of bone
thinning of the bones, fragile
kidney stones, too much going through here and it cant cope

Question 21

tretment of too much PTH

Answer 21

surgical removal of the tumour

Question 22

PTH under secretion

Answer 22

hypoparathryoidism
hypocalcaemia, low ca
increased sesntivity of nervous system

Question 23

what are the 2 types of hypoparathyroidism

Answer 23

1. deficient secretion of PTH

2. inability of kidneys and bones to respond to PTH, GPCR not workig

Question 24

symptoms of hypoparathyroidism

Answer 24

mental deficiency
shortness of metacarlaps
round face
parathesia, thingling

Question 25

how can a patient become deficinent in parathyroid hormones?

Answer 25

1. accidental removal durig thyroid surgery

2. idiopathic, no defined cause. couod be just not tissue due to developmental issue or inherited form

Question 26

resitance to PTH

Answer 26

characterised by low calcium levels
they produce PTH find but cant repond to it
G poteins in bone and kineys dont resond and are inactive

Question 27

treatments for hypoparathyrooidism

Answer 27

increase in calcium via diet or tablets

oral calcium

Question 28

vitamin D deficiency

Answer 28

causes rickets in children, bone are soft and dont close properly
or osteomalacia in adults
requires supplements for treatment