Homeostasis

Question 1

Why is calcium important?

Answer 1

Critical for muscle and nerve function
Found primarily in the bone, extracellular fluid and blood
bones are impacted if anything goes wrong with calcium homeostasis

Question 2

What hormones are involved in homeostasis?

Answer 2

Parathyroid Hormone
Calcitriol
Calcitonin

Question 3

Parathyroid Hormone

Answer 3

Source is the parathyroid glands

stimulates osteoclast activity and elevates extracellular calcium ion concentration

Question 4

calcitriol

Answer 4

source is the kidneys
promotes calcium and phosphate ion absorption along digestive tract
parathyroid hormone stimulates vitamin D to be changed into calcitriol

Question 5

Calcitonin

Answer 5

source is the thyroid gland
inhibits osteoblast activity
promotes calcium loss by kidneys
reduces extracellular calcium ion concentration

Question 6

What hormones change bone density?

Answer 6

Growth hormone
Thyroxine
Sex hormones

Question 7

Growth hormone

Answer 7

source is the pituitary gland

stimulate osteoblast activity and the synthesis of bone matrix

Question 8

Thyroxine

Answer 8

Source is the thyroid gland

with growth hormone, stimulates osteoblast activity and the synthesis of bone matrix

Question 9

Sex hormones

Answer 9

source is the ovaries and the testes
stimulate osteoblast activity and the synthesis of bone matrix
stimulate epiphyseal closure

Question 10

Causes of hypercalcaemia

Answer 10

reneal insufficiency- inability to excrete calcium or retain calcium
Hyperparathyroidism- increases osteoblasts so there is more calcium in our extracellular fluid which leads to calcium leaching out of the bone
hormone problems- not producing thyroxine which will affect osteoblasts
Immobilisation

Question 11

Symptoms of hypercalcaemia

Answer 11

Groans- constipation
Moans- fatigue, depression, lethargic
Bones- calcium mainly stored in bone, stress fractures
Stones- kidney stones, more calcium can crystallise

Question 12

Causes of hypocalcaemia

Answer 12

resistance to PTH
Vitamin D deficiency- can’t be converted in calcitriol which is important for calcium
chronic kidney disease- kidneys produce calcitriol
liver disease- albumin levels help to keep calcium in the blood

Question 13

Symptoms of hypocalcaemia

Answer 13

convulsions
arrhythmias
tetany
spasms
numbness in fingers, hands and feet