Question

2 a) List the functions of calcium in the body. [6 marks]

b) Outline the mechanisms involved in the regulation of calcium. [25 marks]

c) The signs and symptoms of hypercalcemia involve several tissues/organs in the body. Using a table, state these tissues/organs and a related condition associated with each. [8 marks]   

Answer 1

A function of calcium in body

• Building strong bones and teeth - ABOUT 99% of body calcium is in bones and teeth
• Clotting blood
• maintain action of heart muscle
• Sending and receiving nerve signals by calicum channel
• Squeezing and relaxing muscles- when nerve stimulate it release calcium, which cause contraction
• Releasing hormones and other chemicals
• Keeping a norMAL HEART BEAT
• maintain normal blood pressure in pregnancy
• improve cholestrol level
• lower blood pressure in young people

b MECHANISM INVOLVED IN CALCIUM REGULATION

normal calcium level is 10mg/dl

1 when calcium level decreases -

A. parathyroid gland release PTH - when calcium level is low,parathyroid hormone releases,which act on

• Bones – stimulates the release of calcium from large calcium stores in the bones into the bloodstream. This increases bone destruction and decreases the formation of new bone.

• Kidneys –

1. reduces loss of calcium in urine., also stimulates the production of active vitamin D in the kidneys.
2. kidney filter about 250mmol of calcium but absorb about 245mmol so net loss in urine is 5mmol

• Intestine –  

1. indirectly increases calcium absorption from food in the intestine, via its effects on vitamin D metabolism.
2. about 15mmol of calcium is excreated from intestine,from bile ans app 25 mmol from diet
3. in case of no need 5mmol excreted rest absorbed from intestine

2 when calcium level is high

thyroid gland release calcitonin which inhibit osteoclast activity in bone and release calcium from bone and also inhibit resorption of calcium from renal tubule

answer c

on renal system	more calcium,overload the kidney work, so cause frequent urination and thirst, kidney stone
digestive system	nausea,dizziness,vomiting, constipation, peptic ulcer, decrease apppetite,
skeletal system	bone pain and muscle weakness due to leach of calcium in blood
nervous system	confusion lethargy fatigue
heart	palpitations and fainting, indications of cardiac arrhythmia,