A complete blood count (CBC) indicates that the number of erythrocytes (red bloo

Question

A complete blood count (CBC) indicates that the number of erythrocytes (red blood cells, RBCs) in Felix’s blood is abnormally low.

(a) Describe how the kidney is involved in the maintenance of the number of RBCs in Felix’s blood.

(b) Felix has had problems with low blood pressure. What role does the kidney, as a secondary endocrine organ, play in the maintenance of systemic blood pressure?

(c) Felix is at risk for developing a deficient bone calcium level which increases his risk for bone fractures even without a significant fall. Describe how the parathyroid gland, the skin, and the kidneys are linked, and how kidney failure could lead to osteoporosis or inadequately calcified bones.

Explanation / Answer

a) Kidneys secrete the hormone erythropoietin which stimulates haematopoetic stem cells to form red blood corpuscles. Thus kidneys are essential for the formation of RBCs.

b) Kidneys control the systemic blood pressure by renin-angiotensin system. When the blood pressure is high, kidneys secrete the enzyme renin from juxtaglomerular cells. Renin converts angiotensinogen into angiotensin which causes dilatation of blood vessels leading to decrease in blood pressure.

c) Kidneys are involved in the synthesis of 1,25 dihydroxy calciferol. This is also known as calcitriol. This causes increase in absorption of calcium from intestine and also from renal tubules. So, if kidneys are affected, calcium levels will be low in blood leading to deficient bone formation which increases the risk of bone fractures.

Skin is involved in the synthesis of vitamin D. Parathyroid glands secrete parathormone. Thus skin, kidneys and parathyroid glands damage could lead to osteoporosis and inadequately calcified bones.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.