Give reasons : a.) Diameter of afferent astride is bigger than efferent arteriole? b.) Urine is slightly thicker in summer than in winter c.) Always vasopressin is not secured? d.) Expand ESRD?

a. Diameter of afferent astride is bigger than efferent arteriole to generate force for efficient filtration

b. Urine is slightly thicker in summer than in winter to reduce water loss from the body

c. Always vasopressin is not secreted when a person drinks sufficient water

d. ESRD stands for End stage renal disease

Explanation:

a. While transferring blood from afferent astride to efferent arteriole blood gets filtered. Filtration is efficient when the blood flows with force which is generated when blood flows from large arteriole to the small arteriole. Hence the diameter of afferent astride is bigger than efferent arteriole.

b. Urine is slightly thicker in summer than in winter to reduce water loss from the body. In summer water is lost in the form of sweat as well. Hence, urine gets concentrated to compensate for the lost body fluid.

c. Always vasopressin is not secreted when a person drinks sufficient water. The osmoregulation is maintained  externally.

d. ESRD stands for End stage renal disease