BIOA02H3 : Lec22 - Osmotic and Ionic Regulation.doc

Describe the hormones that regulate water retention and release in the body and discuss how the kidneys filter out materials from the blood as well as regulate fluid and mineral composition.

The function of the kidneys is to filter blood and in so doing, maintain blood homeostasis. Toxins and excess materials are removed from the blood to be voided in the urine. In addition, the kidney is responsive to antidiuretic hormone (ADH) from the posterior lobe of the pituitary gland, and aldosterone from the adrenal cortex. These hormones play a role in regulating body fluid compartments, blood pressure, and electrolyte balance. Furthermore, the kidneys help maintain the pH of the blood.

1.Sunstroke was a common danger in biblical days (2 Kings 4:18-20). Comment on the role the kidneys play in adjusting electrolyte and fluid balance as a result of sunstroke. (PLEASE DO NOT COPY WORD FROM WORD FROM A SOURCE! THANK YOU!) :)

Which of the following statements is true? (select all that apply)

a)The size of pores in the capillaries at the glomerulus is larger than pores found in other membranes.

b)Proteins found in the blood are normally filtered out at the glomerulus and then reabsorbed in the Loop of Henle.

c)Release of aldosterone increases the ionic strength of the urine.

d)Vasopressin tends to decrease urine output.

e)Exposure to chromium is associated with glycosuria.

f)Halogenated solvents are associated with damage to proximal tubules in the kidney.

g)About 10% of the blood volume that passes through the glomerulus passes out of the capillaries and is collected in the Bowman’s capsule.

h)About 1% of the glomerular fluid is not reabsorbed in the tubules and is excreted as urine.

i)Inulin clearance is a measure of the efficiency of the efficiency of glomerular filtration.