Structure and function of the kidney III

Question 1

What does Angiotensin II do?

Answer 1

It acts on the PCT to increase Na+/Cl-/water reabsorption to increase blood volume when it’s low.

Question 2

What does aldosterone do?

Answer 2

It acts on the collecting duct to increase K+ secretion and Na+/Cl-/water reabsorption to increase blood volume. It is released with increased angiotensin II secretion.

Question 3

What does Antidiuretic hormone do?

Answer 3

It acts on the collecting duct to increase the reabsorption of water to increase blood water concentration.

Question 4

What does atrial natriuretic peptide do?

Answer 4

It acts on the PCT and collecting duct to increase Na+ excretion and inhibit aldosterone and ADH secretion which will decrease blood volume. It decreases reabsorption of Na+ and water in the DCT and collecting duct.

Question 5

What does parathyroid hormone do?

Answer 5

It acts on the DCT to increase Ca2+ reabsorption and HPO43- excretion.

Question 6

What happens when the kidneys detect a decrease in blood pressure?

Answer 6

The secretion of renin into the general circulation is increased.

Question 7

What does renin do?

Answer 7

It converts angiotensinogen to aniotensin I. An enzyme then converts this to angiotensin II to constrict blood vessels to increase blood pressure.

Question 8

What does aldosterone do to the kidneys?

Answer 8

It causes Na+ retention, K+ excretion and decreased water loss.

Question 9

What happens when blood levels of K+ increase or Na+ levels decrease?

Answer 9

The adrenal cortex releases more aldosterone into the general circulation.

Question 10

What does ADH do specifically?

Answer 10

It inserts water channels (aquaporins) into the collecting tubule to increase water reabsorption.

Question 11

What receptors does ADH bind to?

Answer 11

Basopressor receptors that activate secondary messenger system that involves cyclic AMP.

Question 12

What does cyclic AMP do in terms of ADH?

Answer 12

It causes the vesicles present in tubular cells to become inserted into the apical membrane.

Question 13

What is clearance?

Answer 13

The amount of excretion of product through the kidney tubules.

Question 14

What can be used to find GFR?

Answer 14

Inulin (a plant substance polysaccharide) that is filtered through the glomerulus and none is reabsorbed or secreted from the body. The level in the urine should reflect the level of filtration.

Question 15

What does it mean if a substance has a higher clearing than GFR?

Answer 15

It is secreted into the kidney from the capillaries as well as being filtered through the glomerulus.

Question 16

What is paresthesia?

Answer 16

An abnormal condition when you feel a sensation of burning, numbness, tingling, itching or prickling.

Question 17

What is trousseau sign of latent tetany?

Answer 17

A medical sign observed in patients with low calcium.

Question 18

What are signs of metabolic acidosis?

Answer 18

Headaches, confusion, nausea, vomiting, hyperventilation.

Question 19

What are signs of metabolic alkalosis?

Answer 19

Dizziness, paresthesias, positive trousseau’s sign, hyperactive deep tendon reflexes, depressed respirations.

Question 20

What are signs of respiratory acidosis?

Answer 20

Fullness in head, mental cloudiness, warm, flush skin, dizziness, muscle twitching, seizures, cardiac dysrhythmias, weakness and dull headache.

Question 21

What are signs of respiratory alkalosis?

Answer 21

Light headedness, hyperventilation syndrome - palpitatations, shortness of breath, loss of consciousness, paresthesias

Question 22

What forms carbonic acid?

Answer 22

CO2 and H2O.

Question 23

What does carbonic acid dissociate into?

Answer 23

HCO3- and H+.

Question 24

How can proton concentration be decreased?

Answer 24

There can be more ventilation to remove CO2.