Chapter 38-Excretory System

Home

Get App

Create

What (simply) happens in secretion by the nephron?

Secretion: some substances pass from blood into nephron
The secretion of what helps maintain the pH of blood?

The secretion of potassium ions and hydrogen ions (into the distal convoluted tubule- highly folded) helps maintain the pH of blood.
Where is potassium ions and hydrogen ions secreted to?

Potassium ions and hydrogen ions are secreted into the distal convoluted tubule (highly folded), helping maintain pH of blood.
Where does urine pass to?

Urine passes into pelvis of the kidney and then to bladder for storage.
What percentage of filtered blood is reabsorbed?

99% of the 180L of filtered blood is reabsorbed
Where does the reabsorbtion of useful materials take place?

In proximal convoluted tubule
What percentage of water is reabsorbed in the proximal convoluted tubule?

80% of water is reabsorbed in the proximal convoluted tubule.
How much is water is reabsorbed in the descending limb of the loop of Henle?

5% of water is reabsorbed in the descending limb of the loop of Henle.
What is salt reabsorbed by?

Salt is reabsorbed by diffusion then active transport (in the ascending limb of loop of Henle).
What does the proximal convoluted tubule reabsorb?
- Proximal convoluted tubule reabsorbs useful materials- eg. most salts, glucose, amino acids, vitamins.
- 80% of water.
What does the descending limb of the loop of Henle reabsorb?

5% of water and some minerals.
What does the ascending limb of the loop of Henle reabsorb?
- Salts by diffusion and then by active transport.
- No water.
What does the distal convoluted tubule reabsorb?
- 10% of water
- Some salts
What does the collecting duct absorb?
- 4.9% of water if ADH is present
- No substances
What is an example of an osmoregulatory organ?

The kidney
What is an example of homeostasis?

Osmoregulation
How does the kidney perform osmoregulation?

The kidney regulates the amount of water in the body by varying the amount of urine produced.
What does ADH stand for?

Anti-diuretic hormone
What does ADH control?

ADH controls whether the distal tubule and the collecting duct reabsorbs water or not.
How does ADH control osmoregulation?
- Anti-diuretic hormones control osmoregulation by:
- regulating the amount of water in the body and by varying the amount of urine produced.
Where is ADH produced?

ADH is produced in the hypothalamus in the brain and secreted by the pituitary gland.
What in the brain detects the concentration of blood?

Hypothalamus in the brain detects the diluted blood and turns off ADH production.
What happens in the nephron when a high volume of fluid is taken in?
- The hypothalamus in the brain detects the diluted blood and turns off ADH production.
- Less water is reabsorbed, so more water is allowed to escape to the bladder.
- A larger volume of dilute urine is produced.
What happens when a low volume of fluid is taken in?
- Low fluid intake causes salt concentration of plasma to rise.
- This is detected by the hypothalamus in the brain.
- Pituitary gland releases ADH (Anti-diuretic hormone)
- ADH makes distal convoluted tubule and collecting ducts more permeable.
- More water is reabsorbed and less urine is produced.
- Salt concentration of plasma then falls.
What gland secretes ADH?

Pituitary gland
What does ADH make more permeable?

ADH makes distal convoluted tubule and collecting ducts more permeable.
What does a high protein diet and normal water consumption cause?

High urea content in urine (strong colour).
What in the blood does the hypothalamus detect?

The hypothalamus detects the concentration of plasma.

Author

jacquelineglynn

356731

Card Set

Chapter 38-Excretory System

Description

Questions

Updated

2021-04-29T20:11:43Z

Show Answers