The Kidneys And The Excretory System - Part 5 (T2)

Question 1

The kidneys produce around ……. of glomerular filtrate per minute, or about ……. per day

Answer 1

The kidneys produce around 25 cm3 of glomerular filtrate per minute, or about 180 dm3 per day

Question 2

How much urine is lost from the body every day, equating to what % of of the volume filtered through the capsules?

Answer 2

Around 1.5 dm3 - less than 1% of the volume filtered through the capsules

Question 3

What happens to the glomerular filtrate (about 99% of what is produced) that is not lost?

Answer 3

It is reabsorbed back into the blood

Question 4

What does the terms diuresis refer to?

Answer 4

The flow of urine from the body

Question 5

What does anti-diuresis mean?

Answer 5

Producing less urine

Question 6

What region of the brain detects water loss, leading to blood becoming more concentrated?

Answer 6

The hypothalamus

Question 7

Explain in detail how the hypothalamus and ADH maintain the amount of water in our bodies…

Answer 7

• upon detecting a lack / loss of water in the blood, the hypothalamus cause the pituitary gland to release more ADH
• the ADH travels in the blood stream to the kidney tubules
• when it reaches it causes the collecting duct to become more permeable to water, so more water is reabsorbed back into the blood
• when the water content returns to normal, this acts as a signal to switch off the release of ADH
• less ADH will then reach the kidney tubules which consequently reabsorbed less water
• is you were to then drink a large quantity of water the blood will become too dilute and this will lead to even less ADH secretion
• in turn, the kidney tubules become less permeable to water and retain less water, so more water passes out of the body in the urine

Question 8

Explain in brief steps how the body rectifies things when there is too little water in the blood…

Answer 8

• hypothalamus detects water level
• pituitary gland releases ADH
• more water is reabsorbed by the kidneys
• less water is lost in the urine
• blood water level returns to normal

Question 9

Explain in brief steps how the body rectifies things when there is too much water in the blood…

Answer 9

• hypothalamus detects water level
• the pituitary gland release less ADH
• less water is reabsorbed by the kidneys
• more water is lost in the urine
• blood water level returns to normal

Question 10

A kidney transplant involves connecting two blood vessels and tube to the transplanted kidney. Name the two blood vessels and the tube..

Answer 10

• pelvic artery
• pelvic vein
• ureter