2.9 - The role of the kidneys in homeostasis

Question 1

What are the kidneys 2 important roles in the body?

Answer 1

1) Regulate water content in blood

2) Remove the toxic waste products of metabolism

Question 2

1) Blood is brought to the kidney in the _____ ____ which branches off the aorta.
2) The kidney regulates/controls the water and salt content and removes ____.
3) The filtered excess ____,____,___ form a liquid called urine.
4) The urine is transported to the bladder along tubes called _____.
5) The bladder stores the urine until it is convenient to expel it from the body through the _____.
6) The purified blood returns to the circulation through the _____ and to the heart through the _____

Answer 2

1) renal artery
2) urea
3) water, salts and urea
4) ureters
5) urethra
6) renal vain, vena cava

Question 3

The kidney is packed with millions of structures called…

Answer 3

nephrons

Question 4

What do nephrons regulate?

Answer 4

levels of water, slats and remove’s urea from blood.

Question 5

The Bowman’s capsule:

1) Surrounds a ball of _____ called the ____ ____.
2) High _____ is created in the capillary knot by the diameter of the capillary leaving the knot being narrower than the capillary entering
3) This pressure results in ______ where water, salts, glucose, and other small molecules pass out of the capillary and into the Bowman’s capsule
4) _____ and ____ ___ are too big to leave the capillaries to go into the tubule

Answer 5

1) capillaries, capillary knot
2) pressure
3) ultrafiltration
4) Proteins and blood cells

Question 6

What is the rest of the tubule responsible for?

Answer 6

selective reabsorption of glucose, some salts, and lots of the water

Question 7

What is the collecting duct responsible for?

Answer 7

selective reabsorption of water and for sending urine to the ureter.

Question 8

What does the hormone Anti - diuretic hormone (ADH) control?

Answer 8

Water content of the blood

Question 9

What can the concentration of blood be altered by?

Answer 9

excess drinking ( increases water content)
excess sweating (decreases water content)
consumption of salty foods (decreases water content)

Question 10

If there is too little water in blood what happens?

Answer 10

1) Brain detects water level
2) ADH is released
3) More water absorbed in kidneys (nephrons)
4) Less water lots in urine

Question 11

What is a negative feedback mechanism?

Answer 11

A mechanism to lower raised levels of something, and to raise reduced levels of something.

Question 12

______ in the urine indicates the person is suffering from _____ . The ______ levels in the blood are so high the kidney is unable to reabsorb it and it leaves the body in urine.

Answer 12

Glucose
Diabetes
Glucose

Question 13

_____ in the urine indicates damage in the _____, as generally _____ in the blood are too large to pass through into the nephron tubule.

Answer 13

Protein
Kidney
Proteins

Question 14

What is a dialysis machine?

Answer 14

A machine attached to a patient that helps maintain the correct balance of salt and water in blood.

Question 15

What are the advantages of dialysis?

Answer 15

Keeps patient alive whilst waiting for donor

Doesn’t involve major surgery

Question 16

What are the disadvantages of dialysis?

Answer 16

Patients need to follow a careful diet
Patients need to spend many hours on the machine
Dialysis machines are expensive
Dialysis is only successful for a certain amount of time

Question 17

What are the problems with having a kidney transplant?

Answer 17

Rejection
Transplant needs to be similar in tissue type
Patients must take immunosuppressant drugs for the rest of their life

Question 18

What happens when a patient body rejects a kidney transplant?

Answer 18

The immune system of the patient receiving the kidney recognises the transplant as non-self and destroys it.

Question 19

Explain the process of Dialysis?

Answer 19

1) Blood removed from patient into dialyzer Where blood is kept separated from dialysis fluid by partially permeable membrane
2) Dialysis fluid contains same conc of glucose and salts as normal blood plasma
3) excess salts diffuse into dialysis fluid
4) The dialysis fluid contains no urea, so urea in blood (which is high conc) diffuses into dialysis fluid (which is lower conc)
5) The blood and dialysis fluid move in opposite directions across the membrane (a counter current system) in order to maintain concentration gradients all the way along
6) clean blood is returned to patient, dialysis fluid disposed of.