The kidney

Question 1

What artery supplies the kidney with blood to be filtered?

Answer 1

The renal artery

Question 2

What vein carries the filters blood away from the kidneys?

Answer 2

The renal vein

Question 3

What is the cortex?

Answer 3

This id the dark outer layer which contains many capillary networks

Question 4

What is the medulla?

Answer 4

Contains nephrons

Question 5

What is the pelvis?

Answer 5

Where the urine collects before travelling to the ureter

Question 6

What ia the nephron?

Answer 6

structures within the kidney where the blood is filtered and useful substances are reabsorbed into the blood

Question 7

What is the glomerulus?

Answer 7

When the renal artery splits to form many different arteries leading to a knit of capillaries called the glomerulus

Question 8

how does fluid enter the bowmans capsule?

Answer 8

fluid pushed into the bowmans capsule because afferent arteriole is wider than efferent arteriole so high hydrostatic pressure pushed fluid from blood into bowmans capsule

Question 9

What is the filter?

Answer 9

The barrier between blood in the capillary and lumen of the bowmans capsule

Question 10

Describe the endothelium of the capillary

Answer 10

has narrow gaps between cells of endothelium which allows blood plasma and substances dissolved in it to pass out of the capillary

Question 11

Describe the basement membrane

Answer 11

this is a fine. mesh of collagen and glycoproteins which act as a filter to prebent the passage of molecules or a relative molecular mass grater than 69000

Question 12

Describe the epithelial cells of the bowmans capsule

Answer 12

these contain podocytes which have finger like projections which create gaps between cells so fluid from the blood in the glomerulus can pass between these cells into the lumen of the bowmans capsule

Question 13

Describe ultrafiltration

Answer 13

• blood enters through the afferent arterioles
• high hydrostatic pressure ,mans that water and small molecules are forced out of the capillaries and form the glomerulus filtrate
• once it exits the capillary it passes through the basement membrane which acts as a sieve pre-empting large proteins and blood cells passing through the gaps in the capillary endothelium

Question 14

Where does selective reabsorption occur?

Answer 14

in the proximal convoluted tube

Question 15

Summarise selective reabsorption

Answer 15

1. sodium ions are actively pumped out of cells lining the proximal convoluted tubule
2. concentration of sodium ions in cell decreases creating a concentration gradient
3. sodium ions diffuse down gradient from lumen into cells via a cotranporter protein which also carries glucose or amino acids at the same time
4. water moves in via osmosis
5. glucose and amino acids diffuse into the blood so are reabsorbed

Question 16

What is osmoregulation?

Answer 16

the control of the water potential in the body

Question 17

where is the changes in water potential detected/

Answer 17

osmorecpetors found in the hypothalamus

Question 18

What happens if you need to conserve less water?

Answer 18

the walls of the collecting duct become less permeable so less water is reabsorbed and a greater volume of urine is produced

Question 19

What happens if you need to conserve more water?

Answer 19

the walls of the collecting duct become more permeable so more water can be reabsorbed into the blood and produces a smaller volume of urine

Question 20

What happens when there is a decrease in the water potential of the blood?

Answer 20

this is detected by osmorecpetors in the hypothalamus which asues more ADH to be released from the posterior pituitary, this is detected by cell surface receptors and makes the collecting duct walls more permeable so more water is reabsorbed into the blood which creates less urine and increases the water potentialw

Question 21

what happens when there is an increase in the water potential of the blood?

Answer 21

the osmoreceptors in the hypothalamus detect this and causes less ADH to be released so that the walls of the collecting duct are less permeable therefore less eater is reabsorbed and more urine is produced which will reduce the water potential

Question 22

What is kidney failure?

Answer 22

this is when the kidneys are unable to regulate levels of water and electrolytes in the body or unable to remove waste products

Question 23

how is kidney function assessed?

Answer 23

assessed by estimating gate glomerulus filtration rate and also by analysing the urine for substances such as proteins which would indicate that the filtration mechanism is damaged

Question 24

What does dialysis do?

Answer 24

This artificially regulates the concentrations of solutes in the blood

Question 25

What is haemodialysis?

Answer 25

when the patient is attached to a machine and their blood passes though it to be filters. The fluid contains no urea and has normal plasma levels

Question 26

What is peritoneal dialysis?

Answer 26

The dialysis membrane is the bodys own abdominal membrane, a tube is implanted and solution is poured through the tube

Question 27

What are the advantages of a kidney transplant?

Answer 27

Not time consuming
fell fitter and not chronically ill
improved quality of life

Question 28

what are the disadvantages of a kidney transplant?

Answer 28

immunosuppression drugs
may be side effects to the drugs
major surgery
have to go to regular check ups

Question 29

Describe pregnancy testing

Answer 29

an embryo produces a hormone called human chorionic gonadotrophin which is a small glycoprotein that can be found in urine. pregnancy tests use monoclonal antibodies which bind to hcg in urine

Question 30

describe urine analysis

Answer 30

anything with a molecular mass less than 69000 can enter the nephron therefore you can tis for
- glucose
- alcohol
- recreational drugs
- hcg
- anabolic steroids