Urine Formation

Question 1

What are the three stages of urine formation

Answer 1

1) glomerulus filtration
2) reabsorption
3) tubular secretion

Question 2

Where does glomerulus filtration occur

Answer 2

bowman capsule + glomerulus

Question 3

How much of the blood content is squeezed into the capsule and why

Answer 3

20% otherwise blood would be too thick to move

Question 4

why is fluid forced out during filtration

Answer 4

as the afferent arteriole has a wider diameter than the efferent, narrowing increases resistance to flow of blood and produces higher pressure in the glomerulus, which is relieved by squeezing fluid out into capsule

Question 5

What is the name of the fluid forced out during filtration?

Answer 5

filtrate

Question 6

What does filtrate contain

Answer 6

water, salts, amino acids, glucose, fatty acids, urea, uric acid, creatinine, ions (K, Cl, Na)

Question 7

What does filtrate not contain and why?

Answer 7

RBC, WBC, proteins= too large to pass through membrane

Question 8

Where does reabsorption take place

Answer 8

PCT and Loop OF H

Question 9

How much filtrate is reabsorbed into the body?

Answer 9

99%

Question 10

What materials are reabsorbed into the body during reabsorption and by what process and why?

Answer 10

(water) ions (K, Na, Cl), glucose, some urea, creatinine , amino acids
by diffusion due to concentration grad.

Question 11

How is water absorbed during reabsorption

Answer 11

osmosis

Question 12

Where does tubular secretion take place?

Answer 12

DCT

Question 13

Is secretion in tubular secretion active or passive

Answer 13

both, depends on concentration

Question 14

What is the main function during tubular secretion?

Answer 14

control of pH

Question 15

What happens in the DCT?

Answer 15

control of pH, water content controlled

Question 16

Why is water not considered secretion?

Answer 16

processed by facilitated diffusion

Question 17

How is the pH of the blood controlled

Answer 17

secretions of hydrogen and ammonia into tubule to balance

Question 18

What determines the amount of water absorbed in the distal convoluted tubule

Answer 18

depends on how much water consumed- will change permiablity of tubule (controlled by hormone that recognises levels in body)

Question 19

What will happen to water absorption in DCT when dehydrated?

Answer 19

reabsorb lots= little urine at high concentration of ammonia resulting in dark yellow colour and strong odour

Question 20

What, besides water ammonia and hydrogen is removed from the blood into the tubule

Answer 20

creatinine, urea

Question 21

What does it mean if glucose is found in the urine

Answer 21

means too much in Prox. CT, and can’t be reabsorbed therefore meaning body is making too much = sign for diebetes

Question 22

Why isn’t protein found in the urine

Answer 22

too large to pass through into capsule

Question 23

What shouldn’t be in urine?

Answer 23

glucose, protein

Question 24

What makes the amber colour of urine

Answer 24

presence of bile pigments

Question 25

Name the define features of the kidneys (5)

Answer 25

1) efferent artery smaller diameter than afferent leading in= raises b.p. so more fluid is filtered in
2) capsule almost surrounds glomerulus= collected squeezed fluid
3) millions of nephron= SA for reabsorption and secre
4) peritubular cap. surround tubule= close blood supply
5) two sets of convo. tubule and long loop= SA + long time to reab.