Excretion

Question 1

where does ultra filtration occur ?

Answer 1

Glomerulus / Bowman’s capsule

Question 2

where does selective reabsorption occur ?

Answer 2

proximal convoluted tubule

Question 3

where does water conservation occur (in nephron) ?

Answer 3

loop of Henle

Question 4

where does osmo regulation occur in the nephron ?

Answer 4

distal convoluted tubule and collecting duct

Question 5

what is reabsorbed in the proximal convoluted tubule ?

Answer 5

glucose, amino acids, vitamins and some salts

Question 6

name the arteriole going into glomerulus

Answer 6

afferent arteriole

Question 7

name the arteriole going out glomerulus

Answer 7

efferent arteriole

Question 8

how is high hydrostatic pressure created in the glomerulus ?

Answer 8

lumen gets smaller (afferent compared to efferent)

Question 9

state the ways the proximal convoluted tubule is adapted

Answer 9

• micro villi for SA
• sodium pump
• uses co transporter proteins

Question 10

define excretion

Answer 10

removal of metabolic waste from the body

Question 11

what are the 3 main roles of the liver ?

Answer 11

1. breaks down excess amino acids
2. breaks down harmful substances
3. stores glycogen

Question 12

why must excess amino acids be broken down ?

Answer 12

nitrogenous substances can’t be stored by the body (cause damage)

Question 13

Describe how excess amino acids are broken down

Answer 13

• deamination to form ammonia + organic acids

- ammonia + CO2 in orithine cycle to form urea

Question 14

what is deamination ?

Answer 14

removal of amine group from excess amino acids

Question 15

what happens to the organic acids from deamination ?

Answer 15

can be respired for ATP or converted to carbohydrate and stored as glycogen

Question 16

Describe the detoxification of alcohol

Answer 16

• broken down into ethanal

- then broken into acetic acid

Question 17

give 3 examples of harmful substances that would be broken down

Answer 17

ethanol / paracetemol / insulin

Question 18

what is the hepatic portal vein ?

Answer 18

brings blood from duodenum and ileum (parts of small intestine) to liver

Question 19

what is carried through hepatic portal vein to liver ?

Answer 19

any harmful substances ingested

Question 20

where is bile made / stored / transported ?

Answer 20

made - liver
taken to gall bladder by bile duct to be stored
goes into duodenum

Question 21

what is in the middle of a hepatocyte ?

Answer 21

central vein that connects to hepatic vein

Question 22

what are the capillaries called in hepatocytes ?

Answer 22

sinusoids

Question 23

what are Kupffer cells and what do they do ?

Answer 23

• cells attached to walls of sinusoids

- remove bacteria and break down old erythrocytes

Question 24

what are the tubes called that connect the bile duct to the central vein in a hepatocyte ?

Answer 24

canaliculi

Question 25

which parts of nephron are in cortex ?

Answer 25

Glomerulus / PCT / DCT / some collecting ducts

Question 26

which parts of nephron are in medulla ?

Answer 26

loop of Henle / some of collecting ducts

Question 27

what is the counter current multiplier mechanism ?

Answer 27

mechanism that helps reabsorb water back into blood (in loop of Henle)

Question 28

what cells monitor water potential of blood ?

Answer 28

osmoreceptors

Question 29

what happens when osmoreceptors are stimulated ?

Answer 29

hypothalamus sends impulse to posterior pituitary gland - ADH released

Question 30

how is kidney failure detected ?

Answer 30

measuring glomerular filtration rate (low rate is bad)

Question 31

how can kidney infections cause kidney failure ?

Answer 31

- cause inflammation which can damage cells | - interferes with filtering / reabsorption

Question 32

how can high blood pressure cause kidney failure ?

Answer 32

pressure too high for glomeruli capillaries to cope, so are damaged, allowing large molecules (proteins) to pass

Question 33

what happens w/ kidney failure ?

Answer 33

- waste products build in blood - kidneys can't remove excess water from blood - electrolytes in blood becomes unbalanced - anaemia

Question 34

how does renal dialysis treat kidney failure ?

Answer 34

- blood flows through tube anti parallel to dialysis fluid tube - water products / ions / water diffuse into dialysis fluid

Question 35

what are cons of renal dialysis ?

Answer 35

- patient feels unwell between sessions | - expensive and inconvenient

Question 36

what are cons of kidney transplant ?

Answer 36

- risky major operation | - immune system may reject transplant so patient has to take drugs to suppress

Question 37

what hormone do pregnancy tests detect ?

Answer 37

hCG (in pregnant women)

Question 38

how is fatty liver caused by alcohol intake ?

Answer 38

- breakdown of ethanol uses NAD - less available NAD for fatty acid resp - fatty acids -> triglycerides (stored in hepatocytes)

Question 39

state another name for central vein

Answer 39

intralobular vein

Question 40

describe process of water conservation in loop of Henle

Answer 40

1. salts pumped from asc limb into interstitial fluid 2. water pot int decreases 3. water moves out of des limb 4. water enters (vasa recta) capillary 5. water pot filtrate decreases

Question 41

describe the effect of ADH on kidney

Answer 41

1. ADH binds to membrane receptor of collecting ducts / DCT 2. cAMP activated 3. aquaporins form in side of plasma membrane 4. permeability increased

Question 42

describe how pregnancy tests work

Answer 42

1. hormone binds to specific antibody 2. antibody complex moves along 3. A.C. binds w/ specific immobilised antibodies 4. binding causes coloured line 5. control antibodies - immob anti 6. two lines is +ve

Question 43

how are steroids tested for ?

Answer 43

gas chromatography + mass spectrometry | urine vaporized to separate substances - then identified w/ MS

Question 44

how to test for recreational drugs ?

Answer 44

- test strip w/ antibodies that changes colour when drug binds - then sent for GC + MS