Excretion

Question 0

Peritoneal dialysis

Answer 0

• layer of tissue that lines the abdominal cavity
• dialysis fluid injected into the peritoneum through a catheter and left to exchange
• drained off after half/three quarters of an hour
• repeated up to 3x a day

Question 1

Kidney transplant

Answer 1

• most effective treatment

- but short supply & have to be a close match

Question 2

Peritoneal

Answer 2

• layer of tissue that lines the abdominal cavity

Question 3

Haem vs peritoneal dialysis

Answer 3

Haem
- more efficent
- less frequent
- less risk of infection
Peritoneal
- less time consuming
- less expensive
- less controlling of diet

Question 4

Haemodialysis

Answer 4

• blood from a patients artery travels through small tubes soaked in dialysis fluid
• fluid has the right concentration of nutrients to diffuse in and out
• anticoagulant added
• & returned to a vein
• every few days takes about 3 hours

Question 5

Chronic kidney failure

Answer 5

• usually caused by inflammation of the glomeruli
• common in older people with diabetes
• unlikely to recover

Question 6

Acute kidney failure

Answer 6

• maybe when have other conditions
• following surgery
• inflammation in the glomeruli
• sepsis
• likely to recover

Question 7

Pregnancy testing

Answer 7

• use monoclonal antibodies to detect for human chorionic gonadotrophin (HGC)
• for antigen- antibody complex
• forms another antigen complex with immobilised antibodies
• lines up coloured particles that form a line if colour

Question 8

Urine for diagnosis

Answer 8

• can find the products in urine -> give clues for diagnosis
• used for drugs testing
• show pregnancy

Question 9

ADH

Answer 9

• anti-diuretic hormone
• synthesised in the cell bodies of osmoreceptors
• binds to receptors on the collecting duct& increases permeability to water
• more aquaporin channels

Question 10

Osmoregulation (stages)

Answer 10

• blood found to be concentrated by osmoreceptors in the hypothalamus
• stimulate neurosecretory cells that produce and secrete ADH down their axon to the terminal bud in the posterior pituitary gland
• travels in the blood to the kidney
• causes aquaporin proteins to insert themselves in the plasma membrane of the collecting duct
• water can pass through back into the blood

Question 11

Osmoreceptors

Answer 11

• sensory neurones in the hypothalamus
• sensitive to the water potential in the blood
• they produce ADH which travels down the axon & released into the blood from the posterior pituitary gland

Question 12

Osmoregulation

Answer 12

• the regulation of the water content of the body

Question 13

Collecting duct

Answer 13

• can be made more permeable to water by ADH

- also water passes back through tge medulla do to the low water potential so more water reabsorbed by osomosis

Question 14

Distal convoluted tubule

Answer 14

• actively transports na+ ions out

- actively transports k* ions in

Question 15

Descending limb (loop of henle)

Answer 15

• permeable to water and ions

- allows water to move out by osmosis to the low water potential in the medulla

Question 16

Counter current system

Answer 16

• fluid flows in 2 vessels close to each other
• in opposite directions
• to maximise concentration gradients

Question 17

Ascending limb (loop of henle)

Answer 17

• impermeable to water
• permeable to na+ cl-
• ions are actively transported out into the medulla
• later diffuse out

Question 18

Selective reabsorption (stages)

Answer 18

• Na+ actively transported out of cells into tissue fluid = conc gradient
• Na+ & amino acids/glucose travel through carrier proteins through facilitated diffusion& diffuse into tissue fluid (and some actively transported)
• increase in water potential in glomerular filtrate
• water moves down the water potential gradient by osmosis into cells into tissue fluid

Question 19

Selective reabsorption

Answer 19

The absorption of wanted molecules from the glomeruli filtrate back into the blood in the proximal convoluted tubule

Question 20

Bottleneck effect

Answer 20

• in the glomerulus
• formed by the larger afferent arteriole and smaller efferent arteriole
• and a build up of hydrostatic pressure

Question 21

Renal capsule epithelium

Answer 21

• formed of podocytes

- that have major processes that join together to leave tiny slits

Question 22

Endothelium of blood capillaries

Answer 22

• has small pores to allow plasma and small molecules to move in and out

Question 23

Basement membrane

Answer 23

• A layer of connective tissue
• collagen and glycoproteins
• holds the epithelium in place
• doesnt let molecules bigger than 69,000 through

Question 24

Ultrafiltration

Answer 24

- filters out small molecules from the blood into the glomerulus under high pressure

Question 25

Nephrons

Answer 25

- a kidney tubule | - made up of glomerulus, proximal convoluted tubule, loop of henle, distal convoluted tubule, collecting duct

Question 26

Kidney structure

Answer 26

- blood from renal artery take away by renal vein - dark outer cortex - lighter medulla - inner white pelvis attached to ureter

Question 27

Detoxification of other substances in the liver

Answer 27

- breaks down hormones ie testosterone | - breaks down drugs

Question 28

Cirrohosis

Answer 28

- damaged hepatocytes are replaced by fibrous tissue - lose structure of blood supply - lots of health risks ie liver disease

Question 29

Fatty liver

Answer 29

- if lots of alcohol consumed + (obesity& diabetes) - lots of nadRED - no nad for respiration - fatty acids accumulate and form fat stores in hepatocytes reducing efficiency

Question 30

Ammonia

Answer 30

- NH3 - very soluble & very toxic - combines with CO2 to form urea

Question 31

Deamination

Answer 31

- The removal of the amino group from an amino acid - in the liver - and forms ammonia

Question 32

Kupffer cells

Answer 32

- macrophages that line sinusoids | - they capture and destroy bacteria by phagocytosis

Question 33

Sinusoids

Answer 33

- channels in the lobules of the liver - mix blood from the hepatic artery and hepatic portal vein - lined with hepatocytes and kupffer cells

Question 34

Bile canaliculi

Answer 34

- channels between cells in the liver that carry bile

Question 35

Bile

Answer 35

- made in the liver - stored in the gall bladder - contains bile salts which helps to emulsify lipids

Question 36

Hepatocytes

Answer 36

- liver cells - lined with microvilli - remove excess molecules from the blood - perform protein synthesis - perform bile synthesis - detoxification - pass other molecules into the blood

Question 37

Ornithine cycle

Answer 37

Ornithine -> CO2 + NH3 (lose H2O) -> citruline -> NH3 (lose H2O) -> arginine -> H2O -> urea

Question 38

Detoxification of alchohol

Answer 38

Ethanol -> alcohol dehydrogenase + reducing NAD -> Ethanal -> aldehyde dehydrogenase + reduces NAD -> ethanoate (acetate) -> Krebs cycle

Question 39

Liver structure

Answer 39

- made up of lobules centred around a branch of the hepatic vein - blood from the hepatic artery and portal vein mix in sinusoids - next to bile canaliculi flowing in the opposite direction to a branch of the bile duct

Question 40

Hepatic vein

Answer 40

- takes blood away from the liver to the vena cava

Question 41

Hepatic portal vein

Answer 41

- from the small intestine & brings blood rich in nutrients | - but deoxygenated and low pressure

Question 42

Hepatic artery

Answer 42

From the aorta delivers oxygenated blood to the liver

Question 43

Urea

Answer 43

- made in the liver from excess amino acids | - transported to the kidneys where filtered out& stored in the bladder as urine

Question 44

Excretion

Answer 44

- the removal from the body of metabolic waste | - mainly CO2 and urea