lec 20

Question 1

what is the relationship bw urine conc and body size?

Answer 1

as body size incr, urine conc decreases

Question 2

what is the relationship bw body size and water turnover?

Answer 2

as body size incr, water turnover decr (drink more/pee less)

Question 3

what is a adaptation the waxy tree frog has to retain water?

Answer 3

secretes waxy layer all over the body to prevent water loss (water cant get through waxy layer)

they need to do this bc frogs are amphibians and need to stay really moist

Question 4

how do diurnal desert ants adapt to heat?

Answer 4

sand gets super hot – super long legs keep body off the ground and prevents extra heating

also they’re diurnal, and only come out at night or for short periods during the day time

Question 5

its been found that u can breed flies for surviving dessication, increasing water content being retained. why might we not see this in the WT flies?

Answer 5

extra water = extra weight, and this can be an issue if ur doing cost of metabolism transport strategy (more weight = more energy to move)

Question 6

what is the water avail index? how does it affect the ecological breakdown of animal habitats?

Answer 6

index of water avail in a given environ. in more arid environ (around 1.5) there are less animals around, while in more moist environ (around 3.5) there are less animals –> competition becomes pressure

Question 7

alright babey we’re gaming

describe the process of ultrafiltration

Answer 7

ultrafiltration: filtration that goes one step further and uses pressure

Question 8

capillaries have some gaps between them, as do podocytes. why is this?

Answer 8

in the process of filtration, there are things u can get rid of things u need to hold on to, which tend to be bigger (ex glucose) – filtration system lets smaller ions go through while holding onto bigger things

Question 9

what is the net filtration pressure? explain the various pressures that the filters experience

Answer 9

there is a net filtration process favouring filtration (outward movement)

blood pressure from glomerular capsule: +6.7 kPa

colloid osmotic pressure: -3.5 kPa
(caused by colloids exerting some pressure from inside the [blood?])

capsular fluid hydrostatic pressure: -1.9 kPa [something pushback?]

Question 10

idk how to format this into a question

in the slides theres a 4 step process about how solutes X and Y get into tubules. explain it

Answer 10

1. solutions in tubule and interstitial are at eq for solutes X and Y
2. active transport brings solute X from interstitial into the tubule
3. water follows bc diffusion gradient is formed
4. solute Y follows bc there’s a diffusion gradient for it

Question 11

what is the order of the nephron?

Answer 11

bowmans capsule
proximal tubule (fat as fuck)
intermediate segment (skinny queen)
distal tubule

Question 12

what is diuresis? conversely, what is antidiuresis?

Answer 12

diuresis is the production of urine by releasing water. salts will be taken back at this point, depending on ur relative salt levels

in antidiuresis, ADH is prod to tell ur body to not pee - water is not reabsorbed into the kidney therefore no pee

TAKEAWAY! salt is always taken back but ADH decides if water goes or not

Question 13

there are hella capillaries by the kidney. why?

Answer 13

lotta resorption going on

Question 14

as the medulla gets thicker, what happens to urine concentration? how does an arid habitat dweller - say a sand rat - demonstrate this?

Answer 14

urine conc increases (gets saltier)

sand rats have a renal medulla thats super specialized for prod highly conc urine (holds water)