lec 17

Question 1

what are four roles that the nose plays?

Answer 1

heat retention, brain cooling, water retention, olfactory

Question 2

a cross section of a tuna shows the lateral rete. what does this do?

Answer 2

the lateral rete use the principle of counter current heat exchange, except kinda backwards
what the lateral rete does is heat up cool arterial blood (moving toward the muscle) using warm venous blood (moving away from the muscle). the result is to have muscles running at hot temps, where they are most optimal

Question 3

what is the difference between poikilotherm and homeotherm? how would we make this distinction based on a graph demonstrating different red muscle temperatures?

Answer 3

poikilotherm: can withstand wider range of internal temps
homeotherm: can withstand narrower range of internal temps (usually has to regulate self)

fish that are poikilotherm would be similar to the isotherm, while homeotherms would deviate (do their own thing)

Question 4

how do flying honeybees exhibit regional heterothermy?

Answer 4

regional heterothermy is having diff parts of the body heated to diff temps
ex. thorax tends to be way higher temp, while abdomen tends to be way lower temp
we also observe diff slopes for the thorax and abdomen
–> ANOTHER observation: regional heterothermy declines as temp incr (the slopes converge)

Question 5

as cells age, what happens to their ability to retain water?

Answer 5

cells naturally worsen at holding water

Question 6

how do osmotic regulators and conformers differ in their ability to maintain blood osmotic pressure in the face of environ osmotic pressure?

Answer 6

regulators maintain blood pressure while conformers conform. u can also have hybrids where at most times they are regulators, but at the extremes they become conformers (may be less of a survival strategy than regulation mechanisms getting overwhelmed idk)

Question 7

what does the fog beetle do to get water in low water environ?

Answer 7

when fog comes in from the ocean, usually it is not usable. what the fog beetle does is flip its body upside down, and on its skin its got bumps and grooves that collect water to be slurped :3

Question 8

what is the urine:plasma ratio? why is it important?

Answer 8

urine:plasma ratio indicates the relative conc of solutes in the urine. this can be used to show osmolarity with respect to the environ
U:P = 1 indicates isomotic;
U:P > 1 indicates more urine and therefore water is held back (concentrated urine)
U:P < 1 indicates more plasma and therefore salts are held back (dilute urine)