lec 8 homeostasis

Question 1

review how kidneys work

Answer 1

5:50-end of vid

Question 2

why must organisms maintain their internal environment?

Answer 2

most organisms fxn best under narrow range of internal conditions

Question 3

organisms gain and lose water by..?

Answer 3

diffusion

Question 4

organisms regulate solutes by…?

Answer 4

active transport

Question 5

how do organisms maintain temperature?

Answer 5

exchange heat with environment

Question 6

what is osmosis?

Answer 6

water moves passively along concentration gradients across semipermeable membrane

Question 7

water concentration is influenced by..?

Answer 7

solute concentration

ex. high solute conc. means low water conc.

Question 8

water and some solutes diffuse from ________concentration, through the process of __________

Answer 8

high to low

active transport

Question 9

t/f solutes cannot be actively transported across a cell membrane

Answer 9

false, they can thru channel or carrier protiens

Question 10

regulation of water and solutes is controlled by…?

Answer 10

kidneys

Question 11

aside from regulating water and solutes, what is another function of the kidney? Provide an example

Answer 11

dispose of metabolic waste

eg.
-toxic byproduct of protein metabolism is ammonia
-liver turns ammonia–> urea
-urea carried to kidney + disposed in urine

Question 12

what are 4 main functions of kidneys?

Answer 12

-control amt of water leaving via urine

-filter blood

-release excess solutes

-urea released in urine

Question 13

what controls kidney function?

Answer 13

hormones

Question 14

blood enters kidneys through..?

Answer 14

renal artery

Question 15

functional unit of a kidney is called..?

Answer 15

nephron

Question 16

specialized capillaries that renal artery branches into

Answer 16

glomerulus

Question 17

tubule and collecting duct are made of which type of cell?

Answer 17

epithelial

Question 18

explain how filtration in the kidneys work

(4 steps)

Answer 18

-blood enters thru renal artery
-blood enters glomerulus
-pressure forces water+solutes out of glomerulus
-water+solutes go to tubule–>collecting duct

Question 19

explain the process of reabsorption in the kidneys

Answer 19

-some solutes pumped from collecting duct into kidney tissue

-causes water to flow out of duct (osmosis)

-urine more concentrated w/ waste+solutes

Question 20

water that flows into the tubule+duct not only contain solutes and waste but also contain____ and ____?

Answer 20

sugars and amino acids

Question 21

what happens to the sugars and amino acids found in the tubule and duct?

Answer 21

pumped back into blood by active transport

Question 22

what is the basic goal of osmosis

Answer 22

equal concentration of FREE water molecules on either side of a semipermeable membrane