Ianowski - theme 3 and 4

Question 1

Osmoregulatory organs:

Answer 1

External surfaces (gills/skin), salt glands, gut, kidneys

Question 2

What are kidneys called in insects? worms?

Answer 2

Insect - protonephrones

Worms - metanephrones, malphigian tubules

Question 3

Gills:

Answer 3

Involved in ion transport and waste excretion. In teleost (bony) fish, they play a major role in osmoregulation. Gills are great for osmoreg because they have lots of contact between water and blood.

Question 4

Skin:

Answer 4

Used when you can’t have gills :(

In frogs and stuff

Question 5

Marine osmoregulators:

Answer 5

Water leaks out, ions leak in. Need to drink a lot of water and pump ions out. Pee out ions.

Question 6

mOsm of osmoregulators:

Answer 6

300 mOsm.

Question 7

Freshwater osmoregulators:

Answer 7

Water leaks in, ions leak out. Don’t drink water, pee lots of water.

Question 8

Transporting epithelia:

Answer 8

Cells specialized for ion transport. Necessary for osmoregulation. Highly conserved across animal groups.

Question 9

The story of transporting epithelia: marine fish

Answer 9

Fish loses water.
Chloride cells bring in chloride. Interior of cell becomes more positive than sewater, so they draw Na+ and K+ out of the blood and to the outside. *** this is so hard

Question 10

Salmon alternate between hypo- and hyper-osmoregulation.

Answer 10

Acclimatization regulation and anticipatory mechanisms.
Going to salt: Cortisol triggers growth of seawater chloride transport epithelium and increases Na/K ATPase.
Going to fresh: prolactin triggers growth of freshwater chloride transport epithelium, reversing the direction of ion transport.

Question 11

Salt glands, in birds and reptiles.

Answer 11

Cry out 0.9M NaCl solution from 0.45M sea water - keep half of seawater intake. NaCl is actively transported from blood into secretory tubules through secretory cells. Blood flows in opposite direction of salt solution.

Question 12

Endocrine regulation of salt glands:

Answer 12

In high blood osmolarity…
PNS, corticosterone (from adrenal glands), ANP (from heart) stimulates salt gland. Kidney is shut down to conserve water.

Question 13

The process of filtering through kidneys: beginning at proximal end

Answer 13

Filtration: small molecules and ions are nonselectively exchanged between blood/fluid and inside of tubule.
Reabsorption: nutrient molecules, ions, and water are actively transported out of the tubule.
Secretion: excess ions and toxins are pushed back into the tubule.
Release: pee

Question 14

Where does osmolarity of pee vs blood change?

Answer 14

Collecting duct: equal osm
Proximal tubule: minor changes
Distal tubule: major changes
Storage bladder: no change

Question 15

Primary urine:

Answer 15

Collecting duct urine that hasn’t been modified. Formed by ultrafiltration or active secretion.

Question 16

Ultrafiltration:

Answer 16

Exchange between blood and primary urine. Solutes travel into the urine by blood pressure but plasma is blocked by a filter.

Question 17

Active secretion:

Answer 17

Used by organisms with open circulatory systems because blood pressure can’t drive this. Active transport of ions creates concentration gradients for water and other stuff (sugars, AAs) to get into the primary urine.

Question 18

Malphigian tubules of blood-drinking Rhodnius prolixus:

Answer 18

Blood is 50% plasma - need to get rid of this. Plasma is hyposmotic so it brings water and . Produces hyposmotic urine.
***

Question 19

Insect excretory system:

Answer 19

h

Question 20

What can get through membranes?

Answer 20

Non polar is good. If polar, must be small and uncharged. Too big or too charged can’t get through.

Question 21

Aquaporin:

Answer 21

Passive transport of water.

Question 22

K+ voltage-gated channel:

Answer 22

Under normal charge, K+ can’t move. With a charge difference, K+ is passively transported.

Question 23

Primary active transport: follow (p)

Answer 23

Carrier protein is phosphorylated to make it active. It does its conformation changey magic to transport ions. Returns to inactive form when dephosphorylated.

Question 24

Na/K pump:

Answer 24

Cytosol-facing: high affinity for Na.

Outside-facing: conformational change lowers affinity for Na and raises affinity for K.

Question 25

Symport:

Answer 25

A passively travels and brings B against B’s gradient.

Question 26

Antiport:

Answer 26

A actively travels and B can sneak the opposite direction with its gradient.