Excretion (Ch 41) Key Concepts

Question 1

How do freshwater osmoregulators deal with their hypotonic environment?

Answer 1

By avoiding excess water uptake into their tissues and controlling the loss of electrolytes from their body.

Question 2

How do marine osmoregulators deal with their hypertonic environment?

Answer 2

By avoiding excessive uptake of electrolytes and loss of water.

Question 3

What are some survival adaptations for terrestrial osmoregulators?

Answer 3

Many have evolved specialized nasal salt glands to rid themselves of high salt concentrations in their diet.

Question 4

What is the difference between cortical and juxtamedullary nephrons?

Answer 4

Cortical nephrons have their Loop of Henle in the renal medulla near its junction with the renal cortex, while the Loop of Henle of juxtamedullary nephrons is located deep in the renal medulla; they are called juxtamedullary because their renal corpuscle is located near the medulla (but still in the cortex).

Question 5

Which type of nephrons would you expect to see on a desert dweller?

Answer 5

Cortical nephrons

Question 6

At what point is our filtrate most highly concentrated?

Answer 6

In the inner medulla.