Question 1

Multiple Choice

(1 points)

Question:

As food is ingested, gastrin is released from stomach mucosal cells. Which of the following is true following this release?

Gastrin stimulates release of HCl and pepsin in the stomach.
Gastrin causes release of insulin from the pancreas.
Gastrin lowers the pH of the stomach.
Gastrin causes release of bile from the gallbladder.

 Question 2

Multiple Choice

(1 points)

Question:

Which of the following is the best example of negative feedback?

Release of cholecystokinin by intestinal mucosa stimulates release of digestive enzymes from the pancreas.
Release of secretin by intestinal mucosa in response to acidic chyme entering small intestine causes release of bicarbonate solution from pancreas.
Secretion of HCl in the stomach causes low pH.
Food in the stomach causes release of gastrin and pepsin.

 Question 3

Short Answer / Essay

(1 points)

Question:

Describe the role of the liver in fuel traffic during the absorptive period.

 Question 4

Multiple Choice

(1 points)

Question:

All organisms need to be able to maintain a proper water balance. Which of the following statements about salt and water balance is false?

Filtration, secretion, and reabsorption are used in excretory systems that excrete water and conserve salts and in systems that conserve water and excrete salts.
Extracellular fluid acted upon by secretion and reabsorption becomes urine.
If the solute potential of the extracellular fluid is less negative than a cell, then that cell has a greater solute concentration than the fluid.
Active transport of water out of cells is an important mechanism for many animals living in fresh water.
Most excretory organs consist of a series of tubules.

 Question 5

Short Answer / Essay

(2 points)

Question:

Identify one habitat where you would expect to find an osmoregulator, and in that habitat would you expect it to be excreting urine hyper-, iso- or hypotonic to their extracellular fluid?

 Question 6

Short Answer / Essay

(1 points)

Question:

Using your answer from the previous question, identify a likely type of nitrogenous waste produced by animals in that habitat. Give an example of a specific group of animals that excrete the nitrogenous waste you identified.

Question 7 

Multiple Choice

(1 points)

Question:

Which of the following is true of the relationship between the circulatory and excretory systems of mammals?

Kidneys autoregulate blood pressure by constricting afferent renal arterioles.
In order for kidneys to function properly, blood pressure must be constant, but blood volume can vary.
Hormones secreted by the kidney affect water retention and arterial blood pressure.
Vasopressin is released by the kidneys and causes more water to be reabsorbed in the proximal convoluted tubules.
Blood volume sensors are located in the aortic arch and stimulate the thirst center in the medulla if volume is too low.

Question 8 

Short Answer / Essay

(2 points)

Question:

Describe one effect of diabetes on the excretory system.