Name Date Per

STUDY QUESTIONS: CH 44 – Regulating the Internal Environment

(Homeostasis & The Urinary System)

1) In the space below, list the primary structures (organs) of the urinary system and their corresponding functions.

Structures: Function(s):

2) What is the primary function of the urinary system?

3) What are 2 additional functions of the urinary system?

4) What is the relationship between the AFFERENT ARTERIOLE and the EFFERENT ARTERIOLE?

5) List the normal constituents of urine.

RENAL PHYSIOLOGY: There are 3 processes which take place in the NEPHRON to allow urine to form as a liquid waste product of the human body. These three processes are (1) glomerular filtration; (2) tubular reabsorption; and (3) tubular secretion. The following questions ask you to identify significant events that take place during each of these three processes.

6) Glomerular filtration is the first step in urine formation. What circumstance allows water and dissolved substances to be easily filtered out of the glomerulus and into the Bowman’s capsule?

7) What is the composition of the glomerular filtrate?

8) During a 24 hour time period 45 gallons of liquid are filtered from the blood plasma.

Why do we not excrete all 45 gallons as urine?


9) Describe what occurs during the second step of urine formation called REABSORPTION.

10) Where in the nephron does most of the process of tubular reabsorption occur?

11) Name specific substances that are reabsorbed through:

è active transport:

è passive transport:

12) What is the impact of the hormone ADH (antidiuretic hormone) on urine volume? Include where it is produced and stored, where it’s target cells are (where it acts), and what effect it has on the target tissue.

13) The third step in the process of urine formation is SECRETION. What specifically takes place during this step?

14) Summarize how the renin-angiotensin-aldosterone system (RAAS) responds to a drop in blood pressure in your body.

15) What is the function of the hormone atrial natriuretic peptice (ANP)? Where / why is it produced?
*Using Chapter 44 (Urinary System) in your textbook AND the supplementary reading (“Animal Physiology – The Mammalian Kidney”), complete the following chart. (see fig. 44.15 & 44.16))

16) Complete the following chart which describes the pathway of filtrate within a nephron:

Location / Process(es) occurring here; passive or active? / Substances being transported / Urine becoming more or less concentrated?
glomerulus / glomerular capsule
proximal tubule
descending limb of loop of Henle
ascending limb of loop of Henle
distal tubule
collecting duct

16) Label the diagram below

showing the regional functions

of the nephron & collecting duct:

(see fig. 44.15)


17) Label the following diagram showing how the human kidney concentrates urine. (see fig. 44.16)