Chapter 26 Reading Questions Continued
The Urinary System

Part 2: Renal Physiology
    A. Glomerular filtration
    B. Tubular reabsortion
    C. Tubular secretion

12. List three important physiological functions of the kidney that deal with glomerular  
      filtration.

1. _______________________________________________
2. _______________________________________________
3. _______________________________________________

13. List the solutes that pass from the blood into Bowman's capsule.
      Amazingly, every minute 125 mls of blood plasma passes into the nephron.
      As this moves through the tubules, 124 mls of filtrate is returned to the
      blood stream and the remaining filtrate becomes urine.

A. List the solutes pushed out of the blood into the filtrate. ______________________________________________________
______________________________________________________
______________________________________________________

B. List the solutes you would expect to find left in the urine.
    1._____________________________
    2._____________________________
    3._____________________________
    4._____________________________

C. Once plasma enters Bowman's capsule, it is called ____________

D. Filtrate contains all materials dissoved in the blood EXCEPT
     ________________________ and __________________________.

14. Describe the formation of FILTRATE by the process of glomerular filtration.

D. Calculate NFP, the filtration pressure in the glomerulus. It is possible to
measure the effective filtration pressure using the following formula.

NPF = HP - (CHP + BCOP)

If Hydrostatic Pressure = 55 mmHg
Capsular Hydrostatic Pressure = 15 mmHg
Blood Osmotic Pressure = 30 mmHg,

then, how much pressure is moving blood plasma into Bowman's capsule? ____
(Your answer means that 125 mls of plasma can flow into Bowman's capsule each minute.)

15. Factors that affect the Glomerular Filtration Rate.

A. Gushy Gail has glomerulonephritis. This is a kidney disease whereby  
     streptococcus toxins cause an allergic reaction.
     The glomeruli become inflamed and engorged with blood
     causing an increase in permeability. List the three changes
     that occur in glomerular filtration.

1. ___________________________________________
2. ___________________________________________
3. albuminuria
What happens to the NFP? _______________________
Explain the reasons for your answer. ____________________________________________
____________________________________________

B. The affect of hemorrhaging on blood pressure is
     __________________________________________________.
    What would you expect to happen to the amount of filtrate      
     produced?_________________________________________

C. The sympathetic nervous system releases epinephrine. Describe the
      effect of this hormone/neurotransmitter on the afferent arteriole. 
      _________________________________________________
    Explain what happens to Hydrostatic Pressure and to the glomerular
    filtration pressure with impulses from the sympathetic nervous system.
    __________________________________________________         
    __________________________________________________

16. Now you will examine tubular reabsorption, the pull-back of molecules
    from the filtrate into the blood. This is a very selective process and depends
    upon the molecules the body needs. List the molecules that are reabsorbed
    into the peritubular capillaries.

1.______________, 2._______________, 3.________________,
4.______________, 5._______________, 6.________________,
7.______________, 8._______________, 9.________________,
10._____________, 11, _____________, 12.________________,

17. Define tubular reabsorption.
    _____________________________________________________
    _____________________________________________________

A. Describe how sodium ions are reabsorbed in the proximal convoluted tubule.
_____________________________________________________
_____________________________________________________
_____________________________________________________

B. Describe how glucose and amino acids are reabsorbed in the proximal
convoluted tubule
_____________________________________________________
_____________________________________________________
What does Tm mean? _________________________________

C. A sign of diabetes mellitus is glycosuria. Explain why polyuria and polydipsea
accompany glycosuria.
_____________________________________________________
_____________________________________________________
_____________________________________________________

18. A third kidney function is the process of tubular secretion, the opposite of tubular     
      reabsorption. This process puts materials into the filtrate and controls pH. List the 
      materials added to the filtrate.

1. __________________________________
2. __________________________________
3. __________________________________
4. __________________________________

19. Summarize the reactions involved in H ⁺ secretion and the generation
    of HCO₃ ^- in the proximal convoluted tubules and collecting tubules.

A. Carbon dioxide diffuses from from the blood into the tubular
____________________.

B. A source of CO₂ is the____________________ cycle.

C. CO₂ combines with ____________, the acid formed is called
____________________________________.

D. The enzyme that catalyzes this reaction is
____________________________________.

E. Carbonic acid is a weak acid and partially dissociates. The
ions formed are ________________ and __________________.

F. The H ⁺ are secreted into the __________________________
thereby lowering the pH of urine.

G. The HCO₃ ^- is returned to the _________________________,
thereby replacing this BASE buffer which is lost when
counteracting strong acids such as _______________________,
________________________, and _________________________.

H. For every H ⁺ entering the filtrate, a HCO₃ ^- and Na ⁺ is returned to the blood.

20. Summarize, in your own words, the role of tubular secretion in
    maintaining the pH of the blood.     
    _______________________________________________________
    _______________________________________________________
    _______________________________________________________
With tubular secretion, it becomes clear that the kidneys control the
metabolic component of acid base balance.

Define metabolic acidosis.
_______________________________________________________
_______________________________________________________
_______________________________________________________
How does the Respiratory system compensate?_____________

Describe metabolic alkalosis. _________________________________
_______________________________________________________
_______________________________________________________
How does the Respiratory system compensate?______________

Focus Question
Describe the three roles of kidney, glomerular filtration, tubular reabsorption, and tubular secretion.

Part 3: Hormone Regulation
    A. Renin-Angiotensin Pathway
    B. Antidiuretic hormone
    C. Counter-current mechanism

21. Describe the role of aldosterone in the renin angiotensin pathway.

A. Between the afferent and efferent arterioles, there are a group
    of cells called  ____________________________________.

B. These act as monitors of blood pressure in the kidney.
    If the blood pressure drops, these cells secrete an enzyme
    called renin. In the blood, renin converts a protein called
    angiotensinogen . The following reaction occurs:

renin + angiotensinogen --> angiotensin I ---> angiotensin II

C. Angiotensin II has four roles.

1. ___________________________________________
2. ___________________________________________
3. ___________________________________________
4. ___________________________________________

Here is a poem to help you remember the renin angiotensin pathway.

If blood pressure drops, the kidney's defending
    juxtaglomerular cells, will renin a send in.
The little enzyme will convert,
    angiotensinogen on alert.
It's angiotensin II that you derive
    the benefits of Blood Pressure to survive.
First the Efferent arteriole vasoconstricts,
    then aldosterone gets its kicks
Na ⁺ to the blood, K ⁺ the filtrate,
    water pulled back completes the slate.

There is a drug on the market called Vasotec which is used in
treating hypertension. Vasotec is an angiotensin-converting
enzyme inhibitor. This means that angiotensin I cannot be
converted to angiotensin II. This leads to a decrease in
vasoconstricition and a small decrease in aldosterone secretion.

22. Explain the role of the antidiuretic hormone (ADH) in water reabsorption.

"Wherever sodium goes, so goes water!"

A. Sodium reabsorption is a massive effort on every part of the
    kidney tubules. Name the section of the kidney tubules where
    90% of the water in the filtrate is reabsorbed by following sodium.         
    ________________________________________________

This is obligatory water reabsorption!

B. Water is also reabsorbed in the DCT and CD, however, this process
    is under the control of a hormone called _______________________.
    This hormone is produced by the _____________________________
    and stored in the __________________________________________.
    ADH is secreted when blood osmotic pressure is _________________
    (that means water concentration in the blood is low).
C. The function of ADH is to ______________________________
    ____________________________________________________
    ____________________________________________________
    ____________________________________________________
D. How much water reabsorption is regulated by ADH? _________

This is facultative water reabsorption!

ADH doth water control,
    keeping plasma concentration at .3 osmoles.
If, in fact BOP should rise
    water IS needed to prevent demise
Open the floodgates ADH commands
    water is reabsorbed at this demand.
If the plasma should become dilute.
    then the urine filtrate must follow suit.
ADH must be kept in hiding
    to keep the floodgates closed from sliding.

23. "Close the floodgates and stand by the toilet all day." This sentence describes another form of     
    diabetes (NO RELATION TO GLUCOSE) called diabetes insipidis. If the hypothalamus is
    damaged, then the hormone ___________________is not secreted. 
    Symptoms of diabetes insipidis include:

1._______________________________________________
2._______________________________________________
3._______________________________________________

    How can this disease be treated? ____________________________

24. Let's start this section with part of "The Rhyme of the Ancient Mariner"
by Samuel Taylor Colleridge.

Day after day, day after day,
We stuck, nor breath nor motion;
As idle as a painted ship
Upon a painted ocean.

Water, water every where,
And all the boards did shrink;
Water water everywhere,
Nor any drop to drink.

Your last exercise on the kidney is to study how the kidneys regulate the amount of fluid in the blood. For example, if you drink a large amount of fluid, what happens to your urine output?____________
If you drink little fluid, visit Egypt, or sweat profusely what happens to your urine output? ________
How does the kidney know what to do? Have you noticed we have not discussed the role of those tubules in the juxtamedullary nephrons.
Here it is!

25. Draw and label the tubules that lie within the medulla.

descending limb
Henles loop
ascending limb

27. Define the term milliosomole.
    ____________________________________________________
    ____________________________________________________
    ____________________________________________________

cortex
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

medulla                         350                         350

                                    550                         550

                                    750                          750

                                                    900

Concentration of solutes on the medulla is increased three ways.
1.____________________________________________________
   ____________________________________________________
2.____________________________________________________
   ____________________________________________________
3.____________________________________________________
   ____________________________________________________

29. The countercurrent mechanism takes advantage of this concentration
of solutes in the medulla interstitial fluid. Filtrate in the collecting ducts can
be diluted or concentrated depending on the needs of the body. Water
does not flow out of the ascending limb, under the control of ADH, the
collecting tubules can become permeable to water.
Describe what happens in the collecting tubule when ADH is present.
______________________________________________________
______________________________________________________
______________________________________________________
______________________________________________________

Focus Question
Summarize the functions of the nephron by comparing
the activity of each region.

Renal corpuscle
___________________________________________________
___________________________________________________
___________________________________________________
___________________________________________________
___________________________________________________

Proximal convoluted tubule
___________________________________________________
___________________________________________________
___________________________________________________
___________________________________________________
___________________________________________________

Descending limb
___________________________________________________

Ascending limb
___________________________________________________

Distal convoluted tubule
___________________________________________________
___________________________________________________
___________________________________________________
___________________________________________________

Collecting duct _______________________________________
___________________________________________________
___________________________________________________
___________________________________________________

30. Careful Carl has cystitis. This is an ______________________
His symptoms include:

1. ______________________________________
2. ______________________________________
3. ______________________________________

31. In the presence of testosterone, the hereditary disorder called gout can occur.
High blood levels of uric acid cause salts of this acid to deposit in

1. _______________________________
2. _______________________________
  with accompanying inflammation, pain, and swelling.

32. Once upon a time, your were incontinent, and it may happen again.
Describe the events that lead to incontinence in the adult.

1. _________________________________________________
2. _________________________________________________
3. _________________________________________________

33. Do not confuse incontinence with renal retention. List three conditions
that result in renal retention.

1. _________________________________________________
2. _________________________________________________
3. _________________________________________________

36. In the laboratory, you will perform a urinalysis. List the diseases that can
be screened through a routine urinalysis.

1. _________________________________________________
2. _________________________________________________
3. _________________________________________________
4. _________________________________________________
5. _________________________________________________
6. _________________________________________________