______

PRINT your name, please

BSCI 440: Exam III Your TA is ______

Spring 2003; W. J. Higgins

DIRECTIONS:

1. PRINT your name on each page of the examination NOW.

2. Tear off the last page of the examination. It contains the data you will need to answer Question #1. Use it for scratch paper. It will NOT be collected.

3. You absolutely, positively MUST confine your answers to the spaces provided. Failure to do so may result in an inaccurate evaluation of your knowledge.

4. Complete the exam using a PEN if you wish to retain the right to discussing your answers with Dr. K-I-A.

SCOREBOARD

Question / Higgins Points / Visitor’s
Points / Question / Higgins Points / Visitor’s Points
1 / 45 / 5 / 30
2 / 15 / 6 / 20
3 / 10 / 7 / 10
4 / 20 / 8 / 50
TOTAL / 200

#1. Use the data on the last page and answer the following. You MUST include UNITS where appropriate.

a. Renal BLOOD Flow = a. 20.83 ml/min______

b. Filtration Fraction = b. ____0.24______

c. Glomerular Filtration Rate = c. ______3.0 ml/min_____

d. Rate of water reabsorption by the kidney d. ______2.5 ml/min______

e. Extraction ratio of Substance Q e. _____0______

f. Cardiac Output f. ______480 ml/min______

g. Alveolar Ventilation Rate g. ____67.2 ml/min______

h. Mean Arterial Blood pressure (MAP) h. ______140 mm Hg_____

i. Rate at which D is put into glomerular filtrate i. ______0.014 mg/min_____

j. What does the kidney do with Substance D? j. ______F & S______

k. At what rate is D reabsorbed or secreted? k. ____0.0156 mg/min______

l. Rate at which D is put into urine l. ______0.03 mg/min______

m. What are two alternative but reasonable assumptions about what happens to Substance Q in the nephrons:

1.______it is too large to be filtered, e.g., MW > 69,000______

2.______it is filtered and completely reabsorbed______

n. Use one of your assumptions from part m (above) and

calculate the animal’s PLASMA volume n. 400 ml______

o. Now use your other assumption for substance Q.

At what rate is Q reabsorbed? o. ______0.018 mg/min_____

#2. Aldosterone secretion results in increased blood volume.

a. List two different stimuli or signal molecules that initiate aldosterone secretion (you may NOT list decreased blood volume or atrial EDV)):

2 of these 3: High plasma K+ , angiotensin II or ADH

b. What is the specific molecular result of aldosterone on the cells of the kidney tubules?

INCREASED (SYNTHESIS OF) Na+ - K+ ATPase

c. What are the effects of aldosterone on ion reabsorption/secretion? (Which ions???)

ALDOSTERONE INCREASES THE RENAL REABSORPTION OF SODIUM AND INCREASES THE SECRETION OF POTASSIUM

d. Explain how this action increases blood volume?

WATER PASSIVELY FOLLOWS THE MOVEMENT OF Na+ (may indicate 3 Na for 2 K moving the other way, so water follows Na) into blood

#3. Using only the space below, describe / explain the Haldane effect and its benefit:

In the lungs, as oxygen binds to hemoglobin, it becomes a stronger acid and releases a proton (H+). This combines with HCO3- forming CO2 which is then blown off. Thus increased oxygen promotes unloading of CO2 from the blood in the lungs.

#4. In the space below, neatly draw an ACCURATE and anatomically correct representation of cell of the Proximal Convoluted Tubule. Label the apical (the side facing the tubule lumen) and the basolateral (the side facing the interstitial fluid) membranes. Now carefully indicate the specific transport mechanisms for the following solutes in each membrane of the tubule cell: Na+, glucose, Cl-, K+, and urea.

SEE FIGS 17.15, 17, AND 18: Must have microvilli on apical surface.

Na+ : Symport on Apical membrane and antiport on basolateral. Also correct but not required, passive or facilitated diffusion through channels on basolateral

Glucose: symport (apical) and then facilitated diffusion (basolateral)

Cl- : diffusion following Na+ on both borders May also have antiport, but not required.

K+ : Diffusion out through channels at apical and then antiport at basolateral

Urea is simple diffusion at both

#5. Upon entering the examination this morning, your recitation team partner realized that he cannot solve renal clearance problems! His respiration temporarily ceased due to fright. List all of the steps beginning with the stimulus (!) that will ultimately result in an increase in Alveolar ventilation to make up for this temporary failure to inhale. Be complete and concise, of course.

Increased CO2 in plasma à increased CO2 in CSF à decreased CSF pH à stimulate medullary chemoreceptors to stimulate DRG or A Pool neurons which in turn increase their rate of firing, increasing rate and depth of respiration à increased alveolar ventilation à return plasma CO2 and pH to normal

b. Now on the axes below, draw the pattern of action potentials for two breaths in the A pool of respiratory neurons BEFORE (i.e., normal, control) and DURING the increased alveolar ventilation:

#5. Fill in the following graphs:

#7. At each location below, fill in the partial pressures of oxygen and carbon dioxide:

LOCATION / Partial Pressure of O2 / Partial Pressure of CO2
Alveolar Air / 100 / 40
Pulmonary Veins / 100 / 40
Systemic Arteries / 100 / 40
Systemic Veins / 40 / 46
Pulmonary Arteries / 40 / 46

#8. How about a few UP - DOWNS???? Of course, you will answer each with I, D, or NoD:

a. As [a1 agonist] increases, GFR

a.___D_____

b. As DCT [Na+] decreases, TPR

b.____I_____

c. As plasma renin increases, plasma [aldosterone]

c.____I____

d. As plasma [K+] increases, tubular Na+ reabsorption

d.____I_____

e. As plasma angiotensin II levels increase, ADH

secretion e._____I_____

f. As plasma osmotic pressure increases, collecting duct cell

cyclic AMP levels f.____I_____

g. As MAP decreases, ADH secretion by the

posterior pituitary g.____I_____

h. As plasma [HPO4++] increases, plasma PTH

h.____I_____

i. As plasma ethyl alcohol levels increase, renal water

reabsorption i._____D____

j. As fluid pressure inside Bowman’s capsule increases

GFR j.____D_____

k. As efferent arteriole diameter increases, GFR

k.____D_____

l. As plasma CO2 increases, tidal volume will

l.___I_____

m. As blood enters systemic capillaries, plasma [HCO3-]

m.___I______

n. As one exhales, alveolar surface tension

n.____D_____

o. As PO2 around a glomus cell decreases, the magnitude of its

membrane potential (forget sign! The magnitude!) o.____D____

p. As inhalation progresses, afferent vagal nerve activity

p.___I______

q. As anaerobic exercise continues, the P50 of hemoglobin

q._____I____

r. As progressive cardiovascular shock continues,

venous return r.____D______

s. As progressive cardiovascular shock continues,

sympathetic cardiac nerve activity s.___D______

t. As intrapleural pressure decreases, lung volume

t.____I_____

u. As inhalation progresses, B pool neuron activity

u.____I_____

v. As plasma glucose levels decrease, the rate of glucose

reabsorption by the nephrons v.____D_____

w. As plasma PAH levels increase above Tmax,

the renal clearance of PAH w.____D____

x. As lung compliance decreases, the work of breathing

x.____I_____

y. As plasma ANP increases plasma aldosterone

y.____D_____

The Experiment:

Dr. Harley Schmedlap, Jr., noted physiologist and part-time three star chef at the South Campus Dining Hall has made a remarkable discovery. He has captured a ferocious and voracious little creature lurking about in the vegetable bins of the kitchen. Schmedlap has ascertained that this creature used to inhabit the Stamp Union feeding on Krispy Kremes. Displaced by the renovations in progress, this beast is now forced to forage for healthy foods and is rapidly wasting away from lack of grease and calories. In an effort to acquire information required to preserve the species, which he aptly named Krispus kremius higginsonii, Schmedlap has gathered the following physiological data. You must complete the calculations required to answer question #1 on page 1.

Substance D / Substance Q
PA (mg/100 ml plasma) / 0.48 / 0.6
PV in renal vein
(mg/100 ml plasma) / 0.24 / 0.6
[Urine] (mg/ ml urine) / 0.06 / 0.0
Amount of substance
originally injected (mg) / 1.2 / 2.4

Rate or urine formation = 0.5 ml/min

Clearance of Inulin = 3 mls/min

Hematocrit = 0.40

Heart Rate = 120 beats/min

Blood ejected per beat = 4 mls

Respiratory Tidal volume = 4.0 mls

Respiratory Rate = 24 breaths/min

Conducting airway volume = 1.2 ml

Bp = 180/120 mm Hg

5