physioex 9 exercises 6-9 answer key

PhysioEx 9 Answer Key for Exercises 6-9

Exercise 5: Cardiovascular Dynamics: Activity 1: Studying the Effect of Blood Vessel Radius on Blood Flow Rate Lab ReportPre-lab Quiz ResultsYou scored 100% by answering 5 out of 5 questions correctly.1. Blood flow is measured inYou correctly answered: b. ml/min.2. Which of the following has the greatest effect on blood flow?You correctly answered: a. blood vessel radius3. Which of the following would not result in a decrease in the blood vessel radius?You correctly answered: c. vasodilation4. The diameter of the blood vessel is the same asYou correctly answered: b. two times the radius of the blood vessel.5. The opening of the blood vessel where the blood flows is called theYou correctly answered: b. lumen.

Post-lab Quiz ResultsYou scored 75% by answering 3 out of 4 questions correctly.1. The variable that you altered in this activity wasYou correctly answered: c. vessel radius.2. Vessel radius and fluid flowYour answer: a. are inversely proportional.Correct answer: b. are directly proportional.3. After a heavy meal, when we are relatively inactive, we might expect blood vessels in the skeletal muscles to besomewhat __________ and the blood vessels in the digestive organs to be somewhat __________.You correctly answered: d. constricted, dilated4. When you increased the flow tube radius, the fluid flow rateYou correctly answered: a. increased.

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Activity 2: Studying the Effect of Blood Vessel Length on Blood Flow Rate Lab Report

Pre-lab Quiz ResultsYou scored 100% by answering 4 out of 4 questions correctly.1. When the length of the blood vessel increases, which of the following also increases?You correctly answered: d. both friction and surface area2. Blood vessel length decreasesYou correctly answered: c. when we lose weight.3. Blood flow isYou correctly answered: b. directly proportional to vessel radius to the fourth power.4. Which of the following correctly describes resistance to flow?You correctly answered: a. Resistance to flow increases with increased vessel length.

Post-lab Quiz ResultsYou scored 50% by answering 2 out of 4 questions correctly.1. Increasing the flow tube length is analogous to increasing blood vessel length. How did this affect the flow rate?You correctly answered: b. The flow rate decreased.2. Which of the following correctly describes the relationships between blood vessel length, resistance, and blood flow?Your answer: a. Blood vessel length is inversely proportional to resistance and inversely proportional to blood flow.Correct answer: c. Blood vessel length is directly proportional to resistance and inversely proportional to blood flow.3. Which of the following correctly describes the relationships between blood vessel radius, resistance, and blood flow?Your answer: c. Blood vessel radius is directly proportional to resistance and inversely proportional to blood flow.Correct answer: d. Blood vessel radius is inversely proportional to resistance and directly proportional to blood flow.4. Which of the following describes why the body might require an increase in vessel radius?You correctly answered: a. to provide more blood flow and, therefore, nutrients to a particular body part



Activity 4: Studying the Effect of Blood Pressure on Blood Flow Rate Lab Report

Pre-lab Quiz ResultsYou scored 100% by answering 4 out of 4 questions correctly.1. Pressure changes in the cardiovascular system primarily result fromYou correctly answered: b. changes in the force of contraction of the heart.2. What is the driving force for blood flow?You correctly answered: d. pressure gradient3. Which of the following is directly proportional to blood flow?You correctly answered: e. blood vessel radius and pressure gradient4. Arteries close to the heart need to be able to compensate forYou correctly answered: c. pressure changes.

Post-lab Quiz ResultsYou scored 75% by answering 3 out of 4 questions correctly.1. The effect of increasing pressure was toYou correctly answered: b. increase flow rate.2. Blood pressure is measured inYou correctly answered: c. mm Hg.3. Which of the following variables has the greatest effect on blood flow?Your answer: b. pressure differencesCorrect answer: d. vessel radius4. Blood flow is measured inYou correctly answered: a. ml/min.



Activity 5: Studying the Effect of Blood Vessel Radius on Pump Activity Lab Report

Pre-lab Quiz ResultsYou scored 100% by answering 5 out of 5 questions correctly.1. The heart is resting duringYou correctly answered: c. ventricular diastole.2. The right side of the heart pumps bloodYou correctly answered: d. to the lungs.3. The layer of the blood vessel that is stimulated by the autonomic nervous system isYou correctly answered: b. smooth muscle.4. In the experiment, the pump simulatesYou correctly answered: b. the left ventricle of the heart.5. If the right beaker simulates the flow of blood to the systemic circuit of the body, what do the right valve and flow tuberepresent?You correctly answered: d. aortic valve and aorta

Post-lab Quiz ResultsYou scored 100% by answering 5 out of 5 questions correctly.1. The pump piston in the simulation is up duringYou correctly answered: b. diastole.2. The pump in the simulation represents theYou correctly answered: c. left ventricle.3. The amount of blood flowing into the destination beaker (right beaker) with a single pump is called theYou correctly answered: d. stroke volume.4. In this experiment, the increase in right flow tube radius resulted inYou correctly answered: b. an increase in flow rate, which increased the pump rate.5. Which chamber should be present in the flow pattern of the experiment, given that the vessels and valves surrounding itare present (the chamber was omitted from the experiment for simplicity)?You correctly answered: d. left atrium



Activity 6:Studying the Effect of Stroke Volume on Pump Activity Lab ReportPre-lab Quiz ResultsYou scored 100% by answering 5 out of 5 questions correctly.1. Which of the following variables directly contributes to preload?You correctly answered: b. venous return2. Which of the following would not increase end diastolic volume?You correctly answered: c. dehydration3. Increased contractility of the heart results in all but which of the following?You correctly answered: d. increased end systolic volume4. Which of the following does not affect stroke volume?You correctly answered: d. All of these affect stroke volume.5. Which of the following is not equivalent to the others?You correctly answered: c. end diastolic volume

Post-lab Quiz ResultsYou scored 25% by answering 1 out of 4 questions correctly.1. What do you think would happen when stroke volume is decreased?Your answer: d. Blood flow would decrease.Correct answer: b. Pump rate would increase.2. Why might an athlete's resting heart rate be lower than that of the average person?Your answer: c. Stroke volume has increased.Correct answer: e. Stroke volume and contractility have increased.3. In this activity, which of the following stayed constant?You correctly answered: c. flow rate4. Which of the following is true?Your answer: b. SV = ESV - EDVCorrect answer: d. ESV = EDV – SV



Activity 7: Compensation in Pathological Cardiovascular Conditions Lab Report

Pre-lab Quiz ResultsYou scored 100% by answering 4 out of 4 questions correctly.1. Which of the following could cause an increase in peripheral resistance in the blood vessel?You correctly answered: b. atherosclerosis2. Which structures in the heart ensure that one-way flow occurs?You correctly answered: d. valves3. Which of the following might be seen in both the diseased heart and the athlete's heart?You correctly answered: c. thicker myocardium4. The type of resistance increased in aortic valve stenosis isYou correctly answered: d. increased left-ventricular afterload.

Post-lab Quiz ResultsYou scored 75% by answering 3 out of 4 questions correctly.1. Which of the following compensatory mechanisms was not tested?You correctly answered: c. decreasing the pressure in the left (source) beaker2. In an actual heart, what is the most logical way to compensate for a decrease in flow tube radius?Your answer: c. adjust viscosityCorrect answer: b. adjust the force of contraction of the heart3. Without a difference in pressure between the pump and the destination beakerYou correctly answered: a. the valve will not open.4. Athletes experience an overall __________ in peripheral resistance, so the heart generates __________ pressure todeliver the same amount of blood. An athlete's arterial pressure would likely be __________ than that in a non-athlete.You correctly answered: d. decrease, less, lower



Exercise 6: Cardiovascular Physiology: Activity 1: Investigating the Refractory Period of Cardiac Muscle Lab Report

Pre-lab Quiz ResultsYou scored 100% by answering 4 out of 4 questions correctly.1. The cardiac muscle is capable of which of the following?You correctly answered: c. autorhythmicity2. Phase 2 of the cardiac action potential, when the calcium channels remain open and potassium channels are closed, iscalled theYou correctly answered: a. plateau phase.3. Which of the following is true of the cardiac action potential?You correctly answered: b. The cardiac action potential is longer than the skeletal muscle action potential.4. The main anatomical difference between the frog heart and the human heart is that the frog heart hasYou correctly answered: c. a single, fused ventricle.

Post-lab Quiz ResultsYou scored 100% by answering 4 out of 4 questions correctly.1. The amplitude of the ventricular systole did not change with the more frequent stimulation becauseYou correctly answered: a. a new contraction could not begin until the relaxation phase2. Which of the following do you think contribute to the inability of cardiac muscle to be tetanized?You correctly answered: a. the long refractory period of the cardiac action potential3. Given the function of the heart, why is it important that cardiac muscle cannot reach tetanus?You correctly answered: b. The ventricles must contract and relax fully with each beat to pump blood.4. An extrasystole corresponds toYou correctly answered: c. an extra ventricular contraction.



Activity 2: Examining the Effect of Vagus Nerve Stimulation Lab ReportPre-lab Quiz ResultsYou scored 100% by answering 4 out of 4 questions correctly.1. The effect of the parasympathetic nervous system on the heart is toYou correctly answered: a. decrease the heart rate.2. The branch of the autonomic nervous system that dominates during exercise isYou correctly answered: b. the sympathetic branch.3. Parasympathetic stimulation reaches the heart throughYou correctly answered: d. vagus nerves, which are cranial nerves.4. The usual pacemaker of the heartYou correctly answered: c. is the sinoatrial node.

Post-lab Quiz ResultsYou scored 100% by answering 4 out of 4 questions correctly.1. Extreme vagus nerve stimulation affects the heart byYou correctly answered: a. stopping the heart completely.2. Vagal escape probably involvesYou correctly answered: c. sympathetic reflexes.3. Research shows that, in the absence of neural and hormonal influences, the SA node generates action potentials at afrequency of approximately 100 times per minute. However, the resting heart rate is approximately 70 beats per minute,which suggests thatYou correctly answered: b. the parasympathetic nervous system has more control over heart rate.4. The SA (sinoatrial) node in the human heart is locatedYou correctly answered: c. in the right atrium



Activity 3: Examining the Effect of Temperature on Heart Rate Lab ReportPre-lab Quiz ResultsYou scored 100% by answering 4 out of 4 questions correctly.1. Organisms that usually maintain the same internal body temperature in spite of environmental temperature changes areYou correctly answered: c. homeothermic.2. The general name for the process that maintains the internal body temperature in humans isYou correctly answered: a. homeostasis.3. The electrolytes in a Ringer's solution are required toYou correctly answered: b. provide for autorhythmicity.4. An internal body temperature that is above the normal range isYou correctly answered: b. hyperthermic.

Post-lab Quiz ResultsYou scored 100% by answering 4 out of 4 questions correctly.1. In the 5°C Ringer’s solution, the frog heartYou correctly answered: c. beat slower than baseline.2. In the 32°C Ringer’s solution, the frog heartYou correctly answered: b. beat faster than baseline.3. If the human heart were experiencing hypothermia, what do you think would be the effect on heart rate?You correctly answered: c. a decrease in heart rate4. Without the Ringer's solutionYou correctly answered: d. spontaneous cardiac action potentials would not occur.



Activity 4: Examining the Effects of Chemical Modifiers on Heart Rate Lab ReportPre-lab Quiz ResultsYou scored 100% by answering 4 out of 4 questions correctly.1. The parasympathetic nervous system releases __________ to affect heart rate.You correctly answered: d. acetylcholine2. A cholinergic drug that worked the same as acetylcholine wouldYou correctly answered: c. be an agonist and decrease heart rate.3. Norepinephrine affects the heart rate byYou correctly answered: a. increasing the rate of depolarization and increasing the frequency of action potentials.4. The __________ receptor binds norepinephrine and epinephrine.You correctly answered: b. ß-1 adrenergic

Post-lab Quiz ResultsYou scored 100% by answering 4 out of 4 questions correctly.1. Pilocarpine decreased the heart rate. Typical of cholinergic agonists, itYou correctly answered: b. decreased the frequency of action potentials.2. The effect of atropine was toYou correctly answered: c. mimic the sympathetic nervous system.3. The modifiers tested that decrease the heart rate wereYou correctly answered: c. digitalis and pilocarpine.4. To increase the heart rate, the best choices would beYou correctly answered: b. epinephrine and atropine.



Activity 5: Examining the Effects of Various Ions on Heart Rate Lab ReportPre-lab Quiz ResultsYou scored 100% by answering 4 out of 4 questions correctly.1. Which organelle in the cardiac muscle cell stores calcium?You correctly answered: b. sarcoplasmic reticulum2. Verapamil is a calcium-channel blocker. Its effects could be described asYou correctly answered: d. negative chronotropic and negative inotropic.3. When the cardiac muscle cell is at rest, where is most of the potassium found?You correctly answered: c. in the cytosol4. Resting cardiac muscle cells are most permeable toYou correctly answered: b. potassium.

Post-lab Quiz ResultsYou scored 100% by answering 4 out of 4 questions correctly.1. The addition of most of the ions resulted inYou correctly answered: c. an erratic heart rate.2. The effect of potassium on the heart isYou correctly answered: b. negative chronotropic, negative inotropic.3. The ion that had the most pronounced effect on heart rate wasYou correctly answered: c. potassium.4. Ectopic pacemakers can be caused by excessive leakage of potassium into cardiac cells, resulting in pacemakersappearing in abnormal locations in the heart muscle. This hyperkalemia (excess potassium) decreases the resting potentialof the cardiac muscle cell. What effect do you think this would have on the force of contraction?You correctly answered: d. decrease, negative inotropic



Exercise 7: Respiratory Mechanics: ACTIVITY 1: Measuring Respiratory Volumes and Calculating Capacities Answers1. Which of the following processes does not occur during inspiration?a. The diaphragm moves to a flattened position.b. Gas pressure inside the lungs is lowered. c. Inspiratory muscles relax.d. The size of the thoracic cavity increases. c. inspiratory muscles relax2. During normal quiet breathing, about ______ ml of air moves into and out of the lungs with each breath.a. 300b. 500 c. 1000d. 1500 B. 5003. True or False: At the beginning of expiration, the air pressure of the atmosphere decreases so that air can flow from the lungs outward. false4. The changing of the airway radius in this lab simulation represents changing the size of the a. Nose and mouthb. Pharynx c. Trachead. Primary bronchi, secondary bronchi, other bronchi and bronchioles d. 5. When the airway radius was decreased to 4.00 mm, the airflow changed to _______ L/minute and the FEV1 changed to ________ ml. 3.075/ 1422 ml6. If the TV of a person’s lungs is 600ml, the ERV is 1200ml, the RV is 1200ml, and the IRV is 3000 ml, the total lung capacity (TLC) is _______ ml. 6000 ml7. What would be an example of an everyday respiratory event the ERV simulates? The ERV button represents a forced expiration. 8. What additional skeletal muscles are utilized in an ERV activity? Abdominal-wall muscles, internal intercostals, internal/external oblique, transverses abdominis9. What was the FEV1 (in %) at the original radius of 5.00 mm? 74%10. What happened to the FEV1 (in %) as the radius of the airways decreased? FEV1 (%) decreased as the airway radius was decreased.11. Explain why the results from the experiment suggest that there is an obstructive, rather than a restrictive, lung problem? The results show that it is an obstructive airway because the airflow is constantly decreasing, if it was restrictive the volumes and capacities would have been affected more than what it was.



ACTIVITY 2: Comparative Spirometry12. Which of these volumes or capacities of the lungs changed the most in the patient with emphysema?a. TVb. IRVc. FVC d. FEV1 d. FEV113. In the patient having an acute asthma attack, the FEV1 (%) decreased to _____ %. 40%14. Which of these volumes or capacities changed the most in the person doing the heavy aerobic exercise?a. TVb. ERV c. FVCd. TLC A. TV15. What happened to the RV for both the emphysema patient and the asthma patient (before inhaled medication)?a. It decreased for both patients.b. It increased for the emphysema patient and decreased for the asthma patient. c. It remained unchanged for both patients.d. It increased for both patients. D. It increased for both patients16. What lung values changed (from those of the normal patient) in the spirogram when the patient with emphysema was selected? Why did these values change as they did? ERV, RV, FVC, FEV1, & FEV %The lung values changed the way that they did because with emphysema, there is a significant loss of elastic recoil in the lung tissue and a noticeable, exhausting muscular effort is required for expiration. Inspiration becomes easier because the lungs are more compliant.17. Which of these two values changed more for the patient with emphysema, the FVC or the FEV1? FVC changed by 1750ml and FEV1 changed by 2375ml or 30%.FEV1 changed more for the patient with emphysema.18. What lung values changed (from those of the normal patient) in the spirogram when the patient experiencing an acute asthma attack was selected? Why did these values change as they did? TV, ERV, IRV, RV, FVC, FEV1 (ml), & FEV1 (%) changed.The values changed the way they did because during an acute asthma attack, airway resistance is significantly increased by 1) thick mucus secretions and 2) airway smooth muscle spasms.19. How is having an acute asthma attack similar to having emphysema? How is it different? Having an acute asthma attack is similar to having emphysema in that the airways collapse and pinch closed before a forced expiration is completed. They are different in that the volumes and peak flow rates are significantly reduced during an asthma attack, unlike with emphysema; the elastic recoil is not diminished in an acute asthma attack.20. Describe the effect that the inhaler medication had on the asthmatic patient. Did all the spirogram values return to “normal”? Why do you think some values did not return all the way to normal? The inhaler medication relieved the bronchospasms and induced bronchiole dilation. The inhaler also reduces airway resistance. No all of the values did not return normal. The IRV, FVC, FEV1 (ml), and FEV1 (%) returned to near normal levels. Some of the values did not return all the way to normal because there is still remaining mucus and residual inflammation.



21. How much of an increase in FEV1 do you think is required for it to be considered significantly improved by the medication? I think that a 20-30% FEV1 increase is required for there to be a significant improvement by the medication.22. With moderate aerobic exercise, which changed more from normal breathing, the ERV or the IRV? With moderate exercise the IRV changed more23. Compare the breathing rates during normal breathing, moderate exercise, and heavy exercise. During normal breathing most normal adults breathe at a rate of 15 breaths per minute. During moderate exercise breathingrates increase but tidal volumes increases more. During heavy exercise both breathing rates and tidal volumes increase tomaximum tolerable levels.



ACTIVITY 3: Effect of Surfactant and Intrapleural Pressure on Respiration24. True or False: Surfactant is often added to the lungs of a very premature infant in a hospital in order for her/him to be able to breathe better. True25. If a person suffers a severe chest injury such as a gunshot or explosion or auto accident, the pressure in the intrapleural cavity becomes the same as the atmospheric pressure. The patient then is said to have developed a _____________. pneumothorax26. In this lab simulation, when the valve on the left side of the glass bell jar was opened, the total airflow decreased to about ________ ml/minute. 49.69 ml/minute27. If a chest tube is placed into the pleural cavity of the patient in question 2 and the opposite end is placed to suction or to an “underwater” seal, we are trying toa. remove any blood that might be present in the thoracic cavity.b. re-expand the lung.c. decrease the pressure in the intrapleural cavity. d. accomplish all of the above. d. accomplish all of the above28. What effect does the addition of surfactant have on the airflow? Surfactant increased the airflow29. Why does surfactant affect airflow in this manner? Surfactant has this affect on airflow because it reduces resistance to lung inflation30. What effect did opening the valve have on the left lung? Opening the valve caused the left lung to deflate31. What effect on the collapsed lung in the left side of the glass bell jar did you observe when you closed the valve? When the valve was closed the lung remained deflated.32. What is the name of the emergency medical condition that opening the left valve simulates? Atelectasis (collapsed lung)33. When you clicked the “Reset” button, the air was drawn out of the intrapleural space and the lung returned to its normal condition. What emergency procedure would be used to achieve this result if these were the lungs in a living person? A chest tube would be inserted 34. What do you think would happen when the valve is opened if the two lungs were in a single large cavity rather than separate cavities? I think that if the valve was opened and the two lungs were in a single large cavity rather than separate cavities both lungs would collapse.



Exercise 8: Chemical and Physical Processes of Digestion: Activity 1: Assessing Starch Digestion by Salivary Amylase Lab ReportPre-lab Quiz Results You scored 100% by answering 6 out of 6 questions correctly.

1. The substrate for amylase is You correctly answered: e. starch and carbohydrate.

2. Which of the following is true of enzymes? You correctly answered: c. Their activity can be affected by temperature and pH.

3. The reagent IKI tests for the presence of You correctly answered: a. starch.

4. Which of the following is not true of controls? You correctly answered: d. A negative result with a positive control is required to validate the test

5. Which of the following is an end product of starch digestion? You correctly answered: e. maltose and glucose

6. Hydrolases are enzymes that break down large molecules into smaller subunits through the addition of _____________. You correctly answered: b. water

Post-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly.

1. Tubes 3, 7, and 8 reveal that You correctly answered: d. amylase activity was highest at pH 7.

2. This activity includes a number of negative controls. Which tube indicates that the amylase solution was not contaminated with maltose? You correctly answered: b. tube 4

3. Which tubes indicate that the deionized water did not contain contaminating starch or maltose? You correctly answered: c. tubes 4, 5, and 6

4. Explain where and why salivary amylase would be most active. You correctly answered: d. Salivary amylase would be most active in the mouth because pH 7 is where its peak activity is.

Review Sheet Results 1. List the substrate and the subunit product of amylase. Your answer: starch & maltose respectively

2. What effect did boiling have on enzyme activity? Why? How well did the results this compare with your prediction? Your answer: Boiling caused amylase to be denatured, thus inactivating the enzyme. Freezing has no effect. The function of an enzyme is directly related to its environment, like temperature. My prediction was wrong. I said that they would both decrease in activity.

3. At what pH was the amylase activity the most active? Describe the significance of this result. Your answer: It was most active at the pH 7.0. Amylase is most active in neutral areas, such as the mouth and the small intestine (duodenum).

4. Briefly describe the need for controls and give an example used in this activity. Your answer: Controls are needed to validate the results of the experiment. One example is testing for sugar using Benedict's test on Amylase. The negative control was used to detect if amylase was contaminated with maltose or not.



5. Describe the significance of using a 37°C incubation temperature to test salivary amylase activity. Your answer: 37°C simulates an environment of normal body temperature.



Exercise 8: Chemical and Physical Processes of Digestion:

Activity 2: Exploring Amylase Substrate Specificity Lab ReportPre-lab Quiz Results You scored 100% by answering 5 out of 5 questions correctly.

1. Which of the following is true of enzymes and substrates? You correctly answered: c. Enzymes are specific about the substrates they can act upon.

2. Which of the following is/are reducing sugars? You correctly answered: e. both glucose and maltose

3. Cellulose and starch are both You correctly answered: e. polymers of glucose and polysaccharides.

4. Proteins and peptides are formed by joining amino acids with a special type of covalent bond called a peptide bond. Which of the following enzymes do you think would be specific for a peptide bond? You correctly answered: c. peptidase

5. The Benedict's assay tests for the presence of You correctly answered: c. reducing sugar.


1. The substrate(s) for amylase is/are You correctly answered: a. starch.

2. The results of tube 5 demonstrated that You correctly answered: b. peptidase does not digest starch.

3. Why was the cellulose in tube 6 hydrolyzed to glucose? You correctly answered: d. The bacterial suspension contained the enzyme cellulase, which digested the cellulose.

4. Can you detect the presence of contaminating amylase from your experiments? You correctly answered: c. It is not possible to determine whether contaminating amylase is present because amylase doesn't digest cellulos

Review Sheet Results 1. Describe why the results in tube 1 and tube 2 are the same. Your answer: In tube #1 the amylase is hydrolyzing the starch to glucose and in tube #2 the glucose is already present in the hydrolyzed form.

2. Describe the result in tube 3. How well did the results compare with your prediction? Your answer: Tube #3 should not be positive for the Benedict’s test because amylase should not digest cellulose. I predicted correctly.

3. Describe the usual substrate for peptidase. Your answer: The substrate for peptidase are peptides, which are small proteins.

4. Explain how bacteria can aid in digestion. Your answer: Bacteria can aid in digestion by breaking down cellulose with the enzyme cellulase. Humans do not produce this enzyme.




Activity 3: Assessing Pepsin Digestion of Protein Lab ReportPre-lab Quiz Results You scored 100% by answering 5 out of 5 questions correctly.

1. Where in the body does protein digestion begin? You correctly answered: b. the stomach

2. The substrate for pepsin is You correctly answered: d. protein and peptides.

3. In this activity the substrate you will be using to detect protein digestion is You correctly answered: d. BAPNA.

4. Negative results with the negative controls You correctly answered: d. are expected and validate the experiment.

5. A spectrophometer measures You correctly answered: c. optical density.


1. Pepsin would be most active You correctly answered: b. in the stomach.

2. Which two tubes validated the results of the experiment? You correctly answered: c. tubes 3 and 4

3. With more enzyme activity the optical density You correctly answered: a. increased.

4. If pepsin were digesting an actual protein substrate, the product would be You correctly answered: c. peptides and amino acids.

Review Sheet Results 1. Describe the effect that boiling had on pepsin and how you could tell that it had that effect. Your answer: Boiling denatured the enzyme. You can tell because the protein was not digested in tube #1. There was no color change and a density of 0.

2. Was your prediction correct about the optimal pH for pepsin activity? Discuss the physiological correlation behind your results. Your answer: The optimum pH matches the pH secreted by gastric glands. Gastric juice is also close to pH 2.

3. What do you think would happen if you reduce the incubation time to 30 minutes for tube 5? Your answer: This would reduce digestion in tube 5.




Activity 4: Assessing Lipase Digestion of Fat Lab ReportPre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly.

1. Which of the following is/are true of bile? You correctly answered: b. It works by a physical process.

2. The substrate used in this simulation is You correctly answered: c. vegetable oil.

3. When fatty acids are liberated by lipase, the pH You correctly answered: b. decreases.

4. One of the products of the chemical digestion of lipids is You correctly answered: d. fatty acids.


1. What is the product of lipase hydrolysis? You correctly answered: d. fatty acids

2. From your results, which pH is ideal for pancreatic lipase digestion? You correctly answered: b. pH 7.0

3. Which tube confirms that there is no lipase in bile salts or vegetable oil? You correctly answered: c. tube 4

4. From your results, where (in theory) would pancreatic lipase be active? You correctly answered: d. mouth and pancreas

Review Sheet Results 1. Explain why you can't fully test the lipase activity in tube 5. Your answer: Measurement of lipase activity uses a decrease in pH. Because the pH in Tube #5 is already very low, it is hard to tell if fatty acids are released.

2. Which tube had the highest lipase activity? How well did the results compare with your prediction? Discuss possible reasons why it may or may not have matched. Your answer: Test tube #1 had the highest activity because the pH is closest to that of the small intestine.

3. Explain why pancreatic lipase would be active in both the mouth and the pancreas. Your answer: Pancreatic lipase is most active at pH 7.0 The pH of the mouth is 7.0 and the pH of the small intestine is close to 8.0. The enzyme would function in both places.

4. Describe the process of bile emulsification of lipids and how it improves lipase activity. Your answer: Fat globules are separated into droplets by bile salts through an emulsification process which is physical not chemical, which promote lipase activity.



Exercise 9: Renal System Physiology: Activity 1: The Effect of Arteriole Radius on Glomerular Filtration Lab ReportPre-lab Quiz Results You scored 100% by answering 5 out of 5 questions correctly.

1. There are approximately __________ nephrons in a healthy human kidney. You correctly answered: c. 1 × 106

2. Which of the following lists the anatomical structures in the correct order as they are encountered by the blood and filtered fluid during the process of filtration? You correctly answered: d. afferent arteriole, glomerular capillary, Bowman's capsule

3. Bowman's capsule is connected to the beginning of the You correctly answered: b. proximal convoluted tubule.

4. The functional unit of the kidney is the You correctly answered: c. nephron.

5. During the process of renal reabsorption, fluid and solutes move from the You correctly answered: b. renal tubule into the peritubular capillaries.


1. If you increase the afferent arteriole radius and keep all other variables constant, the glomerular filtration rate would You correctly answered: a. increase.

2. If you decrease the efferent arteriole radius and keep all other variables constant, the volume of urine flowing into the urinary bladder would You correctly answered: a. increase.

3. If you increase the efferent arteriole radius and keep all other variables constant, the glomerular filtration rate would You correctly answered: b. decrease.

4. If you decrease the afferent arteriole radius and keep all other variables constant, the volume of urine flowing into the urinary bladder would __________. You correctly answered: b. decrease.

Review Sheet Results 1. What are two primary functions of the kidney? Your answer: The two primary functions of the kidney are excretion and regulation.

2. What are the components of the renal corpuscle? Your answer: The two components of the renal corpuscle are the Bowman’s capsule and the glomerular capillaries (glomerulus).

3. Starting with the renal corpuscle, list the components of the renal tubule as they are encountered by filtrate. Your answer: The filtrate flows from the Bowman's capsule into the renal tubule called the proximal convoluted tubule then into the loop of Henle

4. Describe the effect of decreasing the afferent arteriole radius on glomerular capillary pressure and filtration rate. How well did the results compare with your prediction? Your answer: The glomerular capillary pressure decreased and the filtration rate decreased. I was incorrect.

5. Describe the effect of increasing the afferent arteriole radius on glomerular capillary pressure and filtration rate. How well did the results compare with your prediction? Your answer: The glomerular capillary pressure increased and the filtration rate increased.



6. Describe the effect of decreasing the efferent arteriole radius on glomerular capillary pressure and filtration rate. How well did the results compare with your prediction? Your answer: The glomerular capillary pressure increased and the filtration rate increased.

7. Describe the effect of increasing the efferent radius on glomerular capillary pressure and filtration rate. Your answer: They both will decrease.



Exercise 9: Renal System Physiology:

Activity 2: The Effect of Pressure on Glomerular Filtration Lab ReportPre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly.

1. Which of the following forces promotes filtration? You correctly answered: c. blood pressure in the glomerular capillaries

2. The glomerular filtration rate can be altered by You correctly answered: b. changing the afferent arteriole resistance.

3. In 24 hours human glomerular capillaries can filter as much as __________ liters of filtrate. You correctly answered: c. 180

4. Which of the following statements about the filtrate in the renal corpuscle is false? You correctly answered: d. Normally, more than 40% of the blood that enters the glomerular capillaries becomes filtrate.


1. In humans, the glomerular filtration rate normally ranges from You correctly answered: b. 80 to 140 ml/min.

2. Which of the following does not have a significant impact on the glomerular filtration rate? You correctly answered: d. renal tubule length

3. In the absence of any regulatory mechanisms, what do you think would happen to the glomerular filtration rate of a person who experiences an increase in blood pressure? You correctly answered: a. The glomerular filtration rate could increase.

4. What would happen to the glomerular filtration rate of a person who experiences a large hemorrhage? You correctly answered: b. The glomerular filtration rate would decrease.

Review Sheet Results 1. As blood pressure increased, what happened to the glomerular capillary pressure and the glomerular filtration rate? How well did the results compare with your prediction? Your answer: As the systemic blood pressure increased, the glomerular capillary pressure and GFR increased.

2. Compare the urine volume in your baseline data with the urine volume as you increased the blood pressure. How did the urine volume change? Your answer: Urine volume was increased as systemic blood pressure increased.

3. How could the change in urine volume with the increase in blood pressure be viewed as being beneficial to the body? Your answer: Increased urine volume causes more filtrates such as salt to be excreted. This can affect any harming effects of accumulating excess fluid or waste. The increase of blood pressure can increase blood volume and the increase of urine volume will help to stabilize blood volume.

4. When the one-way valve between the collecting duct and the urinary bladder was closed, what happened to the filtrate pressure in Bowman's capsule (this is not directly measured in this experiment) and the glomerular filtration rate? How well did the results compare with your prediction? Your answer: The filtrate pressure and GFR increased.



5. How did increasing the blood pressure alter the results when the valve was closed? Your answer: Increase in blood pressure can be increase in blood volume. An increase in urine volume can stabilize blood volume. Increase of pressure caused GFR to increase.




Activity 3: Renal Response to Altered Blood Pressure Lab ReportPre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly.

1. If all other variables are kept constant, how does the afferent arteriole radius affect the rate of glomerular filtration (select all that apply)? You correctly answered: c. An increased afferent arteriole radius will increase the rate of glomerular filtration. d. A decreased afferent arteriole radius will decrease the rate of glomerular filtration.

2. If all other variables are kept constant, how does the efferent arteriole radius affect the rate of glomerular filtration (select all that apply)? You correctly answered: a. An increased efferent arteriole radius will decrease the rate of glomerular filtration. b. A decreased efferent arteriole radius will increase the rate of glomerular filtration.

3. If all other variables are kept constant, how does blood pressure affect the rate of glomerular filtration (select all that apply)? You correctly answered: b. If blood pressure goes up, the rate of glomerular filtration goes up. d. If blood pressure goes down, the rate of glomerular filtration goes down.

4. In the absence of other renal processes (including tubular reabsorption and secretion), more glomerular filtration leads to a larger urine volume. You correctly answered: a. true


1. If all other variables are kept constant, when blood pressure decreases, glomerular filtration You correctly answered: c. decreases.

2. If afferent arteriole radius decreases in response to an increase in blood pressure, then glomerular filtration You correctly answered: b. remains approximately the same.

3. If all other variables are kept constant, when the efferent arteriole radius decreases, glomerular filtration You correctly answered: a. increases.

4. With blood pressure held at a constant value, which of the following combinations will raise the glomerular filtration rate above baseline values? You correctly answered: b. afferent arteriole dilation and efferent arteriole constriction

Review Sheet Results 1. List the several mechanisms you have explored that change the glomerular filtration rate. How does each mechanism specifically alter the glomerular filtration rate? Your answer: Renal mechanisms have effects on water excretion. GFR is large compared to the amount of urine produced.

2. Describe and explain what happened to the glomerular capillary pressure and glomerular filtration rate when both arteriole radii changes were implemented simultaneously with the low blood pressure condition. How well did the results compare with your prediction? Your answer: When both arteriole radii changes were implemented, glomerular filtration rate and pressure rose above baseline values. I was incorrect.

3. How could you adjust the afferent or efferent radius to compensate for the effect of reduced blood pressure on the glomerular filtration rate? Your answer: Increase the afferent radius or decrease the efferent radius.



4. Which arteriole radius adjustment was more effective at compensating for the effect of low blood pressure on the glomerular filtration rate? Explain why you think this difference occurs. Your answer: There was a greater increase of glomerular pressure when afferent radius is increased rather than the decrease of the efferent radius.

5. In the body, how does a nephron maintain a near-constant glomerular filtration rate despite a constantly fluctuating blood pressure? Your answer: Nephrons maintain its filteration rate constant by secretion and reabsorption.




Activity 4: Solute Gradients and Their Impact on Urine Concentration Lab ReportPre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly.

1. As filtrate passes through the nephron, the renal process of reabsorption describes You correctly answered: d. the movement of water and solutes from the tubule lumen, into the interstitial space, and, finally, into the peritubular capillaries.

2. The maximum solute concentration refers to the amount of solutes You correctly answered: b. in the interstitial space.

3. Antidiuretic hormone (ADH) affects the permeability of You correctly answered: c. the collecting duct.

4. ADH aids the reabsorption of You correctly answered: a. water.


1. Tubule fluid osmolarity will always be the greatest in which of these locations? You correctly answered: b. the bottom of the loop of Henle

2. Tubule fluid volume will always be the greatest in which of these locations? You correctly answered: a. the proximal convoluted tubule

3. Where does ADH directly alter the urine volume? Your answer: c. in the loop of Henle Correct answer: d. in the collecting duct

Review Sheet Results 1. What happened to the urine concentration as the solute concentration in the interstitial space was increased? How well did the results compare to your prediction? Your answer: Concentration of urine was increased. I was correct.

2. What happened to the volume of urine as the solute concentration in the interstitial space was increased? How well did the results compare to your prediction? Your answer: The volume of urine decreased. I was correct.

3. What do you think would happen to urine volume if you did not add ADH to the collecting duct? Your answer: Without adding ADH to the collecting duct, urine volume would increase highly and no significant amount of water permeability would be in collecting duct or distal tubule. Less water is reabsorbed, so more urine is formed.

4. Is most of the tubule filtrate reabsorbed into the body or excreted in urine? Explain. Your answer: To maintain homeostasis balance and loss of fluid, most tubule filtrate is reabsorbed into the blood stream.

5. Can the reabsorption of solutes influence water reabsorption from the tubule fluid? Explain. Your answer: Yes. The movement of solutes into peritubular capillaries decreases the solute concentration of the tubular fluid, but increases the solute concentration in the peritubular capillaries. As a result, water moves by osmosis into peritubular capillaries.




Activity 5: Reabsorption of Glucose via Carrier Proteins Lab ReportPre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly.

1. Renal processing of plasma glucose does not normally include You correctly answered: b. secretion.

2. How does antidiuretic hormone (ADH) affect the renal processing of plasma glucose? You correctly answered: c. ADH has no direct effects on renal processing of plasma glucose.

3. Glucose reabsorption in the nephron includes You correctly answered: d. secondary active transport along the apical membrane of proximal tubule cells.

4. Because carrier proteins are required to move glucose from the lumen of the nephron into the interstitial spaces, which of the following statements is false? You correctly answered: d. The number of glucose carriers in a nephron can be altered as needed by the body.


1. Glucose carrier proteins are located in which region of the nephron? You correctly answered: b. the proximal convoluted tubule

2. If the concentration of glucose in the filtrate exceeds the transport capacity of the carrier proteins, then You correctly answered: d. a transport maximum has been reached.

3. Why does glucose appear in the urine of untreated diabetic patients? You correctly answered: c. An excessive amount of glucose is present in their filtrate.

Review Sheet Results 1. What happens to the concentration of glucose in the urinary bladder as the number of glucose carriers increases? Your answer: There is a decrease in the glucose concentration. The carriers are able to carry glucose across the walls of the glomerulus for the reabsorption.

2. What types of transport are utilized during glucose reabsorption and where do they occur? Your answer: The first absorption is by active transport. This occurs at the apical membrane of PCT cells. Then a facilitated diffusion along the basolateral membrane.

3. Why does the glucose concentration in the urinary bladder become zero in these experiments? Your answer: The concentration of glucose becomes zero because when 400 glucose carriers were added, enough were added to facilitate the re-up of glucose. This left nothing in the unabsorbed water and became urine.

4. A person with type I diabetes cannot make insulin in the pancreas, and a person with untreated type II diabetes does not respond to the insulin that is made in the pancreas. In either case, why would you expect to find glucose in the person's urine? Your answer: There is a high glucose concentration in the urine of a diabetic. With the lack of glucose carriers, a less amount of glucose is transported. A high amount of the glucose cannot be transported across and leaves a high concentration to be discarded with the formation of urine.




Activity 6: The Effect of Hormones on Urine Formation Lab ReportPre-lab Quiz Results You scored 100% by answering 5 out of 5 questions correctly.

1. Which of the following has a role in altering the urine volume and concentration? You correctly answered: d. all of these

2. The total solute concentration surrounding the tubule lumen refers to the solutes in You correctly answered: b. the interstitial space.

3. Aldosterone is produced in the You correctly answered: c. adrenal cortex.

4. ADH promotes the renal reabsorption of You correctly answered: a. water.

5. Aldosterone promotes renal reabsorption of __________ and secretion of __________. You correctly answered: c. NaCl, potassium


1. If there has been a significant loss of fluid from the body, the kidneys will generate __________ urine. You correctly answered: d. hyperosmotic

2. If you drink a large volume of water, the kidneys will generate __________ urine. You correctly answered: b. hypo-osmotic

3. In response to dehydration, ADH will be released from the You correctly answered: c. posterior pituitary gland.

4. In response to abnormally low plasma osmolality, aldosterone will increase You correctly answered: a. sodium reabsorption along the distal tubule and the collecting duct.

Review Sheet Results 1. How did the addition of aldosterone affect urine volume (compared with baseline)? Can the reabsorption of solutes influence water reabsorption in the nephron? Explain. How well did the results compare with your prediction? Your answer: It increased the concentraion. The reabsorption of solutes does influence water reabsorption in the nephron.The movement of solutes into peritubular capillaries decreases the solute concentration of the tubular fluid but increases the solute concentration in the peritubular capillaries. As a result, water moves by osmosis into peritubular capillaries.

2. How did the addition of ADH affect urine volume (compared with baseline)? How well did the results compare with your prediction? Why did the addition of ADH also affect the concentration of potassium in urine (compared with baseline)? Your answer: Adding ADH increases urine and potassium concentration, and decreases urine volume. This causes water to be absorbed from the urine back into the body. The potassium concentration is 10 times the amount without ADH, and urine volume is 1/10 without ADH.

3. What is the principal determinant for the release of aldosterone from the adrenal cortex? Your answer: Aldosterone is stimulated by production of angiotensin II. The renin-angiotensin system in which the body controls this.

4. How did the addition of both aldosterone and ADH affect urine volume (compared with baseline)? How well did the results compare with your prediction? Your answer: Adding both



aldosterone and ADH decreases urine volume. When both were absent the volume was 201.00 and decreased when both were present to 12.67

5. What is the principal determinant for the release of ADH from the posterior pituitary gland? Does ADH favor the formation of dilute or concentrated urine? Explain why. Your answer: Water is reabsorbed back into the blood and raises blood pressure. ADH favors the formation of concentrated urine. ADH is to increase the permeability of the collection ducts, so more water is reabsorbed by the body. ADH is influenced by volume, pressure of cardiovascular system, and osmolality of fluids.

6. Which hormone (aldosterone or ADH) has the greater effect on urine volume? Why? Your answer: ADH causes decreases in the amount. ADH increases water permeability of the distal tubule, and collecting duct. This means more water can be reabsorbed making urine volume less and keep water balance. Aldosterone only decreases urine volume a small amount.

7. If ADH is not available, can the urine concentration still vary? Explain your answer. Your answer: If ADH is not available, then the body will make huge amounts of very dilute urine. The primary action of ADH is to increase permeability of the collecting duct to water so that more water is reabsorbed into the body by inserting aquaporins, or waterchannels, in the apical membrane. Without this water reabsorption, the body would quickly dehydrate. Diabetes Insipidus is the name of the disease that results from damage that disrupts the normal production, storage and release of ADH. Diabetes insipidus is a condition in which the kidneys are unable to conserve water.

8. Consider this situation: you want to reabsorb sodium ions but you do not want to increase the volume of the blood by reabsorbing large amounts of water from the filtrate. Assuming that aldosterone and ADH are both present, how would you adjust the hormones to accomplish the task? Your answer: I would increase aldosterone and decrease ADH.


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