Exam 2 2010

Front 1

1. Insulin is made from a prohormone. State one of the things that are done to make insulin from this prohormone.

Back 1

A peptide fragment is removed from between the 2 that are part of insulin and these are linked by 2 disulfide bonds

Hint 1

Proprotein convertase 1 = enzyme responsible for the first step in the biosynthesis of insulin. A carboxypeptidase is required to remove the basic residues from the processing intermediate and generate the bioactive form of insulin.

Front 2

2. The long term health of a person with type 1 diabetes is best if the right amount of insulin is given, keeping the person's blood sugar just above the level that would result in coma. What would happen if less than that amount of insulin were injected one time?

Back 2

the blood glucose would not be quite as low, that's all

Hint 2

insulin allows body to use sugar and keeps your blood sugar level from getting too high or low.

Front 3

3. Answer either (1) for gluconeogenesis, where did the glucose come from? Or (2) for ketogenesis, where did the ketone bodies come from?

Back 3

1 from amino acids, 2 from triglycerides

Hint 3

gluconeogeneisis=metabolic pathway that makes glucose from noncarb substrates (amino acids)ketogenisis=ketone bodies produced from fatty acid breakdown

Front 4

4. Suppose there were a new substance, a potential drug or poison, that depolarized all the beta cells in your islets of Langerhans. What do you expect would happen if you tested this substance on an animal?

Back 4

more insulin release, lower blood glucose, maybe coma

Hint 4

islets of Langerhans are the endocrine glands in the pancreas where the beta cells make insulin.too much insulin=not enough sugar=not enough energy=coma

Front 5

5. For the atrial beat, answer either (1) Why does it contribute only minimally to ventricular filling? Or (2) What would keep the blood from flowing backward into the veins coming into the atria?

Back 5

1 blood goes from atria to ventricles even before the beat, 2 nothing except those valves that are in veins

Hint 5

atrial beat = in atrium

valves open and close in a way that prevents reverse flow.

Front 6

6. The first few moments of ventricular contraction fail to move blood into the arteries. Why?

Back 6

isovolumetric contraction is because semilunars remain closed until ventricular pressure is higher than afterial pressure

Hint 6

movement of blood depends on pressure

Front 7

7. You feel chest pain so you take nitroglycerine. How did this save you from a heart attack?

Back 7

relaxation of smooth muscle in coronary arteries would alleviate the block (that likely resulted from a thrombus or an embolism in an artery already partially occluded from atherosclerosis)

Hint 7

if youre gonna have a heart attack, relax!

nitroglycerin has been used medically as a potent vasodilator to treat heart conditions

Front 8

8. Why do the textbook artists color the pulmonary arteries blue?

Back 8

they carry blood low in oxygen and high in carbon dioxide

Hint 8

oxygenated blood is red.

Front 9

9. Why can you hear the brachial artery below the blood pressure cuff when the cuff pressure is between the systolic and diastolic levels?

Back 9

Korotkoff sounds are when blood flow is turbulent from partly closed artery

Hint 9

anything with sound = korotkoff

Front 10

10. In the atria, all that was needed to propagate the electrical signal was the connections from one myocardial cell to the next. For the ventricles, why was it important to have the added feature for propagation (bundle of His and bundle branches)?

Back 10

to start the contraction at the "apex" (bottom), to send the action potential quickly

Hint 10

The bundle of His is a collection of heart muscle cells specialized for electrical conduction that transmits the electrical impulses from the AV node (located between the atria and the ventricles) to the point of the apex of the fascicular branches via the bundle branches.

Front 11

11. Three "leads" describe 3 different ways both wrists might be fed in for measuring the ECG. Why might different people have differences in how the ECG looks with the 3 leads?

Back 11

orientation of heart (axis) can differ, abnormalities like murmurs might create an asymetry in heart muscle

Hint 11

different people=different hears duh

Front 12

12. What would the sympathetic nervous system do to the shape of a myocardial cell's action potential?

Back 12

shorten that prolonged spike

Hint 12

sns= fight or flight

Front 13

13. A person drops over and has no pulse. To keep him or her alive until medical equipment and personnel arrive, (answer either) (1) What is the name of the procedure you would perform? Or (2) How would this keep the victim alive?

Back 13

CPR, it keeps the brain alive

Front 14

14. "Re-entry of excitation:" After recovering from a heart attack, why might some myocardial cells be excitable (no longer refractory), and be triggered to fire, before the appropriate time (that appropriate time being the time synchronized from the SA and AV nodes)?

Back 14

a pathway of myocardial cells around the scar might be long

Hint 14

myocardial = pertaining to the muscular tissue of the heart

A heart attack happens when the flow of oxygen-rich blood to a section of heart muscle suddenly becomes blocked and the heart can't get oxygen. If blood flow isn't restored quickly, the section of heart muscle begins to die.

Front 15

15. Why was a reminder of the process of receptor-mediated endocytosis by clathrin-coated pits relevant in the context of heart attacks?

Back 15

LDL is removed by that process

Hint 15

Clathrin-coated pits form vessicles that remove LDL

Low-density lipoproteins contain a large amount of cholesterol and their principal role is to deliver two forms of cholesterol to peripheral tissues.

Front 16

16. Why is asbestos more of a problem for smokers?

Back 16

their cilia are paralyzed and cannot remove asbestos by the mucus elevator

Front 17

17. Pick one: (1) A drug that specifically affects beta-2 adrenergic receptors (terbutaline), or (2) a drug that blocks leukotriene action (Singulair). What is the specific action that would help in asthma?

Back 17

1 open airways by mimicing adrenalin or the sympathetic nervous system, 2 decrease inflammation

Hint 17

ADRB2, is a cell membrane-spanning beta-adrenergic receptor that binds with epinephrine (adrenaline) and mediates physiologic responses such as smooth muscle relaxation and bronchodilation.

Front 18

18. The partial pressure for oxygen in the atmosphere is atmospheric pressure times the fraction of the atmosphere that is oxygen. What are the major reasons that the partial pressure for oxygen in the alveoli is much lower?

Back 18

there are higher proportions of water vapor and carbon dioxide

Hint 18

air enters lungs, it is humidified by upper airway and partial pressure of water vapor reduces partial pressure of oxygen

continual diffusion of CO2 out of cappilaries and into alveoli

Front 19

19. You have a subject and a spirometer. What value, a portion of total lung capacity, cannot be obtained?

Back 19

residual volume

Hint 19

Residual volume (RV) is a lung volume representing the amount of air left in the lungs after a forced exhalation; this volume cannot be measured, only calculated.

Front 20

20. Give either the approximate number or the value relative to atmospheric pressure of the intrapleural during inhalation.

Back 20

book says 754 mm Hg, the point is that it is slightly less than lungs which are slightly less than atmospheric

Hint 20

the pressure within the pleural cavity is slightly less than the atmospheric pressure

Front 21

21. Why does a premature baby have trouble breathing?

Back 21

type 2 alveolar cells mature late and without surfactant, water pressure impedes alveolar opening

Hint 21

babies can't breathe while floating in baby fluid.

Front 22

22. Where, other than the medulla oblongata, are chemoreceptors located that feed by nerves to the respiratory control centers?

Back 22

aortic and carotid bodies

Hint 22

The carotid body detects changes in the partial pressure of oxygen and carbon dioxide.

aortic bodies are chemoreceptors which regulate Circulatory system

Front 23

23. Relative to curve where % oxygen saturation is plotted as a function of partial pressure for oxygen for adult hemoglobin, how would you place the curve for fetal hemoglobin?

Back 23

fetal oxyhemoglobin dissociation curve is to the left of the adult

Front 24

24. Why does chloride come out of red blood cells in the lungs?

Back 24

so bicarbonate can come in for the generation of carbon dioxide to be exhaled

Hint 24

inhale oxygen, exhale carbon dioxide

Front 25

25. Why is it advantageous for some animals to use uric acid rather than urea in their excretory systems?

Back 25

less water is lost

Hint 25

urea=waste product (also in sweat

uric acid=final product in urine metabolism

Front 26

26. "Upwelling of nutrients off the coast of Peru." Answer either (1) What ocean current helps with this? Or (2) What is the climate abnormality that disrupts current and upwelling?

Back 26

Humboldt current, El Nino

Front 27

27. Non-steroidal anti-inflammatory drugs (NSAIDS) inhibit the formation of what mediator of inflammation?

Back 27

prostaglandins

Hint 27

Prostaglandins have two derivatives:

1. powerful locally acting vasodilators, inhibit the aggregation of blood platelets and prevent needless clot formation

2. vasoconstrictors, facilitate platelet aggregation, and play role in clot formation

Front 28

28. Peritubular capillaries (the vasa recta) form part of the kidney's portal system. Where is the other capillary bed?

Back 28

the glomerulus

Hint 28

A glomerulus is a network of capillaries located at the beginning of a nephron in the kidney. It serves as the first stage in the filtering process of the blood carried out by the nephron in its formation of urine.

Front 29

29. A basement lamina separates two components of the glomerular sieve. Name one of these two cellular components.

Back 29

podocyte's foot processes and fenestrated capillary

Hint 29

The side of the basement membrane that faces outwards from the capillary is lined with folds called podocytes.

Capillaries of the glomerulus are lined by endothelial cells. These contain numerous pores (called fenestrae)

Front 30

30. Facilitated diffusion for glucose takes place on the basolateral surface of a proximal tubule cell. For EITHER of the other two essential components of glucose transport in this cell type, give BOTH the membrane transporter PLUS the location of the membrane.

Back 30

cotransport-apical, sodium pump-basolateral

Front 31

31. What function does it serve to have salt but not water transport in the ascending limb from the loop of Henle?

Back 31

to increase the osmolarity of the interstitial fluid

Hint 31

loop of Henle creates an area of high urea concentration deep in the medulla, reabsorbs water and creates a concentrated urine for excretion

Front 32

32. Elimination of what hormone from your body would make you crave salt?

Back 32

aldosterone

Hint 32

Aldosterone is a steroid hormon and increases reabsorption of ions and water in the kidney, causes the conservation of sodium.

Front 33

33. ACE=angiotensin converting enzyme: Answer EITHER (1) What hormone from the kidney activates ACE? Or (2) For what disorder might you want to inhibit ACE?

Back 33

renin, hypertension

Hint 33

"ACE" indirectly increases blood pressure by causing blood vessels to constrict. ACE inhibitors lower blood pressure.

renin–angiotensin system (RAS) or the renin–angiotensin–aldosterone system (RAAS) is a hormone system that regulates blood pressure and fluid balance

Front 34

34. What, if any, type of polymer would be broken into monomers if given enough time in the presence of salivary amylase?

Back 34

starch

Hint 34

Amlyase is an enzyme that breaks down starch to sugar.

Front 35

35. Chief cells: answer EITHER (1) What is the name of the zymogen (precursor) in the granules of these cells. (2) Acid secreted (from what cell?) helps to form the active enzyme from the precursor?

Back 35

pepsinogen, parietal

Front 36

36. A SEVERE stomach disorder was once attributed to excess stomach acid. A further elucidation of this disorder was worthy of the 2005 Nobel prize in medicine (awarded to Marshall and Warren). Answer either (1) What disorder? Or (2) What was the cause of the disorder they discovered?

Back 36

ulcer, bacterium (Helicobacter pylori)

Front 37

37. Enzyme activity as a function of pH: describe the graphs for pepsin vs. salivary amylase.

Back 37

peaks are at 2 and 7 respectively

Front 38

38. Say something about how or where trypsin is activated.

Back 38

trypsin is activated in the intestinal lumen by chopping a fragment from the zymogen under the influence of enderokinase on the brush border (or by trypsin that has already been activated)

Front 39

39. In reference to lipase in the intestinal lumen, tell me either (1) What is the source of lipase? Or (2) What are the products when it acts on a triglyceride?

Back 39

pancreas, monoglyceride plus two fatty acids

Hint 39

Hydrolysis of triglyceride into monoglyceride and free fatty acids is accomplished predominantly by pancreatic lipase.

Front 40

40. Why is the function of the hepatic portal vein so important?

Back 40

It delivers materials absorbed from the intestines to the liver for detoxification

Hint 40

The hepatic portal vein is a blood vessel that conducts blood from the gastrointestinal tract and spleen to the liver,

Front 41

41. Amino acids stimulate G cells to release gastrin. State one of the secretions that result from this.

Back 41

One cell (ECL cell) puts out histamine causing parietal cell to put out HCl

Front 42

42. Using the correct terminology about the drug's affect on appetite (hunger), tell me about amphetamine.

Back 42

it is anorexogenid (it causes anorexia)

Front 43

43. In its effects in the mammary gland and uterus, what kind of cell is affected by oxytocin?

Back 43

smooth muscle

Hint 43

"love hormone" = indispensable for healthy muscle maintenance

might help fight the effects of aging on our muscles

Front 44

44. If a body builder abuses growth hormone, what is likely to happen to his or her bones?

Back 44

they will grow in thickness

Hint 44

growth hormone causes growth, duh

Front 45

45. What is a general term that takes into account the trophic influence for both males and females of FSH, LH, ICSH and HCG?

Back 45

gonadotropin

Hint 45

family of mammalian hormones, central to the complex endocrine system that regulates normal growth, sexual development, and reproductive function

Front 46

46. What happens if there is too little thyroid hormone during an infant's development?

Back 46

brain development is compromised (cretinism)

Front 47

47. "The follicle includes a 'rind' of cells and the egg enclosed in this rind." What does this rind do?

Back 47

secretes estrogen

Front 48

48. "There is a surge of LH." Answer one (1) Where did this LH come from? (2) What kind of molecule is that LH? Or (3) Name one of the effects that has on the ovary.

Back 48

pituitary, peptide, convert flooicle to corpus luteum, cause ovulation

Hint 48

Luteinizing hormone is a hormone produced by gonadotropic cells in the anterior pituitary gland. In females, triggers ovulation and development of the corpus luteum.

corpus luteum=a hormone-secreting structure that develops in an ovary after an ovum has been discharged but degenerates after a few days unless pregnancy has begun.

Front 49

49. Would the endometrium build up and break down in women who are taking the pill? (Include in your answer why or why not.)

Back 49

yes, steroids would cause build up and duds (without steroids) would allow break down

Hint 49

endometrium is the mucous membrane that lines the inside of the uterus (womb)

aka periods.

Front 50

50. What happens to the corpus luteum after implantation?

Back 50

It is maintained and continues to secrete progesterone under the influence of HCG

Hint 50

corpeus luteum=a hormone-secreting structure that develops in an ovary after an ovum has been discharged but degenerates after a few days unless pregnancy has begun.

PREGNANCY