Problem_Set3 - Name ID GSI Iswar Hariharan’s portion(90...

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Name: ID: GSI: _________________________ Iswar Hariharan’s portion (90 points total) (allow approximately 90 minutes) Question 1 (12 points) In each of the cases indicate whether the concentration of the molecule indicated is higher, lower or the same as that found in plasma under normal conditions (1 point each) a) The concentration of K+ in saliva b) The concentration of H+ in gastric secretions c) The concentration of H+ in interstitial fluid on the basal side of a gastric parietal cell d) The concentration of H+ in the interstitial fluid on the basal side of a pancreatic duct cell e) The concentration of glucose in the plasma of a person in the early stages of type II diabetes f) The concentration of insulin in the plasma in a person in the early stages of type II diabetes g) The concentration of H+ in urine in a person on a typical American diet h) The concentration of HCO3- in urine in a person on a typical American diet i) The plasma concentration of HCO3- in a patient with respiratory acidosis following renal compensation. j) The PCO2 in a patient with metabolic acidosis following respiratory compensation k) The plasma Na+ concentration in a patient with diabetes insipidus l) The plasma Na+ concentration in a patient with aldosterone deficiency 2 Name: ID: GSI: _________________________ Question 2 Secretion and digestion in the GI tract (10 points) (2 points) In the vesicle prepared from gastric mucosa draw a schematic of the proton pump indicate the directions of transport of H+ and K+. (2 points) Two other compounds needed to be added to the vesicles for optimal function of the pump. What were they? (2 point) Why was each of those two compounds necessary? (Write one sentence for each) A friend tells you that the anti-histamine drugs used to treat allergies can also reduce acid production by the stomach very effectively. (1 point) Is this statement true or false? (1 points) Do gastric parietal cells express receptors for histamine? (2 points) Explain why is the statement true or false? 3 Name: ID: GSI: _________________________ Question 3: Digestion and absorption: (11 points) (3 points) In the intestinal epithelial cells, explain why ATP hydrolysis is necessary for the absorption of glucose and many amino acids (4 points) Draw a cartoon of the intestinal epithelium cell. Draw the mechanism by which free fatty acids are absorbed by the body. Make sure you include information on how they enter the circulation. (4 points) Are the following statements True or False? The enzymes that break down triglycerides into fatty acids in the lumen of the intestine can act on the triglycerides because they themselves are fat soluble Vitamin B12 is secreted by the epithelial cells of the stomach Secretin acts primarily on the pancreatic acinar cells Cholecystokinin (CCK) regulates contraction of the gall bladder 4 Name: ID: GSI: _________________________ Question 4 Glomerular filtration and tubular re-absorption (10 points) Circle the correct answer (only one is correct in each case) a) (1 point) The amount of filtered fluid re-absorbed by the kidneys each day is closest to: 1.8 liters 18 liters 180 liters b) (1 point) The percent of filtered glucose that is reabsorbed by the kidneys in a non-diabetic individual is closest to: 95% 99% 100% c) (1 point) In the complete absence of aldosterone, what percentage of filtered Na+ is excreted? 2% 0.2% 0.02% A patient has a kidney removed surgically. Blood samples are taken immediately before the operation, immediately after the operation and 2 months after the operation. The creatinine concentration immediately before surgery was 0.8 mg/100 ml. d) (1 point) What would you expect the creatinine concentration to be immediately after the operation? e) (1 point) What would you expect the creatinine concentration to be two months after the operation? f) (1 point) How would the loss of one kidney affect the re-absorption of filtered glucose? g) A person is making concentrated urine. In the diagram of the nephron shown below, write the approximate osmolarity of the fluid in the nephron at the four locations shown (4 points): 5 Name: ID: GSI: _________________________ Question 5 Regulation of fluid and electrolytes (11 points) Aldosterone and vasopressin a) (1 point) What issue makes vasopressin (ADH) b) (1 point) Which cells in the nephron are especially sensitive to vasopressin? c) (1 point) What is the protein in those cells whose localization is altered by vasopressin? d) (1 points) How does this change in localization change the properties of the epithelium? e) (1 point) What would happen to plasma Na+ levels if these cells are unresponsive to vasopressin? f) (2 points) In addition to the juxtamedullary nephrons, there are cortical nephrons that do not have loops of Henle that run deep into the renal medulla. Yet the urine produced from these nephrons can also be concentrated. Why? g) (1 point) What is the main protein whose levels change in distal tubular cells that are exposed to higher levels of aldosterone? h) (1 point) What would the effect of constricting the renal artery be on glomerular filtration rate (GFR)? i) (2 points) Constriction of the efferent arteriole has a more complicated effect on GFR. In what way does GFR change with increased constriction of the efferent arteriole? 6 Name: ID: GSI: _________________________ Question 6: Acid-base regulation and metabolism (13 points) a) (1 point) What is the main buffer system within cells? b) (1 point) The ratio of H+ to HCO3- in plasma is closest to (circle the correct answer): 1:102 1:104 1:106 c) (5 points) Draw a cartoon to show how the cells of the renal tubules (not collecting ducts) recover filtered HCO3- d) (2 points) In a patient with respiratory alkalosis with renal compensation, what happens to the concentration of HCO3- in the urine? How does this change occur (i.e. in the renal tubules)? e) (2 points) What is the Warburg effect? f) (2 points) What are the two main tissues that use GLUT4 to take in increased levels of glucose when insulin is present? 7 Name: ID: GSI: _________________________ Question 7 – Distribution of nutrients (11 points) (4 points) The brain primarily uses glucose as an energy source. Explain why the brain can absorb glucose, but not fatty acids, from the circulation. (3 points) How does an increase in ATP levels in the beta cells of the pancreatic islets promote insulin secretion? (2 points) During starvation, glucose levels in the blood are replenished by gluconeogenesis occurring mostly in the liver and kidney. Explain why the skeletal muscle is not an important source of glucose during starvation. (2 points) In patients with Type 2 diabetes, gluconeogenesis is increased. What is the main mechanism by which this happens? 8 Name: ID: GSI: _________________________ Question 8 Energy homeostasis, thermogenesis and endocrinology (12 points) Are the following statements true or false? (1 point each) a) Mice homozygous for mutations in the diabetic (db/db) gene have elevated leptin levels b) Leptin is a steroid hormone. c) Most humans with obesity have reduced levels of leptin d) Leptin can cross the blood-brain barrier e) Ghrelin levels increase during starvation f) Some cases of malignant hyperthermia are caused by mutations in the ryanodine receptor (RYR1) (2 points) In lecture, we discussed a group of people in Ecuador that had mutations in the growth hormone receptor (GhR). What two diseases were extremely rate in this group of people? (4 points) How do the location and biochemical activity of receptors for peptide hormones differ from those of steroid hormones 9...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern