bio test 3

Neuroendocrine signaling is an important part of digestion. Which neuroendocrine in the small intestine cell responds to sugar and what is the name of the hormone it releases?

K-cell; gastric inhibitory peptide

Next, what is the master enzyme that controls protein breakdown in the small intestine, and where does this enzyme come from? Also, what is the endocrine trigger that causes the release of this enzyme and where does this endocrine signal come from?

MASTER ENZYME: trypsin ENZYME SOURCE: pancreas ENZYME TRIGGER: CCK TRIGGER SOURCE: I-cells

A patient complains of severe food poisoning and states that he has vomited over a dozen times in the last 12 hours. In addition to dehydration, you suspect he is suffering from a metabolic pH imbalance since vomiting depletes the body of hydrochloric acid. Which of the following most correctly describes this patient's current condition?

Metabolic alkalosis

the formation of HCl in the stomach involves the

active transport of hydrogen ions from parietal cells into the lumen of the stomach in exchange for K+

when protein is broken down the end result is

amino acid

micelles

are small droplets of lipids surrounded by bile salts

Furosemide is a drug that inhibits NKCC2 symporter. what is the most likely site of action?

ascending loop of henle

SLC4A4 is a Na+/HCO3- symporter located on the basolateral surface of PCT epithelial cells. This co-transporter is driven by the HCO3- gradient and helps maintain a low intracellular concentration of Na+. Which statement below most directly accounts for the HCO3- gradient observed across the cell?

Apical sodium-H+ antiporter

Creatinine is used by physicians to evaluate GFR because it is freely filtered, not reabsorbed, and not secreted. Assuming penicillin is also freely filtered, predict the clearance of penicillin compared creatinine.

Higher

The use of bumetanide increases water reabsorption by reducing the salt gradient T/F

false

Water permeability is higher in the ascending loop than in the descending loop T/F

false its higher in the descending loop

67% of water reabsorption takes place in the loop of Henle in juxtamedullary nephrons T/F

false that takes place in the proximal convoluted tubule

which of the following would be the most important for the digestion of fat

gallbladder and bile

Which of the following would inhibit both gastric secretion and gastric motility?

gastric inhibitory peptide (GIP)

_______ stimulates ECL cells to secrete histamine which stimulates HCl release from parietal cells.

gastrin

which of these hormones stimulates stomach secretions?

gastrin

The duodenum

has an increased surface area due to circular folds and villi

the pancreas

has both endocrine and exocrine tissues releases hormones to regulate blood sugar levels releases enzymatic secretions to assist in chemical breakdown of food

which of these lipoprotein molecules transports excess lipids from cells back to the liver?

high-density lipoprotein (HDL)

which of the following is primarily responsible for stomach emptying?

hormones released by the duodenum

match the secretion with the correct cell type

hydrochloric acid= parietal cells bile = hepatocyte gastrin = endocrine cells mucus = goblet cells

spironolactone is an aldosterone inhibitor that is prescribed in low doses for people with advanced systolic heart failure. Patients taking this drug must be regularly checked for which of the following conditions?

hyperkalemia

The primary function of the large intestine is

i dont know

A patient complains of severe food poisoning and states that he has vomited over a dozen times in the last 12 hours. In addition to dehydration, you suspect he is suffering from a metabolic pH imbalance since vomiting depletes the body of hydrochloric acid. To corroborate your diagnosis (from the previous question), you measure the following: plasma HCO3- levels, blood pH, ventilation rate, and pCO2. Accordingly, HCO3- levels are predicted to be...

increased

Emulsification

increases surface area for lipid digestion.

functions of CCK cholecystokinin

inhibits gastric secretions decreases gastric motility increases contraction of the gallbladder

lipid digestion and absorption requires the coordinated actions of

lipase and bile

The organ that stores excess glucose and releases it later into the blood is the

liver

Which layer of the digestive tract is in direct contract with the food that is consumed?

mucosa

Which of the following GI tract layers is correctly matched?

muscularis - responsible for peristalsis

The portion of the digestive tract in which digestion begins is the

oral cavity

which cell type produced and secreted hydrochloric acid?

parietal cells

which cell type produces and secretes intrinsic factor

parietal cells

what enzyme functions at the lowest pH

pepsin

which of the following events occurs because of the low pH of the stomach

pepsin can become activated

It is a proven fact that french fries taste better when dipped in a soft ice cream frosty. Which statement best describes the relationship between sugar and salt in the small intestine?

salt is required for sugar absorption

when chyme enters the duodenum _____ is released and stimulates the pancreas to secrete bicarbonates

secretin

once activated, S-cells secrete the hormone

secretin which promotes HCO3- secretion from the pancreas

functions of the digestive system

secretion absorption pH regulation chemical breakdown

In the duodenum

secretion of hormones occurs chemical digestion continues absorption begins

Most of the water absorbed in the digestive tract occurs

small intestine

amino acids, monosaccharides, and fatty acids are absorbed in the

small intestine

enzymes for the digestion of disaccharides are produced in the

small intestine

why are several digestive enzymes secreted as zymogens?

so they act in the lume and do not digest the tissues that secrete them

SGLT, a transport pump of the small intestine, can only absorb by simultaneously transporting

sodium

Which statement best describes carbohydrate digestion?

starts in the mouth; stops in the stomach; continues in the small intestine

The chemical digestive process of proteins begins in the

stomach

which of the following provide enzymes that aid in the digestion of protein?

stomach duodenum pancreas

which of these cell types is correctly matched with their function

surface mucous cells-produce mucus parietal cells- produce hydrochloric acid endocrine cells- produce regulatory hormones

what is the primary difference between cortical nephrons and juxtamedullary nephrons?

the filtrate osmolarity at the base of the loop of henle is much higher in juxtamedullary nephrons

bile is stored and released from

the gallbladder

bile is produced by

the liver

High concentrations of urea in the collecting duct will increase water reabsorption in the loop of Henle T/F

true

Mastication is the process of breaking down food into smaller particles

true

Salt concentrations within the medulla can reach up to 1200mOsm T/F

true

The concentration gradient achieved by the NKCC2 channel typically cannot exceed 200mOsm T/F

true

The use of bumetanide can cause hypokalemia T/F

true

Urea contributes to the medullary osmotic gradient T/F

true

bile breaks down fats

true

the gastric phase of stomach secretion begins with the presence of food in the stomach

true

pancreatic juice is composed of

trypsinogen chymotrypsinogen deoxyribonuclease sodium bicarbonate

Pepsin would have the greatest activity

when the pH of the chyme is less than 3.

Arrange the following in proper sequence:(1) digestion(2) elimination(3) ingestion(4) absorption

3, 1, 4, 2

Which of the following statements correctly describes glomerular filtration rate?

-filtration is based on the size, charge, and pressure -smooth muscle contraction (juxtaglomerular cells) around efferent arterioles will lead to increased GFR -macular densa cells in the distal convoluted tubule regulate juxtaglomerular cell contraction

which of the following affect GFR?

-glomerular hydrostatic pressure -plasma colloid osmotic pressure -hydrostatic pressure within Bowmans capsule

pernicious anemia develops if there is

-vitamin B12 deficiency -intrinsic factor

arrange the following events in the correct order

1. emulsification 2.micelle formation 3.digestion of lipids by the pancreatic lipases 4. absorption of lipids

Creatinine is used as a baseline measurement for GFR because it is freely filtered, not reabsorbed, and not actively secreted. In 5 words or less, describe why glucose turns from a flat line to parallel creatinine clearance?

100% reabsorbed until it reaches threshold

The proximal convoluted tubule is the major site of reabsorption in the nephron. The following lists molecules that are reabsorbed by the PCT under normal, healthy conditions. For which of these is the PCT the major site of reabsorption?

-Bicarb ion (HCO3-) -Amino acids -Glucose -Na+ -K+ -water

Regarding digestion of carbohydrates in general, which statements below are true?

-Both chemical and mechanical digestion of carbohydrates begins in the mouth

Which of the following are targets of CCK?

-Brain -pyloric sphincter -gallbladder -pancreas

Filtration describes the movement of fluid from capillaries of the glomerulus into Bowman's Capsule. Which of the following significantly contribute to filtration and GFR (glomerular filtration rate)?

-Capillary hydrostatic pressure -Bowman's capsule hydrostatic pressure -Blood colloid osmotic pressure -Bowman's capsule (interstitial) colloid osmotic pressure -Albumin -Afferent arteriole diameter -Efferent arteriole diameter

Daily protein concentrations in the urine greater than 300mg can be a sign of preeclampsia in a pregnant woman. Preeclampsia is characterized by high blood pressure and is often associated with kidney damage. How would high blood pressure affect the following kidney functions?

-GFR would increase -renin release would decrease

In response to glucose, which statement are true regarding the function of the pancreas?

-GIP from cells in the small intestine causes the release of insulin -GIP from the intestine causes the release of amylase -glucose entering the blood causes the release of insulin

Regarding digestion of carbohydrates in general, which statements below are true?

-Glucose absorption is indirectly dependent on the Na+/K+ ATPase -Enterocytes typically express Glut2 on their basolateral surface, which allows for the transport of glucose, fructose, and galactose into the blood by facilitated diffusion

Your next patient is a life-long coal miner who suffers from chronic emphysema. However, it appears that the patient has not been following the prescribed treatment plan. In your evaluation, you examine plasma HCO3- levels, blood pH, pCO2, and ventilation rate. Which of the following statements are true regarding this patient's condition?

-HCO3- levels are significantly elevated -Type A intercalated cellls in the collecting duct are using ATP to pump H+ ions into the filtrate -Blood pH is likely within normal range due to the body's compensatory mechanisms

Macula densa cells located within the early distal convoluted tubule are in an ideal location to regulate glomerular capillary hydrostatic pressure. Which of the following statements are true regarding the juxtoglomerular apparatus?

-Macula densa cells sense NaCl concentrations -Macula densa cells control juxtaglomerular cell smooth muscle contractility -If Macula densa cells detect decreased salt concentrations, then juxtaglomerular cells will release renin

The carbohydrates in your meal can be classified as monosaccharides (high fructose corn syrup), disaccharides (sucrose, lactose, maltose), and polysaccharides (starches, including amylose and amylopectin). Because only monosaccharides are absorbed by the small intestine, please select the location(s) of enzymes responsible for the hydrolysis of carbohydrates.

-Mouth (salivary gland) -Small intestine (enterocyte) -Pancreas

Which of the following contribute to the hyperosmolarity of the renal medulla?

-Na+ -Cl-

Oral glucose administration leads to a rapid rise in plasma glucose concentrations. Which statements below accurately describe the digestion of glucose?

-Na+ significantly facilitates glucose absorption by enterocytes in the gut -The pancreas releases both insulin and amylase in response to glucose ingestion

Typical potatoes contain a lot of starch, typically with a 3:1 ratio of amylopectin to amylose. However, the potatoes used for your french fries were a variant strain with containing more amylose (a 2:1 ratio). Which statements below correctly describe the digestion of your french fries?

-Na+ significantly facilitates the absorption of carbohydrates through the enterocytes in the gut via secondary active transport -Amylose can be broken down to maltose by pancreatic amylase -Enzymes in the brush border help to break down the starches from your fries

Reabsorption and active secretion most commonly occur within the proximal convoluted tubule. The image below describes the function of organic anion transporters (OAT) located on the basolateral surface of the cell and responsible for the active secretion of large, hydrophobic anionic molecules such as penicillin. Based on the image, which of the following statements are correct regarding the active secretion of penicillin?

-Penicillin in the blood is actively pumped into the filtrate -Primary active transport is necessary -Secondary active transport (symport) is necessary o -Secondary active transport (antiport) is necessary

D-cell

-Releases somatostatin -Acts as negative feedback

Parietal cell

-Secretes hydrochloric acid

which of the following is most likely to causehyperkalemia?

-acidosis

List 2 key purposes of acid production by the stomach

-activate pepsinogen -immune defense

Spironolactone is a potassium-sparing diuretic commonly used to treat high blood pressure. However, this drug is actively secreted by the kidney, resulting in the need for higher dosages in order to see clinical effects. Which statement best describes the process of active secretion?

-active transport from peritubular capillaries into the proximal convoluted tubule

Place the following terms in order of action within the Loop of Henle (this is countercurrent multiplication)

-active transport of salt in thick ascending limb -salt concentration within the descending loop increases -passive transport of salt into the interstitial space of the medulla

increase filtration rate

-afferent arteriole dilation -efferent arteriole constriction

a patient with a history of kidney stones presents with lower back pain, nausea, drowsiness, and shortness of breath. Upon examination you observe significant edema and the patient reports that she has only urinated a couple of times over the past two days. Assuming a kidney stone lodged in the kidney which of the following statements are correct?

-capsular hydrostatic pressure is likely increased -GFR is likely decreased

Assume we could alter the conditions in the duodenum. If we inserted a large volume of highly acidic chyme which contained a large amount of fat, which of the following responses are consistent with that?

-decreased gastric acid secretion -increased bile production -increased pancreatic bicarbonate production and pancreatic enzyme secretion -increased secretin and cholecystokinin

Juxtamedullary nephrons are more susceptible to pressure-related damage than cortical nephrons and albuminuria is commonly associated with damage to juxtamedullary nephrons induced by high blood pressure. In addition to albumin in the urine, what other statements would be true regarding damage to juxtamedullary nephrons (assuming cortical nephrons remain intact)?

-dehydration resulting from increased urine output -increased K+ in the urine -decreased salt in the medulla

Match the following anatomical references to their attributes

-descending loop: permeable to water -ascending loop: squamous and cuboidal -thickness ascending loop: active salt transport -thin ascending loop: passive salt transport

by inhibiting NKCC2, an over dose of furosemide would likely lead to which of the following?

-diuresis -electrolyte depletion -pH imbalance

A hiker was found deceased on a trail in the Grand Canyon (a hot desert environment). An autopsy revealed that the hiker died of dehydration. However, you were surprised to learn that at the time of death, the hiker's stomach was full of water. If only the hiker had eaten something salty...At the time of the hiker's death, predict whether ADH levels are elevated, reduced, or unchanged

-elevated

A hiker was found deceased on a trail in the Grand Canyon (a hot desert environment). An autopsy revealed that the hiker died of dehydration. However, you were surprised to learn that at the time of death, the hiker's stomach was full of water. If only the hiker had eaten something salty...At the time of the hiker's death, predict whether HCO3- levels are elevated, reduced, or unchanged

-elevated

A hiker was found deceased on a trail in the Grand Canyon (a hot desert environment). An autopsy revealed that the hiker died of dehydration. However, you were surprised to learn that at the time of death, the hiker's stomach was full of water. If only the hiker had eaten something salty...At the time of the hiker's death, predict whether aldosterone levels are elevated, reduced, or unchanged

-elevated

A hiker was found deceased on a trail in the Grand Canyon (a hot desert environment). An autopsy revealed that the hiker died of dehydration. However, you were surprised to learn that at the time of death, the hiker's stomach was full of water. If only the hiker had eaten something salty...At the time of the hiker's death, predict whether renin levels are elevated, reduced, or unchanged

-elevated

A patient presents with shortness of breath and severe edema. Further analysis reveals heart failure. To ease the symptoms of edema the physician prescribes furosemide, a loop diuretic. Loop diuretics work by inhibiting the NKCC2 channels on the thick ascending loop of Henle. Which statements best reflect the effects of furosemide on blood K+ levels?

-hypokalemia is likely -Na+/K+ ATPase activity within principle cells of the collecting duct is high due to increased aldosterone -release of renin by the kidney due to decreased blood pressure is a likely cause of altered book K+ levels

Ima Wheezer presents at the clinic with lower-than-normal values for both pCO2 and HCO3-. However, her blood pH is slightly acidic. How is the possible?

-improper regulation of HCO3- by the kidneys (metabolic acidosis) is being compensated for by an increased rate of respiration

imagine a drug that could block carbonic anhydrase. Which of the following would be true?

-less CO2 would be exhaled from the lung -less stomach acid would be created -less HCO3- would be secreted by the exocrine pancreas

Which of the following accurately describe a chylomicron?

-packaged in the smooth ER of absorptive enterocytes -carry triglycerides and cholesterol -leave the enterocyte by exocytosis

Pepsin would not be found in the stomach if the _____cells were destroyed

-parietal cells -chief or zymogenic

Normal red blood cells maintain a diameter of 7 um (micrometers). List 3 specific structures within the filtration membrane that would likely be damaged if blood is seen in the urine.

-podocyte -basement membrane -fenestra -(mesangial cells)

A hiker was found deceased on a trail in the Grand Canyon (a hot desert environment). An autopsy revealed that the hiker died of dehydration. However, you were surprised to learn that at the time of death, the hiker's stomach was full of water. If only the hiker had eaten something salty...At the time of the hiker's death, predict whether potassium levels are elevated, reduced, or unchanged

-reduced

which of the following provide enzymes that aid in the digestion of carbohydrates?

-salivary gland -duodenum -pancreas

which of the following provide enzymes that aid in the digestion of lipids?

-salivary gland -pancreas -liver

Which of the following are functions of CCK?

-satiety -reduced stomach emptying -pancreatic release of digestive enzymes -bile release

chemicals involved in the regulation of the digestive system?

-serotonin -gastrin -secretin -histamine

Which of the following signals are meant to decrease gastrin release from G-cells?

-somatostatin -secretin

With regard to protein absorption in the small intestine, which statement/s is/are correct:

-some intact protein can be absorbed -sodium directly involved in the absorption of amino acids

bacteria in the colon

-synthesize vitamin k -produce some of the gases found in flatus -digest cellulose -form part of the feces

A person suffering from COPD, will likely present which of the following symptoms

-the kidney will increase the rate of HCO- excretion in the collecting duct

The enteric nervous system (ENS) is

-the submucosal and myenteric plexuses combined -is a network of neurons and mechanoreceptors that cause peristaltic movement

Which of the following statements is true regarding the function of the proximal convoluted tubule?

-two thirds of water reabsorption occurs here -100% of glucose in actively reabsorbed here through secondary active transport -Na+ is required for glucose reabsorption

You decide to treat the vegetarian's hypocobalaminemia with a vitamin supplement. However, the patient displays a severe allergic reaction to an ingredient in the vitamin supplement. This necessitates the administration of high levels of anti-histamine. As a result of long-term anti-histamine use, predict whether cholecystokinin levels are increased, decreased, or unchanged.

-unchanged

Aldosterone can be released from the adrenal cortex by 2 different signals: 1) angiotensin; 2) high K+. The first signal is designed to regulate blood pressure by increasing water reabsorption while the second signal is designed for ion concentration regulation. The absence of what other hormone allows aldosterone to regulate K+ without affecting blood pressure?

ADH

in your exhaustion form fasting for 24 hours, your mind starts to ponder eternal truths related to the kidney. you realize that in you dehydrated state, cells in the collecting duct are responding to

ADH: increased capacity to transport water

The renin -> angiotensin -> aldosterone system is designed to increase blood pressure. What is the direct protein target of aldosterone and what cell type is targeted by aldosterone?

ALDOSTERONE TARGET: Na+/K+ pump CELL TYPE: principle cell

Chief cell

Activated by gastrin to release pepsinogen

How does hypokalemia cause alkalosis? Specifically, what cell type is affected by hypokalemia and where is this cell located?

CELL TYPE: intercalated B-cells CELL LOCATION:collecting duct (basolateral)

Chemical protein digestion begins in the stomach, where a low pH is essential for proper enzyme function. What cell is responsible for producing stomach acid, and which two ions are moved by the ATP-driven pump responsible for acid secretion?

CELL TYPE: parietal cells IONS: hydrogen and potasium

A high level of sympathetic stimulation is MOST likely to cause which of the following effects on gastrointestinal function?

Decrease in motility

G-cell

Distension causes release of gastrin

The active reabsorption of HCO3-, Na+, H2o, and glucose all depend of this one protein

Na+/K+ATPase

which cell type in the duodenum is activated by the presence of acid?

S-cell

As stomach chyme is moved into the small intestine, HCO3- secretions from the pancreas help neutralize the acid. Only about 10% of protein breakdown occurs in the stomach. First, what endocrine signal is responsible for the pancreatic release of bicarb ion?

Signal for HCO3-: secretin from S-cells

A 25-year-old woman enters the hospital with persistent diarrhea and abdominal pain. An upper gastrointestinal radiologic series suggests the presence of a duodenal ulcer, which is confirmed by endoscopy. The patient's basal rate of secretion of gastric HCl is about 12 mmole/hr (the normal range is 1 to 5 mmole/hr). The patient's gastrin level is 1145 pg/ml (the normal range is 50 to 150 pg/ml). When the patient's gastric juice is removed via a tube during a 24 hour period, the diarrhea is corrected. The patient also has moderate steatorrhea (excess fat in the stool). After a test meal, the patient's gastrin level is immediately tested and does not increase any more than the already high 1145 pg/ml. In the average normal individual, the same meal produces a doubling of gastrin levels. Infusion of exogenous secretin results in a peak serum gastrin level that is three times the basal level! In normal individuals, infusion of secretin results in a reduction of gastrin. The patient's rate of HCL secretion can be brought to lower levels by treatment with a histamine receptor blocker called cimetidine. However, the dose of cimetidine required to do this is several times greater than that usually used for patients with duodenal ulcers. Administration of an acetylcholine blocker enhances the effect of cimetidine but still requires large doses. A single daily dose of an H+, K+ ATPase blocker called omeprazole is effective in bringing HCL secretion to below normal levels.Why does the patient have a duodenal ulcer?

The amount of HCL leaving the stomach may be too great to be neutralized by pancreatic secretions

_________ is secreted from the ____________ and acts in the digestion of proteins and the activation of other digestive enzymes.

Trypsinogen, pancreas

Peristalsis consists of

a wave of relaxation in front of the bolus followed by a wave of contraction behind the bolus

Acid chyme is buffered by _________________ secreted from the pancreas.

bicarbonate

functions of the liver

bicarbonate production and secretion production of plasma proteins storage of glycogen bile production

A patient presents with shortness of breath and severe edema. Further analysis reveals heart failure. To ease the symptoms of edema the physician prescribes furosemide, a loop diuretic. Loop diuretics work by inhibiting the NKCC2 channels on the thick ascending loop of Henle. Which statements below best reflect the loop function of furosemide?

by increasing the amount of urine production furosemide will lead to decreased blood pressure

which cell type produces pepsinogen?

chief cells

Bumetamide is an organic acid (OA) that reaches very high concentrations in the kidney very quickly. In what part of the kidney would you expect to find the cell depicted below?

collecting duct

A patient complains of severe food poisoning and states that he has vomited over a dozen times in the last 12 hours. In addition to dehydration, you suspect he is suffering from a metabolic pH imbalance since vomiting depletes the body of hydrochloric acid. To corroborate your diagnosis (from the previous question), you measure the following: plasma HCO3- levels, blood pH, ventilation rate, and pCO2. Accordingly, pCO2 is predicted to be...

decreased

A patient complains of severe food poisoning and states that he has vomited over a dozen times in the last 12 hours. In addition to dehydration, you suspect he is suffering from a metabolic pH imbalance since vomiting depletes the body of hydrochloric acid. To corroborate your diagnosis (from the previous question), you measure the following: plasma HCO3- levels, blood pH, ventilation rate, and pCO2. Accordingly, ventilation rate is predicted to be...

decreased

stress (stimulation of the sympathetic nervous system) would cause GI motility and secretions to be

decreased

most nutrients absorption occurs in the

duodenum and the rest of the small intestine

A hiker was found deceased on a trail in the Grand Canyon (a hot desert environment). An autopsy revealed that the hiker died of dehydration. However, you were surprised to learn that at the time of death, the hiker's stomach was full of water. If only the hiker had eaten something salty...At the time of the hiker's death, predict whether blood pH is elevated, reduced, or unchanged

elevated above normal range

trypsin is activated by the enzyme

enterokinase