GI Endocrinology

Question 1

_____ cells secrete and _____ cells modify.

Answer 1

ACINAR cells secrete and DUCT cells modify.

Acinar cells: Serous cells = protein part including enzymes + ionic solutions; Mucous cells = mucins

Duct cells = modify ionic concentrations

Question 2

In the parietal cells, the enzyme carbonic anhydrase causes a reaction between...
	A)	carbon dioxide and water.
	B)	carbonic acid and water.
	C)	bicarbonate ions and hydrogen ions.
	D)	hydrogen ions and potassium ions.
	E)	hydrogen ions and chloride ions.

Answer 2

A) carbon dioxide and water.

Question 3

Ion exchange molecules in the plasma membrane of the parietal cells…
A) exchange a hydrogen ion coming in for a potassium ion going out.
B) exchange bicarbonate ions going out for hydrogen ions coming in.
C) exchange chloride ions going out for potassium ions coming in.
D) exchange hydrogen ions going out for chloride ions coming in.
E) exchange bicarbonate ions going out for chloride ions coming in.

Answer 3

E) exchange bicarbonate ions going out for chloride ions coming in.

Question 4

Hydrochloric acid is formed when…
A) hydrogen ions and chloride ions join in the parietal cell cytoplasm.
B) hydrogen ions and chloride ions join in the parietal cell nucleus.
C) hydrogen ions and chloride ions join in the stomach lumen.
D) hydrogen ions and chloride ions join in the duct of the gastric gland.

Answer 4

D) hydrogen ions and chloride ions join in the duct of the gastric gland.

Question 5

In the parietal cell, carbonic acid dissociates into a bicarbonate ion and a hydrogen ion.
A) True
B) False

Answer 5

A) True

Question 6

The carbonic acid ion is then joined to a hydrogen ion by the enzyme carbonic anhydrase.
A) True
B) False

Answer 6

B) False

Question 7

What is the “alkaline tide”?

Answer 7

For each H+ pumped into lumen, one HCO3- enters blood.

Question 8

Which of the following chemical messengers do NOT regulate insertion of H+/K+-ATPase into plasma membrane:

A) ACh
B) Somatostatin
C) Ghrelin
D) Histamine

Answer 8

C) Ghrelin

*The other chemical messenger is gastrin

Question 9

What are “zymogens”?

Answer 9

Enzymes released in inactive forms.

*The release of enzymes in inactive forms is common in the GI tract and protects the epithelial lining from being digested.

Question 10

Which of the following hormones does not inhibit gastric gland secretions?

A)	secretin	
B)	gastrin
C)	gastric inhibitory peptide
D)	cholecystokinin

Answer 10

B) gastrin

Question 11

Which of the following does not occur during the gastric phase of gastric secretion?

A)	Gastrin begins to be secreted by the lower part of the stomach.
B)	Hydrochloric acid and pepsin secretion is stimulated in the upper and middle parts of the stomach.
C)	Tactile sensation of food in the mouth sends nervous impulses to the medulla oblongata.
D)	all of the above
E)	none of the above

Answer 11

D) all of the above

Question 12

Which of the following inhibits the secretion of the gastric glands?

	A)	duodenum pH of less than two
	B)	lipids in the stomach
	C)	gastrin
	D)	A and B		
	E)	A and C

Answer 12

A) duodenum pH of less than two

Question 13

The medulla oblongata controls gastric secretion both by the parasympathetic branch of the nervous system and the endocrine system.

A)	True
B)	False

Answer 13

B) False

Question 14

Distention of the stomach activates has a direct stimulatory effect on the gastric glands.

A)	True
B)	False

Answer 14

A) True

Question 15

Gastric secretion begins during the \_\_\_\_\_\_\_\_ phase and ends during the \_\_\_\_\_\_\_\_ phase.
	A)	cephalic ; gastric
	B)	cephalic ; intestinal
	C)	gastric ; cephalic
	D)	gastric ; intestinal
	E)	intestinal ; gastric

Answer 15

B) cephalic ; intestinal

Question 16

The hormone \_\_\_\_\_\_\_\_ stimulates the secretion of the hormone \_\_\_\_\_\_\_\_ in the stomach.
	A)	gastrin ; pepsin
	B)	gastrin ; secretin
	C)	gastrin ; cholecystokinin
	D)	pepsin ; secretin
	E)	pepsin ; gastrin

Answer 16

A) gastrin ; pepsin

Question 17

\_\_\_\_\_\_\_\_stimulation via the \_\_\_\_\_\_\_\_ nerve causes the secretion of HCl in the stomach.
	A)	Sympathetic ; gastric
	B)	Sympathetic ; vagus
	C)	Sympathetic ; trigeminal
	D)	Parasympathetic ; gastric
	E)	Parasympathetic ; vagus

Answer 17

E) Parasympathetic ; vagus

Question 18

Cholecystokinin, which is produced in the small intestine, inhibits gastric secretions in the stomach.
A) True
B) False

Answer 18

A) True

Question 19

Secretin is released from the duodenum in response to acidic chyme.
A) True
B) False

Answer 19

A) True

Question 20

Which of the following regarding cholecystokinin (CCK) is FALSE:

A) CCK primarily targets acinar cells releasing enzymes
B) CCK release is controlled by CCK-releasing protein and monitor peptide
C) CCK-RP released from duodenal cells in response to fatty acids and amino acids
D) During a fasting state, there is less degradation of modulators and more CCK released
E) CCK is the major hormone responsible for gallbladder contraction and pancreatic enzyme secretion

Answer 20

D) During fasting state, MORE degradation of modulators and releasing LESS CCK

*During fed state, CCK peptide broken down slowly due to competition for proteases stimulating more CCK release

Question 21

In which pair of hormones does the first cause increased secretion of the second?
	A)	ACTH; cortisol
	B)	FSH; aldosterone
	C)	LH; insulin
	D)	TSH; prolactin

Answer 21

A) ACTH; cortisol

Question 22

Which of the following events could be a result of damage to the hypothalamo-hypophyseal portal system?
A) decreased secretion of ADH (vasopressin)
B) decreased secretion of oxytocin
C) decreased secretion of thyroid stimulating hormone
D) decreased secretion of parathyroid hormone

Answer 22

C) decreased secretion of thyroid stimulating hormone

Question 23

Secretion of many anterior pituitary hormones is controlled by other hormones from the
	A)	pancreatic islets
	B)	thyroid gland
	C)	hypothalamus
	D)	adrenal gland

Answer 23

C) hypothalamus

Question 24

The primary stimulus for the release of cortisol is
A) nerve stimulation from hypothalamus
B) ACTH
C) increased blood glucose levels
D) increased levels of sodium in the blood

Answer 24

B) ACTH

Question 25

``` Hypersecretion of which of the following hormones causes increased metabolic rate, sensitivity to heat, weight loss, and protruding eyes? A) parathyroid hormone B) estrogen C) cortisol D) thyroid hormone ```

Answer 25

D) thyroid hormone

Question 26

``` Which of the following hormones helps to maintain blood glucose levels by stimulating gluconeogenesis? A) thyroid hormone B) cortisol C) insulin D) aldosterone ```

Answer 26

B) cortisol

Question 27

Type II (non-insulin-dependent) diabetes mellitus is usually caused by A) failure of target cells to respond to insulin B) hyposecretion of insulin C) autoimmune destruction of the insulin-secreting cells D) hypersecretion of insulin

Answer 27

A) failure of target cells to respond to insulin

Question 28

``` The presence of ketone bodies in the blood is associated with which endocrine disorder? A) Grave's disease B) Cushing's syndrome C) diabetes mellitus D) acromegaly ```

Answer 28

C) diabetes mellitus

Question 29

In which sequence do these cause and effect events occur in someone with diabetes mellitus? 1. Cells cannot absorb glucose. 2. Fat catabolism elevates blood ketone bodies. 3. Ketone bodies cause osmotic diuresis and ketoacidosis. 4. Cells switch to using fat and protein. A) 1, 4, 2, 3 B) 4, 1, 2, 3 C) 1, 2, 3, 4 D) 1, 2, 4, 3

Answer 29

A) 1, 4, 2, 3

Question 30

When comparing the endocrine system and the nervous system, generally speaking, the endocrine system A) is faster-acting than the nervous system. B) produces effects that are of shorter duration. C) uses amplitude-modulated signals. D) produces more localized effects. E) relies less on chemical signals.

Answer 30

C) uses amplitude-modulated signals.

Question 31

``` A chemical signal released from a cell that has a local effect on the same cell type from which the chemical signal is released is a(n) A) paracrine chemical signal. B) pheromone. C) autocrine chemical signal. D) hormone. E) intracellular mediator. ```

Answer 31

C) autocrine chemical signal.

Question 32

``` Which of these regulates secretion of a hormone from an endocrine tissue? A) other hormones B) negative-feedback mechanisms C) nonhormone substance in the blood D) the nervous system E) all of the above ```

Answer 32

E) all of the above

Question 33

Which of these is not a means by which hormones are eliminated from the circulatory system? A) excreted into urine or bile B) bound to plasma proteins C) metabolism (enzymatically degraded in the blood) D) actively transported into cells E) conjugated with sulfate or glucuronic acid

Answer 33

B) bound to plasma proteins