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Physiology Block 3 > GI Digestion & Absorption > Flashcards

Flashcards in GI Digestion & Absorption Deck (55)
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1
Q

T/F: “Fiber” refers to a complex polysachharide (carbohydrate) that cannot be broken down by enzymes.

A

TRUE

2
Q

Where is sucrose found in the human body?
A) on the gastric surface
B) in the liver
C) on the microvilli of the small intestine
D) in the pancreas

A

C) on the microvilli of the small intestine

3
Q

In simple terms sucrase
A) joins glucose and fructose together to form sucrose.
B) breaks sucrose into glucose and fructose.
C) forms a disaccharide from a monosaccharide.
D) breaks sucrose into hydrogen, oxygen and carbon atoms.

A

B) breaks sucrose into glucose and fructose.

4
Q

How does sucrose change the configuration of sucrase?
A) by significant trauma when they collide randomly
B) by changing the pH of the solvent
C) by force when under pressure
D) by binding to the active site

A

D) by binding to the active site

5
Q
How often can a sucrase molecule be used to hydrolyze sucrose?
	A)	once
	B)	twice
	C)	many times
	D)	never
A

C) many times

6
Q

Where is the location of the enzyme used to hydrolyze sucrose?

A

Right in-between the fingers of the microvillus!

7
Q
Blood sugar refers to what molecule circulating in blood?
	A)	glucose
	B)	sucrose
	C)	fructose
	D)	sucrase
A

A) glucose

8
Q

Carbohydrate digestion results in these three monosaccharide products:

A
  • Glucose
  • Galactose
  • Fructose
9
Q

Lactose is a disaccharide that breaks down into the monomers ____ and ____ by the enzyme ______.

A

Lactose is a disaccharide that breaks down into the monomers GLUCOSE and GALACTOSE by the enzyme LACTASE.

10
Q

For what monosaccharide is there no sodium transporter?
A) Glucose
B) Galactose
C) Fructose

A

C) Fructose - we have facilitated transport (GLUT5) for fructose

11
Q

T/F: The older we get, the weaker the brush border enzyme “lactase” becomes.

A

TRUE - this causes “lactose intolerance” that can cause diarrhea (because it is osmotically active); we are also providing a sugar supply to the bacteria further down in the gut (large intestine). They will create gases –> cramps –> distention.

12
Q

T/F: There is no problem created if we fail to absorb all the glucose from the lumen in the small intestines.

A

False - there is a problem passing ANY nutrient source into the large intestine

13
Q

What cleaves inactive Trypsinogen into Trypsin?

A

Membrane-bound enterokinase released by epithelial cells int he pancreas

14
Q

How does a HUGE molecule such as IgA get across the cells?

A

ENDOCYTOSIS

15
Q

How does a HUGE molecule such as IgA get across the cells?

A

ENDOCYTOSIS

16
Q
Which of the following transporters are essential in the luminal membrane for protein absorption? 
A) Sodium-amino acid symporter
B) Sodium-proton antiporters
C) Protein-peptide symporters
D) All of the above are essential
A

D) All the above

17
Q

How does a HUGE molecule such as IgA get across the cells?

A

ENDOCYTOSIS

18
Q
Which of the following transporters are essential in the luminal membrane for protein absorption? 
A) Sodium-amino acid symporter
B) Sodium-proton antiporters
C) Protein-peptide symporters
D) All of the above are essential
A

D) All the above

19
Q

Most of the fat in a typical diet is in the form of:

A

Triglycerides

20
Q

Breakdown of fat requires what two processes?

A

Mechanical disruption and Emulsification

21
Q

T/F: Micelles have triglycerides.

A

False

22
Q
The components of a micelle include all of the following EXCEPT:
 A) Bile salt
B) Triglycerides
C) Phospholipid
D) Fatty acids
A

B) Triglycerides

23
Q

What helps form emulsification droplets?

A

Bile salts and phospholipids

24
Q

Where are triglycerides resynthesizes?

A

In the smooth Endoplasmic Reticulum

25
Q
The components of a chylomicron include all of the following EXCEPT:
A) cholesterol esterase
B) triglycerides
C) phospholipids
D) fatty acids
A

D) fatty acids - these combine before getting packaged up in the chylomicron.

Phospholipids help stabilize the structure.

*The goal of the chylomicron is to decrease the amount of fatty acids and phospholipids within the cells.

26
Q

What helps carry lipid-soluble vitamins in the blood?

A

chylomicrons

27
Q
What function do many B vitamins serve in the production of energy?
	A)	they function as enzymes
	B)	they function as co-enzymes
	C)	they function as energy sources
	D)	they function as hypoenzymes
A

B) they function as co-enzymes

28
Q
Enzymes assist in the occurrence of reactions by
	A)	lowering of activation energy.
	B)	raising of activation energy.
	C)	providing ATP.
	D)	using ATP.
A

A) lowering of activation energy.

29
Q
Which B vitamin is found in egg yolk (and other foods) and functions as part of Coenzyme A?
	A)	riboflavin
	B)	niacin
	C)	pantothenic acid
	D)	biotin
A

A) decrease formation of energy (ATP).

30
Q
Consuming B vitamins in excess of need will
	A)	decrease formation of energy (ATP).
	B)	increase formation of energy (ATP).
	C)	increase rate of muscle formation.
	D)	increase B vitamins in urine.
A

C) pantothenic acid

31
Q

In the activation of B vitamins, what co-enzyme is used to assist in the production of ATP from pyruvate?
A) Carbon dioxide
B) An apoenzyme
C) Thiamine pyrophosphate

A

C) Thiamine pyrophosphate

32
Q
Which of the following hormones does not inhibit gastric gland secretions?
	A)	secretin
	B)	gastrin
	C)	gastric inhibitory peptide
	D)	cholecystokinin
A

B) gastrin

33
Q

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

A

D) all of the above

34
Q
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
A

A) duodenum pH of less than two

35
Q

The medulla oblongata controls gastric secretion both by the parasympathetic branch of the nervous system and the endocrine system.
A) True
B) False

A

B) False

36
Q

Distention of the stomach activates has a direct stimulatory effect on the gastric glands.
A) True
B) False

A

A) True

37
Q
Mass movements in the colon are stimulated by...
	A)	food in the stomach.
	B)	chyme in the duodenum.
	C)	feces in the rectum.
	D)	A and B
	E)	A, B, and C
A

D) A and B

38
Q
Mass movements of the colon are integrated by...
	A)	the enteric plexus.
	B)	parasympathetic reflexes.
	C)	local reflexes.
	D)	A and B
	E)	B and C
A

A) the enteric plexus.

39
Q
Defecation is stimulated by...
	A)	the enteric plexus.
	B)	parasympathetic reflexes.
	C)	local reflexes.
	D)	A and B
	E)	B and C
A

E) B and C

40
Q

Defecation reflexes are stimulated by the presence of feces in the rectum.
A) True
B) False

A

A) True

41
Q

Mass movements of the colon propel its contents toward the rectum.
A) True
B) False

A

A) True

42
Q
Involuntary muscle contractions which move a bolus through the gastrointestinal tract are called
	A)	mastication.
	B)	peristalsis.
	C)	defecation.
	D)	chime.
A

B) peristalsis.

43
Q
Hydrochloric acid is secreted in the
	A)	esophagus.
	B)	stomach.
	C)	small intestine.
	D)	large intestine.
A

B) stomach.

44
Q
Most nutrient absorption occurs in the
	A)	esophagus.
	B)	stomach.
	C)	small intestine.
	D)	large intestine.
A

C) small intestine.

45
Q
What organ produces bile?
	A)	liver
	B)	small intestine
	C)	pancreas
	D)	stomach
A

A) Liver

46
Q

Which of the following is the correct order for the major parts of the gastrointestinal tract?
A) esophagus, stomach, large intestine, small intestine, mouth
B) mouth, stomach, esophagus, large intestine, small intestine
C) mouth, small intestine, stomach, esophagus, large intestine
D) mouth, esophagus, stomach, small intestine, large intestine

A

D) mouth, esophagus, stomach, small intestine, large intestine

47
Q
The enteric plexus is found in the
	A)	submucosa layer.
	B)	muscularis layer.
	C)	serosa layer.
	D)	both a and b.
	E)	all of the above.
A

D) both a and b.

48
Q
During deglutition (swallowing),
	A)	movement of food results primarily from gravity.
	B)	the swallowing center in the medulla oblongata is activated.
	C)	food is pushed into the oropharynx during the pharyngeal phase.
	D)	the soft palate closes off the opening into the larynx.
A

B) the swallowing center in the medulla oblongata is activated.

49
Q

Which of these stomach cell types is not correctly matched with its function?
A) surface mucous cells: produce mucus
B) parietal cells: produce hydrochloric acid
C) chief cells: produce intrinsic factor
D) endocrine cells: produce regulatory hormones

A

C) chief cells: produce intrinsic factor

50
Q

Which of these phases of stomach secretion is correctly matched?
A) Cephalic phase: the largest volume of secretion is produced.
B) Gastric phase: gastrin secretion is inhibited by distention of the stomach.
C) Gastric phase: initiated by chewing, swallowing, or thinking of food.
D) Gastrointestinal phase: stomach secretions are inhibited.

A

D) Gastrointestinal phase: stomach secretions are inhibited.

51
Q

The aqueous component of pancreatic secretions
A) is secreted by the pancreatic islets.
B) contains bicarbonate ions.
C) is released primarily in response to cholecystokinin.
D) passes directly into the blood.
E) all of the above.

A

B) contains bicarbonate ions.

52
Q

Defecation
A) can be initiated by stretch of the rectum.
B) can occur as a result of mass movements.
C) involves local reflexes.
D) involves parasympathetic reflexes mediated by the spinal cord.
E) all of the above.

A

E) All of the above

53
Q

Bile
A) is an important enzyme for the digestion of fats.
B) is made by the gallbladder.
C) contains breakdown products from hemoglobin.
D) emulsifies fats.
E) both c and d.

A

E) both c and d.

54
Q
If the thoracic duct were tied off, which of these classes of nutrients would not enter the circulatory system at their normal rate?
	A)	amino acids
	B)	glucose
	C)	lipids
	D)	fructose
	E)	nucleotides
A

C) lipids

55
Q

Which of these lipoprotein molecules transports excess lipids from cells back to the liver?
A) high-density lipoprotein (HDL)
B) low-density lipoprotein (LDL)
C) very low-density lipoprotein (VLDL)

A

A) high-density lipoprotein (HDL)