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Animal Physiology I > Lecture 17: Digestion & Absorption > Flashcards

Lecture 17: Digestion & Absorption Flashcards

1
Q

What is digestion?
a. The process of absorbing nutrients directly into tissues.
b. The process of splitting ingested food into smaller components for distribution to tissues.
c. The storage of nutrients in specialized cells.
d. The excretion of waste products from the digestive system.

A

Answer: b

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2
Q

Where does extracellular digestion occur?
a. In specialized cells like in sponges and flatworms.
b. In the stomach or intestine (lumen) of vertebrates and arthropods.
c. Inside the nucleus of cells.
d. In the liver and kidneys of mammals.

A

Answer: b

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3
Q

Which organisms primarily rely on intracellular digestion?
a. Vertebrates and arthropods
b. Mollusks and insects
c. Sponges, flatworms, and some mollusks
d. Mammals and reptiles

A

Answer: c

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4
Q

What is the function of the headgut in the gastrointestinal tract?
a. Digestion and absorption of nutrients.
b. Transporting food from the esophagus to the stomach.
c. Processing food using the tongue, buccal cavity, and lips.
d. Fermenting food in the cecum.

A

Answer: c

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5
Q

Which part of the gastrointestinal tract is responsible for digestion and absorption?
a. Foregut (esophagus and stomach)
b. Headgut (tongue and buccal cavity)
c. Midgut (small intestine)
d. Hindgut (large intestine and cecum)

A

Answer: c

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6
Q

What occurs in the hindgut?
a. Digestion of proteins and lipids.
b. Transport and excretion of waste materials.
c. Absorption of nutrients like carbohydrates.
d. Production of digestive enzymes.

A

Answer: b

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7
Q

Which of the following is a feature of extracellular digestion?
a. It occurs entirely within the cytoplasm of cells.
b. It requires enzymes released into the digestive lumen.
c. It does not involve breaking down macromolecules.
d. It is exclusive to flatworms and sponges.

A

Answer: b

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8
Q

Which of the following is a characteristic of the midgut?
a. It contains the cecum for fermentation.
b. It is responsible for the initial breakdown of food.
c. It involves digestion and absorption in the small intestine.
d. It plays no role in nutrient absorption.

A

Answer: c

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9
Q

In which group of animals would you expect to find significant intracellular digestion?
a. Mammals
b. Birds
c. Sponges
d. Arthropods

A

Answer: c

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10
Q

What is the role of the foregut in digestion?
a. Transporting food to the small intestine.
b. Performing the majority of nutrient absorption.
c. Breaking down food in the esophagus and stomach.
d. Storing bile for fat digestion.

A

Answer: c

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11
Q

What is the role of hydrolytic enzymes in digestion?
a. To store energy in large molecules.
b. To break down large molecules into smaller components for absorption.
c. To transport nutrients across cell membranes.
d. To synthesize proteins from amino acids.

A

Answer: b

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12
Q

Why are specific enzymes required for digestion?
a. Each enzyme is specific to the type of bond it breaks.
b. Enzymes are non-specific and break down all types of molecules.
c. Enzymes only work at high temperatures.
d. Digestion does not require enzymes.

A

Answer: a

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13
Q

Which of the following enzymes is used to break down cellulose?
a. Lactase
b. Cellulase
c. Chitinase
d. Amylase

A

Answer: b

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14
Q

What is true about lactase?
a. It breaks down proteins in the stomach.
b. It is produced only in cattle.
c. Its activity varies among human populations and with age.
d. It breaks down cellulose in plant material.

A

Answer: c

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15
Q

Where are intraluminal enzymes secreted?
a. Into the cytoplasm of cells.
b. Into the lumen of body cavities such as the stomach or oral cavity.
c. Onto the surface of epithelial cells.
d. Into the bloodstream for transport.

A

Answer: b

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16
Q

What is the role of membrane-associated enzymes?
a. They break down food particles within cells.
b. They are secreted into the bloodstream.
c. They are synthesized by epithelial cells and have catalytic sites exposed to the lumen.
d. They are stored in the liver and pancreas.

A

Answer: c

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17
Q

What is the role of intracellular enzymes in digestion?
a. They digest food particles taken into the cell.
b. They break down food in the lumen of the stomach.
c. They catalyze reactions on the epithelial cell surface.
d. They store nutrients for future use.

A

Answer: a

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18
Q

Which of the following organisms can digest chitin using chitinase?
a. Humans
b. Cattle
c. Bats and rodents
d. Rabbits

A

Answer: c

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19
Q

What is the relationship between catabolism and digestion?
a. Catabolism stores energy in large molecules during digestion.
b. Catabolism involves breaking down large molecules into smaller ones, releasing energy in the process.
c. Catabolism transports enzymes into the lumen for digestion.
d. Catabolism synthesizes enzymes used in digestion.

A

Answer: b

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20
Q

What type of enzymes are predominantly used in vertebrate digestion?
a. Intracellular enzymes
b. Extracellular enzymes
c. Photosynthetic enzymes
d. Hormonal enzymes

A

Answer: b

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21
Q

What is the primary role of the stomach in digestion?
a. To absorb monosaccharides directly into the bloodstream.
b. To act as the major site for digestion of macromolecules using acid and enzymes.
c. To neutralize stomach acid and transport food to the small intestine.
d. To store food for long periods of time.

A

Answer: b

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22
Q

Which cell type in the gastric pit secretes hydrochloric acid (HCl)?
a. Mucous neck cells
b. Parietal cells
c. Chief cells
d. Enteroendocrine cells

A

Answer: b

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23
Q

What do chief cells in the stomach secrete?
a. Acidic mucous
b. Pepsinogen, which is converted to pepsin in the presence of acid
c. Gastrin, a hormone regulating digestion
d. Sodium bicarbonate to neutralize acid

A

Answer: b

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24
Q

What is the function of enteroendocrine cells in the gastric pit?
a. To secrete enzymes for protein digestion.
b. To produce hormones like gastrin that regulate digestion.
c. To create a protective mucous layer in the stomach.
d. To neutralize acids during digestion.

A

Answer: b

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25
Q

Which vertebrates lack stomach acid secretion?
a. Amphibians and reptiles
b. Platypus and gastric-brooding frogs
c. Mammals and birds
d. Fish and mollusks

A

Answer: b

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26
Q

What is the primary difference between digestion and absorption?
a. Digestion involves breaking down food molecules, while absorption involves transporting these molecules into blood or lymph.
b. Digestion occurs in the small intestine, while absorption occurs in the stomach.
c. Digestion only occurs for proteins, while absorption occurs for lipids.
d. Absorption happens before digestion in mammals.

A

Answer: a

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27
Q

What molecules are absorbed during digestion?
a. Only carbohydrates and proteins.
b. Monosaccharides, free amino acids, and lipids.
c. Vitamins and water only.
d. Entire macromolecules without breakdown.

A

Answer: b

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28
Q

What mechanism is responsible for moving food from the stomach to the small intestine?
a. Passive diffusion
b. Enzymatic action
c. Smooth muscle peristalsis
d. Active transport

A

Answer: c

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29
Q

How are carbohydrates and amino acids absorbed into the bloodstream?
a. Through simple diffusion only.
b. Via active transport and facilitated diffusion.
c. By binding to stomach acid and entering lymph vessels.
d. Using endocytosis in the stomach.

A

Answer: b

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30
Q

Which of the following is an example of absorption through simple diffusion?
a. Free amino acids
b. Lipids
c. Monosaccharides
d. Proteins

A

Answer: b

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31
Q

How are carbohydrates and amino acids absorbed into the bloodstream?
a. Through simple diffusion only.
b. Via active transport and facilitated diffusion.
c. By binding to stomach acid and entering lymph vessels.
d. Using endocytosis in the stomach.

A

Answer: b

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32
Q

What mechanism is responsible for moving food from the stomach to the small intestine?
a. Passive diffusion
b. Enzymatic action
c. Smooth muscle peristalsis
d. Active transport

A

Answer: c

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33
Q

What is the primary enzyme responsible for breaking down glycogen in the mouth?
a. Pancreatic amylase
b. Salivary amylase
c. Disaccharidase
d. Cellulase

A

Answer: b

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34
Q

What is an oligosaccharide?
a. A carbohydrate containing only one sugar molecule.
b. A carbohydrate containing between 3–10 monosaccharides.
c. A carbohydrate containing more than 10 sugar molecules.
d. A carbohydrate that cannot be broken down by enzymes.

A

Answer: b

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35
Q

Where does the breakdown of disaccharides, such as sucrose, primarily occur?
a. Mouth
b. Stomach
c. Small intestine
d. Liver

A

Answer: c

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36
Q

Why can’t cellulose be digested by humans?
a. It is absorbed directly as a monosaccharide.
b. Humans lack the enzyme to break it down.
c. It is digested in the stomach, which humans do not have.
d. Cellulose is too small to be broken down further.

A

Answer: b

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37
Q

What is the primary function of pancreatic amylase?
a. To break down glycogen into oligosaccharides in the stomach.
b. To break disaccharides into monosaccharides in the mouth.
c. To convert polysaccharides into disaccharides in the small intestine.
d. To digest cellulose in the small intestine.

A

Answer: c

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38
Q

Why must polysaccharides like starch be broken down before absorption?
a. Polysaccharides are toxic in their natural state.
b. The body only absorbs smaller molecules like monosaccharides.
c. Polysaccharides are absorbed directly into the bloodstream.
d. The stomach enzymes cannot process large molecules.

A

Answer: b

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39
Q

What enzyme converts disaccharides into monosaccharides?
a. Pancreatic amylase
b. Salivary amylase
c. Disaccharidase
d. Lipase

A

Answer: c

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40
Q

What happens to sucrose consumed by a hummingbird?
a. It is absorbed in the stomach.
b. It passes through the stomach and is broken down in the small intestine.
c. It is broken down into monosaccharides in the mouth.
d. It is digested by pancreatic amylase in the liver.

A

Answer: b

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41
Q

What is the key difference between polysaccharides and disaccharides?
a. Polysaccharides are digested by disaccharidases.
b. Disaccharides contain fewer sugar molecules than polysaccharides.
c. Disaccharides are absorbed directly without further breakdown.
d. Polysaccharides cannot be consumed by humans.

A

Answer: b

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42
Q

What must happen to glycogen, oligosaccharides, or starch before they can be absorbed?
a. They must be broken down into disaccharides and then into monosaccharides.
b. They are absorbed directly into the bloodstream from the stomach.
c. They are broken down by enzymes in the liver.
d. They are stored as energy in the pancreas before absorption.

A

Answer: a

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43
Q

Which enzyme group breaks down polysaccharides into smaller molecules?
a. Lipases
b. Polysaccharidases
c. Disaccharidases
d. Proteases

A

Answer: b

44
Q

What is the function of polysaccharidases like amylase?
a. To break down disaccharides into monosaccharides.
b. To break down large molecules like glycogen into disaccharides.
c. To digest lipids into fatty acids.
d. To transport glucose into cells.

A

Answer: b

45
Q

What do disaccharidases like sucrase and lactase break down?
a. Starch into glycogen.
b. Monosaccharides into glucose.
c. Disaccharides (e.g., sucrose) into monosaccharides (e.g., glucose and fructose).
d. Oligosaccharides into polysaccharides.

A

Answer: c

46
Q

Where are disaccharidases primarily found?
a. In the stomach lining.
b. In the pancreas.
c. Membrane-associated enzymes in the small intestine (midgut).
d. In the oral cavity.

A

Answer: c

47
Q

Which sequence of enzymes is involved in carbohydrate digestion?
a. Proteases followed by polysaccharidases.
b. Polysaccharidases followed by disaccharidases.
c. Disaccharidases followed by lipases.
d. Polysaccharidases followed by proteases.

A

Answer: b

48
Q

Why do carbohydrate digestion processes involve two or more enzymes?
a. Because monosaccharides must be formed in multiple steps from polysaccharides.
b. Because carbohydrates are absorbed directly as polysaccharides.
c. Because disaccharidases cannot function in the stomach.
d. Because amylase and sucrase work simultaneously in the stomach.

A

Answer: a

49
Q

Which enzyme is responsible for breaking down sucrose into glucose and fructose?
a. Amylase
b. Lactase
c. Sucrase
d. Maltase

A

Answer: c

50
Q

What would happen if disaccharidases were absent from the small intestine?
a. Polysaccharides would not be broken down.
b. Monosaccharides could not be absorbed.
c. Lipid digestion would be impaired.
d. Starch digestion would occur directly in the stomach.

A

Answer: b

51
Q

What type of carbohydrate is targeted first by polysaccharidases?
a. Monosaccharides
b. Disaccharides
c. Polysaccharides (e.g., glycogen)
d. Oligosaccharides

A

Answer: c

52
Q

Which enzyme is required for the final step of carbohydrate digestion?
a. Amylase
b. Sucrase
c. Pancreatic lipase
d. Lactase

A

Answer: d

53
Q

Why can monosaccharides not pass directly through lipid membranes?
a. They are too small to interact with the membrane.
b. They are hydrophilic and require transporters for passage.
c. They are broken down into amino acids before absorption.
d. They are lipid-soluble and do not require transporters.

A

Answer: b

54
Q

What is the primary transporter involved in glucose absorption in the small intestine?
a. GLUT-4 transporter
b. Sodium-glucose transporter 1 (SGLT-1)
c. Lactase transporter
d. Pancreatic amylase

A

Answer: b

55
Q

Where are most nutrients absorbed in the digestive system?
a. The stomach lining
b. The cells of the small intestine
c. The liver
d. The large intestine

A

Answer: b

56
Q

What is the function of villi and microvilli in the small intestine?
a. To increase the length of the intestine.
b. To secrete digestive enzymes.
c. To increase surface area for absorption.
d. To transport nutrients directly to the liver.

A

Answer: c

57
Q

What are the primary types of cells found in the villi of the small intestine?
a. Chief cells, parietal cells, and goblet cells
b. Enterocytes, goblet cells, and enteroendocrine cells
c. Hepatocytes, enterocytes, and mucous cells
d. Paneth cells, parietal cells, and enteroendocrine cells

A

Answer: b

58
Q

What is the primary function of enterocytes in the small intestine?
a. To secrete mucus for protection.
b. To absorb nutrients using microvilli.
c. To produce digestive enzymes for the stomach.
d. To transport bile salts to the pancreas.

A

Answer: b

59
Q

What is the role of the brush border in nutrient absorption?
a. It neutralizes stomach acid.
b. It increases the surface area for nutrient absorption.
c. It secretes hormones to regulate digestion.
d. It breaks down fats into smaller molecules.

A

Answer: b

60
Q

What type of nutrients are absorbed via transporters in the small intestine?
a. Only lipids
b. Monosaccharides and amino acids
c. Polysaccharides and disaccharides
d. Lipids and nucleic acids

A

Answer: b

61
Q

Which of the following is NOT a function of the cells in the villi?
a. Absorbing nutrients into the bloodstream.
b. Secreting digestive enzymes into the stomach.
c. Secreting hormones to regulate digestion.
d. Producing mucus for protection.

A

Answer: b

62
Q

How does the structure of the small intestine maximize absorption?
a. By being longer than the large intestine.
b. By having folds, villi, and microvilli to increase surface area.
c. By producing acid to digest nutrients.
d. By absorbing nutrients directly through smooth muscle.

A

Answer: b

63
Q

What is the role of SGLT-1 in glucose uptake?
a. It passively diffuses glucose into the bloodstream.
b. It actively transports glucose and sodium from the gut into enterocytes.
c. It facilitates the movement of fructose into the bloodstream.
d. It only functions during high glucose levels in the gut.

A

Answer: b

64
Q

Which transporter allows glucose to exit enterocytes into the bloodstream?
a. SGLT-1
b. GLUT-5
c. GLUT-2
d. Sodium-glucose transporter 1

A

Answer: c

65
Q

What happens to GLUT-2 transporters during high glucose levels?
a. They move to the microvilli to enhance glucose uptake into enterocytes.
b. They become inactive due to feedback inhibition.
c. They are replaced by GLUT-5 to transport fructose.
d. They primarily transport sodium into the cell.

A

Answer: a

66
Q

Which transporter is specifically involved in fructose absorption?
a. SGLT-1
b. GLUT-2
c. GLUT-5
d. Sodium-fructose transporter 1

A

Answer: c

67
Q

How does glucose uptake differ at low glucose levels compared to high glucose levels?
a. GLUT-5 is the primary transporter at low glucose levels.
b. SGLT-1 is active at low levels, while GLUT-2 plays a larger role at high levels.
c. Both SGLT-1 and GLUT-2 are inactive at low glucose levels.
d. Glucose is absorbed only through diffusion at both levels.

A

Answer: b

68
Q

What triggers the movement of GLUT-2 to the microvilli during high glucose levels?
a. A signal transduction cascade
b. Sodium binding to the transporter
c. The presence of fructose in the gut
d. Feedback inhibition of SGLT-1

A

Answer: a

69
Q

Which of the following is true about SGLT-1?
a. It functions via facilitated diffusion.
b. It transports fructose into enterocytes.
c. It requires sodium for glucose transport into enterocytes.
d. It exits glucose from enterocytes to the bloodstream.

A

Answer: c

70
Q

What happens to glucose inside enterocytes after uptake?
a. It is stored as glycogen.
b. It exits the cell via GLUT-2 into the bloodstream.
c. It binds to sodium for energy production.
d. It is broken down into fructose and galactose.

A

Answer: b

71
Q

Which process occurs in the presence of low glucose levels in the gut?
a. GLUT-2 facilitates diffusion of glucose into the bloodstream.
b. SGLT-1 actively transports glucose into enterocytes.
c. GLUT-5 actively transports glucose into enterocytes.
d. All glucose uptake ceases at low glucose levels.

A

Answer: b

72
Q

Explain the process of glucose uptake by enterocytes during low glucose levels and high glucose levels.

A

Low Glucose Levels:

SGLT-1 actively transports glucose into enterocytes from the gut, using sodium as a cotransporter.
Glucose exits enterocytes into the bloodstream via GLUT-2.

High Glucose Levels:

High glucose levels trigger a signal transduction cascade that increases the synthesis of GLUT-2 transporters.
GLUT-2 transporters migrate to the microvilli, increasing the rate of glucose uptake into enterocytes.
Excess glucose exits the enterocytes into the bloodstream via GLUT-2.

73
Q

Which transporter is responsible for transporting fructose into enterocytes?
A) SGLT-1
B) GLUT-2
C) GLUT-5
D) GLUT-4

A

Answer: C) GLUT-5

74
Q

What triggers GLUT-2 transporters to move to the microvilli during high glucose levels?
A) Sodium concentration
B) Signal transduction cascade
C) Fructose levels
D) GLUT-5 activation

A

Answer: B) Signal transduction cascade

75
Q

How does glucose exit enterocytes into the bloodstream?
A) SGLT-1
B) GLUT-5
C) GLUT-2
D) Active transport using sodium

A

Answer: C) GLUT-2

76
Q

What is the role of SGLT-1 in the absorption process?
A) Facilitates diffusion of glucose
B) Actively transports glucose and sodium into enterocytes
C) Channels fructose into the bloodstream
D) Moves glucose out of the cell

A

Answer: B) Actively transports glucose and sodium into enterocytes

77
Q

Which transporter is utilized for glucose uptake during low glucose levels in the gut?
A) GLUT-5
B) GLUT-4
C) SGLT-1
D) GLUT-2

A

Answer: C) SGLT-1

78
Q

During high glucose levels, which transporter aids in faster glucose uptake at the microvilli?
A) SGLT-1
B) GLUT-5
C) GLUT-2
D) GLUT-4

A

Answer: C) GLUT-2

79
Q

Which enzyme establishes the gradient necessary for secondary active transport of glucose?
A) GLUT-2
B) GLUT-5
C) Na⁺/K⁺ ATPase
D) SGLT-1

A

Answer: C) Na⁺/K⁺ ATPase

80
Q

How does SGLT-1 facilitate glucose absorption into enterocytes?
A) By facilitated diffusion.
B) By co-transporting glucose with sodium.
C) By utilizing ATP directly.
D) By removing glucose from the bloodstream.

A

Answer: B) By co-transporting glucose with sodium.

81
Q

What transporter is responsible for glucose exiting the enterocyte into the bloodstream?
A) GLUT-5
B) GLUT-2
C) SGLT-1
D) Na⁺/K⁺ ATPase

A

Answer: B) GLUT-2

82
Q

Which of the following is absorbed via facilitated diffusion?
A) Glucose via SGLT-1
B) Fructose via GLUT-5
C) Sodium via Na⁺/K⁺ ATPase
D) Glucose via GLUT-2

A

Answer: B) Fructose via GLUT-5

83
Q

What drives the transport of glucose against its concentration gradient into enterocytes?
A) ATP hydrolysis by GLUT-2
B) Sodium gradient established by Na⁺/K⁺ ATPase
C) Active transport by GLUT-5
D) Diffusion of sodium down its concentration gradient

A

Answer: B) Sodium gradient established by Na⁺/K⁺ ATPase

84
Q

Which adaptation is especially important for lactating mammals to increase glucose absorption?
A) Increased transporter density in enterocytes
B) Greater length of the midgut
C) Enhanced secretion of digestive enzymes
D) Increased blood supply to the gut

A

Answer: B) Greater length of the midgut

85
Q

In a small mammal shivering in the cold, what mechanism would likely enhance glucose absorption?
A) Shortening the midgut length
B) Increasing surface undulations and transporter density
C) Inhibiting the Na⁺/K⁺ ATPase to save energy
D) Increasing fat absorption to replace glucose

A

Answer: B) Increasing surface undulations and transporter density

86
Q

Which of the following correctly summarizes glucose absorption in enterocytes?
A) Sodium-glucose co-transport occurs at the apical membrane, and glucose exits via GLUT-2 on the basolateral side.
B) Sodium is actively transported into the enterocyte, and glucose diffuses into the bloodstream.
C) Fructose is absorbed by SGLT-1 and transported to the blood by GLUT-5.
D) Glucose uptake does not rely on sodium gradients.

A

Answer: A) Sodium-glucose co-transport occurs at the apical membrane, and glucose exits via GLUT-2 on the basolateral side.

87
Q

What is the unique feature of glucose absorption in hummingbirds compared to other species?
A) They primarily rely on active transport via SGLT-1.
B) They use paracellular transport due to solvent-drag.
C) They do not digest disaccharides into glucose.
D) They absorb glucose only via facilitated diffusion.

A

Answer: B) They use paracellular transport due to solvent-drag.

88
Q

Why is paracellular transport in hummingbirds potentially problematic?
A) It relies heavily on Na⁺/K⁺ ATPase, which uses too much ATP.
B) It allows toxins to pass through the gut lining.
C) It decreases the efficiency of glucose absorption.
D) It disrupts tight junctions permanently.

A

Answer: B) It allows toxins to pass through the gut lining.

89
Q

Hummingbirds absorb glucose at extremely high rates. This is achieved by:
A) Relying solely on GLUT-5 for glucose uptake.
B) Increasing glucose transporter levels and using solvent-drag.
C) Utilizing only SGLT-1 for facilitated diffusion.
D) Breaking down glucose in the liver for faster absorption.

A

Answer: B) Increasing glucose transporter levels and using solvent-drag.

90
Q

Which two transport mechanisms are primarily involved in glucose absorption in birds using secondary active transport?
A) SGLT-1 and GLUT-2
B) GLUT-5 and Na⁺/K⁺ ATPase
C) SGLT-1 and GLUT-5
D) Na⁺/K⁺ ATPase and solvent-drag

A

Answer: A) SGLT-1 and GLUT-2

91
Q

In secondary active transport of glucose, the sodium-glucose cotransporter (SGLT-1) relies on the gradient of _______ created by the _______ pump to transport glucose into the cell.
a) Calcium; Ca²⁺ ATPase
b) Sodium; Na⁺/K⁺ ATPase
c) Potassium; K⁺ ATPase
d) Hydrogen; Proton pump

A

Answer: b) Sodium; Na⁺/K⁺ ATPase

92
Q

The _______ transporter allows glucose to exit the enterocyte and enter the bloodstream by _______.
a) GLUT-1; active transport
b) GLUT-2; facilitated diffusion
c) SGLT-1; secondary active transport
d) GLUT-5; osmosis

A

Answer: b) GLUT-2; facilitated diffusion

93
Q

At high glucose levels in the gut, _______ increases in the microvilli to enhance glucose uptake.
a) SGLT-1
b) GLUT-2
c) GLUT-5
d) Na⁺/K⁺ ATPase

A

Answer: b) GLUT-2

94
Q

Paracellular transport, used by hummingbirds for glucose absorption, bypasses _______ and allows glucose to pass between cells.
a) Microvilli
b) Cell membranes
c) Tight junctions
d) Brush border enzymes

A

Answer: c) Tight junctions

95
Q

The primary transporter responsible for fructose uptake into enterocytes is _______.
a) SGLT-1
b) GLUT-2
c) GLUT-5
d) Na⁺/K⁺ ATPase

A

Answer: c) GLUT-5

96
Q

The process of creating an electrochemical gradient for secondary active transport of glucose involves pumping _______ out of the cell and bringing _______ into the cell using Na⁺/K⁺ ATPase.
a) Sodium; potassium
b) Potassium; sodium
c) Glucose; sodium
d) Hydrogen; potassium

A

Answer: a) Sodium; potassium

97
Q

In conditions of low glucose levels in the gut, _______ is the primary transporter responsible for glucose uptake into enterocytes.
a) GLUT-2
b) GLUT-5
c) SGLT-1
d) Na⁺/K⁺ ATPase

A

Answer: c) SGLT-1

98
Q

Glucose absorption is maximized by increasing surface area through _______ in the intestine, such as villi and microvilli.
a) Circular folds
b) Smooth muscle
c) Surface undulations
d) Brush border enzymes

A

Answer: c) Surface undulations

99
Q

G-cells in the stomach secrete __________, which acts on parietal cells to release acid.

a) Pepsin
b) Gastrin
c) Secretin
d) Cholecystokinin

A

Answer: b) Gastrin

100
Q

The hormone __________ slows down gastric emptying, decreases acid secretion, and delays stomach contractions.

a) Cholecystokinin (CCK)
b) Gastric inhibitory polypeptide (GIP)
c) Secretin
d) Pepsinogen

A

Answer: b) Gastric inhibitory polypeptide (GIP)

101
Q

__________ is secreted by chief cells in the gastric pit and is converted to pepsin in the presence of acid.

a) Gastrin
b) Secretin
c) Pepsinogen
d) Lipase

A

Answer: c) Pepsinogen

102
Q

Acidity in the small intestine triggers the release of __________, which stimulates the pancreas to secrete bicarbonate.

a) Gastrin
b) Secretin
c) GIP
d) Pepsin

A

Answer: b) Secretin

103
Q

Cholecystokinin (CCK) acts on the liver to stimulate the secretion of __________ for digestion and absorption of fats.

a) Bicarbonate
b) Enzymes
c) Bile
d) Gastrin

A

Answer: c) Bile

104
Q

The gastric pit contains __________ cells, which are responsible for secreting HCl.

a) Chief
b) Parietal
c) Enteroendocrine
d) Goblet

A

Answer: b) Parietal

105
Q

The primary role of gastrin is to __________.

a) Stimulate acid secretion
b) Slow gastric emptying
c) Neutralize stomach acid
d) Activate bile secretion

A

Answer: a) Stimulate acid secretion

106
Q

Secretin acts to decrease acidity by stimulating the pancreas to release __________.

a) Digestive enzymes
b) Bicarbonate
c) Pepsin
d) Cholecystokinin

A

Answer: b) Bicarbonate

Animal Physiology I (20 decks)

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