Deck 14: Digestion and Energy Metabolism

Question 1

Digestive physiology is concerned with

A)the sensory system employed to locate food.
B)the mechanical disruption of food.
C)the chemical conversion of food molecules into transportable forms.
D)all of the above

Answer 1

D

Question 2

Which one of the following enzymes is incorrectly paired with its substrate?

A)lipase : triglycerides
B)trypsin : proteins
C)amylase : polysaccharides
D)nuclease : oligosaccharides

Answer 2

D

Question 3

Which statement(s)is (are)true with respect to the giant vent worms (Riftia pachyptila)?

A)These worms have a complete digestive tract.
B)Nutrients are derived from a trophosome filled with chemolithotrophic bacteria.
C)The worm's hemoglobin transports hydrogen sulfide and oxygen to its symbiont.
D)B and C

Answer 3

D

Question 4

Animals have been shown to increase the total number of SGLT-1 transporters in the gut by

A)producing more transporters per unit surface area of the gut.
B)increasing the surface area of the gut per unit length.
C)increasing the total length of the intestine.
D)all of the above

Question 5

Which of the following generally passes through the GI tracts of animals undigested?

A)glycogen
B)disaccharides
C)cellulose
D)proteins

Question 6

By which process do the fatty acids and monoglycerides of micelles cross the enterocyte cell membranes?

A)active transport
B)diffusion
C)pinocytosis
D)phagocytosis

Question 7

Pancreatic proteases include which of the following?

A)trypsin
B)chymotrypsin
C)carboxypeptidase
D)all of the above

Question 8

Which one of the following vitamins is fat soluble,can be stored,and has the potential to be toxic?

A)vitamin A
B)niacin (B₃)
C)riboflavin (B₂)
D)vitamin C

Question 9

Which vitamin plays a major role in the absorption of dietary calcium (Ca²⁺)?

A)vitamin A
B)vitamin C
C)vitamin D
D)vitamin E

Question 10

Of the 20 amino acids that animals use to construct proteins,how many are essential?

A)8
B)10
C)12
D)all 20

Question 11

What is the composition of bile?

A)cholesterol
B)phospholipids
C)pigments and salts
D)all of the above

Question 12

Which type of lipoprotein is synthesized by the enterocytes of the small intestine?

A)chylomicron
B)VLDL
C)LDL
D)HDL

Question 13

Which animal is incorrectly matched with the anatomical feature associated with feeding?

A)sponge : choanocytes
B)Hydra : tentacles
C)snail : radula
D)spider : proboscis

Question 14

Whales house chitinolytic bacteria in their

A)esophagus
B)crop
C)ceca
D)stomach

Question 15

The root cause of beriberi is

A)vitamin C deficiency.
B)thiamine deficiency.
C)niacin deficiency.
D)vitamin D deficiency.

Question 16

Which of the following is the standard unit of measurement that describes the energy of dietary items?

A)joules
B)moles
C)B)T.U.
D)°C

Question 17

Lacking a mouth and digestive system,in many ways the anatomy of this invertebrate resembles that of a gut turned inside out.

A)sponge
B)Hydra
C)cestode
D)sea urchin

Question 18

The most important phagostimulants of insects are

A)Sugars.
B)amino acids.
C)fatty acids.
D)both A and B

Question 19

The same caloric equivalent of a gram of protein or carbohydrate is

A)2 kcal.
B)4 kcal.
C)9 kcal.
D)12 kcal.

Question 20

The bacterium,Clostridium difficile,

A)is readily treated with drugs.
B)is dangerous because it causes severe digestive dysfunction.
C)is outcompeted by ingesting "good" bacteria.
D)A and B

Question 21

Hyperphagy

A)is an important adaptation for survival in all animals,including humans.
B)is common in large mammals,but rare in small mammals and birds.
C)translates into fat deposition,which is important for migration,reproduction,and dormancy.
D)A and C

Question 22

The space between the body wall and the GI tract of vertebrates is known as the

A)gastric vestibule.
B)peritoneal cavity.
C)visceral mass.
D)abdominal lumen.

Question 23

Although derived from three germ layers,the __________ lack coeloms.

A)cnidarians
B)platyhelminths
C)rotifers
D)nematodes

Question 24

The four types of teeth that occur in mammals are the

A)incisors,molars,precanines,and canines.
B)incisors,bicuspids,tricuspids,and canines.
C)incisors,canines,premolars,and molars.
D)incisors,canines,epimolars,and molars.

Question 25

The enamel of the mammalian tooth is composed of crystals of

A)calcium carbonate.
B)calcium fluoride.
C)calcium phosphate.
D)calcium chloride.

Question 26

__________ is a hormone secreted by the stomach that stimulates appetite.

A)Gastrin
B)Ghrelin
C)Leptin
D)Secretin

Question 27

__________ is an appetite-suppressing hormone secreted by white adipose tissue.

A)Gastrin
B)Ghrelin
C)Leptin
D)Secretin

Question 28

Of the cells lining the gastric pits of the stomach,which does NOT secrete a substance into the lumen?

A)mucous neck cells
B)parietal cells
C)chief cells
D)enteroendocrine cells

Question 29

During embryonic development in vertebrates,the foregut gives rise to the

A)esophagus.
B)stomach.
C)anterior region of the duodenum.
D)all of the above

Question 30

Treatments for excessive stomach-acid secretion target the

A)K⁺/H⁺ ATPase proton pump of the parietal cells.
B)H₂ receptors of the parietal cells.
C)neuroendocrine G cells of the stomach that release gastrin.
D)both A and B

Question 31

What is the function of saliva?

A)initiation of enzymatic degradation
B)lubrication and dissolution of ingested food
C)antimicrobial cleansing of the mouth
D)all of the above

Question 32

The interior lining of the stomach is composed of __________ epithelial cells.

A)squamous
B)cuboidal
C)columnar
D)transitional

Question 33

The __________ layer of the intestinal wall is primarily composed of connective tissue.

A)mucosa
B)submucosa
C)circular smooth muscle
D)longitudinal smooth muscle

Question 34

What is the role of the myenteric plexus?

A)regulation of gut motility and enzyme secretion
B)ion and water transport by the gut
C)regeneration of the intestinal epithelium and mucus secretion
D)all of the above

Question 35

Moving from the lumen outward,which of the following describes the correct order of the layers comprising the intestinal wall?

A)mucosa,submucosa,circular smooth muscle,longitudinal smooth muscle
B)circular smooth muscle,longitudinal smooth muscle,mucosa,submucosa
C)circular smooth muscle,mucosa,submucosa,longitudinal smooth muscle
D)submucosa,mucosa,circular smooth muscle,longitudinal smooth muscle

Question 36

A two-way gut system (i.e. ,gastrovascular cavity)is a characteristic of

A)platyhelminths.
B)annelids.
C)arthropods.
D)molluscs.

Question 37

During development in __________,the blastopore develops into the anus and the mouth is secondarily derived.

A)molluscs
B)annelids
C)arthropods
D)echinoderms

Question 38

The beak of birds is covered by a sheath of overlapping keratin scales called the

A)rhamphotheca.
B)rostrum.
C)osculum.
D)manubrium.

Question 39

The upper GI tract of __________ is more complex than that of other vertebrates due to the presence of a crop.

A)sharks
B)amphibians
C)reptiles
D)birds

Question 40

The mechanism of acid secretion by the parietal cells of the stomach involves the actions of the

A)enzyme pepsid anhydrase.
B)K⁺/H⁺ ATPase proton pump.
C)Cl⁻/H⁺ exchanger.
D)all of the above

Question 41

The main metabolic effects of obesity include all but which one of the following?

A)high blood pressure
B)insulin resistance
C)low blood glucose levels
D)low HDL

Question 42

Adipose tissue acts as an endocrine tissue,playing roles related to

A)inflammation.
B)blood clotting and blood pressure.
C)dietary status.
D)all of the above

Question 43

Bile is produced by the __________ and stored in the __________.

Question 44

In one-way digestive tracts,muscular valves called __________ control the passage of food from one compartment to the next.

Question 45

Protein digestion takes place in the __________ and the __________.

Question 46

Which of the following events is most likely to occur when blood glucose levels are high and the pancreas responds by secreting insulin?

A)glycogen breakdown in the liver is stimulated
B)adipose tissue uptake of glucose and its conversion to triglycerides is stimulated
C)down regulation of the GLUT-4 transporter in skeletal muscle
D)all of the above

Question 47

Glucocorticoids serve which of the following functions?

A)induction of gluconeogenesis
B)reduction of glucose uptake by peripheral tissues
C)mobilization of triglycerides in the form of fatty acids
D)all of the above

Question 48

The function of adipokinetic hormone in insects is the

A)mobilization of energy stores of the fat body.
B)stimulation of the corpora cardiacum to release ecdysteroids.
C)conversion of flight muscle proteins into the blood sugar trehalose.
D)all of the above

Question 49

During long-term starvation,

A)glycogen stores become depleted.
B)skeletal muscle experiences protein degradation.
C)fatty acids and amino acids are converted into ketone bodies.
D)all of the above

Question 50

The early embryonic gut of vertebrates is derived from the __________.

Question 51

The surface area of enterocytes is increased by the presence of microscopic protrusions called __________.

Question 52

What accounts for the differences in metabolic rates of animals?

A)body size
B)activity level
C)temperature
D)all of the above

Question 53

The gross energy of food materials can be quantified experimentally using the technique known as __________.

Question 54

The heat generated in the body of an endotherm from its ingested food is known as the __________.

Question 55

The middle layer of the mammalian tooth is a living tissue known as the __________.

Question 56

In the small intestine,the __________ and __________ found in bile act in concert to organize lipids into small droplets called micelles.

Question 57

__________ are lipid complexes synthesized by the cells of the small intestine and released into circulation by way of the lymph.

Question 58

The functional length of the straight gut of a shark is increased by an internal membranous network known as the __________.

Question 59

__________ are most important as part of a metabolic stress response.

A)Glucocorticoids
B)Insulin and glucagon
C)Epinephrine and norepinephrine
D)Acetylcholine and nitric oxide

Question 60

_____________ is the bacterium that causes gastric ulcers.

Question 61

__________ is the hormone antagonist of insulin.

Question 62

Describe the processes by which animals can produce de novo a variety of fatty acids that differ in chain length and desaturation.

Question 63

Describe the processing of vegetation through the stomach of a ruminant.

Question 64

The secretion of pepsinogen by the chief cells of the gastric pits is induced by the hormone __________.

Question 65

When blood glucose levels are high,the __________ cells of the pancreas respond by secreting insulin.

Question 66

Peptide YY,leptin,and ghrelin,the appetite-controlling hormones,exert their effects on the region of the brain called the __________.

Question 67

Insulin insensitivity causes the liver to __________ (increase or decrease)lipid storage.

Question 68

In vertebrates,early starvation is characterized by utilization of stored _____________ and ___________ to meet the metabolic needs of tissues.

Question 69

In the insects,the product of the corpora cardiacum called __________ triggers the mobilization of triglycerides stored in the fat body.

Question 70

Why do animals require lipids for normal physiological function? While animals can produce some fatty acids on their own (de novo),others must be acquired from the diet.Which are the two essential fatty acids that animals cannot manufacture themselves,and what are their sources?

Question 71

What is the mechanism by which the glucose transporter SGLT-1 increases the ability of the small intestine to absorb glucose?

Question 72

Nervous tissue relies almost exclusively on __________ as fuel.

Question 73

Describe the process of the enzymatic digestion of carbohydrates.

Question 74

__________ is the slow wave of contraction that progresses down the GI tract to push food along its length.

Question 75

Describe the various forms of energy that are NOT available from the food an animal ingests.

Question 76

Describe the events of the trypsinogen cascade.

Question 77

What is the importance of digestive enzymes? Briefly describe the four different classes of enzymes that most animals utilize,despite the fact that there is a large variation in diet in the animal kingdom.

Question 78

Pancreatic proteases are produced in an inactive form called __________.

Question 79

Explain how the molecular structure of bile salts permits them to function as emulsifiers.

Question 80

Describe the roles of leptin,ghrelin,and peptide YY in regulating appetite.