Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Z BIO II Exam #3 > Digestive System > Flashcards

Digestive System Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What is animal nutrition?

A

animal nutrition includes the processes by which food is ingested, digested, and absorbed into body cells and fluids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is ingestion?

A

ingestion is the feeding method used to take food into the digestive cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is digestion?

A

digestion is the splitting of carbohydrates, proteins, lipids, and nucleic acids in foods into chemical subunits small enough to be absorbed into an animal’s body fluids and cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

all organisms require sources of ____ and ____ for metabolism, homeostasis, growth, and reproduction

A

Matter and energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

all organisms require sources of matter and energy for ____, ____, ____, and ____

A

metabolism, homeostasis, growth, and reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is feeding?

A

for animals, meeting these nutritional requirements involves feeding, the uptake of food from the surroundings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What happens to food once it is ingested?

A

once food is ingested, digestive processes convert its molecules into absorbable subunits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are herbivores?
Examples?

A

herbivores such as antelopes, horses, bison, giraffes, kangaroos, manatees, and grasshoppers obtain organic molecules primarily by eating plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are carnivores?
Examples?

A

carnivores such as cats, Tasmanian devils, penguins, sharks, and spiders, primarily eat other animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are omnivores?
Example?

A

such as crows, cockroaches, and humans, eat both plants and animals and, with appropriate digestive enzymes, may consume any source of organic matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is energy described?

A

energy requirements are described in terms of calories

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How much is a calorie and a Calorie?

A

a calorie is the amount of energy required to raise the temperature of 1 g of pure water by 1°C
a kilocalorie [1 kcal = 4.2 kilojoules] equals 1,000 calories or one Calorie (capital C)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How many calories is fat, protein, and carbs?

A

carbohydrates contain about 4.2 kcal per gram, fats about 9.5 kcal per gram, and proteins about 4.1 kcal per gram

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is undernutrition?

A

animals whose intake of organic fuels is inadequate, or whose assimilation of such fuels is abnormal, suffer from undernutrition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is malnutrition?

A

undernutrition is a form of malnutrition, a condition resulting from an improper diet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is overnutrition?

A

overnutrition, the condition caused by excessive intake of specific nutrients, is another type of malnutrition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

an animal suffering from undernutrition is starving for ____ ____ ____ ____ – taking in fewer calories than needed for daily activities

A

one or more nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens in animals with chronic undernutrition?

A

animals with chronic undernutrition lose weight because they have to use energy-providing molecules of their own bodies as fuels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What do mammals used for food when undernourished?
What does this lead to?

A

mammals use stored fats and glycogen first, then proteins

use of proteins as fuel leads to muscle wastage and, in the long term, organ and brain damage, which leads to death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What do organic molecules serve as building blocks for?

A

organic molecules serve as building blocks for carbohydrates, lipids, proteins, and nucleic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is it called when an animal cannot synthesize an organic molecule?

What is an example if an animal does not get these molecules?

A

animals synthesize many organic molecules – however, they cannot make certain essential amino acids and essential fatty acids, which must be obtained in the diet

EXAMPLE: In the absence of essential amino acids in the diet, an animal would have to break down its own proteins to provide amino acids for new protein synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are vitamins?
What is there general function?

A

vitamins are organic molecules required in small quantities that the animal cannot synthesize for itself

many are coenzymes, nonprotein
organic subunits that assist in enzymatic catalysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are essential minerals?

A

essential minerals are required inorganic elements such as calcium, iron, and magnesium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are essential nutrients?
What do the vary between?

A

essential amino acids, fatty acids, vitamins, and minerals are known collectively as an animal’s essential nutrients

the list of essential nutrients differs from animal to animal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are fluid feeders?
Example?

A

fluid feeders ingest liquids that contain organic molecules in solution (e.g., mosquitoes, hummingbirds)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are suspension feeders?
Example?

A

suspension feeders ingest small organisms that are suspended in water (e.g., clams, baleen whales)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are deposit feeders?
Example?

A

deposit feeders ingest particles of organic matter from solid material they live in or on (e.g., earthworms, crabs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are bulk feeders?
Example?

A

bulk feeders consume sizeable food items whole or in large chunks (most adult mammals, reptiles, birds, amphibians)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the four types of feeder?

A

fluid
suspension
deposit
bulk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What does the digestive process do?

A

digestive processes break food molecules into molecular subunits that can be absorbed into body fluids and cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What does the breakdown of food molecules occur by?

A

breakdown occurs by enzymatic hydrolysis, in which chemical bonds are broken by the addition of H+ and OH–

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is enzymatic hydrolysis?

A

Enzymatic hydrolysis is the breakdown of a compound in presence of enzymes following its reaction with water

Hydrolysis reactions are the reverse of condensation reactions. In a hydrolysis reaction, a larger molecule forms two (or more) smaller molecules and water is consumed as a reactant. Hydrolysis (“hydro” = water and “lysis” = break) involves adding water to one large molecule to break it into multiple smaller molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Function:
amylase?
lipases?
proteases?
nucleases?

A

amylases hydrolyze starches
lipases hydrolyze fats and other lipids
proteases hydrolyze proteins
nucleases hydrolyze nucleic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

sponges and some cnidarians break down food exclusively by ____ ____

A

intracellular digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the four step process of intracellular digestion?

A

cells take in food particles by endocytosis

an endocytic vesicle containing food particles fuses with a lysosome

containing hydrolytic enzymes
molecular subunits produced by hydrolysis pass from the vesicle to the cytosol

undigested material remaining in the vesicle is released to the outside of the cell by exocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

most invertebrates and all vertebrates digest food primarily by ____ ____

A

extracellular digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are features of extracellular digestion?

A

specialized compartments prevent the animal from digesting its own body tissues

epithelial cells secrete enzymes that digest the food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is extracellular digestion?

A

extracellular digestion – outside body cells, in a pouch or tube that is enclosed within the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is benefit of extracellular digestion?

A

extracellular digestion greatly expands the range of available food sources, and allows animals to eat large batches of food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

____ and ____ (____) have a saclike digestive system with a single opening (a mouth) which serves both as the entrance for food and the exit for undigested material

A

flatworms and cnidarians (jellyfish)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What type of digestive system do flatworms and cnidarians (jellyfish) feature?

A

flatworms and cnidarians (jellyfish) have a saclike digestive system with a single opening (a mouth) which serves both as the entrance for food and the exit for undigested material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What system do flatworms and cnidarians lack?

How do they circulate nutrients to make up for this?

A

these animals lack a separate vascular system – water taken into the gastrovascular cavity circulates nutrients and other materials through the various tissue layers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

flatworms and cnidarians (jellyfish) lack a separate vascular system – water taken into the ____ ____ circulates nutrients and other materials through the various tissue layers

A

gastrovascular cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

In flatworms and cnidarians (jellyfish) where does digestion begin and where is it completed?

A

digestion begins in the gastrovascular cavity, and is completed intracellularly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

most invertebrates and all vertebrates have a ____ ____ ____ ____ with two openings – the digestive contents move in one direction, from the ____ to the _____

A

tubular digestive tract system

mouth to the anus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

the inside of the digestive tube (____) is functionally ____ to all body tissues (outside of the body)

A

lumen . . . external

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Mechanical processing?

A

Mechanical processing:
chewing, grinding, and tearing food chunks into smaller pieces increases their mobility and the surface area exposed to digestive enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Secretion of enzymes and other digestive aids?

A

release of enzymes and other substances that aid the process of digestion, such as acids, emulsifiers, and lubricating mucus, into the tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Enzymatic hydrolysis?

A

food molecules are broken down through enzyme-catalyzed reactions into absorbable molecular subunits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Absorption?

A

the molecular subunits are absorbed from the digestive contents into body fluids and cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Elimination?

A

undigested materials are expelled through the anus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What are five steps of digestion?

A

mechanical processing
secretion of enzymes and other digestive aids
enzymatic hydrolysis
absorption
elimination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What type of feeder is an earthworm? What does it feed on?

A

earthworm is a deposit feeder that feeds on soil particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

5 main steps of earthworm digestion?

A
  1. muscular activity moves particles through the esophagus into the crop, where they are stored and mixed with mucus
  2. this mixture enters the gizzard, which contains grains of sand, and is ground into fine particles
  3. the mixture enters a long intestine, where organic matter is hydrolyzed by enzymes
  4. muscular contractions move the mixture along
    cells lining the intestine absorb molecular subunits
  5. undigested residue is expelled through the anus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

How do grasshoppers initially ingest food?

A

the grasshopper tear plant parts into small particles with hard external mouth parts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is the digestive process of a grasshopper?
What structures does the plant material (food) pass through?

A
  1. salivary secretions in the pharynx begin digestion
  2. food moves through the esophagus, crop, and gizzard to the stomach, where it is hydrolyzed by enzymes in gastric ceca
  3. products are absorbed through walls of the ceca
  4. undigested contents move to the intestine for further digestion and absorption
  5. at the end of the intestine, water is absorbed and remnants are expelled through the anus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What do pigeons pick up and swallow whole?

A

a pigeon picks up seeds and swallows them whole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Digestive system of pigeon?

A
  1. seeds are moistened by mucus-filled saliva in the mouth
  2. seeds pass through the pharynx and tubelike anterior end of the esophagus to the pouchlike crop, which stores food
  3. the glandular anterior portion of the stomach (proventriculus) secretes digestive enzymes and acids
  4. seeds are ground up in the posterior end (gizzard)
  5. in the intestine, the liver secretes bile and the pancreas adds digestive enzymes
  6. products are absorbed, and undigested residues are expelled through the anus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What does the human digestive system provide?

A

the human digestive system provides fuel molecules and a wide range of nutrients, including the molecular building blocks of carbohydrates, lipids, proteins, and nucleic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What does types of nutrients does the digestive system absorb?

Can these nutrients be synthesized in the human body?

A

the digestive system also absorbs essential nutrients (amino acids, fatty acids, vitamins, and minerals) that cannot be synthesized within our bodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What is the mammalian digestive system under the control of?

What are the structures with this system in order?

A

the mammalian digestive system is a series of specialized digestive regions under control of the nervous and endocrine systems: the mouth, pharynx, esophagus, stomach, small and large intestines, rectum, and anus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What are accessory organs of digestive system?

A

accessory organs include the salivary glands, exocrine pancreas, liver, and gallbladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Is the digestive system identical between animals?

A

the digestive system is not identical in all mammals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

How many essential amino acids? Name three?

A

there are 8 essential amino acids for adult humans: lysine, tryptophan, phenylalanine, threonine, valine, methionine, leucine, and isoleucine –

infants and young children also require histidine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What foods supply all essential amino acids?

A

proteins in fish, meat, egg whites, milk, and cheese supply all essential amino acids when eaten in adequate quantities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What is wrong with plan protein?
How to remedy this?

A

proteins of many plants are deficient in one or more essential amino acids, but certain combinations of plants, when taken together, contain all essential amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What are two essential fatty acids?

A

2 fatty acids, linoleic acid and linolenic acid, are essential in the human diet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What are essential fatty acids required for?

A

both are required for synthesis of phospholipids that form parts of biological membranes and certain hormones

69
Q

What is risk of low fat diet?

A

almost all foods contain these fatty acids – however, people on a low-fat diet that is deficient in linoleic acid and linolenic acid are at serious risk for developing coronary heart disease

70
Q

How many known vitamins?

A

humans require 13 known vitamins in their diet

71
Q

What general function of vitamins?

A

many metabolic reactions depend on vitamins, and the absence of one vitamin can affect the functions of others

72
Q

What two general categories of vitamins?

A

vitamins fall into two classes: water-soluble (hydrophilic) vitamins and fat-soluble (hydrophobic) vitamins

73
Q

Are vitamins stored in the body?

A

the body stores fat-soluble vitamins in adipose tissues – any amount of water-soluble vitamins above daily nutritional requirements is excreted in the urine

74
Q

Where do most people get vitamins from?

A

most people get enough vitamins through a normal and varied diet that includes meats, fish, eggs, cheese, and vegetables

75
Q

Who may need vitamin supplements?

A

supplements are usually necessary only for strict vegetarians, newborns, the elderly, and when taking certain medications

76
Q

What is unique about vitamin D?

A

vitamin D differs from other vitamins because humans can synthesize it in the skin when exposed to ultraviolet light

77
Q

What is unique about vitamin K?

A

humans cannot make vitamin K, but much of the requirement is supplied by bacterial activity in the large intestine

78
Q

Vitamin A:
Common Source?
Main Function?
Effects of Deficiency?

A

Liver; fish oils; milk; eggs. (Beta-carotene, which is converted to vitamin A in the body, is in many plant foods such as sweet potato, spinach, and carrots.)

Component of visual pigments; bone metabolism; epithelial tissue maintenance

Night blindness; total blindness; skin disorders; decreased immunity

79
Q

Vitamin D:
Common Source?
Main Function?
Effects of Deficiency?

A

Fish liver oil; egg yolk; fortified milk; produced in skin exposed to sunshine

Calcium and phosphorus absorption from gut

Bone deformities (rickets) in children; bone softening in adults

80
Q

Vitamin E:
Common Source?
Main Function?
Effects of Deficiency?

A

Nuts; seeds; vegetable oils

Antioxidant; maintenance of cell membranes

Neuromuscular problems

81
Q

Vitamin K:
Common Source?
Main Function?
Effects of Deficiency?

A

Intestinal bacteria; green vegetables

Promotes synthesis of blood-clotting protein by liver

Abnormal blood clotting, bleeding

82
Q

Vitamin B1:
Common Source?
Main Function?
Effects of Deficiency?

A

Thiamine

Yeast; cereal grains; beans; nuts; meat

Connective tissue formation; needed for folate utilization; coenzyme forming part of enzyme in oxidative reactions

Beriberi (nervous system disorder that includes impaired sensory perception, limb weakness and pain, weight loss, cardiovascular malfunction)

83
Q

Vitamin B2:
Common Source?
Main Function?
Effects of Deficiency?

A

Riboflavin

Whole grains, poultry, fish, egg white, milk, lean meat

Coenzyme

Skin lesions

84
Q

Vitamin B3:
Common Source?
Main Function?
Effects of Deficiency?

A

Niacin

Fruits and vegetables; nuts; grains; meats

Coenzyme of oxidative phosphorylation

Pellagra (diarrhea, dermatitis, dementia)

85
Q

Vitamin B5:
Common Source?
Main Function?
Effects of Deficiency?

A

Pantothenic acid

In many foods (meat, yeast, egg yolk especially)

Coenzyme in carbohydrate and fat oxidation; fatty acid and steroid synthesis

Fatigue; tingling in hands; headaches; nausea

86
Q

Vitamin B6:
Common Source?
Main Function?
Effects of Deficiency?

A

Pyridoxine

Spinach, whole grains, tomatoes, potatoes, meat

Coenzyme in amino acid and fatty acid metabolism

Skin, muscle, and nerve damage

87
Q

Vitamin B7:
Common Source?
Main Function?
Effects of Deficiency?

A

Biotin

Legumes; egg yolk; some synthesized by colon bacteria

Coenzyme in fat and glycogen formation and amino acid metabolism

Scaly skin (dermatitis); sore tongue; brittle hair; depression; weakness

88
Q

Vitamin B9:
Common Source?
Main Function?
Effects of Deficiency?

A

Folic acid

Leafy vegetables; legumes; whole grains; yeast; liver; egg yolks

Coenzyme in nucleic acid and amino acid metabolism

Megablastic anemia

89
Q

Vitamin B12:
Common Source?
Main Function?
Effects of Deficiency?

A

Cobalamin

Eggs; meats; dairy products

Coenzyme in nucleic acid metabolism; red blood cell formation

Anemia; brain and nervous system damage

90
Q

What are the doses of macro and trace minerals?

A

many minerals are essential in the human diet:

macrominerals are required in large amounts (50 mg to more than 1 gram per day)

trace minerals are required in small amounts (some less than 1 mg per day)

91
Q

What forms are minerals typically ingested in?

Overdose cause?

A

all minerals are ingested as compounds or as ions in solution

overdoses of some minerals (e.g., iron, sodium) can cause various problems

92
Q

Ca:
Common Source?
Main Function?
Effects of Deficiency?

A

Calcium (Ca)

legumes; whole grains; nuts; dairy products; eggs

Bone and tooth formation; blood clotting; neural and muscle action

Stunted growth; loss of bone mass

93
Q

Cl:
Common Source?
Main Function?
Effects of Deficiency?

A

Chlorine (Cl)

Table salt; vegetables; meat; dairy products; eggs

HCl formation in stomach; contributes to body’s acid–base balance; necessary for neural function and water balance

Muscle cramps; impaired growth; poor appetite

94
Q

Mg:
Common Source?
Main Function?
Effects of Deficiency?

A

Magnesium (Mg)

Green leafy vegetables; legumes; nuts; dairy products; meat

Required for many enzymes; in bones and teeth; ATP processing

Weak, sore muscles; nervous system problems

95
Q

P:
Common Source?
Main Function?
Effects of Deficiency?

A

Phosphorus (P)

Whole grains; legumes; nuts; dairy products; eggs; meats

In bones and teeth; component of nucleic acids, ATP, and phospholipids; energy processing

Muscular weakness; loss of minerals from bone

96
Q

K:
Common Source?
Main Function?
Effects of Deficiency?

A

Potassium (K)

Many vegetables and fruits; whole grains; dairy products

Muscle and neural function; water balance; acid– base balance; main positive ion in cell

Muscular weakness; cardiac abnormalities or failure

97
Q

Na:
Common Source?
Main Function?
Effects of Deficiency?

A

Sodium (Na)

Table salt; dairy products; eggs; meat

Acid–base balance; water balance; muscle and neural function; main positive ion in extracellular fluid

Muscle cramps

98
Q

S:
Common Source?
Main Function?
Effects of Deficiency?

A

Sulfur (S)

Proteins from food sources, including legumes, nuts, dairy products, eggs, and meat

Component of body proteins

Same as protein deficiencies

99
Q

I:
Common Source?
Main Function?
Effects of Deficiency?

A

Iodine (I)

Seafood; iodized salt

Thyroid hormone formation

Goiter (enlarged thyroid), with metabolic disorders

100
Q

Fe:
Common Source?
Main Function?
Effects of Deficiency?

A

Iron (Fe)

Green leafy vegetables; legumes; whole grains; nuts; eggs; meats (particularly liver)

Component of hemoglobin, myoglobin, and electron carriers

Iron-deficiency anemia; weakness

101
Q

Zn:
Common Source?
Main Function?
Effects of Deficiency?

A

Zinc (Zn)

Some vegetables; whole grains; legumes; nuts; fish; meats; many other foods

Component of many enzymes and some transcription factors; protein synthesis; DNA synthesis; cell division; immunity; wound healing

Impaired growth; loss of appetite; impaired immune function

102
Q

What are 7 macrominerals?

A

Ca
Cl
Na
K
Mg
P
S

103
Q

What are 3 trace minerals?

A

Iodine
Iron
Zinc

104
Q

4 layer of digestive tract

A

Mucosa
Submucosa
Muscularis
Serosa

105
Q

What is the mucosa?
What does it contain/what type of cells?
What is the function?

A

the mucosa, which contains epithelial and glandular cells, lines the inside of the gut

epithelial cells, which absorb digested nutrients, seal off the digestive contents from body fluids

106
Q

What do glandular cells in the mucosa do?

A

glandular cells secrete enzymes, lubricating mucus that aids digestion, and substances that adjust the pH of the digestive contents

107
Q

What is the submucosa?
What does it contain?
What type of tissue?
Function?

A

the submucosa is a thick layer of elastic connective tissue that contains neuron networks and blood and lymph vessels

neuron networks provide local control of digestive activity and carry signals between the gut and the central nervous system

108
Q

What do lymph vessels do in relation to the digestive system?

A

lymph vessels carry absorbed lipids to other parts of the body

109
Q

What is the muscularis?
What forms it?
What two layers?
Function?

A

in most regions of the gut, the muscularis is formed by two smooth muscle layers, a circular layer and a longitudinal layer

contraction of circular muscles and relaxation of the longitudinal muscles lengthens the gut, and vice versa

these muscles produce peristalsis – a wave of contractions that passes along the gut, constricting the gut and pushing the digestive contents onward

110
Q

What action do smooth muscle of gut produce?

A

these muscles produce peristalsis – a wave of contractions that passes along the gut, constricting the gut and pushing the digestive contents onward

111
Q

What is serosa?
Type of tissue?

A

the outermost gut layer, the serosa, consists of connective tissue that secretes a slippery fluid that lubricates the areas between the digestive organs and other organs

112
Q

What is the serosa continuous with?
What does this tissue do?

A

along much of the length of the digestive system, the serosa is continuous with the mesentery, a tissue that suspends the digestive system from the inner wall of the abdominal cavity

113
Q

What forms separations between major regions of the digestive tract?

A

powerful rings of smooth muscle called sphincters form valves between major regions of the digestive tract

114
Q

What do sphincters do?

A

by contracting and relaxing, sphincters control the passage of digestive contents from one region to the next, and ultimately through the anus

115
Q

What is sphincter between stomach and small intestine?

A

Pyloric sphincter

116
Q

What is another name for chewing?

A

Mastication

117
Q

What process do teeth assist in?

A

teeth cut, tear, and crush food items into small pieces during mastication (chewing)

118
Q

What is food prepared into before swallowing?

A

the food mass forms a bolus, a ball of chewed or liquid food, in preparation for swallowing

119
Q

What secretes saliva?
What is in saliva? (4)

A

salivary glands secrete saliva containing salivary amylase (which hydrolyzes starches), mucus, bicarbonate ions (HCO3–), and lysozyme (which kills bacteria)

120
Q

When does the swallowing reflex start?

A

Swallowing reflex begins
when bolus reaches the pharynx.

121
Q

the ____ ____ moves the bolus into the pharynx

the ____ prevents food from entering the trachea

____ in the esophagus moves the bolus downward and through the ____ ____

imperfect closure of the sphincter can result in acidic stomach contents reentering the esophagus, producing ____ ____(heartburn)

A

the swallowing reflex moves the bolus into the pharynx

the epiglottis prevents food from entering the trachea

peristalsis in the esophagus moves the bolus downward and through the gastroesophageal sphincter

imperfect closure of the sphincter can result in acidic stomach contents reentering the esophagus, producing acid reflux (heartburn)

122
Q

9 phases of swallowing?

A
  1. The pharyngoesophageal
    sphincter muscle is contracted, closing the esophagus, the epiglottis is up, and the glottis is open to let air enter the lungs.
  2. Swallowing reflex begins
    when bolus reaches the pharynx.
  3. Elevation of soft palate
    prevents food bolus from
    entering nasal passages.
  4. Pressure of tongue seals
    back of mouth and prevents
    bolus from backing up.
  5. Larynx moves upward, pushing glottis against epiglottis to prevent bolus from entering airway.
  6. Pharyngoesophageal sphincter muscle relaxes, permitting bolus to enter the esophagus.
  7. Once food is in the
    esophagus, the structures of the
    mouth and pharynx reset to the
    non-swallowing state.
  8. Circular muscles of the
    esophagus contract behind the
    food, constricting the esophagus
    and blocking upward movement.
  9. Longitudinal muscles of the
    esophagus contract, opening up
    the esophagus. In concert with the
    constricting circular muscles, this
    pushes the bolus down the
    esophagus. A series of alternating
    contractions and relaxations of the
    circular and longitudinal muscles
    produces peristaltic waves that
    move the bolus to the stomach.
123
Q

What does the stomach do?

A

Stomach - stores food and adds digestive secretions

124
Q

What is the mucosal layer of the stomach covered with?

A

the mucosal layer (epithelium) is covered with gastric pits containing gastric glands

125
Q

What three things do stretch receptors in the stomach stimulate?
What cells produce these three things?

A

stretch receptors stimulate secretion of gastric juice containing pepsinogen (precursor of pepsin), hydrochloric acid (HCl), and lubricating mucus

chief cells in gastric pits secrete pepsinogen

parietal cells secrete H+ and Cl–

mucous cells secrete alkaline mucus that protects the stomach lining (epithelium)

126
Q

What is stomach ulcer caused by, what does it cause, and what is treatment?

A

the bacterium Helicobacter pylori lives in the highly acid environment of the stomach

in some people, H. pylori breaks down the mucous barrier, exposing the stomach wall to attack by HCl and pepsin

the resulting peptic or stomach ulcer, causes stomach bleeding and pain

ulcers are treated with an antibiotic that kills H. pylori

127
Q

What combine in the lumen of the stomach and what does this do functionally?

A

H+ and Cl– form HCl in the lumen of the stomach – lowering the pH to 2 or lower, which converts pepsinogen to pepsin

128
Q

What does pepsin do?

A

pepsin begins protein digestion by breaking polypeptide chains

129
Q

What is partially digested food in stomach called?

A

the partially digested mixture of food and gastric juices in the stomach is called chyme

130
Q

What is between stomach and small intestine?
What moves chyme through this structure?

A

peristaltic contractions of the stomach wall move chyme through the pyloric sphincter into the small intestine

131
Q

What is the main function of small intestine?

A

most absorption begins, and digestion is completed, in the small intestine

132
Q

What lines the small intestine?
What is the purpose of these structures?

A

the lining folds into ridges covered by microscopic extensions (intestinal villi)

epithelial cells covering the villi have a brush border of fingerlike projections of plasma membrane (microvilli)

intestinal villi and microvilli increase the absorptive surface area of the small intestine to as much as 300 m2 – about the size of a doubles tennis court

133
Q

secretions from the ____ (which are stored in the ____) and the ____ enter a common duct that empties into the lumen of the first segment of the small intestine (the ____)

A

secretions from the liver (stored in the gallbladder) and the pancreas enter a common duct that empties into the lumen of the first segment of the small intestine (the duodenum)

134
Q

What does exocrine pancreas secrete?

A

exocrine cells in the pancreas secrete bicarbonate ions (H2CO3–) to neutralize acid in the chyme, and pancreatic enzymes (proteases, an amylase, nucleases, and lipases)

135
Q

What are the active forms of the proteases secreted by pancreas?

A

proteases are secreted in inactive precursor forms – active forms are trypsin, chymotrypsin, and carboxypeptidase

136
Q

What does the liver secrete?

A

the liver secretes bicarbonate ions and bile – a mixture of substances including bile salts, cholesterol, and bilirubin

137
Q

What is the function of bile salts?

A

bile salts form a hydrophilic coating around fats which allows them to be to emulsified into tiny droplets

138
Q

What does lipase do? Where is it secreted from?

A

lipase, a pancreatic enzyme, hydrolyzes the fats in micelles into monoglycerides and free fatty acids

139
Q

What give bile its color? What does this come from?

A

bilirubin, the yellow pigment that gives bile its color, is a waste product derived from worn-out red blood cells

140
Q

What happens in brush-border epithelial cells?

A

products of digestion in the lumen are transported across the plasma membranes of brush-border epithelial cells, which produce enzymes that complete digestion

141
Q

Disaccharidases?

A

disaccharidases break maltose, lactose, and sucrose into individual monosaccharides

142
Q

Aminopeptidases?

A

aminopeptidases hydrolyze small peptides to individual amino acids

143
Q

Nucledotidases?

A

nucleotidases break nucleic acids into nucleosides

144
Q

Nucleosidases?

A

nucleosidases convert nucleosides to nitrogenous bases, five-carbon sugars, and phosphates

145
Q

What is between the small and large intestine?

A

The ileocecal valve-a sphincter between the small and large intestines controls the passage of materials into the large intestine

146
Q

at the junction with the small intestine, part of the large intestine forms a blind pouch called the ____

A

cecum

147
Q

What comes of the cecum?

A

appendix

148
Q

What does the cecum merge with?

A

the cecum merges with the colon, which forms an inverted U

149
Q

What are the final segments of the large intestine?

A

the final segment of the large intestine is the rectum, which terminates at the anal sphincter

150
Q

What does the large intestine do?

A

the large intestine secretes mucus and bicarbonate ions and absorbs water and other ions, primarily sodium and chloride

151
Q

What does the absorption of water in the large intestine do?

A

the absorption of water condenses and compacts the digestive contents into solid masses (feces)

152
Q

What is else is contained in feces besides for waste?
What percent is this?
What do these do?

A

in vertebrates, 30-50% of the dry matter of feces consists of intestinal bacteria, which metabolize sugars and other nutrients and produce useful fatty acids and vitamins (such as vitamin K and the B vitamins folic acid and biotin)

153
Q

What do intestinal bacteria do?

A

intestinal bacteria metabolize sugars and other nutrients remaining in the digestive residue, and produce useful fatty acids and vitamins

their activity also produces large quantities of gas (flatus) primarily CO2, methane, and hydrogen sulfide

154
Q

What happens to gas produced by intestinal bacteria?

A

most of the gas is absorbed through the intestinal mucosa, and the rest is expelled through the anus in the process of flatulence

155
Q

What happens when feces enter the rectum?

A

when feces enter the rectum, they stretch the rectal wall; the stretching triggers a defecation reflex that opens the anal sphincter and expels the feces through the anus

156
Q

What does human digestion provide humans?

A

the human digestive system provides fuel molecules and a wide range of nutrients, including the molecular building blocks of carbohydrates, lipids, proteins, and nucleic acids

the digestive system also absorbs essential nutrients (amino acids, fatty acids, vitamins, and minerals) that cannot be synthesized within our bodies

157
Q

What does an animals dentition reflect?

In what species is tooth specialization evident in?

A

an animal’s dentition reflects its diet, feeding method, habitat and life style

tooth specialization is especially evident among mammals, which have four types of teeth:

158
Q

What are four types of teeth?
Function

A

incisors, at the front of the mouth, are chisel-shaped – used to nip or cut food

pointed canines at the sides of the incisors are specialized for biting and piercing

premolars and molars, at the sides of the mouth, crush and grind food

159
Q

What the difference between carnivore and herbivore digestive tract?

A

vertebrates that feed primarily on nutrient-rich foods such as meat, blood, nectar, or insects (including carnivores) have a relatively short intestine

herbivores (e.g., rabbits) have a long intestinal tract and specializations of the esophagus, stomach, cecum, or other structures that store large volumes of plant material

160
Q

What is microbiome?

A

microbiomes are the complete collections of microorganisms associated with a particular organism

161
Q

What do microbiomes consist of?

A

microbiomes consist mostly of bacteria, but archaea, protists, yeasts and other fungi, and viruses may also be present

162
Q

What does microbiome play an important role in?

A

microbiomes in digestive tracts — gut microbiomes — play important roles in digestion in many organisms

163
Q

unlike vertebrates, many microorganisms can synthesize ____, the enzyme that hydrolyzes the cellulose of plant cell walls into glucose subunits

many ____ use microorganisms to aid digestion of plant material, housing them in specialized structures of the esophagus, stomach, or cecum

this is an example of ____; the herbivores benefit from the digestive abilities of the microorganisms, and the microorganisms benefit from an abundant supply of nutrients

A

cellulase

herbivores

mutualism

164
Q

What are ruminants?
Examples?

A

ruminants such as cattle, deer, goats, sheep and antelopes have a complex, four-chambered stomach

165
Q

Where do boluses of plant matter go in ruminants?

What is in here and what happens?

A

boluses of plant matter may go to the rumen or to the reticulum – both of which have symbiotic microorganisms that hydrolyze cellulose for fermentation reactions

fermentations generate nutrients (alcohols, amino acids, fatty acids) and methane gas, a byproduct

166
Q

a ruminant “____ ____ ____” – it regurgitates material from the rumen and reticulum, rechews it, and swallows it again

A

chews its cud

167
Q

Where does reswallowed cud by?

A

reswallowed cud bypasses the rumen and reticulum and goes to the omasum, where water is absorbed

168
Q

What is the fourth part of a ruminant stomach and what happens here?

A

matter then moves to the abomasum (the gastric stomach), where acids and pepsin kill microorganisms and start the process of typical vertebrate digestion

the dead microorganisms are a rich source of proteins, vitamins, and other nutrients

Z BIO II Exam #3 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions