Ch21 Nutrition And Digestion

Front 1

define HERBIVORES

Back 1

eat mainly autotrophs: plants and algae

Front 2

define CARNIVORES

Back 2

eat other animals

Front 3

define OMNIVORES

Back 3

animals that ingest both plants and animals

Front 4

define SUSPENSION FEEDERS

Back 4

feeders taht extract food particles suspended in th esurrounding water

Front 5

define SUBSTRATE FEEDERS

Back 5

feeders that live in or on their food source and eat their way through it

Front 6

define FLUID FEEDERS

Back 6

feeders that obtain food by sucking nutrient-rich fluids from a living host, either a plant or an animal

Front 7

define BULK FEEDERS

Back 7

ingest large pieces of food

Front 8

define INGESTION

Back 8

act of eating, first stage

Front 9

define DIGESTION

Back 9

breaking down of food into molecules small enough for the body to absorb

two phases

Front 10

what are the two phases of digestion?

Back 10

1. food may be mechanically broken into smaller peices. chewing or tearing breaks large chunks of food into smaller ones.
2. chemical breakdown process called HYDROLYSIS. catalyzed by specific enzymes, hydrolysis breaks chemical bonds in food molecules by adding water to them

Front 11

what does th eorganic matter in food consist of?

Back 11

proteins, fats, and carbs-- large polymers

Front 12

why can't animals use organic matter directly?

Back 12

1. as macromolecules, these polymers are too large to pass through plasma membranes and enter cells.
2. an animal needs monomers to make the polymers of its own body.

Front 13

all organims use the same monomers to make their polymers

Back 13

everyone makes their porteins from teh same 20 kinds of amino acids.

Front 14

digestion in an aimal breaks th emacromolcules in food into their component monomers

Back 14

-protiens are split into amino acids, polysaccharides and disaccharides are split into monsaccharides
-nucleic acis split into nucleotides
-fats are split into glycerol and fatty acids

Front 15

define ABSORPTION

Back 15

third stage, cells lining th digestinve tract take up the products of digestion-- small molecules such as amino acids and simple sugars
-these nutrients travel in the blood to body cells, wehre they are joined together to make the macromolecules of the cells or broken down futher to provide energy. some nutriett molcules are converted to fat for storage.

Front 16

define ELIMINATION

Back 16

fourth and last stage, undigested material passes out of the digestive tract

Front 17

how can an animal digest food w/o digesting its own cells and tissues?

Back 17

digestive enzymes hydrolyze the same biological materials taht animals are made of- it is obv important to aavoid digesting oneself. animals avoid the risk of self-digestion by processing food in specialized compartments.

Front 18

what are hte two main digestive processes?

Back 18

mechanical breakdown

chemical breakdown

Front 19

what are the four main stages of food processing/

Back 19

1. ingestion
2. digestion
3. absorption
4. elimination

Front 20

what are the simplest digestive compartments

Back 20

food vacuoles

Front 21

how does a cell engulf food?

Back 21

phagocytosis

Front 22

define GASTROVASCULAR CAVITY

Back 22

a digestive compartment with a single opening, the mouth

Front 23

process occuring in the gastrovastular cavity

Back 23

1. Gland cells lining the gastrovascular cavity secrete digestive enzymes that
2. break down the soft tissues of the prey
3. othe cells enguolt fmall food particles, which
4. are broken down in food vacuoles.
undigested materials are expelled through the mouth

Front 24

define ALIMENTARY CANAL

Back 24

a digestive tube with two openings, a mouth and an anus

Front 25

define PHARYNX

Back 25

throat

Front 26

define ESOPHAGUS

Back 26

channels food to a crop, gizzard, or stomach

Front 27

define CROP

Back 27

pouch-like organ in which food is softended and stored

Front 28

defien STOMACHS and GIZZARDS

Back 28

store food temporarly, more muscular and churn and grind food

Front 29

define INTESTINE

Back 29

wehre chemcial digestion and nutrient absorption occur

Front 30

define ANUS

Back 30

where undigested materials are expelled

Front 31

what is the advantage of an alimentary canal, compared to a gastrovascular cavity?

Back 31

specialized regions can carry out digestion and absorption sequentially

Front 32

what is the main parts of the alimentary anal?

Back 32

mouth, oral cavity, tongue, pharynx, esphagus, stomach, small intestine, large intestine, rectum, and anus

Front 33

what are the digestive glands?

Back 33

salivary glands, pancreas, and liver

they secrete digestive juices that enter the alimentary canal through ducts. secretions from the liver are stored in the gallbladder b4 they are released into the intestine

Front 34

once food is swallowed, muscles protpel it through the alimentary canaly by PERISTALSIS, which are?

Back 34

rhythmic waves of contraction of smooth muscles in the walls of the digestive tract

Front 35

in only 5-10 secs, food passes from they pharynx down the esophagus and into the stomach. then what?

Back 35

a constriction at th ebase of the esophagus keeps food in the stomach

Front 36

a musclular ringlike valve, called the PYLORIC SPHINCTER, which

Back 36

regulates th epassage of food out of the stomach and into the small intestine

-works like a drawstring, closing off th tube and keeping food in the stomach long enough for stomach acids and enzymes to begin digestion

Front 37

the final stesp of digestion and nutrient absorption occur in the small intestine over a period of 5-6 hours

Back 37

undigested material moves slowly through the large intestine 12-24 hrs and feces are expelled through the anus

Front 38

what is peristaalsis, and what is its funciton in our digestive system?

Back 38

wavelike contractiosn of smooth muscle that we move food along th ealimentary canal

Front 39

how is saliva made?

Back 39

the savlivary galnds respond to the sigt, smell, or even though of food. the presence of food in the oral cavity stimulates salivation.

liter in a day

Front 40

what is saliva consist of? and how does it help in food processing

Back 40

-a slippery glycoprotein protects the soft lining of hte mouth and lubricates food for easier swallowing. buffers neutralize food acids, helping prevent tooth deca.
-antipbacterial agents kill the bactiera that enter hte mouth w/ food

Front 41

define SALIVARY AMYLASE

Back 41

a digestive enzyme that begins hydrolyszing

Front 42

where does mechanical and chemical digestion begin?

Back 42

in the oral cavity

Front 43

what are the front incisors used for?

Back 43

used for biting into food like apples

Front 44

behind th eincisors is a single pointed canine tooth

Back 44

next come two premolars and three molasrs which grind and crush the food

Front 45

define TONGUE

Back 45

muscular organ covered w/ taste buds
-manipulates food and helps shape it into a ball called a BOLUS

Front 46

chewing functions in _____________-- digestino, and salivary amylase initiates the chemical digestion of _

Back 46

mechanical

starch

Front 47

define TRACHEA

Back 47

windpipe

Front 48

opeins of both the esophagus aed the trachea are where?

Back 48

in the pharynx

Front 49

most of the time the esophageal opening is open or closed?

Back 49

dclosed of fby a sphincter, and air enters the trachea and procceeds to the lungs

Front 50

when we swallow---

Back 50

a bolus of food enters the pharynx, triggering the swallowing reflex; the esophageal sphincter relaxes and allows the bolus to enter the esophagus

Front 51

define LARYNX

Back 51

voice box/adam's apple

Front 52

the larynx moves upward and tips the EPIGLOTTIS (flap of cartilage and fibrous connective tissue) over the tracheal opening

Back 52

in this position, the epiglottis prevents food from passing into the trachea.

Front 53

what happesn after hte bolus enters the esophagus

Back 53

the larynx moves downward, the epiglottis moves up again, and the breathing passage reopens. the esphageal sphincter contracts above the bolus

Front 54

what prevents food going down the wrong tube?

Back 54

the eppiglotis tips down over the opening to the trachea during swallowing

Front 55

if we swallow something that is too big to pass through th eesophagus, it leads to a blocked

Back 55

pharynx or gtrachea. air cannot flow tinto the trachea, causing the person to choke

Front 56

Heimlich maneuver

Back 56

fist w/ one hand placed agaisnt upper abdomen, below ribcage
-other hand over fist and press w/ upward thurst

Front 57

what happens when the H maneuver occurs

Back 57

the daiphragm is elevated pushing air into the tracae

Front 58

if a piece of food is stuck in the pharynx, what effect could it have on a nearby structure?

Back 58

the epiglottis may be tipped down, blocking th eopening to the trachea

Front 59

what does the esophagus do?

Back 59

it squeezes food along to the stomach by peristalsis

Front 60

define ESOPHAGUS

Back 60

muscular tube tha tconveys food boluses from the pharynx to the stomach.

Front 61

the muscles at the very top of the esophagus are under voluntary contral

Back 61

the act of swallowing begins voluntarily

Front 62

involuntary waves of contraction by smooth muscles in teh rest of the esophagus take over

Back 62

as food is swallowed, muscles above the bolus contract, pushing th ebolus downward

Front 63

muslces around the bolus relax

Back 63

allowign th epassageway to open

Front 64

muscle contractions continue in waves until

Back 64

the bolus enters th stomach

Front 65

how does food get from the pharynx to the stomach of an astronaut in a weightless environment?

Back 65

by peristalsis

Front 66

what does the stomach do?

Back 66

it stores food and breaks it down with acid and enzymes

Front 67

the stomach secretes GASTRIC JUICE, which is?

Back 67

made up of mucus, enzymes, and strong acid.

Front 68

what is the function of stomach acid?

Back 68

-break apart the cells in food
-kills bacteria and other microbes that are swallowed w/ food

Front 69

describe the interior surface of the stomach wall

Back 69

it is highly folded and dotted w/ pits leading down into tubular gastric glands

Front 70

the gastric glands have 3 types of cells that secrete different componets of the gastric juice whcih are?

Back 70

mucous cells
parietal cells
cheif cells

Front 71

define MUCOUS CELLS

Back 71

secrete mucus, which lubricates and protects ht ecells lining th stomach

Front 72

define PARIETAL CELLS

Back 72

secrete hydrochloric acid

Front 73

define CHEIF CELLS

Back 73

secrete pepsinogen, an inactive form of the enzyme pepsin

Front 74

how does pepsinogen, HCl, and pepsin interact in the stomach?

Back 74

1. pepsinogen and HCl are secreted into th elumen (cavity) of the stomach
2. the HCl converts pepsinogen to pepsin
3. pepsin then activates more pepsinogen, starting a chain reaction.

Front 75

what begins the chemical digestion of proteins

Back 75

pepsin

Front 76

what does pepsin do?

Back 76

it splits the polypeptide chains of th eproteins into smaller polypeptides. this action primes the proteins for further digestion, which will occur in the small intestine.

Front 77

what prevents gastic juice from digesting away the stomach lining?

Back 77

secreting pepsin in the inactive form of pepsinogen helps protect the cells of the gastric glands, and mucus helps protect the stomach lining from both pepsin and acid. still, th eepithelium is constantly eroded. enough new cells are genreated by mitosis to replace the stomach lining completely about every three days.

Front 78

do the cells of our gastric glands secrete gastric juice constantly?

Back 78

no, their activity is regulated by nerve signals and hormones. when we see, smell, or taste food, a signal form your brain to yoru stomach stimulates gastric glands to secrete gastric juice.

Front 79

what happens when we have food in our stomach?

Back 79

substances in the food stimulate cells in the stmoach wall to release the hormone GASTRIN into the circulatory system

Front 80

what does gastrin do?

Back 80

it circulates in the bloodstream, returning to the stomach wall. when it arrives there, it stimulates further secretion of gastric juice

too much acid inhinbits the release of gastrin, and w/ less gastrin in the blood, the gastric glands secrete less gastric juice

Front 81

define ACID CHYME

Back 81

nutrient rich borther;; result of the mixing and enzyme action

Front 82

the opening between teh esophagus and the stomach is usually CLOSED unti

Back 82

a bolus arrives

Front 83

occasional backflow of acid chyme into the lower end of the esophagus causes

Back 83

heartburn which should be accurately called esophagus burn

Front 84

some ppl suffer from this backflow rfrequently and enough tot harm th elining of the esophagus, the condition is called

Back 84

GERD: gastroesophageal refulx disease

Front 85

between teh stomach and the small intestine, the phylric sphincter helps regualte what?

Back 85

the passage of acid chyme from the stomach into the small intestine.

Front 86

if you add pepsinogen to a test tube containing protein dissolved in distilled water, not much protein will be digested. what inorganic substance could you add to teh tube to accelerate protein digestino?

Back 86

HYDROCHLORIC ACID that will convert inactive pepsinogen to active pepsin, which will begin the digestion of proteins.

Front 87

bacterial infections can cause

Back 87

ULCERS

Front 88

define GASTRIC ULCERS

Back 88

sores that can develop in the smotach wall if the stomach wall is corroded by digestive juice

Front 89

what are the symptoms of gastric ulcers?

Back 89

gnawing pain in the upper abdomen, which occurs a few hours after eating

Front 90

what is the culpriut iof gastric ulcers?

Back 90

Helicobacter pylori

Front 91

the low pH of the stomach kills most microbes but not the acid tolerant H. pylori

Back 91

this bacterium burrows beneath the mucus adn releases harmful chemicals

Front 92

how does the growht of H plylor result from

Back 92

loss of protective mucus and damage to the cells lining in the stomach. numerous white blood cells move into the stomach wall to fight the infection, and their presence is associated w/ mild inflammation of the stmach , called,GASTRITIS

Front 93

when do gastric ulcers develp?

Back 93

when pepsin and hydrochloric acid destroy cells faster than the cells can regenerate

Front 94

the stomach wall may erode

Back 94

may cause a hole which can lead to life threatinging infection w/in the abdomen or internal bleeding

Front 95

gastric ulcres respond to what?

Back 95

a combo of antibiotics and bismuth (pepto bismol) which eliminates bacteria and promotes healing.

Front 96

in contrast to most microbes, the species tha tcauses ulcers thrines in an environment w/ a very low

Back 96

pH

Front 97

where does all other chemical digestion occur and where does nurtietns get absorbed into the blood

Back 97

small intestine

Front 98

define PANCREAS

Back 98

produces pancreatic jiuce, a mixture of digestive enzymes and an alkaline solution rich in bicarbonate.
-the alkaline solution neutralizes acid chyme as it enters the small intestine

Front 99

define LIVER

Back 99

produces bile

Front 100

define BILE

Back 100

contines bile stalts that emulsify fats, making them more susceptible to attack by digestive enzymes

Front 101

define GALLBLADDER

Back 101

stores bile until it is needed int hte small intestine

Front 102

define DUODENUM

Back 102

first25 cm of small intestine. this is where the acid chyme squired from the stomach mixes w/ bile from the gallbladder, pancreatidc juice form the pancreas and the digestive enzymes from gland cells in the intestinal wall

Front 103

[enzymatic digestion in the small intestine]

CARBS

Back 103

starch

pancreative amylase

maltose

maltase, sugcrase, lactase

monosaccharides

Front 104

[enzymatic digestion in the small intestine]

PROTEINS

Back 104

polypeptides

trypsin, chymotrypsin

smaller polly peptides

aminopeptidase, carboxypeptidase, dipeptidase

amino acids

Front 105

[enzymatic digestion in the small intestine]

NUCLEIC ACIDS

Back 105

DNA and RNA

nucleases

nucleotides

other enzymes

nitrogenous bases, sugars, and phosphates

Front 106

[enzymatic digestion in the small intestine]

FATS

Back 106

fat globules

bile salts

fat droplets (emmulsifed)

lipase

fatty acids and glycerol

Front 107

define VILLI

Back 107

small fingerlike projections

Front 108

define MICROVILLI

Back 108

tiny surface projections each lining a villus

Front 109

some nutrietns are absorbed by diffusion; other nurtients are

Back 109

pumped against concentration gradients into the epithelial cells.

Front 110

the capillaries that drain nutrients away from the villi converge into larger veings and eventually into a main vessel

Back 110

HEPATIC PORTAL VEIN, that leads to the liver

Front 111

what organ gets first access to nurtrients absorbed

Back 111

LIVER

-converts nurtients into substances that the body needs
-remove excess glucose form blood and convert it to glycogen, whcih is sotre din liver cells

Front 112

amylase is to _______________ as _____________ is to DNA

Back 112

starch

nuclease

Front 113

define CECUM

Back 113

one of the T is a blind pouch

Front 114

define APPENDIX

Back 114

small, fingerlike extension of the cecum, contains a mass of whtie blood cells that make a minor contributino to immunity
-prone to infection (appendictis)

Front 115

if appendictis occurs

Back 115

the appendix can be surgically removed w/o weakening the immune system

Front 116

what's the main fucntion of a colon?

Back 116

absorb water from the alimentary canal

as the water is absorbed, the remains of the digested food become more solid as they are conveyed along the colon by peristalsis

Front 117

define FECES

Back 117

waste products of digestion that consist mainly of indigestible plant fibers and prokaryotes that live in the colon

Front 118

what does E. coli produce

Back 118

important vitamins, including biotin, folic acid, B vitamins, and vitamin K. these vitamins are absorbed into the bldostream through the colon

Front 119

define RECTUM

Back 119

the terminal portion of the colon where the feces are stored until they can be eliminated. strong contractions of th colon create the urge to defecate. two rectal sphincters, one voluntary and the other involntary, regulate the opening of th anus

Front 120

what happens if th elinig of th colon is irrated

Back 120

the colon is less effective in reclaiming water, and diarrhea may result

Front 121

when does consitpation occur?

Back 121

when peristalsis moves the feces along too slowly; the colon reabsorbs too much water, and the feces become too compacted. constipation results form a diet that does not includ enough plant fiber or from lack of exercise

Front 122

explain why treatment of a chonic infection w/ antibiotics for an extended period of time may cause a vitamin k deficientcy

Back 122

the anitbiotics may kill the bacteria that synthesizes vitamin k in the colon

Front 123

herbivores and omnivores have longe ralimentary canals, relative to their body size, than carnivors

Back 123

a longer canal provides the extra time it takes to extract nutrients fromvegetation, whcih is more difficult to digest than meat bc of the cell walls in plant material.

a longer conal also provides more surface area for absorbing nutrients which are less concentrated in vegetation than in meat.

Front 124

define RUMINANT MAMMALS

Back 124

cattle, sheep, and deer have a more elaborate system for cellulose digestion

Front 125

the stomach of a ruminant has four chamebrs

Back 125

1. rumen
2. reticulum
3. omasum
4. abomasum

Front 126

how the food goes through this four chambers

Back 126

1. the rumen
2. reiticulum. bacteria and protsits in teh rumen and reitculum go to work on teh cellulose rich meal.
3. swallows into the omasum wehre water is absobed
4. abomasum, the enzymes complete digestion

Front 127

diest of stages in frog's life history

Back 127

the tadbpole is herbivoreous, while th adult frog is carnivorous

Front 128

a healthy diet satisfies three needs

Back 128

1. fuel to power all body activites
2. organic raw materials to make the animal's own molcules
3. essential nutrients, or substances th eanimal cannot make for itself from raw materials

Front 129

what is an "essential nutrient"

Back 129

a substance that an organims requires but cannot make

Front 130

define basal metabolic rate

Back 130

the minimum number of kilocalories that a resting animal needs to maintain life's basic processes

Front 131

define UNDERNOURSIHED

Back 131

an individual whose diet is chronically deefieceint in calories

Front 132

define MALNOURISHED

Back 132

an individual whose diet is missing one or more essential nurtients

Front 133

what are the four classes of essential nutrients

Back 133

essential fatty acidsd
essential amino acids
vitamins
minerals

Front 134

our cells make fats and other lipids by

Back 134

comibing fatty acis w/ other molcules like glycerol

Front 135

essential fatty acis

Back 135

lineoleic acid; makes phospholipids of cell membranes

Front 136

essentail amino acids

Back 136

bc th ebody canot store excess amino acids, a deficiency of a sinclge essential amino acid limits the use of other amino acids, imprairs protein synthesis, and lead to proten deficientcy, a serious type of malnutrition.

MOST COMMON among humans

methionine
valine
histidine
threonine
pbhenlalanine
leucin
isoleucine
tryptophan
lysine

Front 137

easiest way to get essential amino acids

Back 137

eat meat and animal by proudcts: eggs milk cheese

Front 138

define VITAMIN

Back 138

organic nutrient that we must obtain from our diet, required in smaller quantities than esseintial amino acids

Front 139

most viatamines serve as

Back 139

coenzymes of parts of coenzymes; they have catalytic functions and are used over and over in metabolic reactions

Front 140

why are vitamines req in such small doses, compared with other esseential organic nutrients?

Back 140

bc vitaments have catalytic functions as coenzymes, and each vitamin molceule can repeat its function many times

Front 141

define MINERALS

Back 141

simple inorganic nutrients required in small amounts