Ch 41 Digestive System Flashcards Preview

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Flashcards in Ch 41 Digestive System Deck (64):
1

Why is feeding necessary in animals?

To get organic molecules

2

How do animals receive energy from feeding?

The bonds of organic molecules are broken

3

Essential nutritents

Molecules necessary for constuction of the body

4

Can essential nutrients be synthesized by animals?

No

5

Four classes of essential nutrients

1) Essential amino acids
2) Essential fatty acids
3) Vitamins
4) Minerals

6

How many amino acids are needed by the human body?

20

7

How many amino acids needed by the human body can be synthesized by the body?

12

8

How many essential amino acids (amino acids that cannot be synthesized by the human body) are there?

8

9

Complete proteins

Foods that contain all 8 essential amino acids

10

Vitamin

A required organic compound that is not a carbohydrate, fat, protein, or mineral

11

Digestion

The reduction of food by mechanical and chemical means to simple, soluble molecules that can be absorbed and transported to the cells of the body

12

Alimentary system

The system involved in the acquisition of nutrients

13

Five regionalized functions of the alimentary system

1) Ingestion
2) Conduction and storage
3) Grinding and preliminary digestion
4) Final digestion and absorption
5) Water absorption and concentration of waste

14

What are the two layers that compose the mammal tooth?

1) Enamel

2) Dentin

15

Enamel

Almost completely mineral

Hardest material in the body

16

Herbivores typically lack what kind of teeth?

Canines

17

Herbivores typically have what kind of teeth?

Premolars and molars formed into continuous ridged surfaces

18

Monotremes and eutherian anteaters lack what?

All teeth

19

Whales in the suborder Mysticeti lack what?

All teeth

20

How do whales in the suborder Mysticeti feed?

By filtering seawater through baleen plates composed of keratin

21

In addition to oral jaws, some fish have what?

Well-developed pharyngeal (throat) jaws used in the processing of food

22

Gill rakers

Extentions of the gill arches

23

Gill rakers contribute to what?

The collection of food

24

Gill rakers reflect what?

Feeding diversity

25

How do simple multicellular animals digest food?

They combine functions of digestion in single cells

26

How do sponges, cnidarians, and flatworms digest food?

Intracellular digestion

27

Intracellular digestion

Food particles brought into cells by phagocytosis

28

What is the site of extracellular digestion?

A gastrovascular cavity

29

Crop

An expansion of the esophagus used to store food prior to digestion

30

Gizzard

Grinds food

31

What two structures are possessed by birds, insects, and earthworms that facilitate digestion?

1) Crop

2) Gizzard

32

Gastric cecae

Sites of enzyme secretion, extracellular digestion, and absorption of nutrients in insects

33

In insects, what serves primarily in water water absorption?

The hindgut portion of the intestine

34

Salivary glands

Produce mucus secretions

Assist in swallowing and produce amylase

35

Amylase

Enzyme that breaks carbohydrates into maltose

36

Epiglottis

A valve in the pharynx that prevents food from entering the trachea

37

What holds food in the stomach?

Muscular sphincters

38

What happens to food while it is in the stomach?

It is subjected to mixing

39

Gastric juices

Secreted by the stomach

Contain hydrochloric acids and pepsin

40

Pepsin

Enzyme that breaks down proteins into smaller polypeptides

41

Gastric glands give rise to:

1) Gastric juices

2) Mucus (protects stomach from digestion)

42

Pepsinogen

Precursor to pepsin

Changes configuration in response to acid

43

Chyme

Partially digested food

44

Chyme is released from the stomach into what?

The duodenum of the small intestine

45

Pancreatic juice

Increases the pH

46

Pancreatic juice includes what?

Proteases

47

Proteases

Enzymes that split proteins

48

Bile

Separate fat into tiny droplets that can be broken down by lipases

49

Bile is produced where?

Liver

50

Bile is released by what?

Gallbladder

51

Primary function of small intestine

Absorption of nutrients

52

Villi

Finger-like projections of the intestinal epithelium

53

Microvilli

Finger-like projections of the epithelial cells

54

How much do villi and microvilli increase the surface area of the small intestine?

1000 times

55

In the small intestine, what diffuses into the epithelial cells?

1) Amino acids

2) SImple sugars (glucose, fructose)

3) Monoglycerides

56

What happens after molecules are absorbed into the epithelium of the small intestine?

The molecules are then passed to the blood stream

57

Large intestine

Consolidates the indigestible remnants of digestion by reabsorption of water for form feces

58

The large intestine houses what?

Many bacteria

59

Bacteria in the large intestine can synthesize what vitamins?

1) Vitamin K

2) B vitamins

60

Cellulase

Enzyme that digest cellulose (sugar of plant cells)

61

Do any mulicellular animals produce cellulase?

No

62

Fermentation

Process by which many vertebrate herbivores use microorganisms that produce cellulase to digest cellulose

63

Foregut fermenters

Cows, sheep, hippos

Chew vegetation repeatedly, as it is passed back and forth between the fermentation chamber and the mouth

64

Hindgut fermenters

Horses, koalas, pigs