Functions Of Digestive System Flashcards Preview

fundamentals of nutrition > Functions Of Digestive System > Flashcards

Flashcards in Functions Of Digestive System Deck (60):
1

mouth

mixes food with saliva from 3 pairs of exocrine glands (parotid, submandibular and sublingual)
amylase (digestive enzyme) begins chemical breakdown of carbohydrates

2

esophagus

propels food downward to stomach through peristalsis (involuntary muscle contraction)

3

pancreas

secretes endocrine hormones, insulin and glucagon
secretes digestive enzymes into duodenum that breakdown carbs, proteins and fats

4

liver

metabolizes and stores nutrients absorbed from small intestines
produces and secretes bile
detoxifies and purifies blood
maintains normal blood glucose levels
makes cholesterol and blood proteins

5

gallbladder

concentrates and stores bile
releases into duodenum to help breakdown fats

6

stomach

stores and breaks down food by mixing it with gastric secretions such as HCL, pepsins and intrinsic factor
releases the hormones gastrin which stimulate the gastric glands to secrete pepsinogens (protein digesting enzymes), mucus (protects stomach from highly acidic content) and hydrochloric acid (converts pepsinogens into active form
absorbs alcohol and some drugs directly through its wall and into circulatory system

7

name some gastric secretions

HCL, pepsins and intrinsic factor

8

what are pepsinogens?

protein digesting enzymes

9

what does mucus do?

protects stomach fro highly acidic content

10

what does hydrochloric acid do?

converts pepsinogens into active form

11

what is small intestine made up of?

duodenum, ileum, jejunum

12

small intestine

secretes hormones to stimulate the secreation of pancreatic juices, bile and intestinal enzymes

13

what are intestinal enzymes?

secretin (stimulates secretion of sodium bicarbonate from pancreas and bile from liver)
Cholecystokinin [CCK] (stimulates release of digestive enzymes from pancreas and bile from gallbladder)
Gastric Inhibitory Peptide [GIP] (decreases stomach churning which slows the emptying of chyme from the stomach and induces insulin secretion)
Motilin (increases gastrointestinal motility and stimulates production of pepsin, secretes mucus and brush border enzymes, chemically digests and absorbs majority of ingested nutrients, water is absorbed by passive diffusion throughout the small intestine, CHOS and proteins are absorbed in blood vessels, lipids are absorbed in lymph vessels, transports food by peristalsis to large intestines)

14

name the brush border enzymes

maltase, lactase, sucrase, isomaltase, alpha dextrinas

15

what is large intestine made up of?

cecum, colon (ascending, transverse, descending and sigmoid colon) and rectum

16

large intestine

microflora of large intestine break down remaining nutrients (fiber) and make some vitamins (B and K)
absorb most of remaining water, some ions and vitamins
forms and stores feces until eliminated

17

what are proteins broken down into?

amino acids

18

what are fats broken down into?

fatty acids and glycerol

19

what are carbohydrates broken down into?

glucose

20

what is absorption?

process of nutrients passing from intestines into bloodstream or lymph system

21

where are secretory glands found?

all along the digestive tract
they release secretions into a duct (exocrine) or directly into bloodstream (endocrine)

22

what are digestive juices?

various fluids that assist in breakdown of foods

23

digestive enzymes

secreted at various points along digestive tract and are necessary catalysts to all metabolic functions

24

what happens to food when it is chewed

turns into a bolus

25

is stomach acidic or alkaline?

acidic (if it was alkaline bacteria can grow)

26

when is bolus referred to as chyme?

in stomach when food is broken down into smaller fragments

27

how big is stomach when it is emptied?

50ml in size

28

how big can it expand to?

1-1.5 litres of food

29

what is between the stomach and small intestine?

pyloric sphincter

30

what does pyloric sphincter do?

monitors how much chyme can pass from stomach into duodenum (approx. one-five ml twice per minute)

31

where is primary site of absorption?

small intestine

32

what is surface coat of micro-villi referred to?

brush border -hydrolyzes digested material to ready it for absorption

33

how long does absorption process usually take?

24 hours

34

what 3 enzymes does pancreas secrete in order to complete digestion of macronutrients?

amylase to digest carbs
lipase to digest fats
protease to digest proteins

35

which part of body balances our acid-alkaline levels?

pancreas

36

how many different functions does liver have?

over 500

37

food travels to liver via what?

Portal Hepatic Vein

38

how are toxins in liver exported?

through bile, urine, stool

39

where are usable nutrients send?

sent through vena cava to heart and pumped into circulation to appropriate parts of body

40

what are livers other metabolic functions?

production of bile from cholesterol
processing of amino acids into proteins
conversion of glucose into glycogen for storage
regulation of hormones, sugars, proteins and fats in blood

41

how long is large intestine?

5 feet long

42

by time food has reached large intestine most of nutrients have already been removed
which ones haven't?

fiber and cells -make up bulk of feces
water -food will lose about 2/3 of weight as water squeezed out and absorbed via the colon
bacteria -help to further break down food and convert to feces

43

what happens if there is an imbalance of good and bad bacteria in upper GI tract?

Creates fermentation of food and production of gas
in colon it can create health problems such as IBS, constipation and Crohn's disease

44

what are tips for better digestion, absorption and elimination?

maintain healthy bacterial balance
food combining
fiber intake
exercice
sleep
manage fluids around meals
allow adequate time in between meals for "cleanup"
W5 of eating: with whom, what when, where and why

45

which organ secretes bile?

liver

46

which organ is main site for all macronutrient metabolism?

liver

47

what is secreted by the pancreas?

bicarbonate

48

where are lipids first absorbed?

lymph vessels

49

What is the hub of chemical digestion?

Small intestine

50

Which enzyme digests fat?

Lipase

51

Which enzyme digests proteins ?

Protease

52

What % of digestion is pancreatic enzymes responsible for in carbs, fats and proteins?

50% of carbs
50% of proteins
90% of fats

53

When food is absorbed in bloodstream can it be delivered directly to the cells?

No, has to travel to liver first so that toxins are neutralized and nutrients are metabolized into an active and usable form

54

What are tips for Better digestion, absorption and elimination ?

Maintain healthy bacteria balance
Food combining
Eat fiber
Drink enough water
Sleep
Exercise W5 of eating
Manage fluids are meal
Allow sufficient time around meals for "cleanup"

55

How long does it take to digest liquids?

A few minutes

56

How long does it take to digest fruits and vegetables?

30-1 hour
Veggies slightly longer than fruit

57

How long does it take to digest starches?

2-5 hours

58

How long does it take to digest proteins?

4-6 hours. Can take up to 8

59

How long does it take to digest fats

Delay digestion

60

What items accelerate digestion?

Coffee, tea, spices