Digestive System Flashcards Preview

202 Lecture Exam 2 > Digestive System > Flashcards

Flashcards in Digestive System Deck (81):
1

What is ingestion?

Taking of food and liquid into the mouth

2

What is mechanical digestion?

Physically ripping nutrients apart

3

What performs mechanical digestion in the mouth, stomach, and small intestine?

Mouth - teeth
Stomach - rugae
Small intestine - churning

4

What is chemical digestion?

Breaking of larger molecules into smaller particles via hydrolysis through enzymes

5

What is absorbtion?

The moving of ingested and secreted fluids into the epithelial cells lining the lumen of the GI tract

6

What is defecation?

Shit: waste composed of indigestible substances, bacteria, sloughed off cells and digested materials that are not reabsorbed

7

What is propulsion?

Alternate contractions and relaxations of smooth muscle in the walls of the GI tract, mixes food and secretions

8

What intestinal function is included in propulsion?

Peristalsis

9

What is the name of the action of chewing with your teeth?

Dentition

10

What is salivary amylase?

An enzyme in saliva that begins chemical breakdown of starch

11

What is lingual lipase?

Salivary enzyme the begins breakdown of fats

12

What are the three general layers of the tooth?

The crown, the neck, and the root

13

List the teeth

2 incisors, 1 canine, 2 bicuspids, 3 tricuspids

14

What is the mechanism of tasting?

Via taste buds called papillae

15

What is the name of the sense of taste?

Gustation

16

Which 3 glands control salivation?

Parotid, submandibular, and sublingual

17

What are the 4 layers of GI tract histology?

Serosa, muscularis externa, submucosa, mucosa

18

What is the role of the serosa?

To hold organs in place and cover them

19

What is the role of muscularis externa in the stomach?

3 different layers of muscle which aid in churning food and controlling movement of chyme

20

What do chief cells secrete?

Pepsinogen

21

What do parietal cells secrete?

HCl and intrinsic factor

22

What is the function of intrinsic factor?

Vitamin B12 absorption

23

In what disease is vitamin B12 missing?

Pernicious anemia

24

What is the role of mucous cells in the stomach?

To secrete mucus to protect the stomach from HCl

25

What is pepsin?

An enzyme that digests proteins, severs peptide bonds between amino acids

26

What is does HCl do in the stomach?

Partially unfolds protein and stimulates secretion of hormones that promote the flow of bile and pancreatic juice; activates pepsinogen to pepsin

27

What protects the stomach from digesting itself?

Gastric mucus

28

What does the stomach break proteins into?

Tripeptides and bipeptides

29

What is the relationship between carbohydrate digestion and the stomach?

There is minimal carb digestion in the stomach

30

What are the 2 main fluids secreted by the pancreas?

Enzymes and bicarbonate

31

What is the role of bicarbonate?

Raise pH of SI

32

Is the pancreas endocrine or exocrine?

Exocrine (uses ducts and tubes)

33

What is the role of proteases?

Break down proteins in different locations along the amino acid chain

34

What is trypsin?

Initially trypsinogen, activated by enterokinase in the duodenum

35

What is chymotrypsin?

Secreted initially as chymotrypsinogen, activated by trypsin in duodenum

36

What is carboxypeptidase?

Initially procarboxypeptidase, activated by trypsin in duodenum

37

In the pancreas what breaks starches into disaccharides and trisaccharides?

Pancreatic amylase

38

What breaks down emulsified triglycerides into fatty acids and monoglycerides in the pancreas?

Pancreatic lipase

39

What is the role of deoxyribonuclease?

Breaking DNA into nucleiotides

40

What is the role of ribonuclease?

Breaking RNA into molecules

41

What is the primary role of the liver?

To form and secrete bile - bile acids help break down fats

42

What is emulsification?

The process of breaking fat into smaller globules, creating a larger surface for enzyme attack

43

What is the primary detoxifying organ in the body?

The liver - detoxs and processes nutrients just absorbed by the intestines

44

What kind of problems can liver damage cause?

Jaundice, low immunity, abdominal pain

45

What proteins does the liver manufacture and what would the loss of them cause?

Albumin and immunoglobins - loss would cause low albumin with swelling and low immunity

46

Trace the path of a nutrient into the liver

- absorbed in SI to epithelial cells
- cross cells to capillaries
- capillaries merge
- move in portal vein
- in liver which decides how to process them

47

Trace the path of fats through the body

- absorbed through epithelium
- into lacteals
- then into lymph vessels

48

What are the primary liver infections?

Hepatitis A, B, C, D, and E

49

What is Hepatitis A?

Food-borne, acute, common, blood carries it

50

Which form of Hepatitis is less common?

B

51

How is Hep C transmitted?

Blood transfusion, drug needles; chronic, slow progression

52

Where is bile stored?

Gallbladder

53

How long is the SI?

10 feet

54

What is segmentation?

The rhythmic contraction of circular muscles, causes sloshing and mixing of chyme with intestinal fluids; sloshes chyme against mucosa to increase absorption

55

Does segmentation move food along the intestines?

no

56

How long is the Large intestine?

5 feet

57

What is the function of the appendix?

Unknown, perhaps immunity

58

What is the difference between chronic and acute appendicitis?

Chronic is less common and dull pain, acute is intense

59

Trace the pathway of a carbohydrate

- converted to ATP
- stored in liver and muscles
- polysaccharides broken into sugars (mono and di)
- give energy

60

Why do lipases need to remove fatty acids from triglycerides?

We can't absorb the whole triglycerides into the intestinal cells

61

Does glycerol get absorbed alone?

NO, it must have at least one fatty acid attached

62

What nutrient do fats help us absorb?

Fat-soluble vitamins

63

What do proteins provide for the body?

Structures (hair, muscles, ect.), enzymes, antibodies, albumin, etc

64

What does fiber do?

Helps move bulk stool through the intestines

65

How are Carbs absorbed?

Glucose and galactose are absorbed in the SI via active transport (requires energy)

66

How is fructose absorbed?

In the SI via facilitated diffusion and then into the bloodstream

67

How is protein absorbed?

In the SI via active transport (amino acids, dipeps., tripeps.)

68

How are triglycerides absorbed?

In the SI via simple diffusion, then into a lacteal of a villus

69

What are the three distinct phases of digestion?

1. Cephalic reflex
2. Gastric reflex
3. Intestinal reflex

70

How does the cephalic reflex phase work?

See/smell food and brain triggers start of digestive reaction (saliva, gastric juice)

71

How does the gastric reflex phase work?

Stomach distends, peristalsis wave begins, gastric juice flows, happens because stretching triggers stretch and chemoreceptors which cause the release of HCl

72

What activates paristalsis?

Parasympathetic nervous system

73

How does the intestinal reflex phase work?

Food enters intestines, distends duodenum, stomach acid production stops, pyloric sphincter closes, cholecystokinin triggers secretion of pancreatic juice and bile, promotes satiety, secretin releases bicarbonate from pancreas into duodenum

74

What is gastrin?

Hormone, released from G cells of gastric glands in response to stomach distension, contracts LES to prevent reflux; Increases mobility of stomach and relaxes pyloric sphincter

75

What is secretin?

Hormone; released from S cells of SI crypts, releases bicarbonate to buffer acid in chyme from stomach; inhibits secretion of gastric juices

76

What is CCK?

Cholecystokinin; hormone, causes secretion of pancreatic juice/enzymes and bile, promotes satiety; slows gastric emptying through contractions of pyloric sphincter

77

What is the difference between typical flatulence and "stink bombs"?

Flatulence = maldigestion of carbs
Stink bomb = maldigestion of proteins

78

What happens in constipation and diarrhea?

Bowel Transit Time increases or decreases

79

Why is the duodenum the "point central" of digestion?

It is where most digestive juices come together

80

Where is 80% of the body's immunity located?

In the GALT (Gut Associated Lymphatic Tissue)
e.g. Peyer's patches

81

Why doesn't the pancreas digest itself?

Produces proenzymes