Brainscape's Knowledge GenomeTM

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


See full index

Semester 1-Body Logistics > Digestive System > Flashcards

Digestive System Flashcards

1
Q

What are the four layers of the gut wall, starting from the innermost?

A

Mucosa
Submucosa
External muscle layers (muscularis externae)
Serosa

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

What does the submucosa contain?

A

Layer of CT bearing glands, arteries, veins and nerves

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

How many layers of smooth muscle does the muscularis externa contain and what are they?

A

2
Outer longitudinal layer
Inner circular layer

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

What does the muscularis externa do?

A

Creates successive peristaltic waves to move luminal contents along the gut

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

What makes up the serosa? (2)

A

Simple squamous epithelium (mesothelium)

Connective tissue

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

What are the major functions of the GI tract? (8)

A
  1. Port of entry for food into body
  2. Mechanically disrupt food
  3. Temporarily store food
  4. Chemically digest food
  5. Kill pathogens in food
  6. Move food along tract
  7. Absorb nutrients from resultant solution
  8. Eliminate residual waste
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Complete the sentence:

Digestion is the conversion of what we eat by ________ and ________ disruption into a solution (relatively sterile, _______ in pH and _______) from which we can absorb our nutrients.

A

Physical
Chemical
Neutral
Isotonic

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

Which enzymes in saliva start digestion?

A

Amylase

Lipase

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

Saliva is bacteriostatic, what does this mean?

A

Prevents bacteria multiplying without destroying them

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

Why does saliva have a high calcium content?

A

Protects teeth

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

Complete the sentence:

Physical disruption starts in the mouth by the action of _____, ______ and muscles of _____________.

A

Teeth
Tongue
Mastication

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

True or false: the fastest GI transport is on entry and exit

A

TRUE

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

Complete the sentence:

The mouth forms a _____ which enters the oesophagus and is transported to the stomach.

A

Bolus

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

True or false: the upper end of the oesophagus is solely smooth muscle so involuntary control

A

FALSE - lower end, upper end has some striated skeletal muscle so control is voluntary

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

Which type of epithelium is found in the oesophagus?

A

Stratified squamous non-keratinised (withstands abrasion)

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

What does the lamina propria of the oesophageal mucosa contain?

A

Loose CT with blood and lymph vessels, some smooth muscle cells and many immune cells

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

Complete the sentence:

Physical disruption continues in the stomach by _______ (_ muscle layers and ________ ______)

A

Churning
3
Mucosal rugae

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

What is receptive relaxation?

A

Stomach wall relaxes so pressure doesn’t rise

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

Why does the stomach secrete acid and proteolytic enzymes?

A

To break down tissues and disinfect

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

How does the stomach protect its epithelium?

A

By secreting mucus

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

Complete the sentence:

The stomach produces hypertonic ______ by combined action of acid, ________ and agitation

A

Chyme

Enzymes

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

What is chyme?

A

Partially digested stomach content

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

What are the layers of smooth stomach muscle?

A

Oblique
Circular
Longitudinal

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

What are rugae?

A

Fold of gastric mucosa forming longitudinal ridges in the empty stomach

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

True or false: surface mucous cells are abundant in the gastric pits but infrequent in the tubular gastric glands below

A

TRUE

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

Mucus is released by surface mucous cells in the stomach in response to what? (3)

A

Distension
Stomach content
Acid secretion by gastric glands

27
Q

What can damage the surface mucous cells of the stomach?

A

Alcohol or aspirin

28
Q

How is the stomach lining protected?

A

Mucus secreted by surface mucous cells in the stomach contain HCO3- ions which neutralise the effect of H+ ions and thereby protect the stomach lining

29
Q

What is the isthmus?

A

Region in which stem cells divide to populate a gland by upward or downward migration

30
Q

What do chief cells do?

A

Secrete pepsinogens which are converted into pepsin which partly hydrolyse proteins

31
Q

What do enteroendocrine cells do?

A

Include G cells which secrete gastrin

32
Q

How long is the duodenum?

A

20-25cm

33
Q

True or false: the duodenum is the shortest and most proximal portion of the small intestine

A

TRUE

34
Q

What do the walls of the duodenum contain?

A

Brunner’s glands which secrete bicarbonate-rich mucus to neutralise acidic chyme

35
Q

What does bile contain?

A

Water
Bile salts (to emulsify fats)
Alkali

36
Q

True or false: pancreas and liver secrete alkali to neutralise acidic chyme

A

TRUE

37
Q

What do the enzymes from the pancreas and intestine do? (4)

A
  1. Cleave peptides to AA
  2. Cleave polysaccharides to monosaccharides
  3. Break down and re-form lipids
  4. Break down nucleic acids
38
Q

What does absorption require?

A

Lots of energy
Large surface area
Good blood supply/drainage

39
Q

Drainage during absorption occurs via which vessel?

A

Hepatic portal vein

40
Q

What is a lacteal?

A

Dilated lymphatic capillary vessel

41
Q

What are the three parts of the small intestine called?

A

Duodenum
Jejunum
Ileum

42
Q

What does the duodenum absorb?

A

Iron

43
Q

What does the jejunum absorb?

A

Most sugars
AAs
Fatty acids

44
Q

What does the ileum absorb?

A

Vitamin B12
Bile acids
Remaining nutrients

45
Q

What are the different parts of the large intestine, going in a clockwise motion and ending with the rectum?

A 
Caecum
Ascending colon 
Transverse colon
Descending colon
Sigmoid colon
46
Q

True or false: colon contains most of the GI tract’s bacteria

A

TRUE

47
Q

What are the bacteria in the colon involved in? (3)

A
  1. Synthesis of vitamins K, B12, thiamine and riboflavine
  2. Breakdown of primary to secondary bile acids
  3. Conversion of bilirubin to non-pigmented metabolites
48
Q

Decreased absorption or increased secretion can result in what?

A

Life threatening dehydration

Life threatening electrolyte imbalance

49
Q

Motility and secretion need precise control and this is achieved by what three types of overlapping mechanisms?

A

Neural
Paracrine
Endocrine

50
Q

What are the two types of neural control?

A

Somatic

Autonomic

51
Q

Which two processes are involved in somatic control?

A

Ingestion

Excretion (last sphincter of anus)

52
Q

What do post ganglionic neurones form?

A

Plexuses

53
Q

Name two locations of plexuses

A

Between muscle layers of gut wall (myenteric plexus)

Between submucosa and muscularis externa (submucosal plexus)

54
Q

What are two types of paracrine control and what do they do?

A

Histamine - controls production of acid in stomach

Vasoactive substances - affect blood flow in gut

55
Q

What do the range of endocrine hormones involved control?

A

Secretion of stomach acid
Alkali secretion from liver and pancreas
Enzyme secretion

56
Q

What does secretin promote? (2)

A

HCO3- secretion from duct cells of the pancreas

Bile production by the liver

57
Q

What does secretin inhibit?

A

Secretion of acid by parietal cells of the stomach

58
Q

What does CCK stand for?

A

Cholecystokinin

59
Q

What does CCK do? (3)

A

Promotes release of digestive enzymes from pancreas.
Promotes release of bile from gall bladder (stimulates it to contract).
Hunger suppressant.

60
Q

Where is CCK made?

A

Enteroendocrine cells of duodenum

61
Q

Where is gastrin released? (3)

A
  1. G cells of pyloric antrum of stomach
  2. Pancreas
  3. Duodenum
62
Q

What does gastrin do?

A

Promotes the production of HCl (gastric acid) by parietal cells of the stomach

63
Q

What are the overall roles of the gut? (3)

A

Secretion
Movement
Absorption

Semester 1-Body Logistics (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions