Brainscape's Knowledge GenomeTM

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


See full index

ESA1 - Body Logistics > Digestive System > Flashcards

Digestive System Flashcards

1
Q

What are the accessory organs of the digestive system?

A

Salivary glands, liver, gallbladder, pancreas

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

What is the alimentary canal composed of?

A

Mouth, pharynx, oesophagus, stomach, small intestine, large intestine, rectum, anus

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

What are the four layers of the gut?

A

Mucosa (innermost)
Submucosa
External muscle layers (muscularis externae)
Serosa

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

What does the mucosa consist of?

A

Epithelium, lamina propria and musculais mucosae

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

What is the submucosa of the gut wall?

A

A layer of connective tissue bearing glands, arteries, veins and nerves

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

What are the two layers of the external muscle of gut wall?

A

Outer longitudinal layer (cigar-shaped nuclei) and inner circular layer (central nuclei)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does the muscularis externa create?

A

Peristaltic waves to move luminal contents along the gut

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

What does the serosa of the gut wall consist of?

A

Mesothelium and connective tissue

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

What are the major functions of the GI tract?

A

Mechanically disrupt food, temporarily store food chemically digest food, kill pathogens in food, move food along tract, absorb nutrients from resultant solution and eliminate residual waste material

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

What is digestion?

A

Conversion of what we eat by physical and chemical disruption into a solution that is relatively sterile, neutral in pH and isotonic from which we can absorb our nutrients.

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

What does saliva do?

A

It starts digestion as it contains amylase and lipase, is bacteriostatic as it contains immunoglobulin A antibody, protects teeth and assists swallowing.

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

How does physical digestion occur in the mouth?

A

By action of teeth, tongue and muscles of chewing

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

How does chemical digestion occur in the mouth?

A

By action of salivary amylase and lipase

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

What does the mouth form that enters the oesophagus?

A

A bolus

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

How does control differ between the upper and lower ends of the oesophagus?

A

Upper end - voluntary control (some striated skeletal muscle)

Lower end - involuntary control (solely smooth muscle)

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

How long does it take for the bolus to be transported to the stomach?

A

8-9 seconds

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

What are the layers of the oesophagus?

A

Mucosa (epithelium, lamina propria and muscularis mucosae) and submucosa

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

How is the oesophagus innervated?

A

Myentric plexus and submucosal plexus

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

How does physical digestion occur in the stomach?

A

Churning (3 muscle layers and mucosal rugae)

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

How does chemical digestion occur in the stomach?

A

By hydrochloric acid and enzymes eg pepsin

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

What is receptive relaxation of the stomach?

A

Wall relaxes so pressure doesn’t rise

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

How does the stomach protect its epithelium?

A

Secretes mucus

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

What is chyme?

A

Chewed up, partially digested stomach contents

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

The combined action of acid, enzymes and agitation of the stomach produces what?

A 
Hypertonic chyme
(hypertonic = draw in fluid)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What does gastric mucosa secrete?

A

Acid, digestive enzymes and gastrin

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

How many layers of smooth muscle in the mucularis externa of the stomach?

A

3 - oblique, circular and longitudinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are rugae?

A

Folds of gastric mucosa forming longitudinal ridges in empty stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Which type of epithelium in the stomach?

A

Simple columnar epithelia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What can damage mucous cells in the stomach?

A

Alcohol and aspirin

30
Q

Which ions do the secreted mucous of the stomach contain?

A

Bicarbonate ions which neutralise the effect of H+ ions and thereby protect the stomach lining

31
Q

Which cells do gastric glands consist of?

A

Mucus secreting cells, parietal cells, chief cells, enteroendocrine cells

32
Q

What is the gastric pit of the gastric gland lined by?

A

Mucus secreting cells

33
Q

What is the isthmus in a gastric gland?

A

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

34
Q

What do parietal cells in a gastric gland secrete?

A

H+ ions into the lumen and bicarbonate ions into nearby capillaries which move it to surface mucous cells

35
Q

What do chief cells in a gastric gland secrete?

A

Pepsinogens which are converted to pepsins

36
Q

What do enteroendocine cells in a gastric gland secrete?

A

Gastrin - the wider gastric muscosa responds to this hormone by secreting acid

37
Q

What is the duodenum?

A

20-25cm long, C shaped, proximal portion of small intestine that curves around head of pancreas

38
Q

What is contained in the walls of the duodenum?

A

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

39
Q

Which two organs connect with the duodenum?

A

Liver and pancreas

40
Q

What does bile contain?

A

Water, alkali and bile salts to emulsify fat

41
Q

What does the small intestine consist of?

A

Duodenum, Jejunum, Ileum

42
Q

What does the duodenum absorb?

A

Iron

43
Q

What does the jejunum absorb?

A

Most of sugars, amino acids and fatty acids

44
Q

What does the ileum absorb?

A

Vitamin B12, bile acids and remaining nutrients

45
Q

By the terminal ileum, all of the nutrients are absorbed but what is still to be absorbed?

A

Water

46
Q

What does the large intestine consist of?

A

Caecum, ascending colon, transverse colon, descending colon, sigmoid colon

47
Q

Approximately how long and wide is the large intestine?

A

1.2m long and 6-9cm wide

48
Q

Which type of epithelia line the crypts of Lieberkuhn in the mucosa of the colon?

A

Simple columnar epithelia

49
Q

What does the large intestine do?

A

Continues water recovery over a 20 hr transit

50
Q

Where do the contents of the large intestine await expulsion?

A

In colon, not rectum

51
Q

Where is most of the GI tract’s bacteria contained?

A

Colon

52
Q

Are most bacteria in the colon aerobic or anaerobic?

A

Anaerobic

53
Q

What are the bacteria of the colon involved in?

A

Synthesis of [vitamins K, B12, thiamine and riboflavine]

Breakdown of primary and [secondary bile acids]

Coversion of bilirubin to [non-pigmented metabolites]

*Things in square brackets are readily absorbed

54
Q

What is the total volume of fluid produced by GI tract per day, without including fluid we drink?

A

14L

55
Q

How much faeces produced in a day from 1kg of food?

A

0.15kg. So 1kg food to 0.15kg of faeces via 14L fluid

56
Q

What does histamine do involving the stomach?

A

Controls production of acid in stomach

57
Q

What do vasoactive substances do?

A

Affect blood flow in gut

58
Q

What hormones is the gut controlled by?

A

Hormones it makes itself rather than hormones made elsewhere

59
Q

What does secretin do?

A

Promotes bicarbonate secretion from duct cells of panceas, promotes bile production by the liver and inhibits secretion of acid by parietal cells of the stomach.

60
Q

Where is cholecystokinin synthesised?

A

Enteroendocrine cells of the duodenum

61
Q

What does cholecystokinin promote?

A

Release of digestive enzymes from the pancreas and release of bile from the gall bladder as it stimulates it to contract

62
Q

Is cholecystokinin a hunger suppressant or stimulant?

A

Hunger suppressant

63
Q

What is gastrin released by?

A

G cells of pyloric antrum of stomach, pancreas, duodenum

64
Q

What does gastrin promote?

A

Production of gastric acid by parietal cells of the stomach

65
Q

What are the overall roles of the gut?

A

Secretion, movement and absorption

66
Q

What are the three salivary glands?

A

Sublingual gland, parotid gland and submandibular gland

67
Q

What stops us from inhaling what we are trying to swallow?

A

The epiglottis, flap of elastic cartilage attached to the larynx entrance, is open during inhalation and closes while swallowing to force food down the oesophagus

68
Q

Why is it more of a challenge to swallow fluids than solids?

A

More difficult to form a bolus as it needs more control and muscular contraction as well as more guidance into oesophagus

69
Q

Why doesn’t the stomach digest itself?

A

Epithelial cells lining the stomach secrete mucus which provides a physical barrier as well as containing bicarbonate which neutralises the acid. Also, proton pumps are only active in the presence of food and there are inactive enzyme precursors.

70
Q

What are the roles of bile?

A

Emulsify fats - increases surface area for enzymes to break them down

Facilitates fat absorption in the small intestine

Contains bile salts - deriveritive of cholesterol

Many waste products eg bilirubin are eliminated from the body by secretion into bile

Neutralises acid

ESA1 - Body Logistics (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions