Brainscape's Knowledge GenomeTM

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


See full index

BRS GASTROENTEROLOGY > Upper GI Tract > Flashcards

Upper GI Tract Flashcards

1
Q

What is digestion?

A

The process of breaking down macromolecules to allow absorption

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

What is absorption?

A

The process of moving nutrients and water across a membrane

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

What are the 4 main layers of the gut wall?

A

Mucosa
Submucosa
Muscularis
Serosa/ Adventitia

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

What are the three layers of the mucosa?

A
  • epithelium
  • lamina propria (loose connective tissue)
  • muscularis mucosae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which layers of the gut wall contain nerve plexuses?

A

Submucosa and muscularis

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

What are the two types of muscles found in the muscularis?

A

Circular and longitudinal

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

What is found in the submucosa?

A

Nerve plexuses and submucosal glands

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

What is found in the muscularis layer?

A

Longitudinal muscle
Circular muscle
Nerve plexuses

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

How many teeth are present in adults in total?

A

32

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

How many of each type of teeth are present in the oral cavity?

A

8 incisors
4 canines
8 premolars
12 molars

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

Which muscle is the largest jaw muscle and responsible for biting?

A

Masseter

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

What does saliva contain?

A

Aqueous secretion and digestive enzymes

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

Which digestive enzymes does saliva contain?

A

Lingual lipase - fat digestion and salivary amylase - carbohydrate digestion

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

What are the main salivary glands?

A

Parotid gland
Sublingual gland
Submaxillary gland

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

What are the intrinsic muscles of the tongue responsible for?

A

fine motor control & moving food

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

What are the extrinsic muscles of the tongue responsible for?

A

gross movement of tongue (in, out, up & down)

Assists mechanical digestion

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

What are the subdivisions of the oesophagus?

A

Cervical
Thoracic
Abdominal

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

Which vertabrae does the oesophagus lie between?

A

C5 to T10

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

What is the function of the oesophagus?

A

Conduit for food, drink & swallowed secretions from pharynx to stomach

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

Describe the epithelium of the oesophagus?

A
  • Non-keratinising
    ‘- Wear & Tear’ lining (extremes of temp. & texture)
  • Contains mucus secreting glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the muscles found at the top and bottom of the oesophagus?

A

Upper oesophageal sphincter and lower oesophageal sphincter

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

what is the role of mucus in the oesophagus?

A

Aids the passage of food and drink

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

What is the Z line in the oesophagus?

A

Line where the pink mucosa of the oesophageal sqaumous epithelium meets the red mucosa of the gastric columnar epithelium

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

What is the significance of this Z line in Barrett’s oesophagus?

A

Here, the epithelium of the lower oesophagus undergoes metaplasia

So the gastric mucosa extends into the oesophagus, meaning it would be important to determine the Z line in these cases

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

Why does this epithelial transition at the gastro-oesophageal junction occur and how does this develop to cancers?

A

Acid reflux means that the upper oesophagus is more acidic than normal

To cope with this, the squamous cells above the gastro-oesophageal junction become columnar epithelium

This change to columnar epithelium makes the cells unstable, leading to dysplasia and then becomes cancers

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

Is skeletal muscle found in the upper or lower oesophagus?

A

Both

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

Is smooth muscle found in the upper or lower oesophagus?

A

Lower

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

How does the anatomical orientation of the stomach to the oesophagus reduce the risk of acid reflux?

A

reflux is prevented by the diaphragm and the angle of the stomach to the oesophagus

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

What are gastric folds called and what is their purpose?

A

Rugae - they increase surface area so more digestion and absorption can occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the role of circular and longitudinal muscle in peristalsis?

A

Circular muscle pushes, longitudinal muscle propagates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Which type of epithelium can tolerate acidic conditions?

A

Simple columnar epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What happens to the level of the Z line in Barrets oesophagus?

A

Z line is raised due to acid reflux from the stomach

33
Q

Describe the swallowing process.

A

Stage 0: Oral phase

  • Chewing & saliva prepare bolus
  • Both oesophageal sphincters constricted

Stage 1: Pharyngeal phase

  • Pharyngeal musculature guides food bolus towards oesophagus
  • Both oesophageal sphincters open

Stage 2: Upper oesophageal phase

  • Upper sphincter closes
  • Superior circular muscle rings contract & inferior rings dilate
  • Sequential contractions of longitudinal muscle

Stage 3: Lower oesophageal phase
- Lower sphincter closes as food passes through

34
Q

Describe what happens to the upper oesophageal sphincter during each stage of swallowing?

A

1: Oral = Closed
2: Pharyngeal = open
3: Upper oesophageal = closed
4: Lower oesophageal = Closed

35
Q

Describe what happens to the lower oesophageal sphincter during the swallowing process

A

1: Oral = Closed
2: Pharyngeal = open
3: Upper oesophageal = open
4: Lower oesophageal = Closed

36
Q

What are the functions of the stomach?

A
  • Breaks food into smaller particles (acid & pepsin)
  • Holds food, releasing it in controlled steady rate into duodenum
  • Kills parasites & certain bacteria
37
Q

What are the secretions of the cardia and pyloric regions of the stomach?

A

Mucus only

38
Q

What are the secretions of the body and fundus regions of the stomach?

A

Mucus, HCl, and pepsinogen

39
Q

What does the antrum of the stomach secrete?

A

Gastrin

40
Q

Why is a hiatus hernia a risk factor for developing cancer of the oesophagus?

A

Because the opening of the diaphragm causes it to be larger and so there is a portion of the stomach that slips into the chest which prolongues exposure to the lower oesophagus, associating with acid reflux

41
Q

How much acid is produced per day by the stomach and what is the H+ concn. of this acid?

A

2L/day
150mM H+ (3 mill x that in blood)

42
Q

What allows the pH of the epithelial surface to be between 6 and 7 when the lumen is between 1 and 2?

A

Mucus coating with HCO3- trapped in the mucus gel

43
Q

Which layer of muscle carries out segmentational contraction?

A

circular

44
Q

Which layer of muscle carries out peristalsis contraction?

A

longitudinal

45
Q

What are the proportions of stomach contractions which are peristatic and segmental?

A

Peristaltic - 20%
Segmental - 80%

46
Q

Which type of stomach contraction is stronger?

A

Peristaltic - Propels chyme towards colon

47
Q

Which stomach contraction is dependant on the autonomic nervous system?

A

Peristalsis

48
Q

What does segmentation do?

A
  • Pushes fluid chyme towards Pyloric sphincter
  • Solid chyme pushed back to body
49
Q

What does the stretching due to segmentation activate?

A

Enteric nervous system

50
Q

What does the gastric chief cell secrete?

A

Pepsinogen

51
Q

Which cellular component is abundant in chief cells?

A

Rough endoplasmic reticulum and Golgi - due to protein secretion = needed for packaging, modifying and exportation

52
Q

What are the parietal cells responsible for producing and secreting?

A

HCl and intrinsic factor

53
Q

What are three structures found in parietal cells in the resting state?

A

Mitochondria
Internal Canaliculi
Cytoplasmic tubulovesicles

54
Q

What do cytoplasmic tubulovesicles contain?

A

contains H+/K+ ATPase

55
Q

How does the appearance of the parietal cell change in the secreting stage?

A

Microvilli project into canaliculi
Tubulovesicles fuse with membrane

56
Q

How would the inhibition of H+ carbonic anhydrase influence stomach acid secretion?

A

Decrease acid secretion

57
Q

What three drug types could be used to decrease stomach acid secretion?

A
  1. Carbonic anhydrase inhibitor
  2. Histamine receptor antagonist
  3. K+/H+ ATPase inhibitor
58
Q

What is the name of the histamine receptor antagonist used to decrease stomach acid?

A

Ranitidine

59
Q

What is the name of the H+/K+ ATPase inhibitor antagonist used to decrease stomach acid, heart burn and indigestion?

A

Omeprazole

60
Q

What stimuli is most likely to decrease acid secretion in the stomach?

A

Chyme fatty acid content - due to the enterogastric fatty acid content

61
Q

What triggers the process of HCl secretion?

A

The binding of histamine to histamine receptors on the parietal cells

62
Q

Describe the process of HCl secretion

A
  1. Carbonic anhydrase catalyses the conversion of Water and Carbon Dioxide into H+ and HCO3-
  2. The Bicarbonate ion is exchanged for a Cl- ion which enters into the parietal cell, and bicarbonate into the blood
  3. Na+/K+ ATPase pumps sodium out the parietal cell and K+ into the cell and therefore canaliculi
  4. Then, the H+ ions are pumped out the Parietal cell into the canaliculi through the H+/K+ ATPase pump, as K+ ions are pumped from the canaliculi into the parietal cell
  5. The Cl- ions then enter the canaliculi as well through Cl- ion channels
  6. Combine to make HCl
63
Q

What is pepsinogen?

A

A powerful and abundant protein digestive enzyme which is secreted by the chief cells as a proenzyme

64
Q

What effect does HCl have on pepsinogen?

A

Converts pepsinogen into pepsin

65
Q

What can an abnormal increase in gastrin cause?

A

Stomach ulcers

66
Q

what does pepsin do?

A

Breaks down dietary proteins into partially digested proteins

67
Q

Which part of the stomach secretes gastrin?

A

Pyloric antrum

68
Q

What is gastrin secretion stimulated by?

A

Stimulated by distention, small peptides & amino acids, stimulation of vagus nerves

69
Q

What does gastrin stimulate the release of?

A

Stimulate histamine release from chromaffin cells (lamina propia)

70
Q

What is the pH of gastric venous blood?

A

Alkaline

71
Q

What are the three phases of gastric secretion?

A

Cephalic
Gastric
Intestinal

72
Q

How is the parietal cell adapted for this function?

A

It has many mitochondria

It has H+/K+ ATPase which is largely responsible for the secretion of HCl into the lumen of the stomach

HCl secreted into tubulovesicles which then fuse with the membrane of the cell and secrete HCl into lumen of stomach

73
Q

Describe the cephalic phase of gastric secretion

A

Thought, sight, smell and taste of food stimulates gastric secretion

Vagus nerve activates parietal cells through ACh to trigger the whole cascade

74
Q

Describe the gastric phase of gastric secretion

A

Food in stomach activates the stretch- (distension) and chemo-receptors (pH of food chemicals) - G cells secrete gastrin which stimulates HCl secretion

Signals sent to and from the brain via vagus nerve to activate the secretion of acid

75
Q

Describe the intestinal phase of gastric secretion

A

Once the chyme with pH less than 2 reaches the duodenum

Signal is transmitted by the vagus nerve and this causes secretion of hormones that inhibit the secretion of gastric HCl and pepsin too

These hormones are Gatric inhibtory peptide, Cholecystokinin and Secretin

76
Q

What are the three enterogastrones?

A

GIP = Gastric inhibitory Peptide
Cholecystokinin
Secretin

77
Q

What is the enterogastric reflex?

A

Nervous reflex where stretching of the wall of the duodenum results in inhibition of gastric motility and reduced rate of emptying of the stomach

It is a feedback mechanism used to regulate the rate at which partially digested food leaves the stomach and enters the small intestine

78
Q

What is the action of circular muscles in the upper oesophageal phase?

A

Superior circular muscle rings contract and inferior rings dilate

79
Q

What is the action of longitudinal muscles in the upper esophageal phase

A

Sequential contractions of longitudinal muscle

BRS GASTROENTEROLOGY (25 decks)

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