Digestive System: Stomach Flashcards Preview

Organ Histology Final: 7 and 8 > Digestive System: Stomach > Flashcards

Flashcards in Digestive System: Stomach Deck (60)
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1
Q

What are the functions of the stomach?

A

Continue digestion of carbs
Storage (*primary function)
Some nutrient breakdown (mostly chemical, less physical)

2
Q

What are the gross anatomical features of the stomach?

A

Concave lesser curvature
Convex greater curvature
Cardia: narrow region by gastroesophageal sphincter
Fundus: domed region filled with gas
Body/corpus: largest portion
Pylorus: constricted portion by pyloric sphincter
Rugae: longitudinal folds which allow for distention
Gastric pits: tiny depressions in stomach’s surface, 1 pit leads to more than one gland

3
Q

What is the surface epithelium of the mucosa of the stomach?

A

Simple columnar

4
Q

What are the functions of the surface mucosa cells of the stomach?

A

Produce thick visible mucus

Secrete bicarbonate ions (buffering)

5
Q

Where are the regenerative cells found in the stomach?

A

Bases of pits

6
Q

What makes up the lamina propria of the stomach?

A

Loose vascular CT present in small amounts between glands

7
Q

What makes up the muscularis mucosae of the stomach?

A

Smooth muscle layers that is often arranged in three layers

8
Q

What are the three layers of the stomach’s muscularis mucosae?

A
  1. Inner circular
  2. Outer longitudinal
  3. Outermost circular/oblique
9
Q

Is the submucosa of the stomach vascular?

A

Yes, it is highly vascular

10
Q

Where is the submucosa of the stomach located?

A

AVA (arteriovenous anastomosis)

11
Q

What is the function of the AVA?

A

To shut down activity and secretion FAST

12
Q

What is next to the inner circular layer of muscle in the stomach submucosa?

A

Submucosal (Meissner’s) plexus

13
Q

What is the function of the submucosal plexus in the stomach?

A

To influence the mucosa through secretion, blood flow, and any limited muscle contractions

14
Q

How many layers of muscularis externa are possible in the stomach? Where at?

A

3 layers; especially between the cardiac region and greater curvature (all smooth muscle)

15
Q

What are the layers of the stomach’s muscularis externa?

A
  1. Innermost oblique
  2. Middle circular (well developed)
  3. Outer longitudinal (thin)
16
Q

Where is the myenteric (Auerbach’s) plexus located in the stomach?

A

Between circular and longitudinal layers

17
Q

What is the function of the myenteric plexus in the stomach?

A

To stimulate muscularis externa

18
Q

Which is present in the stomach: serosa or adventitia?

A

Serosa

19
Q

What three regions of the stomach is gastric histology based off of?

A

Cardiac, Gastric (fundus and body), Pyloric

20
Q

Why do the cardiac glands have a coiled base in the cardiac region?

A

Due to shorter pits

21
Q

What cells are present in the cardiac region of the stomach?

A

Primarily surface mucous, some neck mucous, a few DNES and parietal cells. NO chief cells

22
Q

Which region of the stomach is the smallest and obtains much mucus?

A

Cardiac region

23
Q

What are the boundaries of the gastric glands of the gastric region?

A

Extends from gastric pit to muscularis mucosae

24
Q

What is another name for the gastric gland?

A

Zymogenic gland

25
Q

What are the three regions in the gastric gland?

A

Isthmus, Neck, Base

26
Q

How long do the surface mucous cells in the isthmus live?

A

3-5 days

27
Q

What do the surface mucous cells of the isthmus produce?

A

Thick visible mucus that traps bicarbonate ions

28
Q

What is the function of the surface mucous cells of the isthmus?

A

To protect mucosa from auto-digestion and the rougher components of chyme

29
Q

What is another name for the DNES cells in the isthmus?

A

Enteroendocrine cells

30
Q

What are types of DNES cells in the isthmus?

A

Type D, Type EC, Type G

31
Q

What do the Type D DNES cells do?

A

Produce somatostatin which inhibits release of hormones/HCL by nearby DNES cells

32
Q

What do the Type EC DNES cells do?

A

Produce serotonin and substance P which increases gut motility

33
Q

What do the Type G DNES cells do?

A

Produce gastrin which stimulates HCL and pepsinogen secretion, aids in gut motility, acts as regenerative cells in body of stomach

34
Q

How long do the mucous cells of the neck live?

A

6 days

35
Q

What do the neck mucous cells produce?

A

A soluble, less alkaline mucus

36
Q

What is the function of the neck mucous cells?

A

To lubricate gastric contents

37
Q

Do the regenerative cells of the neck replace all cell types?

A

Yes

38
Q

How long do the parietal (oxyntic) cells of the neck live?

A

150-200 days

39
Q

What makes up the neck parietal cells?

A

Odd columnar with intracellular canaliculi

40
Q

Do the parietal neck cells produce acid?

A

Yes, very strong HCL with a pH of 0.8 and buffered immediately to 1.2 pH

41
Q

What do the parietal neck cells produce?

A

Very strong HCL

Gastric intrinsic factor

42
Q

What is the function of the parietal neck cells?

A

Necessary for vitamin B12 absorption

43
Q

What can chronic gastritis lead to?

A

Pernicious anemia

44
Q

Low number of which cells can lead to low amounts of intrinsic factor?

A

Parietal cells

45
Q

Low amounts of intrinsic factor causes what?

A

Decreases vitamin B12 absorption which is necessary for RBC maturation

46
Q

Are there a lot of DNES cells present in the neck?

A

No, there are few

47
Q

Where are the chief cells located? What is their other name?

A

Located in the base of the gastric region; also known as Zymogenic cells

48
Q

How long do the chief cells live?

A

60-90 days

49
Q

What do the chief cells produce?

A

Primarily pepsinogen and some gastric lipase

50
Q

What is the purpose of pepsinogen? Gastric lipase?

A

Pepsinogen- break down proteins

Gastric lipase: break down fats

51
Q

Are parietal cells present in the base?

A

Yes, some are

52
Q

How long do the DNES cells of the base live? Are there many or few?

A

60-90 days, few are present

53
Q

What types of cells are present in the isthmus of the gastric region?

A
Surface mucous cells
DNES cells (Types D/EC/G)
54
Q

What types of cells are present in the neck of the gastric region?

A

Neck mucous cells
Regenerative cells
Parietal (oxyntic) cells
DNES cells

55
Q

What types of cells are present in the base of the gastric region?

A

Chief (zymogenic) cells
Parietal cells
DNES cells

56
Q

How are the pits in the pyloric region of the stomach?

A

Deeper; very twisted and branched pyloric glands (shorter glands)

57
Q

What types of cells are present in the pyloric region?

A

Surface mucus (primarily)
DNES cells
Parietal cells
Neck mucous cells

58
Q

What do some of the neck mucous cells of the pyloric region produce?

A

Lysozyme

59
Q

What is the pyloric sphincter?

A

The anatomical sphincter between the pylorus of the stomach and the duodenum

60
Q

What are characteristics of an anatomical sphincter?

A

Well developed inner circular layer of muscle in muscularis externa
Inner circular layer in muscular externa can be independently controlled