Structure + Fnx Upper GI (2) Flashcards

1
Q

There is sharp change from a _______epithelium to a _______epithelium dedicated to secretion at the junction of the esophagus and stomach.

A

stratified squamous

simple columnar

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

Although there are no anatomical sphincters in the esophagus, there are two physiological
sphincters:

A

— pharyngoesophageal sphincter prevents reflux from esophagus into the pharynx
gastroesophageal sphincter prevents reflux from the stomach into the esophagus

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

The stomach is a _______ between the intestine and
esophagus where food undergoes mechanical and
chemical digestion to form_____.

A

dilated sac

chyme

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

Mucosa and submucosa are arranged as prominent folds
called______ in the empty stomach;

holds ~ _____ by distending

A

rugae

1.5 liters

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

Churning food in gastric juice which includes:

A

hydrochloric acid and digestive enzymes including pepsin, rennin, and gastric lipase

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

_____- small area at gastroesophageal junction

______- upper left to cardia; secrete acid and enzymes

A

cardia

fundus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
  • central area of stomach; secrete acid and enzymes

_____- constricted region at base; regulates release of
chyme into duodenum (pyloric sphincter); secretes
gastrin

A

body (corpus)

pyloris

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

Epithelium in stomach mucosa

A

Epithelium: Simple columnar epithelium

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

The epithelial cells lining the lumen generate a thick mucous (visible mucous) covering that functions to:

A

traps bicarbonate ions (alkaline) and protects the mucosa from the low pH in the stomach; soluble mucous acts as a lubricant.

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

Stomach mucosa invaginates into the lamina propria forming

A

gastric pits (GP)

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

secrete histamine in response to the vagus nerve to increase acid secretion

A

Enterochromaffin-type cells

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

Muscularis mucosae (MM): smooth muscle; gastric glands extend to MM influences

A

gastric gland outward flow

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

Thick layer of dense connective tissue
Numerous wandering cells including
lymphocytes, eosinophils, mast cells, and
plasma cells

A

Stomach Submucosa (S):

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

Numerous wandering cells in submucosa include

A

lymphocytes, eosinophils, mast cells, and
plasma cells, May also have adipose cells

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

Muscularis Externa has what 3 layers?

A

(O, C, L):
Three layers of smooth muscle
circular and longitudinal always present
oblique fibers may also be present
contraction controlled by myenteric
(Auerbach’s) plexus between layers

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

The surface of the mucosa is pitted with indentations called

A

gastric pits.

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

Gastric glands are________ of epithelial cells. One to seven gastric glands open into each gastric pit.

A

tubular columns

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

Gastric pits are divided into 3 regions:

A

isthmus, neck, base
different epithelial cell types in each region

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

Gastric glands are made of a
simple columnar epithelium that
consist of 6 cell types

A
  1. Surface mucous/lining cells
    (gastric pit)
  2. Parietal (oxyntic) cells (isthmus,
    neck, and base)
  3. Neck mucous cells (neck and
    base)
  4. Chief (zymogenic, peptic) cells
    (base)
  5. Enteroendocrine cells (base)
    6.Stem (regenerative) cells (neck)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The mucous in ________cells is
thick and dense while the mucous
secreted by ______cells is soluble

A

surface lining

mucous neck

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

Surface lining cell mucous adheres to
the mucosa and protects against

A

acid digestion

22
Q

soluble mucous
lubricates the stomach contents to

A

aid digestion.

23
Q

Differences in the make up of the
mucus can easily be seen in EM of

A

secretory granules

24
Q

__________ are a group of cells that secrete
specific bioactive proteins

A

Enteroendocrine cells

25
Q

Small ovoid or pyramidal cells between the
base of neighboring epithelial cells most easily
detected by immunostaining (

A

enteroendocrine cells

26
Q

G cells secreate

A

gastrin

27
Q

EC cells secreate:

A

serotonin

28
Q

D cells have:

A

somatostatin

29
Q

A cells secreate

A

enteroglucagon

30
Q

ECL cells secreate

A

histamine

31
Q

Enteroendocrine cells release products, which are stored as
granules, into the _______
Substances act either on surrounding cells in
_________fashion or are transported through
the bloodstream to act as_____molecules.

A

lamina propria.

paracrine

endocrine

32
Q

Parietal cells can easily be identified within the
gastric glands because their cytoplasm stains heavily with

A

eosin

33
Q

Pyramidal cells distinctive due to the presence
of an invagination of the apical surface called
the_________, which can almost
encircle the nucleus

A

secretory canaliculus

34
Q
A
35
Q

What cells are in the isthmus of the the gastric pit?

A

Parietal cells

36
Q

What cells are located in the Neck of the gastric pit?

A

neck mucous cells

stem cells

parietal cells

37
Q

What cells are located in the base of the gastric gland?

A

peptic cells

parietal cells

neck mucosa cells

neuroendocrine cells

38
Q

In parietal cells, a dense network of microvilli extend into the
canaliculus that hugely increases the

A

the secretory surface area of the cell

39
Q

In parietal cells, the ________is a unique
ultrastructural feature; its abundance inversely
correlates with HCl secretion.

A

Tubulovesicular network

40
Q

Pariteal cells are rich in:

A

Extremely rich in mitochondria that provide
energy for HCl secretion

41
Q

cell type at the base of the gastric
glands and secrete digestive
enzymes into the stomach lumen

A

Chief cells

42
Q

Cheif cells are full of_____ located zymogen secretory
granules (ZG) containing proenzymes including
pepsinogen, rennin, and gastric lipase with a______
nucleus

A

apically

basal

43
Q

What do chief cells have that allows them to accomplish high protein production?

A

rough ER and golgi

44
Q

In chief cells, what controls granule release?

A

via hormonal and neural action via vagus nerve

45
Q

Binding of the hormone______ to the receptors
on chief cells leads to the rapid exocytosis of
secretory granules.

A

secretin

46
Q

Cells of gastric mucosa are completely renewed every ____ days adn depends on the proliferating stem cell compartment which lies in the ____

A

3 days

neck of gastric gland

47
Q

As the stem cells divide, the daughter cells

A

differentiate and migrate upward
or downward to replace all types of epithelial cells.

48
Q

The surface epithelium is also rapidly repaired after injury (e.g., by aspirin) by the rapid migration of epithelial cells lying deep in the protected environment of the pits in a process called

A
  • mucosal restitution
49
Q

How can we tell fundus and body of stomach apart on histology?

A

Can’t! they are histologically indistinguishable with straight tubular glands

50
Q

Pylorus contains the same cell types as other regions, however, the glands are______ and ______ cells predominate.

A

branched

mucous neck

51
Q

What is characteristic of the cardiac region of the stomach in regards to:

gastric pits

glands

enteroendocrine cells

A

Cardiac region has shallower gastric pits, and the glands are highly coiled.
There is an abundance of enteroendocrine cells.

52
Q

What are the three phases of the stomach after a meal?

A

Cephalic phase
Brain anticipates meal – smells, visual cues
Parasympathetic signals via vagus nerve –> Acetylcholine (ACh) release – >acts on G cells –> gastrin secretion
Gastrin, ACh, and histamine –> act on parietal cells to stimulate limited HClrelease (*30% total gastric acid)
Gastric phase -
Food enters stomach –> distention –> increases G cell activity
Increased gastric juice release (*60% total gastric acid)
Onset of powerful smooth muscle contraction –> mechanical digestion
Intestinal phase -
Chyme released into duodenum
Gastric emptying slows
Distention of intestine –> gastric-inhibitory impulses by ENS = enterogastric reflex
Cholecystokinin and secretin suppress gastric activity (*10% gastric acid)