Brainscape's Knowledge GenomeTM

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


See full index

GI- Week 2 > Downing: Histology of Stomach and Small Intestine > Flashcards

Downing: Histology of Stomach and Small Intestine Flashcards

1
Q

What are important histological features of the stomach?

A
  1. Mucosa
    Simple columnar epithelium
    LP: contains gastric glands, pyloric glands, cardiac glands
    Muscularis mucosa
  2. Submucosa: LCT, large blood vessels and submucosal plexus
  3. Muscularis exerna: 3 layers (myenteric nerve plexus between M and O layer)
  4. Serosa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What layers thicken in the pyloric region of the stomach to form the pyloric sphincter?

A

Inner and middle layer

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

Describe the surface region and glandular region of the body and fundic regions of the stomach?

A

Surface region

  1. Surface- simple columnar epithelium
  2. Mucus secreting cells.
  3. LP forms a gastric pit (1/4 the thickness of the mucosa)
  4. Constant turn over every 4-6 days

Glandular region

  1. Simple columnar
  2. From gastric pit to muscularis mucosae
  3. Isthmus, neck
  4. Mucous neck cells and Parietal cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What parts of the glandular region have mitotically active cells?

A

Isthmus (germinative zone from which surface cells are renewed)

Neck (mucous neck cells and parietal cells)

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

What do mucus neck cells secrete?

A

Secrete clear mucus to protect gland from HCL and proteolytic enzymes

Columnar cells or cuboidal cells

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

Where are parietal cells most numerous in the stomach?

A

In the neck region of gland and upper body

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

What are the functions of parietal cells?

A

Produce secretory glycoprotein called IF that is necesary for absorption of vitamin B from the ileum

Produce HCL

Eosinophilic!

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

What stimulates parietal cells to secrete acid?

A

cholinergic nerve endings (ACh)

histamine (HR)Gastrin (MR) target G cells in the pyloric region

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

Where are chief cell most numerous?

A

Basal region of the gland

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

Why are chief cells basophilic?

A

D/tRER and eosinophilic d/t protein stored in zymogen granules

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

What do chief cells secrete?

A

Zymogen granules in chief cells contain pepsiniogen that is released from the GA and stored in the cytoplasm. Once released pepsinogen is activated by the acidic environment to pepsin. Pepsin can convert proteins to peptides.

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

Enteroendocrine cells produce substances that are secreted where?

A

They are NOT secreted into the lumen but rather secreted on the other side of hte basement membrane, where they accumulate and enter the vasculature.

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

What are three hormones produced by enteroendocrine (DNES) cells?

A

Gastrin
Secretin
Cholecystokinin

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

Gastrin

A

G cell
pylorus

Stimulates gastric acid secretion

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

Secretin

A

S cell
Small intestine

Pancreatic and biliary bicarbonate and water secretion

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

Cholecystokinin

A

I cell
Small intestine

Pancreatic enzyme secretion and gall bladder contraction

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

How does the pyloric region of the stomach differ from the fundic and body regions?

A
  1. Surface region
    - also simple columnar w/ mucus secreting cells to protect the epithelium
    - LP forms gastric pits that are 2/3!! the thickness of hte mucosa
  2. Glandular
    - also simple columnar
    - also has mucus cells nad enteroendocrine cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is unique about the mucosa of the cardiac region?

A

Gastric pits are 1/2 the thickness of the mucosa

Glands are NOT DEEP and are mostly the mucous neck type

19
Q

What are the functions of the stomach?

A

Produce chyme
Produce IF for absorption of B12 from the ileum

VERY little absorption

20
Q

What are the functions of the small intestine?

A

Mostly digestion and absorption

21
Q

What are plicae circulares?

A

Prominent circular folds in the duodenum and upper jejunum but NOT in teh ileum

Extend half way around the lumen and can increase the intestinal SA by a factor of 3

22
Q

What is commonly seen in the mucosa of the small intestine?

A

Villi formed by mucosal lining

Distinct muscularis mucosae to separate the mucosa and underlying submucosa

Plicae circulares are mucosal folds w/ submucosal cores

23
Q

What is commonly seen in the submucosa of the SI?

A

Core of the plicae circulares
larger blood vessels
submucosal nerve plexus

24
Q

What is the muscularis of the SI made up of?

A

ONly TWO layers of smooth muscle (Inner circular and outer longitudinal)

Myenteric plexus in between!

25
Q

Where is serosa found in the SI?

A

Every where except in areas that are retro-peritoneal

26
Q

Describe the epithelium of the SI.

A

Villus epithelium- simple columnar
- absorptive columnar, goblet and enteroendocrine cells

Crypt epithelium- simple columnar
- the three above + Paneth cells and undifferentiated cells

Lymphocytes

Cells held together by junctional complexes

27
Q

Describe the lamina propria of the SI.

A

Forms the CT core of each villus
contains a central lymphatic vessel known as a lacteal
Very cellular

28
Q

What is a characteristic feature of the small intestine?

A

intestinal villi

29
Q

What are the crypts of lieberkuhn?

A

located in the small intestine they open up at the base of hte villi

paneth cells are found at the base of the crypt and mitotic cells are present

30
Q

What are the absorptive columnar cells of hte small intestine?

A

Specialized for absorption and have tones of microvilli

Brush border of these cells contains enzymes that facilitate digestion and absorption

31
Q

What do goblet cells do and what happens to them as you pass form the duodenum to the colon?

A

secrete mucus

number of cells INCREASES

32
Q

Where are DNES cells found in the SI and what do they do?

A

found adjacent to the basement membrane

secrete peptide hormones

33
Q

Where are paneth cells found in the SI and what do they do?

A

Paneth cells are found at the base of crypts and contain zymogen granules taht contain a bacteriolytic lysozyme. They are believed to regulate intestinal bacteria.

34
Q

What is unique about the undifferentiated cells in the SI?

A

contain free ribosomes and undergo frequent mitosis

35
Q

What cells of the SI are associated wtih intestinal carcinoma?

A

undifferentiated cells

36
Q

What are brunner’s glands found?

A

In the submucosa of the Duodenum!

37
Q

What do brunner’s glands do?

A

Secrete alkaline mucus material into the duodenum that NEUTRALIZES the acid chyme of the stomach.

38
Q

Where can you find adventitia and serosa in the SI?

A

Duodenum- adventitia

Jejunum/ileum- serosa

39
Q

Where are peyer’s patches found?

A

Ileum opposite the mesentery attachment

40
Q

What are peyer’s patches?

A

aggregates of lymphatic nodules taht provide the precursors for plasma cells to produce IgA

41
Q

What are M cells?

A

Cells found in peyer’s patches that endocytose antigen and transport it to underlying lympahtic tissue

42
Q

What may be small, few or altogether absent from the distal ileum though it’s a prominent feature throughout much of hte SI?

A

plicae circulares

43
Q

Are there more or less goblet cells in ileum compared to the rest of the SI?

A

MORE

44
Q

What is the significance of tight junctions in the intestinal epithelium?

A
  1. compartmentalizes membrane proteins

2. forces material to be absorbed to pass into the absorptive cell

GI- Week 2 (11 decks)

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