Histology of Esophagus and stomach Flashcards Preview

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Flashcards in Histology of Esophagus and stomach Deck (64)
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1

Four general layers o tube from lumen out?

mucosa (mucous membrane)

  submucosa

  muscularis externa

  adventitia

2

_________________:

lining of internal passages

  barrier between tissues & external environment

  thin enough for absorption and/or secretion

  supplemental mucus glands common in CT (for lubrication

Mucosa

3

3 layers of mucosa?

epithelium

lamina propria

muscularis mucosae

4

__________________:

  loose CT underlying and supporting epithelium

  contains:  small vessels & lymphatics
  nerves
  mucosal glands may be present
  varying amounts of lymphoid tissue

lamina propria of Mucosa in gut tube

5

_____________:

consists of 2 layers of smooth muscle (when present)

  inner circular layer

  outer longitudinal layer

  3rd layer sometimes present (i.e. stomach)

  luminal and longitudinal (or oblique)

  permits localized movement of mucous membrane

Muscularis mucosae of the gut tube

6

_________________:

provides mobility for mucosa

  contains: 

                  plexuses of larger blood vessels
      lymphatics
      nerves
  parasympathetic ganglia (Meissners plexus)
  submucosal glands in some regions
  (esophagus and duodenum)

Submucosa of the gut tube

7

What is Meissners plexus?  What layer is it in?

Parasympathetic ganglia

submucosa

8

What layer is Auerbach's plexus found in?

Muscularis Externa

9

What does muscularis externa do?

  maintains tonus in tube
  propels luminal contents onward

10

How many layers of muscle are in the muscularis externa?

2 layers

inner circular layer
  outer longitudinal layer

11

Is there adventitia in the esophagus?

No, only serosa

12

_________: 

  outermost coat of dense connective tissue

  often blends with CT of surrounding area

Adventitia

13

____________:

hollow organs within or projecting into cavity covered with peritoneum

  single layer of mesothelial cells

  entire coat then called a serosa

      large vessels and nerves found here

Serosa

14

What does epithelial lining of GI tract arise from?

endoderm

15

  CT & smooth muscle are derived from?

 mesoderm

16

How does the surface area of the GI tract change as you progress through it?

surface area (of lumen) increases

  first by:  invaginations (pits)

  then by:  invaginations (now called crypts)
  evaginations (villi)

17

Characterize the musculature of the regions of the GI tract

upper third: mostly Sk. muscle

mid third: sk. and sm. muscle

lower third: mostly sm. muscle

18

What is unique about the muscle of the upper and mid esophagus?

It is involuntary skeletal muscle

19

What percentage of nutrients and water is absorbed in the esophagus?

Zero

20

What does the stomach absorb?

(5)

some salts
  water
  glucose
  alcohol
  drugs

21

Into what regions is the stomach divided into?

body
  fundus
  cardium
  pylorus

22

The duodenum is retroperitoneal, how long is it?  What ducts enter it?

10-12 inches

  bile & pancreatic ducts enter

23

The jejunum is peritoneal, how long is it?

two-fifths (» 8ft)

24

The ileum is peritoneal, how long is it?

  remaining three-fifths (»12ft)

25

________:

site of digestion/absorption
  transport food from stomach to colon
  secrete enzymes & certain hormones

  divided into three parts

Small intestine

26

____________:

principal site of water resorption

  dehydration of chyme

  produces mucous secretion

  some digestion

  continued enzyme & bacterial activity

Fecal storage

27

What are the 6 portions of the large intestine?  Identify which are peritoneal and retroperitoneal.

ascending - retroperitoneal

  transverse - peritoneal

  descending - retroperitoneal

  sigmoid - retroperitoneal

28

__________________:

structure similar to colon, but:

  muscularis externa of rectum is complete

  mucosal folds bulge into lumen

  numerous goblet cells
  occasional enteroendocrine cells

  connects to anal canal

Rectum

29

What is the density of goblet cells in the stomach?

0 goblet cells/cm2

30

________: connects rectum to anus 

anal canal