Histology of Esophagus and stomach

Question 1

Four general layers o tube from lumen out?

Answer 1

mucosa (mucous membrane)

submucosa

muscularis externa

adventitia

Question 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

Answer 2

Mucosa

Question 3

3 layers of mucosa?

Answer 3

epithelium

lamina propria

muscularis mucosae

Question 4

__________________:

loose CT underlying and supporting epithelium

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

Answer 4

lamina propria of Mucosa in gut tube

Question 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

Answer 5

Muscularis mucosae of the gut tube

Question 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)

Answer 6

Submucosa of the gut tube

Question 7

What is Meissners plexus? What layer is it in?

Answer 7

Parasympathetic ganglia

submucosa

Question 8

What layer is Auerbach’s plexus found in?

Answer 8

Muscularis Externa

Question 9

What does muscularis externa do?

Answer 9

maintains tonus in tube
propels luminal contents onward

Question 10

How many layers of muscle are in the muscularis externa?

Answer 10

2 layers

inner circular layer
outer longitudinal layer

Question 11

Is there adventitia in the esophagus?

Answer 11

No, only serosa

Question 12

_________:

outermost coat of dense connective tissue

often blends with CT of surrounding area

Answer 12

Adventitia

Question 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

Answer 13

Serosa

Question 14

What does epithelial lining of GI tract arise from?

Answer 14

endoderm

Question 15

CT & smooth muscle are derived from?

Answer 15

mesoderm

Question 16

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

Answer 16

surface area (of lumen) increases

first by: invaginations (pits)

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

Question 17

Characterize the musculature of the regions of the GI tract

Answer 17

upper third: mostly Sk. muscle

mid third: sk. and sm. muscle

lower third: mostly sm. muscle

Question 18

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

Answer 18

It is involuntary skeletal muscle

Question 19

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

Answer 19

Zero

Question 20

What does the stomach absorb?

(5)

Answer 20

some salts
water
glucose
alcohol
drugs

Question 21

Into what regions is the stomach divided into?

Answer 21

body
fundus
cardium
pylorus

Question 22

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

Answer 22

10-12 inches

bile & pancreatic ducts enter

Question 23

The jejunum is peritoneal, how long is it?

Answer 23

two-fifths (» 8ft)

Question 24

The ileum is peritoneal, how long is it?

Answer 24

remaining three-fifths (»12ft)

Question 25

\_\_\_\_\_\_\_\_: site of digestion/absorption transport food from stomach to colon secrete enzymes & certain hormones divided into three parts

Answer 25

Small intestine

Question 26

\_\_\_\_\_\_\_\_\_\_\_\_: ## Footnote principal site of water resorption dehydration of chyme produces mucous secretion some digestion continued enzyme & bacterial activity Fecal storage

Question 27

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

Answer 27

ascending - retroperitoneal transverse - peritoneal descending - retroperitoneal sigmoid - retroperitoneal

Question 28

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_: ## Footnote 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

Answer 28

Rectum

Question 29

What is the density of goblet cells in the stomach?

Answer 29

0 goblet cells/cm²

Question 30

\_\_\_\_\_\_\_\_: connects rectum to anus

Answer 30

anal canal

Question 31

\_\_\_\_\_\_\_\_\_\_\_: ## Footnote epithelial change or demarcation from simple columnar to strat. squamous, wet. divides the upper two thirds and lower third of the anal canal

Answer 31

Pectinate line (A.K.A - dentate line or mucocutaneous line)

Question 32

\_\_\_\_\_\_\_\_\_\_\_\_\_: ## Footnote epithelium stratified squamous non-cornified epithelium very thick rests on a relatively acellular CT

Answer 32

Esophageal mucosa

Question 33

\_\_\_\_\_\_\_\_\_\_\_\_\_\_: boundary provides better attachment for epithelium peg =downward projections of epithelium papillae = upward projections of connective tissue

Answer 33

Esophageal lamina propria

Question 34

What does the lamina propria of the esophagus contain?

Answer 34

scattered lymphatic nodules cardiac esophageal glands (mucous-secreting)

Question 35

Esophageal muscularis mucosae (muscular layer) is well developed & may contain several layers of _______ and some

Answer 35

smooth muscle elastic fibers

Question 36

Identify

Answer 36

**Esophageal** Mucosa epithelium lamina propria muscularis mucosae

Question 37

\_\_\_\_\_\_\_: thrown into longitudinal folds characteristic star-shaped outline to lumen (x-section) folds allow lumen to dilate for passage of food bolus esophageal glands scattered throughout submucosa secrete mucous via ducts passing through mucosa

Answer 37

Esophageal submucosa

Question 38

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_: ## Footnote smooth/skeletal ratio gradually increases upper esophagus mostly skeletal muscle middle esophagus skeletal & smooth muscle lower esophagus smooth muscle increases finally, no skeletal muscle

Answer 38

Muscularis Externa

Question 39

Is there adventitia in esophagus?

Answer 39

Yes, if I didn't fix the other slide then disregard it. There is adventitia in esophagus. No serosa. Dr. Choudry misspoke

Question 40

Identify

Answer 40

Submucosa muscularis externa adventitia

Question 41

\_\_\_\_\_\_\_\_\_: ## Footnote transition from esophagus to stomach sudden change from stratified squamous to simple columnar epithelium

Answer 41

cardioesophageal junction

Question 42

What are the three histologic regions of the stomach?

Answer 42

Cardia Fundus Pylorus

Question 43

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_: largely serosa mucosa very thick epithelium simple columnar epithelium mucous-secreting cells (not goblet cells) invaginates to line gastric pits filled with many gastric glands open to surface via gastric pits gastric pits are tubular crevices

Answer 43

Stomach

Question 44

\_\_\_\_\_\_\_\_\_\_\_\_: occupies slit-like spaces between gastric glands and pits

Answer 44

Lamina propria of the stomach

Question 45

What is the muscularis mucosa like in the stomach? Where is it present?

Answer 45

Very thin present at level of base of glands

Question 46

\_\_\_\_\_\_\_\_\_: ## Footnote extends into rugae contains: blood and lymph vessels peripheral nerves CT cells

Answer 46

Submucosa of stomach

Question 47

There are three layers of the muscularis externa in the stomach. What are they? What are their orientations?

Answer 47

inner layer - runs obliquely, incomplete middle layer – circular orientation continuous w/ inner m. layer of gut tube thick at pylorus to form sphincter outer layer - longitudinal orientation continuous w/ outer m. layer of gut tube

Question 48

\_\_\_\_\_\_\_\_\_: visceral peritoneum covers loose CT of the stomach continuous with greater & lesser mesenteries

Answer 48

Outer tunic - serosal layer

Question 49

\_\_\_\_\_\_\_\_\_\_\_\_: ## Footnote narrow, ring-shaped area around esophageal opening gastric pits extend »1/4 to 1/2 depth of mucosa cardiac gastric glands empty into base of each pit

Answer 49

Cardiac region of stomach

Question 50

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

Answer 50

surface mucous cell on mucosal surface lining gastric pits undifferentiated cells in base of pits in neck of glands

Question 51

\_\_\_\_\_\_\_: ## Footnote largest area, proximal »2/3 of stomach includes fundus and body gastric pits extend down 1/4 to 1/3 of mucosa each pit yields 3-7 gastric glands gastric glands long & straight

Answer 51

Fundic region of the stomach

Question 52

What iare the four cell types of the fundic region? Where are they found?

Answer 52

mucous neck cell mainly found in neck of gland parietal cells some scattered cells in neck more toward base zymogenic chief cells mainly found in base enteroendocrine cells (argentaffin cells) few in number, mainly in base

Question 53

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_: ## Footnote distal 1/3 of stomach gastric pits extend 1/2 depth of mucosa pyloric glands are short, coiled contain a mucous-secreting cell type similar to the mucous neck cell gastrin producing cells common in pyloric glands also in proximal part of duodenum

Answer 53

Pyloric region

Question 54

How many goblet cells would we find in the intestine?

Answer 54

Lots

Question 55

What type of cells secrete basic mucus?

Answer 55

None, until the intestine. They secrete acidic or neutral mucus only

Question 56

What cell types secrete acidic mucus?

Answer 56

mucous neck cells

Question 57

\_\_\_\_\_\_\_\_\_\_: ## Footnote flattened basal nuclei secretion granules and microvilli are apical produce acidic mucus differ structurally from surface mucous cells

Answer 57

mucous neck cells

Question 58

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_: ## Footnote large, round or triangular, cells with dark, central nuclei cytoplasm stains pink to red with H & E smooth ER prominent in cytoplasm microvilli and intracellular canaliculi present

Answer 58

Parietal cells

Question 59

What do parietal cells produce? What do these things do?

Answer 59

**hydrochloric acid** activates acid-dependent enzymes ** intrinsic factor** required for absorption of vitamin B12 vitamin B12 essential for hemopoiesis

Question 60

Where do gastric enteroendocrine cells secrete their products?

Answer 60

into the lamina propria

Question 61

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_: ## Footnote resemble salivary serous cells in appearance pale staining with H & E oval nuclei and mitochondria are basal in location apical, secretion granules (often poorly preserved) microvilli are present much rough-surfaced endoplasmic reticulum (ER) produce enzymes found in gastric juice pepsin (pepsinogen) begins digestion of proteins (in acid medium) lipase initiates fat digestion

Answer 61

Chief cells

Question 62

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_: present throughout entire GI tract but not so numerous in gastric mucosa (very common in small intestine) in gastric glands lie between chief cells and BM not all seem to reach lumen endocrine function note polarization of secretion granules

Answer 62

Gastric enteroendocrine cells

Question 63

What do gastric enteroendocrine cells synhtesize/secrete?

Answer 63

gastrin somatostatin vasoactive intestinal peptide (VIP) serotonin (5-hydroxytryptamine) glucose-dependent insulinotropic peptide (GIP) [formerly gastric inhibitory peptide]