Choudhury - Esophagus, Stomach

Question 1

What cell type procduces hydrochloric acid?

Answer 1

Parietal cells

Question 2

What cell type procduces mucous?

Answer 2

1) Cardiac esophageal glands (present in lamina propria)
2) Surface (neutral) and neck (acidic) mucous cells of stomach

Question 3

What cell type procduces pepsinogen?

Answer 3

Chief cells (aka zymogenic cells)

Question 4

What cell type procduces lipase (initiates fat digestion)?

Answer 4

Chief cells

Question 5

What cell type procduces chymosin?

Answer 5

Gastric chief cells (in infants)

Question 6

What cell type procduces intrinsic factor?

Answer 6

Parietal cells

IF is required for absorption of vitamin B12 (which is essential for hemopoiesis)

Question 7

What cell type procduces immunoglobulin A (IgA)?

Question 8

What cell type procduces lysozyme?

Question 9

What cell type produces hormones?

Answer 9

enteroendocrine cells (argentaffin cells)

present throughout entire GI tract, not so numerous in gastric mucosa

synthesize/store enteric hormones:
gastrin
somatostatin
vasoactive intestinal peptide (VIP)
serotonin (5-hydroxytryptamine)

glucose-dependent insulinotropic peptide (GIP)

[formerly gastric inhibitory peptide]

Question 10

Be able to differentiate(on a histologic basis) the three regions of the stomach

Question 11

What type of neuronal cell bodies (division and order) are in ganglia of the submucosal plexus?

Question 12

What type of neuronal cell bodies (division and order) are in ganglia of the myenteric plexus?

Question 13

What parts of the G.I. tract have an adventia?

Question 14

What parts of the G.I. tract have a serosa?

Question 15

Describe the general plan, from lumen outward, of the gut tube (four basic layers)

Answer 15

mucosa (mucous membrane –> submucosa –> muscularis externa –> adventitia

Question 16

Why is the mucosa so important?

Answer 16

It serves as a protective barrier AND as an absorbative/secretive barrier…

It is the barrier between tissues & external environment

Question 17

Describe the lamina propria

Answer 17

loose CT underlying and supporting epithelium

contains:

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

Question 18

Three layers of mucosa?

Answer 18

1. epithelium (including basement membrane)
2. lamina propria
3. muscularis mucosae

Question 19

Characteristics of muscularis mucosae

Answer 19

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

Question 20

Submucosa

Answer 20

provides mobility for mucosa

contains:

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

Question 21

Muscularis externa

Answer 21

2 thick layers of smooth muscle

inner circular layer
outer longitudinal layer

both layers actually spirally arranged
vascular and ANS plexi between muscular layers

parasympathetic ganglia (Auerbach’s plexus)

maintains tonus in tube
propels luminal contents onward

Question 22

Where is Meissner’s plexus (PS ganglia) located?

Answer 22

Submucosal layer

Question 23

Where is Auerbach’s plexus (PS ganglia, aka myenteric plexus) located?

Answer 23

Muscularis externa layer

Question 24

Describe the adventitia

Answer 24

outermost coat of dense connective tissue

often blends with CT of surrounding area

Question 25

Describe the serosa

Answer 25

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

Question 26

Is there any serosa on/over the esophagus?

Answer 26

NO! Only adventitia on the esophagus (blends with surrounding CT).

Question 27

GI development...review

Answer 27

epithelial lining of tracts arises from endoderm CT & smooth muscle are derived from mesoderm

Question 28

Goblet cells increase in number as...

Answer 28

...we move from the esophagus to the anus.

Question 29

What types of muscle are the three different portions of the esophagus made up of?

Answer 29

Upper 1/3 = mostly skeletal m. (however, involuntary!) Middle 1/3 = both skeletal and smooth m. (again, involuntary!) Lower 1/3 = Mostly smooth m.

Question 30

Upper and middle thirds of esophagus contain muscle that is...

Answer 30

...involuntary!

Question 31

Stomach: function and parts

Answer 31

retaining/mixing reservoir secrete gastric juices (to begin digestion) absorption limited: some salts water glucose alcohol drugs divided into 4 anatomical regions: body fundus (body and fundus form histological fundus) cardium pylorus

Question 32

What three mentioned substances are absorbed from the stomach very quickly?

Answer 32

Glucose, alcohol, and ASA

Question 33

Characteristics of the small intestine

Answer 33

site of digestion/absorption transport food from stomach to colon secrete enzymes & certain hormones divided into three parts duodenum - retroperitoneal 10-12 inches bile & pancreatic ducts enter jejunum - peritoneal two-fifths (» 8ft) ileum - peritoneal remaining three-fifths (»12ft)

Question 34

Parts/function of large intestine

Answer 34

principal site of water resorption dehydration of chyme produces mucous secretion \*some digestion continued enzyme & bacterial activity fecal storage 6 portions include: cecum (small pouch at junction w/ ileum) appendix (diverticulum of cecum) colon - divided into: ascending - retroperitoneal (2ndary) transverse - peritoneal descending - retroperitoneal (2ndary) sigmoid - retroperitoneal (2ndary)

Question 35

Characteristics of rectum

Answer 35

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

Question 36

Parts of anal canal

Answer 36

connects rectum to anus (external aspect) \*pectinate line epithelial change from simple columnar to strat. squamous, wet retro/extraperitoneal

Question 37

Pectinate line

Answer 37

Line that divides the upper 2/3s and lower 1/3 of the anal canal Epithelial cell change: from simple columnar to strat. squamous, wet

Question 38

What epithelial change occurs at the cardioesophageal junction?

Answer 38

Sudden change from stratified squamous to simple columnar epithelium

Question 39

Are there any goblet cells in the stomach?

Answer 39

NO! Only mucous-secreting cells... this will be a question, if the vinette is talking about goblet cells, it is not talking about the stomach!!!

Question 40

Directionality of three smooth muscle layers of stomach?

Answer 40

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 41

2 cell types of cardiac region of stomach?

Answer 41

surface mucous cell: on mucosal surface, lining gastric pits, secrete acidic mucous\*\*\* undifferentiated cells: in base of pits, in neck of glands

Question 42

4 cell types found in fundus region (largest area)

Answer 42

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 43

Are there any goblet cells in the stomach?

Answer 43

NO

Question 44

Which cells produce acidic mucus?

Answer 44

Mucous neck cells

Question 45

What is the space in between the gastric pits?

Answer 45

Lamina propria

Question 46

Gastric enteroendocrine cells secrete their (multiple) products into the...

Answer 46

bloodstream (vessels found in lamina propria)