Digestive Regional Histology

Question 1

There are four distinct layers of the tract:

Answer 1

1. mucosa.
2. submucosa.
3. muscularis.
4. Adventitia.

Question 2

Muscularis mucosae separates which layers

Answer 2

lamina propria from the submucosa layer.

Question 3

generally the lamina propria has what tissues

Answer 3

lymphoid tissues and plasma cells.
except in the stomach which may also have lymphoid cells in some certain cases.

Question 4

submucosa consist what tissues?

Answer 4

collagenous tissues and adipose connective tissues which bind mucosa to the main bulk of the muscular wall.

Question 5

is scatted throughout the submucosa and forms the submucosal plexus.

Answer 5

tiny parasympathetic ganglia.

Question 6

In the oesophagus the mucosa id folded in a relaxed state why?

Answer 6

allows for swelling (distention) during the passage of bolus.

Question 7

what type of the epithelium lines the lumen surface

Answer 7

stratified squamous epithelium.

Question 8

lamina propria

Answer 8

is narrowed.
contains scattered lymphoid tissue.

Question 9

submucosa in the oesophagus.

Answer 9

loose, several elastin fibers
seromucous glands, similar to salivary glands.

Question 10

Muscularis propria in the oesophagus.

Answer 10

is thick and contains both outer longitudinal muscle and inner circular muscle layers.

Question 11

part of the esophagus that is under voluntary control.

Answer 11

the first part of swallowing.

therefore, skeletal muscle is present.
this is predominant in the upper third of the oesphagus.

gradual transitions occur.
lower oesphagus has only smooth muscle.

Question 12

Oesophago-gastric Junction

Answer 12

From the esophagus to the stomach there is a change in the epithelium.

stratified squamous epithelium is replaced with tightly packed glandular secretory mucosa.

Question 13

Muscularis mucosae is continuous

Answer 13

Muscularis mucosa will appear in patches
Not easily seen in the stomach, when directly beneath the glands.

Question 14

Submucosa and muscularis propria in the oesophago-gastric junction.

Answer 14

continue uninterrupted beneath the mucosal junction

Defined anatomical sphincter is not defined by muscularis propria
A physiological sphincter mechanism is described

Question 15

Body of the stomach

Answer 15

mucosa
thrown into regular folds- rugae.

Consists of regular gastric glands which extend from muscularis mucosae to open in the stomach lumen – occurs via gastric pits or foveolae.

Question 16

the submucosa of the stomach

Answer 16

relatively loose
contains larger blood vessels.

Question 17

muscularis propria

Answer 17

added a reinforcement layer- inner oblique layer.
inner oblique layer lies internal to the circular layer.

Question 18

layer that covers peritoneal surface thin and barely visible.

Answer 18

serous layer.

Question 19

Pylorus of the stomach?

Answer 19

glands of the pylorus region:
> branched and coiled.

> Gastric pits occupy about 1/2 mucosal thickness.

> lined by mucosa-secreting cells and a small number of acid-secreting cells (parietal cells).

Question 20

Prominent muscularis mucosae

Answer 20

separate glands from underlying submucosa.

Question 21

G-cells

Answer 21

secrete gastrin ( peptide hormone).

scattered among pyloric cells
promotes secretions of pepsin and acid by gastric glands to enhance gastric motility.

Question 22

pyloric sphincter.

Answer 22

transition from glandular secretory type mucosa.
stomach to villious

Question 23

Brunners Glands

Answer 23

> Secrete a thin, alkaline mucosa
found in the submucosa of the duodenum, often extending into the mucosa.

Question 24

Muscularis propria.

Answer 24

thickening of the circular layer of muscularis propria at the gastroduodenal junction.

Circular and longitudinal layers of muscularis propria are continuous between pylorus and duodenum.

Question 25

small intestine

Answer 25

mucosa and submucosa are arranged in circular folds - plicae circulares, particularly numerous in the jejunum.

mucosal surface: several villi with microvilli present on the luminal surface of enterocytes.

enterocytes are columnar epithelial cells that cover villi.

Question 26

Muscularis mucosae in the small

Answer 26

lie beneath the crypts, separating mucosa from submucosa..

vascular submucusa

Question 27

Muscularis mucosae in the small

Answer 27

lie beneath the crypts, separating mucosa from submucosa..

vascular submucosa extends into and forms plicae circularis.

Peritoneal aspect of muscular propria is invested by loose collagenous serosa

Question 27

Muscularis mucosae in the small

Answer 27

lie beneath the crypts, separating mucosa from submucosa..

vascular submucosa extends into and forms plicae circularis.

Peritoneal aspect of muscular propria is invested by loose collagenous serosa