Digestive Overview, Upper & Lower GI Histology

Question 1

The mucosa is comprised of an epithelial layer plus the underlying loose, wellvascularized
connective tissue called the ________ .

Answer 1

lamina propria

Question 2

A thin layer of smooth muscle underlying the lamina propria is referred to as the _________

Answer 2

muscularis mucosae.

Question 3

Lymphocytes, plasma cells and macrophages will be

scattered throughout the _______

Answer 3

lamina propria.

Question 4

The submucosa contains connective tissue that is usually more dense than in the mucosa, larger blood vessels, and _________. Lymphoid cells of various types are also scattered throughout

Answer 4

nerve plexes, glands, and lymphatic nodules

Question 5

The muscularis externa is comprised of an inner circularly and outer longitudinally arranged layers of smooth muscle and nerve plexes. Its main function is _______ & ______

Answer 5

peristalsis,

churning of the lumenal contents.

Question 6

The serosa is an outer covering of ______ epithelial cells separated from the underlying muscular layers by a relatively thin layer of connective tissue. It is called the _____ in the case of the esophagus above the diaphragm where this outer layer is absent.

Answer 6

squamous,

adventitia

Question 7

which structure carries out no digestive function but is specialized for passage of food

Answer 7

esophagus

Question 8

the esophahus is lined with ______

Answer 8

non-cornified (non-keratinized) squamous epithelium

Question 9

the _______ in the stomach, is a small area of mainly mucus-secreting glands around the entry of the esophagus

Answer 9

cardia

Question 10

the _____, is the main body of the stomach that secretes acid, peptic digestive products and mucus

Answer 10

fundus

Question 11

the ______ secretes mainly mucus and has a relative

preponderance of endocrine cells that secrete the stomach hormone gastrin

Answer 11

pyloris

Question 12

The wall of the stomach has substantial longitudinal folds called rugae or _______ that disappear upon distension

Answer 12

plicae mucosae

Question 13

Humans have about 3-4 million of these in their stomach

Answer 13

Gastric glands

Question 14

The gastric epithelium is constantly renewing. Surface cells are replaced every ______ days.
The differentiated cells deep in the glands turn over much more slowly (i.e ________ )

Answer 14

3-5,

6-12 months

Question 15

Surface mucous cells contain large vesicles full of stomach ______ & ______ that are discharged locally onto the surface to provide a viscous protective layer that shelters the epithelial cells against stomach acid and abrasion from churning chyme.

Answer 15

mucins,

bicarbonate

Question 16

Directly covering the short microvilli of

surface cells is a more structured layer of cell surface ________, called the _________.

Answer 16

glycoproteins,

glycocalyx

Question 17

The primary secretory product of Chief (peptic) cells is ______

Answer 17

pepsinogen

Question 18

________ are unique acid producing cells specialized for pumping H+ ions (using a H+/K+ ATPase) into the lumen of the gastric glands, against a steep (more than a million-fold) gradient.

Answer 18

Parietal cells

Question 19

The pH of the gastric juice is _____, so production of acid is a vigorous, energy-demanding activity.

Answer 19

1-1.5

Question 20

Parietal cells are stimulated to produce acid by secretion of the local hormones _____ & _____

Answer 20

gastrin,

histamine

Question 21

Parietal cells also secrete an important glycoprotein

required for uptake of vitamin B12, _________ ,which, is crucial for the production of red blood cells in bone marrow.

Answer 21

intrinsic factor

Question 22

_______ cells contain large eosinophilic granules, which contain antibacterial peptides called defensins, in addition to lysozyme and phosopholipase.

Answer 22

Paneth

Question 23

Brunner’s glands are only found in the _______
and release their contents into the crypts of Lieberkuh. They secrete large quantities of bicarbonate to neutralize the acid arriving through the pyloric sphincter

Answer 23

duodenum

Question 24

Specialized epithelial cells (_______) function as antigen-uptake cells, and phagocytose luminal contents and present antigens to underlying lymphocytes and macrophages

Answer 24

M-cells

Question 25

lymphoid tissue is present, both as scattered individual cells and as lymphatic nodules and groups of nodules (called _______) in the mucosa of the intestine

Answer 25

Peyer’s patches

Question 26

98% of the volume of the pancreas is dedicated to its _______ function

Answer 26

exocrine

Question 27

the parotid gland is a ______ secretor

Answer 27

serous

Question 28

The submandibular gland is a ______ secretor

Answer 28

mixed

Question 29

sublingual mostly secretes ______

Answer 29

mucous