GI

Question 1

What are the oral cavity, oropharynx and laryngopharynx lined by?

Answer 1

stratified squamous epithelium

Question 2

What are the nasal cavity and nasopharynx covered by?

Answer 2

respiratory epithelium

Question 3

What is the anterior 2/3 of the tongue covered by?

Answer 3

Stratified squamous epithelium, thin on ventral surface, thick and with papillae on the dorsal surface

Question 4

What is the posterior third of the tongue covered by?

Answer 4

smooth stratified squamous epithelium which, except for the circumvallate papillae, lacks papillae

Question 5

What else does the posterior third of the tongue have in its submucosa?

Answer 5

substantial lymphoid aggregates

Question 6

Which type of papillae has no taste buds?

Answer 6

Filiform

Question 7

Does the tongue contain crypts?

Answer 7

Yes

Question 8

Describe the 4 major layers of the digestive tract, starting with the lumen and going out.

Answer 8

Mucosa: 3 parts

a. Epithelium: sits on a basal lamina
b. Lamina Propria: loose connective tissue
c. Muscularis Mucosae: thin layer of smooth muscle 2. Submucosa: loose connective tissue 3. Muscularis Externa: two thick layers of smooth muscle, an inner 	circular layer and an outer longitudinal layer 4. Serosa or Adventitia: outer layer of connective tissue that either suspends the digestive tract or attaches it to other organs

Question 9

When is there an abrupt change in epithelium type in the digestive tract?

Answer 9

Abrupt transition from stratified squamous epithelium of oesophagus to the columnar epithelium of the cardia of the stomach

Question 10

What are the gastric “holes”?

Answer 10

gastric pits

Question 11

What are contained within the gastric pits?

Answer 11

1-7 gastric glands

Question 12

What are gastric pits lined by?

Answer 12

by surface mucous cells

Question 13

Are the cells of the gastric gland evenly distributed?

Answer 13

No

Question 14

Going down the gastric gland, what is the order of its parts?

Answer 14

Pit, isthmus, neck, base

Question 15

What part of the gland contains mostly parietal cells?

Answer 15

isthmus

Question 16

What cells does the neck of the gastric gland contain?

Answer 16

mostly neck mucous cells and stem cells

Question 17

What cells does the base of the gastric gland contain?

Answer 17

mostly chief cells, with a few parietal cells and neuroendocrine cells

Question 18

What are neuroendocrine cells also called?

Answer 18

enteroendocrine cells

Question 19

What do chief cells do?

Answer 19

secrete digestive enzymes

Question 20

What do parietal cells do?

Answer 20

Produce HCl

Question 21

What is the mucosa of the cardia of the stomach like?

Answer 21

Deep gastric pits that branch into loosely packed, tortuous glands

Question 22

What does the body of the stomach’s mucosa consist of?

Answer 22

Shallow gastric pits with long straight gastric glands

Question 23

What is the mucosa of the pylorus of the stomach like?

Answer 23

Deep gastric pits with branched, coiled gastric glands at a higher density than in the cardia

Question 24

What additional layer does the muscularis externa in the stomach contain and what is it for?

Answer 24

This layer is oblique to the usual circular and longitudinal muscle layers and is located internal to the circular layer. This layer aids the churning action of the stomach.

Question 25

When in the stomach is the the inner, circular layer of smooth muscle is markedly thickened?

Answer 25

pyloric sphincter

Question 26

What are found between the bases of adjacent villi?

Answer 26

pits ‘drilling’ downwards, the crypts of Lieberkuhn

Question 27

Which part of the small intestine is the longest?

Answer 27

ileum

Question 28

What does the duodenum contain in the submucosa?

Answer 28

Brunner’s glands

Question 29

Which part of the small intestine contains the tallest villi and where are they located?

Answer 29

located on permanent circular folds of the mucosa and submucosa, the plicae circularis.

Question 30

What is the ileum characterized by?

Answer 30

aggregations of lymphoid follicles called Peyer’s patches found in the submucosa and often extending into the lamina propria.

Question 31

Which Cells of the Small Intestinal Epithelium are the most numerous and the principle absorptive cell, and what are these like?

Answer 31

enterocytes, tall columnar cells with a brush border

Question 32

Which cells produce mucin to protect epithelium and lubricate passage of material?

Answer 32

goblet cells

Question 33

Which cells Found at the base of the crypts of Lieberkuhn, they have a defensive function?

Answer 33

paneth cells

Question 34

Which cells produce hormones that contribute to the control of secretion and motility?

Answer 34

neuroendocrine cells

Question 35

Which cells are found at the base of the crypts of Lieberkuhn and divide to replenish epithelium?

Answer 35

Stem cells

Question 36

What do Brunner's glands in the duodenum do?

Answer 36

when stimulated by the presence of chyme they produce a thin, alkaline mucous to neutralise the chyme

Question 37

Are the plicae in the jejenum just mucosa?

Answer 37

No, submucosa too

Question 38

What are the 2 principles types of cells in the large intestine?

Answer 38

absorptive and goblet

Question 39

What do large intestine absorptive cells do?

Answer 39

For removal of salts and thereby water

Question 40

What do large intestine goblet cells do?

Answer 40

For the secretion of mucus to lubricate the colon

Question 41

How are large intestine cells arranged?

Answer 41

straight, tubular glands, referred to as crypts, that extend down to the muscularis mucosae

Question 42

in the large intestine, how is the outer, longitudinal smooth muscle found?

Answer 42

in 3 strips called teniae coli

Question 43

Is large intestine muscle distinct or continuous?

Answer 43

Neither

Question 44

What is the digestive tract's nervous system called?

Answer 44

enteric nervous system

Question 45

Where are ganglia of the GI tract found?

Answer 45

between the 2 layers of the muscularis externa

Question 46

What is the interconnected network of fibres in the GI tract called?

Answer 46

myenteric plexus

Question 47

What network of neurons is found in the submucosa and what does it do?

Answer 47

submucosal plexus, controls the muscle of the muscularis mucosae and also helps regulate secretion in the epithelium