Histology

Question 1

What type of epithelium lines the oral cavity oropharynx and laryngopharynx?

Answer 1

Stratified squamous epithelium which is not keratanized

Question 2

What lines the nasal caity and nasopharynx?

Answer 2

Respiratory epithelium

Question 3

What type of epithelium lines the anterior 2/3rd of the tongue?

Answer 3

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

Question 4

What type of epithelium lines the posterior 1/3rd of the tongue?

Answer 4

Covered by smooth stratified squamous epithelium which, except for the circumvallate papillae, lacks papiilae but does have substantional lymphoid aggregates in the submucosa

Question 5

What are the 4 types of tongue papillae?

Answer 5

Fungiform
Circumvallate
Foliate
Filliform (no tastebuds - occupy much of dorsal surface)

Question 6

What are the 3 parts to the mucosae of the digestive tract?

Answer 6

Epithelium - sits on basal lamina
Lamina propria - loose connective tissue
Muscularis mucosae - thin layer of smooth muscle

Question 7

What makes up the submucosae?

Answer 7

Loose connective tissue

Question 8

What makes up the muscularis externa?

Answer 8

Two thik layers of smooth muscle, an inner circular layer and an outer longitudinal layer

Question 9

What makes up the serosa or adventitia?

Answer 9

Outer layer of connective tissue that either suspends the digestive tract or attaches it to other organs

Question 10

What is present in the submucosa of the oesophagus?

Answer 10

Submucosal glands

Question 11

What is the gastro-oesophageal junction?

Answer 11

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

Question 12

What is at the bottom of the gastric pits?

Answer 12

Gastric glands

Question 13

What lines the gastric pits?

Answer 13

Mucous cells

Question 14

What type of gastric glands does the isthmus of the gastric pit contain?

Answer 14

Parietal cells

Question 15

What type of gastric glands does the neck of the gastric pit contain?

Answer 15

Mucous and stem cells

Question 16

What type of gastric glands does the base of the gastric pit contain?

Answer 16

Chief cells, with a few parietal cells and enteroendocrine cells

Question 17

What does the chief cell produce?

Answer 17

Digestive enzyme secreting cell

Question 18

What does the parietal cell produce?

Answer 18

Hydrochloric acid

Question 19

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

Answer 19

Deep gastric pits that branch into loosely packed, tortous glands

Question 20

What is the mucosae like in the body of the stomach?

Answer 20

Shallow gastric pits with long straight gastric glands

Question 21

What is the mucosae like in the pylorus of the stomach?

Answer 21

Deeo gastric pits with branches, colied gastric glands at a higher density that in the cardia

Question 22

What is the muscularis externa of the stomach?

Answer 22

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 23

What is the gastroduodenal junction?

Answer 23

Abrupt transition from stomach mucosa to duodenal mucosa. The inner, circular layer of smooth muslce is markedly thickened to form the pyloric sphincter

Question 24

What is located within the duodenum?

Answer 24

Brunner’s glands in the submucosae

Question 25

What is located within the jejunum?

Answer 25

Tallest villi, located on permanent circular folds of the mucosa and submucosa, the plicae cirularis

Question 26

What is located within the ileum?

Answer 26

Characterized by aggregations of lymphoid follicles called peyer’s patches found in the submucosa and often extending into the lamina propria

Question 27

What is an enterocyte?

Answer 27

Tall columnar cells with a brush border and are the principle absorptive cell

Question 28

What are golbet cells?

Answer 28

Produce mucin to protect epithelium and lubricate passage of material

Question 29

What are paneth cells?

Answer 29

Found at the base of the crypts of Lieberkuhn, they have a defensive function and have a role in regulating bacterial flora (secrete lysozyme and defensins)

Question 30

What are enteroendocrine cells?

Answer 30

Produce hormones that contribute to the control of secretion and motility (gastrin, CCK, vasoactive intestinal pepide)

Question 31

What are stem cells?

Answer 31

Found at the base of the crypts of Lieberkuhn, they divide to replenish epithleium

Question 32

What is the function of brunner’s glands?

Answer 32

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

Question 33

What are the 2 cells of the small intestine?

Answer 33

Absorptive cells - removal of salts and water

Goblet cells - secretion of mucous to lubricate the colon

Question 34

What are crypts?

Answer 34

Straight tubular glands that extend down to the luscularis mucosae

Question 35

What is the rectoanal junction?

Answer 35

A distinct junction between the mucosa of the rectum and the stratified squamous epithelium of the anal canal

Question 36

Where do most of the neurones live in the GI tract?

Answer 36

Most of the neurones live in groups called ganglia between the two muscle layers that make up the muscularis externa

Question 37

What is the myenteric plexus?

Answer 37

Interconnected network of fibers that controls gut motility in the muscularis externa

Question 38

What is the submucosal plexus?

Answer 38

Second network of neurones found in the submucosa that controls the muscle of the muscularis mucosae and helps to regulate secretion in the epithelium