Histology

Question 1

what does stratified squamous mean?

Answer 1

many layers (for protection) of thin cells (good for diffusion)

Question 2

what are the main layers of the GI tract?

Answer 2

mucosa
submucosa
muscularis externa
serosa

Question 3

what is involved in the mucosa?

Answer 3

epithelium
lamina propria
muscularis mucosae

Question 4

what is the Lamina Propria imvolve?

Answer 4

Loose connective tissue
contains GALT (gut associated lymphoid tissue)

Question 5

what does the submucosa involve?

Answer 5

loose connective tissue and Submucous Plexus

Question 6

what does the Muscularis Externa involve?

Answer 6

inner circular layer and outer longitudinal layer

Myenteric Plexus

Question 7

where exactly is the Myenteric PLexus located?

Answer 7

it is located in the muscularis externa, between the 2 muscle layers (circular and longitudinal)

Question 8

what are the 4 types of Papillae?

Answer 8

vallate, fungiform, filiform, folliate

Question 9

what is special about Filiform?

Answer 9

covers most of the dorsal surface and has NO taste buds

Question 10

what are the major cells in the Gastric Glands and what is their functions?

Answer 10

Parietal cells- secrete HCl
Chief cells- secrete digestive enzymes
Stem cells- replenish cells
Enteroendocrine cells- produce hormones to control secretions and motility

Question 11

what is different about the muscularis externa o the stomach?

Answer 11

has an Extra layer to aid churning

Question 12

where are Crypts of Lieberkuhn located?

Answer 12

in the small intestine

Question 13

what are the main cells of the small intestine?

Answer 13

enterocytes, goblet cells, paneth cells, enteroendocrine cells and stem cells

Question 14

what do Paneth cells do?

Answer 14

keep bacterial flora in check via antibacterials

Question 15

what is Brunner’s Glands?

Answer 15

glands located in Duodenum that secrete Alkaline mucus to protect from acidic chyme

Question 16

what is the location of the tallest villi in small intestine?

Answer 16

Jejunum

Question 17

where are Peyer’s Patches located?

Answer 17

Ileum and they are GALTs

they are in the Mucosa but extend into Submucosa

Question 18

Does the large intestine mucosa have Crypts and Villi?

Answer 18

NO, it has crypts but NO villi

Question 19

what do enterocytes in the large intestine do?

Answer 19

remove salt and water from faeces

Question 20

what type of tissue is in large amounts in the appendix?

Answer 20

Lymphoid tissue

Question 21

what shape are the lobules in the liver?

Answer 21

hexagonal lobules

Question 22

what does the hepatic hexagonal lobules contain?

Answer 22

central vein and portal triad

Question 23

what is involved in the portal triad?

Answer 23

portal vein, hepatic artery and bile duct

Question 24

what is a sinusoid?

Answer 24

gaps between the Hepatocytes that blood flows through

they take blood from the portal vein and hepatic artery to the central vein

Question 25

what are Kupffer Cells?

Answer 25

macrophages in the Sinusoids

Question 26

what causes contraction of the Gallbladder?

Answer 26

Vagal nerve

Cholecystekinin from the Duodenum (when fatty food enters)

Question 27

what are Acinar cells?

Answer 27

functional unit of the exocrine pancreas- store and secrete digestive enzymes