Histology of GI

Question 1

Three types of glands found in the stomach

Answer 1

Pyloric, cardiac and fundic/ gastric

Question 2

Which layer of the stomach are gastric pits founds

Answer 2

Mucus layer

Question 3

Three characteristics of gastric pits

Answer 3

Found in mucosa, lined by surface mucous cells and have gastric glands an their base

Question 4

Which type of glands in the stomach has narrow lumen and shallow pits

Answer 4

Fundic glands

Question 5

Which glands in the stomach have wide lumens and deep pits

Answer 5

Pyloric and cardiac glands

Question 6

What do surface mucous cells in gastric pits secrete

Answer 6

Insoluble, viscous, gel-like coating that is rich in bicarbonate ions

Question 7

Five cell types in the fundic gland epithelium

Answer 7

Mucus neck cells
Parietal/oxyntic cells
Chief/peptic cells
Enteroendocrine cells
Stem cells

Question 8

Which fundic epithelial cell type produces SOLUBLE low-alkaline secretions

Answer 8

Mucus neck ells

Question 9

Which fundic epithelial cell type has the longest life span

Answer 9

Parietal cells

Question 10

Which fudic epithelial cell type is acidophilic and why

Answer 10

Parietal/oxyntic cells because they have a lot of mitochondria

Question 11

Why do parietal cells have a lot of mitochondria

Answer 11

ATP is needed for proton pumping

Question 12

Which fundic epithelial cell type has canniculi and many micro villi

Answer 12

Parietal/oxyntic cells

Question 13

Damage to which fundic epithelial cell type causes pernicious anemia

Answer 13

Parietal cells

Question 14

How is pernicous anemia caused

Answer 14

If parietal cells are damaged they cannot make intrinsic factor which is need for vitamin B12 absorption. Vit B12 is needed for DNA synthesis in erythrocytes

Question 15

How is Achlorhydria (no acid production)

Answer 15

Damage to parietal cells

Question 16

How can Achlorhydria also affect protein digestion?

Answer 16

Pepsinogen (secreted form chief cells) need to come into contact with acid to be cleaved into its active form, pepsin

Question 17

Which fundic epithelial cell produces pepsinogen

Answer 17

Chief/peptic cells

Question 18

Which fundic epithelial cells are basophilic

Answer 18

Chief/peptic cells because they have a lot of proteins (and RER)

Question 19

How is pepsinogen activated

Answer 19

Pepsinogen is converted to pepsin when it comes into contact with acid gastric juice

Question 20

Which side of chief cells contain the enzyme precursors

Answer 20

Apical surface

Question 21

What type of epithelium is in the esohagus

Answer 21

non keratinized, stratified squamous

Question 22

What type of epithelium is in the stomach

Answer 22

simple columnar

Question 23

Three components of the gastric mucosal barrier

Answer 23

Viscid mucus from surface cells
Bicarbonate ions from epithelial cells
Tight junction

Question 24

The absorptive surface of the small intestines is increased by

Answer 24

Circular folds (plicae circulares)
Villi
Microvilli

Question 25

What kind of glands extend form the muscularis mucosae to open into the lumen of villi

Answer 25

Simple tubular intestinal glands (crypts of Lieberkühn)

Question 26

Function of enterocytes

Answer 26

Absorptive cells that transport substances from the lumen of the small intestines to the blood or lumphatics

Question 27

Function of goblet cells

Answer 27

Secrete mucin

Question 28

Function of paneth cells

Answer 28

Have antimicrobial activity (eg. lysozome or apha defensins) and are found in the base of the intestinal glands

Question 29

Function of enterendocrine cells

Answer 29

Secretion of endocrine and paracrine hormones

Question 30

Function of M cells

Answer 30

Antigen transporting cells that cover lymphatic nodules

Question 31

Six types of ells lining the crypts of the intestines

Answer 31

Enterocytes, goblet, paneth, | enteroendocrine, stem and M cells

Question 32

What are Payer's patches

Answer 32

Aggregations of lymphatic nodules that contain B and T cells

Question 33

Which structures are a part of the GALT in the small intestines

Answer 33

Payer's patches and M cells

Question 34

What structure in the large intestines condenses to form teniae coli

Answer 34

Muscularis externa

Question 35

Which structure in the large intestines is associated with maturation of immune cells during early life

Answer 35

Appendix

Question 36

Which artery supplies the liver

Answer 36

Hepatic artery

Question 37

Which vein supplies the liver

Answer 37

Hepatic portal vein

Question 38

Structural components of the liver

Answer 38

Parenchyma, sinusoidal capillaries and Connective tissue stroma

Question 39

What is paranchyma

Answer 39

Plates of hepatocytes

Question 40

What are sinusoidal cappillaries

Answer 40

They separate plates of parenchyma

Question 41

What do hepatocytes consist of

Answer 41

Lots of golgi and rough ER- protein sythesis Numerous mitochondria Smooth ER- synthesis of lipids and detoxification of bilirubin Many peroxisomes- detoxification of various toxins Deposits of glycogen Lipid droplets

Question 42

What are the different types of surfaces on a hepatocyte

Answer 42

Sinusoidal surface and a lateral & canalicular surface

Question 43

Describe the sinusoidal surface of hepatocytes

Answer 43

It faces the parasinusoidal space and has many micro villi that open into the space

Question 44

Describe the later& canalicular surface of hepatocytes

Answer 44

It faces the neighboring hepatocytes and had bile canaliculus that is sealed by a tight junction