Gi histology

Question 1

The oral cavity, oropharynx and laryngopharynx is made up of?

Answer 1

Stratified squamous epithelium that is usually non keratinized

Question 2

The nasal cavity and nasopharynx is made up of

Answer 2

Respiratory epithelium normally

Question 3

The tongue consists of 4 types of papillae

Answer 3

Circumvallate
Follate
Fungiform
Filiform

Question 4

The anterior 2/3rds of the tongue consist of

Answer 4

Stratified squamous epithelium
thin on ventral surface
thick on dorsal surface - papillae

Question 5

The posterior 1/3rd of the tongue consists

Answer 5

Smooth stratified squamous epithelium
few tastebuds
extensive lymphoid aggregate

Question 6

The pharynx

Answer 6

Ring of lymphoid tissue
4 tonsils = palatine, lingual, tubal and pharyngeal
-

Question 7

Layers of GI tract

Answer 7

Mucosa
Submucosa
Muscularis Externa
Adventitia/ Serosa

Question 8

The mucosa is made up of

Answer 8

Epithelium
Lamina propria
Muscularis mucosa

Question 9

The submucosa

Answer 9

loose connective tissue

Question 10

muscularis externa

Answer 10

inner layer of circular muscle

outer layer of longitudinal muscle

Question 11

serosa/ adventitia

Answer 11

loose connective tissue

Question 12

what transition occurs at the gastro-oesophageal junction

Answer 12

stratified squamous epithelium –> simple columnar epithelium

Question 13

What are present in the mucous epithelial layer

Answer 13

gastric pits and at the bottom gastric glands

Question 14

What are the three divisions of the gastric pit

Answer 14

isthmus
neck
fundus

Question 15

The isthmus is predominantly made up of

Answer 15

parietal cells

Question 16

The neck is predominantly made up of

Answer 16

mucous cells

Question 17

The fundus is predominantly made u of

Answer 17

chief cells

Question 18

role of parietal cells

Answer 18

secrete hydrochloric acid

Question 19

role of chief cells

Answer 19

produce digestive enzymes

Question 20

describe the differences in gastric pits in various parts of the stomach

Answer 20

cardia - short gastric pits
fundus - narrow gastric pits
pylorus - deep gastric pits

Question 21

describe the differences in glands in various parts of the stomach

Answer 21

cardia - closely packed torturous
pylorus - long straight glands of low density
fundus - greatest density

Question 22

what is special about the muscular layers of the stomach

Answer 22

contains an additional muscular layer which lies internally to the circular layer

Question 23

Gastrodoudenal junction

Answer 23

thickened layer of inner circular muscle

Question 24

3 parts of small intestine

Answer 24

Duodenum - 25cm
Jejunum - 2m
Ileum - 2.5m

Question 25

What is special about the duodenum

Answer 25

Contains Burners glands

Question 26

What does the jejunum mainly consist of

Answer 26

Enterocyes

Question 27

What is special about the ileum

Answer 27

Peyer's Patches

Question 28

What are Burner's Glands

Answer 28

glands in submucosa | produce an alkaline solution in response to chyme

Question 29

What are Enterocytes

Answer 29

Columnar cells with a brush border | Responsible for absorption

Question 30

Peyer's patches

Answer 30

Aggregates of lymphoid tissue

Question 31

What cells does the small intestine contains

Answer 31

Enterocytes Goblet cells Paneth cells Enteroendocrine cells

Question 32

What do enteroendocrine cells do

Answer 32

Produce horomones - gastrin, CCK, VIP

Question 33

Role of paneth cells

Answer 33

Defensive function at base of Liberkuhn | secrete lysosomes + defensins

Question 34

The 2 main cells of the large intestine

Answer 34

Absorptive cells | Goblet cells

Question 35

What is notable about the large intestine histology

Answer 35

Long simple tubular glands which extend to the muscularis mucosae

Question 36

Describe the longitudinal muscle if the large intestine

Answer 36

3 muscular bands - teniae coli

Question 37

Describe the histology of the appendix

Answer 37

Continuation of the caecum Has crypts and circular lymphoid tissue lymphoid tissue decreases with age

Question 38

Rectoanal junction

Answer 38

non keratinized stratified squamous epithelium in the anal canal with keratinized stratified squamous epithelium surrounding the skin

Question 39

What is the nervous system called specific to the GI tract

Answer 39

enteric nervous system

Question 40

How is the enteric nervous system stimulated

Answer 40

Partly by autonomic nervous system | Also has ability to stimulate itself

Question 41

Name the plexuses involved in the enteric nervous system

Answer 41

Submucosa | Myenteric plexus

Question 42

What is the role of the submucosa plexus

Answer 42

Contributes to absorption | Regulates movement of muscularis mucosae

Question 43

Define a ganglion

Answer 43

Nerve cell body which exists outside the brain or spinal cord

Question 44

non-keratinized stratified squamous epithelium

Answer 44

oral cavity pharynx oesophagus anal canal

Question 45

simple columnar epithelium with extensive tubular glands

Answer 45

stomach

Question 46

simple columnar epithelium with villi & tubular glands

Answer 46

small intestine

Question 47

simple columnar epithelium with tubular glands

Answer 47

large intestine

Question 48

what makes up the parenchyma and pancreas

Answer 48

glandular epithelium

Question 49

what is the liver covered by

Answer 49

collagenous connective tissue covered by a layer of mesothelial cells

Question 50

What is the liver divided into

Answer 50

segments/ lobules

Question 51

what does the portal triad consist of

Answer 51

portal vein hepatic artery bile duct

Question 52

What are bile ducts lined by

Answer 52

cholangiocytes

Question 53

Where is the central vein

Answer 53

In the centre of the liver lobule

Question 54

Describe the layout from the red blood cell outwards

Answer 54

Red blood cells which is fenestrated layer of epithelium space of Disse hepatocytes

Question 55

Explain stellate cells

Answer 55

Found in space of Disse Produce collagen Store vit A

Question 56

Explain Kuppfer cells

Answer 56

Resident macrophages in the sinusoids

Question 57

When do stellate cells have the greatest role to play

Answer 57

Scarring = fibrosis

Question 58

What organ is responsible for producing bile

Answer 58

Liver

Question 59

Liver is formed by

Answer 59

Hepatocytes

Question 60

What are the functional cells of the liver

Answer 60

Cholangiocytes

Question 61

What type of cells modify bile

Answer 61

Cholangiocytes

Question 62

What is responsible for the pigmentation of bile

Answer 62

Bilirubin

Question 63

Where is bilirubin produced

Answer 63

Spleen from the breakdown of haem

Question 64

Explain how bile travels

Answer 64

Travels via bile caniculi to bile ducts to portal tracts

Question 65

What are bile caniculi

Answer 65

Tight junctions formed by adjacent hepatocytes

Question 66

What is bile

Answer 66

Alkaline solution formed by H2O, phospholipids, bilirubin and bile salts

Question 67

layers of gallbladder

Answer 67

simple columnar epithelium lamina propria - loose CT, blood vessels and lymphatics layer of smooth muscle adventitia

Question 68

explain the relationship between bile and the gallbladder

Answer 68

Bile from the liver travels via hepatic duct and causes a back up in the common bile duct which leads to bile flowing up via the cystic duct and entering the gallbladder Na and Cl flow through epithelial cells and water follows Bile then drains via the lymphatics which are present in the lamina propria

Question 69

Inflammation of the gallbladder is known as

Answer 69

Cholecystitis

Question 70

What stimulates the gallbladder

Answer 70

Nervous control - vagal | Release of hormone cholecystokinin via enteroendocrine cells

Question 71

What lines the gallbladder

Answer 71

Tall columnar epithelial cells with a brush border

Question 72

What makes the pancreas unique

Answer 72

It is both an endocrine and exocrine organ

Question 73

Outline the exocrine function

Answer 73

Produce a litre of digestive juices

Question 74

name the digestive juices of the exocrine function of the pancreas

Answer 74

proteases - breakdown proteins lipases - breakdown lipids nucleases - breakdown DNA/ RNA

Question 75

What cell is responsible for the exocrine function of the pancreas

Answer 75

acinar cells

Question 76

Where do the digestive juices go

Answer 76

Via pancreatic duct to the 2nd part of the duodenum

Question 77

What is the role of enteropeptidases

Answer 77

converts inactive proenzymes (zymogens) into their active form

Question 78

Why are exocrine cells basophilic and stain easily

Answer 78

high amounts of RER

Question 79

the endocrine pancreas is made up of

Answer 79

Islets of Langerhans

Question 80

What is the role of the islets of langherhans

Answer 80

produce hormones

Question 81

what makes up the islet of langerhans

Answer 81

alpha cells beta cells delta cells

Question 82

alpha cells are responsible for

Answer 82

secreting glucagon

Question 83

beta cells are responsible for

Answer 83

secreting insulin

Question 84

gamma cells are responsible for

Answer 84

secreting somatostatin