GIT Histology and more (nerves, glands etc,)

Question 1

what type of muscle fibres are present in tongue?

Answer 1

skeletal

Question 2

what are the 4 types of inguinal papillae found in the tongue?

Answer 2

-filiform/coniform/lentiform
-fungiform
-circum vallate
-foliate

Question 3

filiform
-function
-appearance
-in cats conifrom is…

Answer 3

-mechanical function
-conical structures project upwards giving it a velvety covering
-larger and more keratinised

Question 4

fungiform
-function
-appearance histologically

Answer 4

-taste and sensory function
-mushroom appearence

Question 5

circum vallate
-function
-APPEARANCE

Answer 5

-sensory and taste function
-cat like appearence
-largest and most prominent

Question 6

foliate papillae
-function
-rare in what species
-common in what species

Answer 6

-sensory and taste
domestic species
rabbits

Question 7

What is the function of keratinisation of the mucosal lining of the oral cavity

Answer 7

Protection from damage from ingested material – keratinisation increases the durability of the oral mucosa.

Question 8

What is the most common type of lingual papilla, and what is its function?

Answer 8

Filiform – mechanical papilla, providing traction for moving food material and some protection of the surface of the tongue.

Question 9

Which cranial nerves innervate the taste buds of the tongue?

Answer 9

glossopharyngeal
chorda tympani from facial nerve

Question 10

Which cranial nerve gives motor innervation to the tongue?

Answer 10

Hypoglossal Nerve (CN XII)

Question 11

what are the 4 salivary glands in the dog

Answer 11

mandibular
sublingual
parotid
zygomatic

Question 12

which salivary gland in dog is a mixed gland?
what does this mean?

Answer 12

mandibular; produces both mucus and serous secretions

Question 13

what unique histological structures are found together only in oesophagus

Answer 13

combination of stratified squamous epithelium and submucosal mucous glands

Question 14

What changes to the epithelium might you expect in ruminants and horses compared to carnivores?

Answer 14

Increased keratinisation to cope with the more abrasive herbivorous diet

Question 15

What is the function of the submucosal mucous glands?

Answer 15

Lubrication of the bolus of food as it passes along the oesophagus

Question 16

what kind of mucosa is found in stomach?

Answer 16

secretory

Question 17

empty stomach has folds or ridges, called…

Answer 17

rugae, formed from mucosa and submucosa

Question 18

what are the 5 main cell types found in mucosa of stomach?

Answer 18

mucous/mucin-producing cells
parietal cells
chief cells
neuroendocrine cells
stem cells

Question 19

where are gastric glands found?

Answer 19

inner lining of stomach

Question 20

function of mucous cells?

Answer 20

mucous secretion for protection of surface cells from acidic gastric juice, produce mucin

Question 21

function of parietal cells (pale-staining)

Answer 21

secrete HCl

Question 22

function of chief cells (dark staining)

Answer 22

secrete enzymes e.g pepsin

Question 23

function of neuroendorcine cells

Answer 23

stimulate secretion of acid and proteases in response to presence of food in stomach

Question 24

function of stem cells

Answer 24

replace worn out epithelial cells

Question 25

What is the average life-span of a surface epithelial (mucosal) cell in the stomach?

Answer 25

2-3 days

Question 26

What is the function of the mucous secretions from the cardia and pyloric regions of the stomach?

Answer 26

Protection of the mucosal surface from damage by the acidic gastric juice.

Question 27

what gland is found in the duodenum?

Answer 27

brunners gland

Question 28

What is the function of Brunner’s Glands?

Answer 28

Production of an alkaline mucous secretion to neutralise the acidic chyme exiting the stomach through the pylorus and so preventing acidic damage to the mucosa of the small intestine

Question 29

What is the function of the long villi in the jejunum?

Answer 29

To increase the surface area for absorption

Question 30

What are the two functions of the mucous produced by the goblet cells in the intestines?

Answer 30

Protection of the mucosal surface and lubrication of intestinal content

Question 31

Periodic Acid-Schiff stains what colour?

Answer 31

stains carbohydrates purple

Question 32

what is the distinguishing feature of the ileum histologically?

Answer 32

peyers patches; dark staining nodules of lymphatic tissue

Question 33

What is the function of Peyer’s patches, and why are they so important in the ileum?

Answer 33

They are lymphatic nodules, and involved in immunosurveillance and immune defence. The importance in the ileum is the proximity to the bacterial population of the colon and the risk of invasion of these colonic bacteria into the small intestine.

Question 34

what is the ileocolic junction? -function

Answer 34

A muscular sphincter is present to minimise the movement of material from the colon back into the ileum.

Question 35

does descending colon of the dog contain villi? what do they contain?

Answer 35

NO crypts of leiberkuhn

Question 36

compared to small intestine, large intestine has a lot more _____ cells?

Answer 36

goblet

Question 37

Why are there proportionally more goblet cells in the mucosa of the large intestine compared to the small intestine?

Answer 37

Increased lubrication of the forming faeces is required

Question 38

From which organs does the hepatic portal vein bring blood to the liver. What is the functional significance of this?

Answer 38

The hepatic portal vein drains blood from the stomach, small and large intestines, spleen and pancreas and carries it directly to the liver (not travelling via the heart). This is so that the liver gets first-pass access to the nutrient-rich blood leaving the gastrointestinal tract, which is important for normal metabolic function.

Question 39

What are the endocrine areas of the pancreas called?

Answer 39

Islets of Langerhans

Question 40

Why are pancreatic enzymes released as proenzymes?

Answer 40

Prevents autodigestion of the pancreas

Question 41

the entire liver sits in what location?

Answer 41

right cranial abdomen

Question 42

what 2 types of cells contribute to composition of pancreatic juice

Answer 42

cells of intercalated duct acinar cells

Question 43

cells of intercalated duct -produce secretions rich in... -what are these for?

Answer 43

HC03- (alkaline substance) -neutralise acidic contents and prevent injury -provide optimal pH for pancreatic juices

Question 44

What do the acinar cells produce?

Answer 44

Enzymes