Histology

Question 1

What type of cell lines the oral cavity?

Answer 1

non-keritinized stratified squamous epithelium

Question 2

What type of cell lines the nasal cavity and nasopharynx?

Answer 2

respiratory epithelium

Question 3

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

Answer 3

stratified squamous epithelium

• thin on ventral side
• thick with papillae on the dorsal side

Question 4

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

Answer 4

smooth stratified squamous epithelium with no papillae but has lymphoid aggregates in the submucosa

Question 5

What are the four types of papillae?

Answer 5

fungiform
circumvallate
foliate
filiform

Question 6

What is at the entrance to the oropharynx?

Answer 6

ring of lymphoid tissue with the palatine, lingual, tubal and pharyngeal tonsils

Question 7

What type of muscle is in the oesophagus?

Answer 7

• upper is skeletal
• middle is both
• lower is smooth

Question 8

What lubricates the oesophagus?

Answer 8

mucous glands in the submucosa

Question 9

What type of cell is in the stomach?

Answer 9

simple columnar epithelium

with gastric pits and 1-7 glands at the bottom of each

Question 10

What cells line the cells of the gland?

Answer 10

• the neck= neck mucous cells and parietal cells which make HCl
• the isthmus= parietal and stem cells
• the fundus/base= chief cells that produce enzymes and some enteroendocrine cells

Question 11

How can the parietal and chief cells be identified?

Answer 11

parietal looks like pink fried eggs

chief looks dark and grainy

Question 12

What are the sections of the stomach called?

Answer 12

• Cardia: deep gastric pits and tortuous glands
• Body: shallow gastric pits and straight glands
• Pylorus: deep pits and many coiled glands

Question 13

What is the extra layer of muscle that the stomach has?

Answer 13

musculares externa is an oblique layer that is internal to the circular layer and churns

Question 14

Where is the pyloric sphincter?

Answer 14

between stomach and duodenum so gasproduodenal junction

Question 15

What is an extra feature of the small intestine?

Answer 15

villi with crypts of Lieberkuhn in between

Question 16

What are the differences in cells in the different parts of the small intestine?

Answer 16

• Duodenum: Brunner’s gland in submucosa to neutralise chyme
• Jejunum: tallest villi
• Ileum: many lymphoid follicles called Peyer’s patches

Question 17

What are the cells and a brief role of each in the small intestine?

Answer 17

• Enterocytes: tall columnar with brush border
• Goblet: mucin producers for lubrication
• Paneth: defense
• Enteroendocrine: hormone production for motility
• Stem: base of crypts to replenish epithelium

Question 18

What are the two types of cells of the large intestine?

Answer 18

• Absorptive: removal of salts and water

- Goblet: secretion of mucous

Question 19

What is the name for the three muscular strips down the side of the large intestine?

Answer 19

teniae coli

Question 20

How does the appendix tissue differ?

Answer 20

less crypts and circular lymphoid tissue

Question 21

What cells line the anal canal?

Answer 21

stratified squamous epithelium that becomes keratinized later on at skin level

Question 22

What is the ENS made up of?

Answer 22

two plexuses of nerve fibres- one in submucosa (submucosal), one in the muscularis externa (myenteric)

Question 23

What is a ganglion?

Answer 23

a group of nerve cells living outside of CNS

Question 24

What is the basic structure of the liver?

Answer 24

• covered with mesothelial cells
• lobules with a central vein in the middle and the hepatic artery, portal veins and the bile duct supplying the ends (portal triads)
• blood enters at the ends and leaves in the middle

Question 25

What makes up the triad of vessels in the liver?

Answer 25

1 - bile duct: lined by simple cuboidal cells called cholangiocytes 2 - hepatic portal vein: large thin walled blood vessel 3 - hepatic artery: round vessel with smooth muscle (sometimes a lymphatic vessel too)

Question 26

What is the relationship between hepatocytes and liver sinusoids?

Answer 26

- hepatocytes form plates or sheets of cells with spaces for blood to flow called sinusoids - lining between these two structures (simple squamous lining) - space is called the space of Disse - connective tissue in the liver in the portal tracts as well as collagen in the space of Disse

Question 27

What is the role of hepatic stellate cells and where are they found?

Answer 27

found in the space of Disse - make connective tissue - store vitamin A in fat droplets - become myofibroblasts and become scar tissue in cirrhosis

Question 28

What are Kupferr cells are where are they found?

Answer 28

sinusoids in the liver and they are macrophages to remove dead matter

Question 29

Where does bile go after being made?

Answer 29

- made in liver by hepatocytes - taken to bile ductules via bile canaliculi - to gallbladder

Question 30

What are bile caniculi?

Answer 30

small channels formed by tight junctions between hepatocytes where bile moves to bile duct

Question 31

What is the gallbladder made up of?

Answer 31

muscular sac lined with tall simple columnar epithelium with lamina propria and brush border

Question 32

How is bile changed in the gallbladder and how is it then released?

Answer 32

- changed by pumping Na and Cl ions so water moves out too | - vagal stimulation to contract to release bile into duodenum and by cholecystokinin

Question 33

What is the special feature of the pancreas?

Answer 33

it is both an endocrine and an exocrine gland

Question 34

What does the exocrine part of the pancreas do?

Answer 34

makes digestive juices with many enzymes and this enters the duodenum via the pancreatic duct (doesn’t digest itself because the enzymes are not yet active until trypsin activates them)

Question 35

What does the endocrine part of the pancreas do?

Answer 35

consists of islets of Langerhans making insulin and glucagon

Question 36

What are the different parts of the pancreatic ducts?

Answer 36

basal pancreatic part is basophilic due to RER but apical part is eosinophilic due to zymogen granules

Question 37

What do the pancreatic ducts then join?

Answer 37

main pancreatic duct joins the common bile duct and opens into the duodenum on a papillae

Question 38

What is special about pancreatic duct cells?

Answer 38

they are centroacinar because the duct Strats within the cell