Paul De Bank

Question 1

What’s the three main roles of the epithelia

Answer 1

Protection, absorption, gas exchange

Question 2

What are the two types of epithelia

Answer 2

One layer= simple

>1 layer= stratified

Question 3

Give an example of a squamous epithelium

Answer 3

Alveoli

Question 4

Name four specific types of epithelial cells

Answer 4

1) Squamous epithelium
2) Stratified squamous epithelium
3) columnar epithelium
4) cuboidal epithelium

Question 5

Name two types of drug absorption

Answer 5

1) transcellular pathway

2) paracellular pathway

Question 6

Define paracellular pathway

Answer 6

Between adjacent epithelial cells

Question 7

What’s rate limiting in the paracellular pathway?

Answer 7

The tight junctions

Question 8

Name 4 types of junction between cells

Answer 8

1) tight junctions
2) adherens junctions
3) desmosomes
4) gap junctions

Question 9

What’s the most common cell junction?

Answer 9

Desmosomes

Question 10

What types of molecules can be absorbed via paracellular pathway

Answer 10

Small hydrophilic molecules

Question 11

What’s transcellular pathway

Answer 11

Occurs across the epithelial cells

Question 12

Name 4 ways a molecule can undergo transcellular pathway

Answer 12

1) passive diffusion
2) aqueous pore
3) facilitated diffusion
4) active transport

Question 13

Is passive diffusion via transcellular pathway the most common pathway of drug absorption?

Answer 13

YES

Question 14

What three things cause the small intestine to have a large surface area

Answer 14

1) folds of kerckring
2) villi
3) microvilli

Question 15

Where in the body is the main site of food and dug absorption

Answer 15

Small intestine mainly the jejunum while the ileum absorbs remaining nutrients

Question 16

The bile ducts release secretions from the pancreas and the gall bladder including what enzymes

Answer 16

Trypsin
Chimotrypsin 
Elastase 
Carboxypeptidase
Amylase
Lipase

Question 17

Ingestion of food stimulates the secretion of what two things in the stomach

Answer 17

HCL

pepsinogen

Question 18

What’s the role of HCL in the stomach

Answer 18

Acts as an antiseptic and promotes the conversion of pepsinogen to pepsin (a potent proteolytic enzyme)

Question 19

What’s another names for fasted state

Answer 19

Interdigestive

Question 20

What’s another name for fed state

Answer 20

Digestive

Question 21

What occurs in the interdigestive state

Answer 21

MMC (migrating motor complex)
Phase 1: quiescence
Phase 2: irregular contractions
Phase 3: house keeper waves

Question 22

List 8 factors that affect gastric emptying rate

Answer 22

1) meal volume
2) type of meal
3) physical state of meal
4) chemicals
5) drugs
6) disease
7) body position
8) exercise

Question 23

There’s a high expression of what enzymes in the small intestine?

Answer 23

CYP450

Question 24

What is the p-gylcoprotein efflux pump?

Answer 24

170Kda protein found in the apical membrane of cells in the small and large intestine

Question 25

Name 5 strategies for improving oral drug delivery

Answer 25

1) increase drug lipophilicity use of prodrugs
2) p-GP inhibitors
3) cytoadhesion
4) mucoadhesive patches
5) new delivery systems eg protective coatings, nanoparticles

Question 26

Name three ways you can improve membrane permeability

Answer 26

1) use of prodrugs
2) lipidisation (attach lipid to drug)
3) penetration enhancers (partially solubilise epithelial membrane)