Drug Absorption #2 Flashcards Preview

Pharmaceutics Spring 2016 > Drug Absorption #2 > Flashcards

Flashcards in Drug Absorption #2 Deck (94)
Loading flashcards...
31

G cells

secrete gastrin (which in turn controls the secretion of HCl)

32

About ___L/day of fluids are secreted by the stomach

3

33

Would you anticipate significant absorption from the stomach? Why?

-no, almost no drug is absorbed by the stomach
-drugs do not stay in the stomach long enough and the stomach has a small surface area

34

Where is the site of most absorption of drug?

small intestine due to the large membrane surface area

35

What is the pH of the stomach? with food?

~ 1-2
food neutralizes the stomach--> pH goes up to around 4,5, or 6

36

What are the 3 segments of the small intestine?

-duodenum: connected to the pylorus (upper)
-jejunum (middle)
-illeum (lower)

37

T/F Each segment of the small intestine have regional differences

TRUE. transporter proteins are located at specific sites in the intestine

38

What components help tribute to the large surface area of the small intestine?

-folds of kerckring (increase 3x)
-villi (increase 30x)
-microvill (increase 600x)

39

Bile:
Is stored in the _______; made by the _____

gall bladder; liver
gall bladder empties bile into the duodenum (ph ~6)

40

Why does the pH change from 2 when it leaves the stomach and go up to 6?

bicarbonate ion-->neutralize acidic fluid that is emptying from the stomach

41

What is the primary function of the large intestine? pH?

storage of waste; pH 5.5-7

42

T/F There are vili present in the Large Intestine.

FALSE; no villi present leading to absorption being poorer

43

_____ are present in the large intestine. What is a downfall of having this there?

microflora--> if a drug makes it to the large intestine it may destroy the bacteria that is already there and the bacteria could absorb the drug and metabolize it

44

As pH varies from a weak acid or base... so does

the degree of ionization

45

Summary of pH in GI tract
-stomach (fasting)
-stomach (fed)
-duodenum
-ileum
-large intestine

-stomach (fasting): less than 2
-stomach (fed): 2-6
-duodenum: 6-6.5
-ileum: 7-8
-large intestine: 5.5-7

46

T/F Solids and liquids are emptied the same way from the stomach

FALSE; emptied differently

47

What do you think is a major factor affecting stomach emptying?

food

48

Fed mode of the stomach (3)

-one type of pattern
-regular, frequent contractions
-grinding and mixing occurs as long as food is present

49

_____ and ___ will empty from the stomach and leave in a FIRST order process

liquids and particles less than about 5-10 mm

50

Liquids empty the stomach _____. High Volume--> _____

immediately; faster emptying

51

_____ leave in a ZERO order process, it is converted at a ______ rate

solids; constant

52

What are the 4 phases of the fasting mode in the stomach?

I: relaxation
II: increase in tone and activity (few contraction of different magnitudes)
III: strong contractions--> HOUSEKEEPER
IV: decline in activity

53

The housekeeping stage of the fasting mode....

sweeps anything left in the stomach out

54

How long does it take for material to move through the entire small intestine?

3-4 hours

55

T/F Solution, pellets, and single units move through the small intestine at about the same rate

TRUE-> it does not depend on the presence of food

56

Absorption _____ occur in the stomach--> but the ____ of emptying of the stomach does effect drug absorption

DOES NOT; RATE

57

What factors affect gastric emptying? (11)

-meal type
-hydrogen ion concentration
-volume
-osmolality
-emotional state
-exercise
-posture
-age
-gender
-disease state
-drug

58

Fats, proteins, and carbs typically have _____ emptying if they are the same caloric value. The presence of these _____ emptying

same; decrease

59

____ (food) have the greatest effect on emptying on a molar basis

fats: they are harder to digest

60

hydrogen ion concentration:
_____ concentration in intestine will INHIBIT emptying

Increased