Pharmacology Flashcards Preview

Gastro > Pharmacology > Flashcards

Flashcards in Pharmacology Deck (85):
1

What are the hollow organs separated by?

Sphincters

2

What do sphincters do?

Control the movement of food

3

What occurs in the mouth and oropharynx?

Chopping of food, lubrication, beginning of carbohydrate and fat digestion and propel food to oesophagus

4

What is the function of the oesophagus?

To deliver food to the stomach

5

What the the main function of the stomach

Temporary storage of food

6

What else does the stomach do?

Continues digestion of carbs and fat and initiates the digestion of proteins

7

What is the main function of the small intestine?

Principal site of digestion and absorption of nutrients

8

What 3 structures does the small intestine consist of?

Duodenum, jejunum and ileum

9

What is the main function of the large intestine?

The reabsorption of fluids and electrolytes back into the body. It also stores fecal matter before regulated expulsion

10

What 7 structures is the large intestine made up of

Cecum, Ascending colon, Transverse colon, Descending Colon, Sigmoid Colon, Rectum, Anus

11

How many accessory structures are there?

3

12

Name the accessory structures

Salivary glands, liver and gall bladder and the pancreas

13

What is the function of the salivary glands

Secrete saliva

14

What is the function of the liver and gall bladder?

Storage and secretion of bile which aids in fat digestion

15

Where is the location of the pancreas?

Inferior to the stomach

16

Gastrointestinal motility is due to what?

The activity of smooth muscle

17

What happens to the lumen when circular muscle contracts?

Becomes long and narrow

18

What happens to the intestine when the longitudinal muscle contracts?

It becomes short and fat

19

What happens when the muscularis mucosae contract

There is a change in absorptive area and the secretory area of mucosa

20

What is motility?

A mechanical activity mostly involving smooth muscle

21

Name the 3 movements of motility

Propulsive, Mixing and Tonic

22

Give an example of propulsive

Peristalsis

23

An example of mixing

elecrtolytes and digestive enzymes

24

Give an example of tonic movement

Sphincters

25

Where can secretion occur?

In the GI tract itself

26

Define digestion

The biochemical breakdown of chemically complex foodstuff into smaller, absorbable units

27

What are carbohydrates broken down to? and name an enzyme for this process

Monosaccharides and amylases

28

What are proteins broken down to? Name an enzyme for this process

AMino acids, dipeptides and tripeptides. Proteases or dipeptidases

29

What are fats mostly broken down to? What is the enzyme mediating this?

Monoglycerides and free fatty acids. Lipases

30

Define absorption

The transfer of absorbable products of digestion from digestive tract to the blood or lymph.

31

Does the structure of the digestive wall vary at all?

No - It is roughly the same throughout

32

Name the layers of the digestive wall from innermost to outermost

Mucosa, Submucosa, Muscularis externa, Serosa

33

How do skeletal muscles cells function with other skeletal muscle cells

Independently of eachother

34

How do smooth muscle cells function with other smooth muscle cell?

Coupled by gap junctions

35

What do gap junctions in smooth muscle allow for?

Spread of electrical current from cell to cell forming a functional synctium in which 100s of cells are depolarised and so contract at the same time.

36

What happens if one smooth muscle cell depolarises?

Its current will be spread to neighbouring cells so the whole sheet of muscle will contract simultaneously

37

What is the spontaneous activity of smooth muscle modulated by?

Intrinsic and extrinsic nerves and also numerous hormones

38

How does spontaneous activity of smooth muscle occur?

Slow waves in the stomach, small intestine and large intestine.

39

What does slow wave electrical activity determine?

The maximum frequency, velocity and direction of rhythmic contractions which occur in smooth muscle sheets

40

What drives slow wave electrical activity? And what are they?

Interstitial Cell of Cajal. Pacemaker cells

41

When will contraction not occur in terms of slow waves?

When the amplitude is insufficient to trigger action potentials

42

What is the force in slow waves related to?

The number of action potentials discharged

43

Where are ICCs located

Between the circular and longitudinal muscle layers and in the submucosa

44

What are slow waves representative of?

Rhythmic patterns of depolarisation, followed by repolarisation

45

The upstroke of the slow wave is regulated by what?

voltage activated Ca++ channels

46

The downstroke of the slow wave is regulated by what?

voltage activated K+ channels

47

What do slow waves determine?

The basic electrical rhythm (BER)

48

What 3 things does the threshold being met depend on?

Neuronal stimuli, hormonal stimuli and mechanical stimuli

49

When is BER at its lowest and where?

During the fed stage in the stomach

50

What is the average number of waves per minute in the stomach?

3

51

What is the average number of waves per minute in the duodenum?

1-10 waves

52

What is the average number of waves per minute in the terminal ileum?

8 waves

53

What is the average number of waves per minute in the proximal colon?

8 waves

54

What is the average number of waves per minute in the distal colon

16 waves

55

What is the importance of the distal colon having double the number of waves of the proximal colon?

It favours backwards movement and retention

56

What would happen if the body did not have different slow waves in different places?

The body would lose substances as loose stool

57

What is the most important factor in terms of autonomic innervation?

Parasympathetic

58

What is the main role of the parasympathetic system?

To increase blood flow, secretions and contractions

59

What inhibitory factors are exerted by the parasympathetic system?

Relaxation of sphincter and stomach

60

Inhibitory actions of the sympathetic system exert what?

Decrease motility, blood flow and secretions

61

What are the 3 broad types of neurones in the Enteric Nervous system

Sensory neurone, interneurone and effector neurone

62

Peristalsis is an example of what type of reflex?

Local reflex

63

Give an example of a short reflex

Interstino-interstinal inhibitory reflex

64

The gastroileal reflex is an example of what type of reflex?

Long reflex

65

Name 3 components that make up sensory neurones

Chemoreceptors, Thermoreceptors and mechanoreceptors

66

What is the role of the interneurones in the ENS

To coordinate reflexes and initiate simple functions such as peristalsis

67

What 5 things do the effector neurones supply?

The longitudinal and circular muscle layers, secretory epithelium, endocrine cells and blood vessels

68

Define peristalsis

A wave of contraction that normally preceeds along the gut wall

69

What route does peristalsis take?

Aboral route

70

Where is the propulsive segment

Behind the bolus

71

Where is the receiving segment?

Infront of the bolus

72

In terms of relaxation and contraction, what occurs in the propulsive segment?

Relaxation of the longitudinal muscle and contraction of the circular muscle

73

In terms of relaxation and contraction, what occurs in the receiving segment?

Relaxation of the circular muscle and contraction of the longitudinal muscle

74

How is contraction accomplished?

The release of a transmitter by excitatory neurones.

75

What neurotransmitters are found during contraction?

ACh and substance P (peptide substance) are the neurotransmitters

76

How is relaxation accomplished?

The release of VIP and Nitric Oxide from inhibitory motoneurone

77

What does segmentation cause?

Rhythmic contractions of circular muscle

78

Where does segmentation occur?

In the small intestine

79

Where are tonic contractions found?

Sphincters

80

How many sphincters are there?

6

81

Name the first 3 sphincters

Upper oesophageal, Lower oesophageal and pyloric

82

Name the last 3 sphincters

Ileocecal, Internal and External sphincters

83

What is the function of the uvula

It helps seal off the nasal passage

84

What is the function of the tongue

To guide food towards to oesophagus

85

What is the pharynx?

A common passageway for respiratory and gastrointestinal systems

Decks in Gastro Class (67):