Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology. Gastrointestinal Physiology. > The Myenteric Nervous System. > Flashcards

The Myenteric Nervous System. Flashcards

1
Q

What are the 2 nervous systems that control the GI tract?

A

The autonomic nervous system.

The enteric nervous system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the components of the enteric nervous system?

A

The myenteric plexus.

The submucosal plexus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The enteric nervous system is found in what parts of the gut?

A

It is found in the gut wall between the oesophagus and the anus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What 2 things are regulated by the enteric nervous system?

A

The smooth muscles of the gut wall.

The endocrine and secretory cells associated with the gut.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What allows different organs of the digestive system to communicate with each other?

A

The enteric nervous system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where in the GI tract wall is the submucosal plexus found?

A

In the submucosa.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where in the GI tract wall is the myenteric plexus found?

A

In the muscular layer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does the enteric nervous system use to control the digestive system?

A

Neurotransmitters.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Is acetylcholine an excitatory or inhibitory neurotransmitter?

A

An excitatory neurotransmitter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Is norepiniephrine an excitatory or inhibitory neurotransmitter?

A

An inhibitory neurotransmitter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What kind of nervous system is the enteric nervous system?

A

A simple reflex system with sensory neurons and receptors and motor neurons and receptors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the steps of the reflex system involving the myenteric plexus of the GI tract?

A

Mechanoreceptors are stimulated by stretching.

Afferent neurons travel to the nerve cell body.

Efferent neurons travel to the muscle cells.

Gut motility is stimulated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the steps of the reflex system involving the submucosal plexus of the GI tract?

A

Chemoreceptors detect chemicals.

Afferent neurons travel to the nerve cell body.

Enzymes etc are secreted.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The myenteric plexus governs what major digestive process?

A

Gut motility.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The submucosal plexus governs what major digestive process?

A

GI secretions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The myenteric plexus will be activated by what kind of receptors?

A

Mechanoreceptors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The submucosal plexus will be activated by what kind of receptors?

A

Chemoreceptors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the 2 nervous systems that supply the GI tract?

A

The enteric nervous system.

The autonomic nervous system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What nerves supply the parasympathetic nervous system?

A

The Vagus nerve.

The pelvic nerves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the main neurotransmitter of the parasympathetic nervous system?

A

Acetylcholine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What information from the GI tract is transmitted through the parasympathetic nervous system?

A

Sensory information from chemoreceptors or mechanoreceptors.

Motor information to muscle cells and gland cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the origin of parasympathetic nerves?

A

Craniosacral.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Parasympathetic and sympathetic nerves are only found in what division of the nervous system.

A

The motor division.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Will the parasympathetic nervous system help or hinder digestion?

A

It helps with digestion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the origin of the sympathetic nervous system?

A

Thoracolumbar.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the main neurotransmitter of the sympathetic nervous system?

A

Norepinephrine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the 3 major effects that the parasympathetic nervous system has on the GI tract?

A

Increased gut motility.

Increased secretion rates.

Decreased muscle sphincter tone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What kind of fibres are found in the sympathetic nervous system?

A

Sensory and motor fibres.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the 3 major effects that the sympathetic nervous system has on the GI tract?

A

Decreases gut motility.

Decreases gut secretions.

Increases sphincter tone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Does the sympathetic nervous system help or hinder digestion?

A

It hinders digestion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What controls the autonomic and enteric reflexes in the GI tract?

A

The same receptors affect both nervous systems.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Which nervous system provides local reflexes for the GI tract?

A

The enteric nervous system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Which nervous system provides central reflexes for the GI tract?

A

The autonomic nervous system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the main stimulus for GI movements?

A

Stretching of the gut wall.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What cells produce the gastro-intestinal hormones?

A

Specialised epithelial cells called GI endocrine cells.

36
Q

What is responsible for stimulating the GI endocrine cells?

A

The enteric and autonomic nervous systems.

37
Q

Where will the GI endothelial cells secrete their hormones into?

A

Into the blood.

38
Q

What happens once GI hormones have been secreted into the blood?

A

They signal to other organs that something is going on and these organs will respond.

39
Q

What name is given to the signalling that involves releasing substances into the blood?

A

Endocrine signalling.

40
Q

What is paracrine signalling?

A

When signalling occurs between 2 cells that are next to each other.

41
Q

What happens during autocrine signalling?

A

The cell signals to itself.

42
Q

What is neurocrine signalling?

A

When the cell signalling involves neurons.

43
Q

Where in the GI tract are the GI mucosa found?

A

Throughout the length of the GI tract.

44
Q

What is the function of the GI mucosa?

A

They sample the contents of the gut and release hormones via endocrine secretion or paracrine secretion.

45
Q

Can the GI mucosa be stimulated by the enteric plexus?

A

Yes.

46
Q

What is the function of the regulatory peptides that are secreted by the GI mucosa?

A

To affect the secretions of the GI tract and the accessory organs and their motility.

47
Q

What is the stimulus for endothelial cells in the duodenum?

A

Low pH.

48
Q

What happens when the endothelial cells in the duodenum are stimulated by low pH?

A

It stimulates the pancreas and the liver to release their secretions into the duodenum.

49
Q

Secretin is produced in what part of the GI tract?

A

The duodenum and upper jejunum.

50
Q

What stimulates the release of secretin?

A

Acids, fats and proteins in the duodenum.

51
Q

What is the action of secretin?

A

It stimulates the release of bicarbonate and prevents more acid secretion.

52
Q

Gastrin is produced in what part of the GI tract?

A

Stomach and duodenum.

53
Q

What stimulates the release of gastrin?

A

Proteins and high pH in the stomach.

54
Q

What is the action of gastrin?

A

Release of stomach acid and increase in gastric secretions.

55
Q

Choleocystokinin is produced in what part of the GI tract?

A

Duodenum, jejunum and ileum.

56
Q

What stimulates the release of choleocystokinin?

A

Fats and proteins in the duodenum.

57
Q

What is the action of choleocystokinin?

A

It leads to the release of pancreatic enzymes and and gall bladder secretions.

It also inhibits food intake and the release of stomach contents into the duodenum.

58
Q

What hormone helps to increase the pH of food in the duodenum?

A

Secretin.

59
Q

What are the 2 processes associated with GI motility?

A

Segmentation/mixing.

Peristalsis/propulsion.

60
Q

What muscles are involved in the segmentation phase of GI motility?

A

The circular muscles.

61
Q

What are the characteristics of segmentation GI motility?

A

Food travels over a short distance.

It mixes the food up.

62
Q

What are the characteristics of peristalsis GI motility?

A

It moves the food along the GI tract.

63
Q

What name is given to the reflex that is associated with peristalsis?

A

Adaptive relaxation.

64
Q

Where are cajal cells located in the GI tract?

A

In the muscle layer.

65
Q

Digestion breaks food into what?

A

Into acidic chyme.

66
Q

What muscle layer is mainly responsible for peristalsis?

A

The longitudinal muscles.

67
Q

What can cajal cells be thought of as?

A

As pacemaker cells as they control the rate of contractions of the GI tract.

68
Q

How do cajal cells carry out their function?

A

They communicate with other cells via tight junctions.

Ions pass through these junction leading to depolarisation and stimulation.

The cajal cells control the membrane potential.

69
Q

Can cajal cells lead to action potentials?

A

No.

70
Q

What is created by the partial depolarisation that is created by the cajal cells?

A

An undulating wave which creates very slow waves in the smooth muscle in the GI tract.

71
Q

How does the resting membrane potential of smooth muscle compare to that of skeletal muscle?

A

It is higher than skeletal muscle and is at around -60.

72
Q

What generates the slow waves of contraction in the GI tract?

A

The cajal cells.

73
Q

When will a full action potential be generated in the GI tract?

A

When certain hormones arrive.

74
Q

What ion is responsible for the contraction of the smooth muscle in the GI tract?

A

Calcium.

75
Q

What part of the brain is mainly responsible for controlling food intake?

A

The arcuate nucleus of the hypothalamus.

76
Q

What tells the animal when to start eating?

A

Signals from the appetite centre.

77
Q

What tells the animal when to stop eating?

A

Signals from the satiety centre.

78
Q

What hormone is responsible for stimulating appetite?

A

Ghrelin.

79
Q

What hormone is responsible for inhibiting food intake?

A

Leptin.

80
Q

What actions lead to an increase in GI blood flow?

A

Increase in gut motility.

Certain hormones such as bradykinin.

Decreased O2 or increased CO2.

81
Q

How will sympathetic stimulation affect blood flow in the GI tract?

A

It leads to vasoconstriction.

82
Q

Can the GI organs survive with reduced bloodflow for a long time?

A

No.

83
Q

What is ischemia?

A

When there is not enough blood arriving at an organ.

84
Q

What might an animal suffer from if it is in a sympathetic state for a long time?

A

Ischemia.

85
Q

What state must the body be in to send blood to the GI tract?

A

A relaxed (parasympathetic) state.

Physiology. Gastrointestinal Physiology. (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions