Brainscape's Knowledge GenomeTM

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


See full index

Gastroenterology > Regulation of gut function > Flashcards

Regulation of gut function Flashcards

1
Q

What sympathetic ganglion supplies the stomach?

A

Ceoliac ganglion

T6-9

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

What sympathetic ganglion supplies the small intestine?

A

Superior mesenteric ganglion

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

What sympathetic ganglion supplies the colon?

A

Inferior mesenteric and pelvic ganglion

L2-5

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

What Neurotransmitter is used for the sympathetic nervous system supplying the gut?

A

Norepinephrine / Noradrenaline

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

What does the activation of the sympathetic nervous system inhibit?

A

Activities of the gastrointestinal tract

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

What nerve supplies the parasympathetic innervation to the stomach, small intestine and proximal colon?

A

Vagus nerve

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

Preganglionic neurones orginate in x within the brainstem from sacral spinal cord?

A

x - dorsal vagal complex

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

What neurotransmitter is used for parasympathetic innervation to gut?

A

Acetylcholine

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

Activation of parasympathetic nervous system x the gastrointestinal tract.

A

x- stimulates

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

What are the characteristics of the enteric nervous system?

A
  • Autonomous
  • Can also interact with sympathetic and parasympathetic nervous system
  • The wall of the gastrointestinal tract contains many neurons – 2nd only to the brain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the myenteric and submucosal plexus?

A

Plexus : network of intersecting nerves

Myenteric is the outer plexus, lies between the circular muscle and longitudinal muscle

Submucosal is the inner plexus and lies between the mucosa and muscles

Found in the walls of the gut

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

What is the function of the myentreric plexus?

A

Myenteric (Auerbach’s) plexus :

controls activity of
- muscularis propria

  • controls gut motor (motility) function
  • tone, velocity of contraction and intensity of contraction.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the function of submucosal plexus?

A

senses the local environment (gut lumen)

controls secretion, blood flow, epithelial and endocrine cell function

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

How does the enteric system control the peristaltic local reflex?

A

Food enters and stretches smooth muscles –>

stimulates sensory neurones in myentric plexus = peristaltic wave ( Sequential contraction/relaxation of circular and longitudinal muscle by inhibitory/excitatory neurotransmitter cause peristalsis, which allows food to move along the GI tract )

  • chemicals in food stimulate sensory nuerones –>

submucosal plexus, increase blood flow and secretion

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

What does the sympathethic nervous system do to digestion? - ( 4 )

A

reduces peristalsis
reduces absorption
reduces secretion
reduces blood flow (via enteric nervous system and also directly)

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

What does the parasympathethic nervous system do to digestion? - ( 4 )

A

increases peristalsis
increases absorption
increases secretion
increases blood flow

  • although the gut can work without the para/sympathetic system these can enhance digestion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the characteristics of Hirschsprung’s disease?

A

Most common cause of neonatal bowel obstruction

  • Congenital absence of ganglion of myenteric and submucosal ( enlarged colon )

Effect:

Tonal contraction without reciprocal relaxation

Intestinal distension proximal to aganglionic segment of bowel

Treatment :

Most will require surgery

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

What Endocrine hormones are involved in gut regulation?

A

gastrin, cholecystokinin, secretin, glucose-dependent insulinotropic peptide (GIP), motilin

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

What Paracrine hormones are involved in gut regulation?

A

somatostatin and histamine

hormones with both endocrine and paracrine mechanisms: glucagon-like peptide-1 (GLP-1), pancreatic polypeptide, and peptide YY

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

What Neurocrine hormones are involved in gut regulation?

A

secreted by postganglionic non-cholinergic neurons of the enteric nervous system
hormone that affects ‘nerves’
vasoactive intestinal peptide (VIP), gastrin release peptide (GRP), and enkephalins

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

Where are enteroendocrine cells found? ( release hormones )

A

specialised epithelial cells located at the base of intestinal crypts throughout the GI tract, from stomach to colon

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

What stimuli cause enteroendocrine cells to release their hormones from their granules?

A

these stimuli include small peptides, amino acids, fatty acids, oral glucose, distension of an organ, and vagal stimulation

23
Q

What stimulates Gastrin release?

A

amino acids and peptides in the lumen of the stomach
gastric distension
vagus nerve

24
Q

What hormones are secreted by duodenum?

A

Secretin

CCK

Somatostatin

25
Q

What hormones are secreted by Pancreas?

A

Insulin

Glucagon

Somatostatin

Pancreatic polypeptide

26
Q

What hormones are secreted by stomach?

A

Gastrin

Ghrelin

Somatostatin

Histamine

27
Q

What hormones are secreted by the small bowel?

A

Peptide YY

Gastric inhibtory peptide

GLP-1

GLP-2

Oxyntomodulin

Neurotensin

Somatostatin

28
Q

What hormones are secreted by colon?

A

PYY

GLP-1

Oxyntomodulin

Neurotensin

Somatostatin

29
Q

What affect does Gastrin have on digestion?

A

Stimulates gastric acid by parietal cells

Trophic effect on mucosa of small intestine, colon and stomach - causing them to growth

gastrin release is stopped when pH falls below 3

30
Q

Where is Secretin secreted from?

When?

A

Secreted by the S cells of the upper duodenum and jejunum

Major stimulus is the presence of acid in the duodenum (pH falls below

31
Q

Functions of Secretin?

A
  • stimulates pancreatic bicarbonate secretion (effect potentiated by CCK)
  • inhibition of gastric acid and gastric emptying
  • inhibits gastrin, acid secretion, and growth of stomach mucosa
  • stimulates biliary secretion of bicarbonate and fluid
    trophic effect on the exocrine pancreas
32
Q

Where is Cholecystokinin secreted from and when?

A

Secreted by cells most densely located in the small intestine

Release stimulated by fat and peptides in the upper small intestine

33
Q

What are the functions of CCK?

A
  • stimulates pancreatic enzyme release (lipase, amylase, proteases)
  • stimulates gallbladder contraction and relaxation of the sphincter of Oddi
  • delays gastric emptying
  • decreases food intake and meal size
    trophic effects on the exocrine pancreas and gallbladder
34
Q

Where does Glucose-dependent insulinotropic peptide (GIP) get secreted from?

A

Secreted by mucosal K cells (predominant in the duodenum and jejunum)

GIP released following ingestion of a mixed meal

Likely stimulated by change in intraluminal osmolarity

35
Q

What is special about GIP?

A

The only hormone with a response to all 3 macronutrient types (glucose, amino acid, fatty acids)

36
Q

What does GIP do?

A

Stimulates insulin secretion

37
Q

What does Motilin do?

A

Increases gastrointestinal motility

38
Q

Where is Somatostatin synthesised and released?

A

Synthesized in endocrine D cells of the gastric and duodenal mucosa, pancreas

Somatostatin is a universal inhibitor (Endocrine Cyanide)

Release in response to a mixed meal

39
Q

What does somatostatin inhibit?

A 
Inhibition of
gastric secretion 
motility
intestinal and pancreatic secretions
release of gut hormones
intestinal nutrient and electrolyte transport
growth and proliferation
40
Q

Where is GLP 1 produed?

A

Produced in the small intestine and secreted from L cells

Release stimulated by the presence ofhexose and fat

41
Q

What are the functions of GLP 1?

A

Induces satiety

Increases sensitivity of pancreatic beta-cells to glucose

42
Q

where is pancreatic polypeptide released and when?

A

Secreted by PP cells in the pancreas

Secretion stimulated by fat

Potential role in satiety

43
Q

Where is Peptide YY secreted from and when?

A

Secreted from cells found throughout the mucosa of the terminal ileum, colon and rectum

Released from L cells post- prandially (particularly protein)

44
Q

What does PYY do?

A

Reduces intestinal motility, gallbladder contraction and pancreatic exocrine secretion

45
Q

Where are neurocine hormones located?

A

Located within nerves in the gut

VIP, GRP, Enkephalins

46
Q

What does VIP do?

A

Vasoactive intestinal peptide (VIP) → relaxation of gut smooth muscle

47
Q

What does GRP do?

A

Gastrin releasing peptide (GRP) → induces gastrin release

48
Q

What do Enkephalins do?

A

Enkephalins → increase smooth muscle tone 0 inhibit peristalisis, work on opoiod receptors

49
Q

What are Neuroendocrine tumours?

A

Tumours of the neuroendocrine cells (which are found predominantly in the gastrointestinal tract and pancreas)

50
Q

What are the characteristics of Zollinger Ellison Syndrome?

A

tumour of gastric cells causing overproduction of gastrin and acid resulting in stomach and intestinal ulceration

- treatment with proton pump inhibitor to inhibit 	acid secretion
- role for somatostatin analogues to halt tumour 	growth and reduce secretion
51
Q

What controls the Cephalic phase?

A

Vagus

52
Q

What controls the Gastric phase

A

Local nervous system - secretion

Vagal reflexes

gastrin-histamine stimulation

53
Q

What controls the Intestinal phase?

A

Nervous mechanisms

Hormonal mechanisms

Gastroenterology (10 decks)

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