GIT Control

Question 1

What are the local factors in the digestive tract?

Answer 1

Prostaglandin,histamine and other chemicals are released into the interstitial fluid
It may affect adjacent cells within a small segment of the tract
Local factors affect only a part of the tract
Ph factors,Chemicals and physical stimuli coordinate conditions

Question 2

Where are motor neurons situated that affect neural mechanisms?

Answer 2

Situated in the Myenteric plexus

Question 3

What is control of Digestive function?

Answer 3

Movements along the digestive tract and Secretory control

Question 4

What do motor neurons do in digestive control?

Answer 4

They control glandular secretions and smooth muscle contraction

Question 5

What are the short reflexes in the digestive tract?

Answer 5

Only controls a small segment of the tract
Is responsible for local reflexes
It operates entirely outside of the CNS
It involves motor,sensory and interneurons

Question 6

What are long reflexes of the digestive tract?

Answer 6

Higher control of glandular and digestive activities
Large scale peralstaltic waves
Also involves inter and motor neurons
May involve parasympathetic nerve fibers that synapse in the myenteric plexus (glosspharengeal,vagus and pelvic nerves)

Question 7

Where are the peptide hormones produced?

Answer 7

In the entero-endocrine cells in the digestive tract and reaches target after distribution in bloodstream

Question 8

What is the control of production of acid and enzymes by the gastric mucosa?

Answer 8

Controlled by CNS
Regulated by short reflexes of the ENs
Regulated by hormones

Question 9

What are the 3 phases of gastric control?

Answer 9

Cephalic
Intestinal
Gastric

Question 10

What are the 2 reflexes in the small intestine?

Answer 10

The gastroileal and gastroenteric reflex

Question 11

What is the gastroenteric reflex ?

Answer 11

It stimulated motility and secretion along the small intestine

Question 12

What is the Gastroileal reflex?

Answer 12

Allows materials to pass from small intestine to large intestine and also triggers relaxation of the ileo Cecil valve

Question 13

What are the hormones in the duodenal entero endocrine cells?

Answer 13

Gastrin
Secretin
Enterocrinin
Cholecystotokinin
Gastric inhibitory peptide
Vasoactive intestinal peptide

Question 14

What is the purpose of Gastrin?

Answer 14

It is produced by the g cells in the duodenum
When it is exposed to incompletely digested proteins it promotes increased stomach motility and acid and enzyme production stimulation

Question 15

What is the purpose of secretin?

Answer 15

It is released when Chyme arrives at the duodenum and increases secretion of Bile and buffers by liver and pancreas

Question 16

What is the purpose of the Gastric Inhibitory Peptide?

Answer 16

It is secreted when fats and carbohydrates enter the small intestine

Question 17

What is the Cholecystotokinin?

Answer 17

It is secreted in the duodenum
And when lipids and proteins ate partially digested
It relaxes he hepatopancreatic sphincter and gallbladder and ejects bile and pancreatic juices in the the duodenum
It accelerates pancreatic production and secretion of digestive enzymes

Question 18

What is the purpose of vasoactive intestinal peptide?

Answer 18

It stimulates secretion of intestinal glands
Dilates regional capillaries and inhibits acid production

Question 19

What is the purpose of enterocrinin?

Answer 19

It is released when chime enters the small intestine
And stimulates mucin production by the submucosal glands of the duodenum

Question 20

How long does intestinal absorption take?

Answer 20

About 5 hours (for materials to reach duodenum to end of illeum)

Question 21

What does the movement of the mucosa do to increase absorptive effectiveness?

Answer 21

Constantly change environment around the epithelial cells and stir and mix intestinal content

Question 22

What are the moments in the large intestine?

Answer 22

Through gastricileal and gastricenteruc reflexes It allows for materials to move from into cencum while you eat

Question 23

What is moment from the cecum to the transverse Colon slow?

Answer 23

To allow for hours of water absorption

Question 24

What type of churning is done in the large intestine ?

Answer 24

Haustrak churning which mixes content of the adjacent haustra

Question 25

What are mass movements in the large intestine?

Answer 25

Movements from the transverse colon to the rest of the large intestine and results in large peralstaltic contractions

Question 26

Where is the stimulus dimension of stomach and duodenum relayed?

Answer 26

It is relayed over intestinal nerve plexuses

Question 27

What are the two positive feedback loops?

Answer 27

The short reflex
Which triggers peralstaltic actions in the Rectum
And Long reflex
Which is coordinated by the parasympathetic system and stimulates mass movements

Question 28

What are the rectal stretch receptors?

Answer 28

The Long reflex
Causes relaxation of the internal analysis sphincter
And mediated by parasympathetic international of pelvic nerves

A somatic reflex
The motor commands are carried by the pudenal nerves and stimulation of the contraction of the external anal sphincter

Question 29

What does the parasympathetic innervation of neural mechanism di?

Answer 29

Prepare digestive tract for activity

Question 30

What does the sympathetic nivveration of the neural mechanism do?

Answer 30

It inhibits gastrointestinal activity