lec 2 (Gastrointestinal Motility)

Question 1

type of muscles in GI

Answer 1

1. unitary smooth muscle

2. striated muscle

Question 2

striated muscle found in

Answer 2

1. pharynx,
2. upper one-third of the esophagus, and
3. external anal sphincter,

Question 3

unitary smooth muscle means

Answer 3

Single-unit smooth muscle tissues (ANS innervates single cell within a sheet و بعدين بنتشر عن طريق ال gap junction

Question 4

type of contraction

Answer 4

1. Phasic contractions

2. Tonic contractions:

Question 5

Phasic contraction is

Answer 5

twitch-like shortening followed by relaxation.

Question 6

.Phasic contraction occur in the

Answer 6

1. esophagus,
2. gastric antrum, and
3. small intestine,

Question 7

Tonic contractions occur in the

Answer 7

1. lower esophageal sphincter,
2. orad stomach
3. ileo-cecal sphincters
4. internal anal sphincters

Question 8

orad stomach

Answer 8

fundus and superior part of the body),

Question 9

Tonic contractions is

Answer 9

sustained contraction of a muscle without relaxation( often ↑or ↓ in intensity but continues. )→lasts several minutes or even hours

Question 10

The tonic contraction is NOT associated with the

Answer 10

Basic electrical slow wave

Question 11

The tonic contraction is caused by

Answer 11

1. Continuous repetitive spike potentials
2. Hormones
3. Continuous entry of calcium ions

Question 12

Hormones cause tonic contraction

Answer 12

continuous partial depolarization of the smooth muscle membrane without causing action potentials

Question 13

Continuous entry of calcium ions

Answer 13

not associated with changes in membrane potential

Question 14

Functional types of movements in GIT

Answer 14

1. Propulsive movement (Peristalsis)

2. .Mixing movement:

Question 15

basic movement of the GIT is

Answer 15

Propulsive movement (Peristalsis)

Question 16

Propulsive movement direction

Answer 16

oral-to-caudal direction

Question 17

Propulsive movement propelling the contents of the lumen forward at rates

Answer 17

from 2 to 25 cm/s.

Question 18

Propulsive movements occurs ( site of action )

Answer 18

in all parts of the GIT from the esophagus to the rectum.

Question 19

Propulsive movements (Peristalsis)activity can be

Answer 19

↑ or ↓ by the autonomic input to the GIT

Question 20

increased or decreased by the autonomic input to the GIT

Answer 20

extrinsic innervation

Question 21

Propulsive movements original position is blocked only if

Answer 21

the segment is reversed before it is sewn خزيطback into place

Question 22

Propulsive movements is not blocked by

Answer 22

removal and re-suture خياطة اعادةof a segment of intestine

Question 23

example of the integrated activity of the enteric nervous system

Answer 23

Propulsive movements (Peristalsis)

Question 24

Propulsive movements (Peristalsis) appears

Answer 24

local stretch
▼
releases serotonin,
▼
activates sensory neurons
▼
 activate the myenteric plexus
\+ 
Cholinergic neurons passing in

Question 25

retrograde direction مهم

Answer 25

release substance P and acetylcholine,

causing smooth muscle contraction

Question 26

anterograde direction

Answer 26

secrete ,Nitric oxide (NO), vasoactive intestinal polypeptide (VIP), and adenosine triphosphate (ATP), causing smooth muscle relaxation

Question 27

stimulus for intestinal peristalsis is

Answer 27

A. distention of the gut
B. chemical or
C. strong parasympathetic nervous signals

Question 28

when a person is treated with atropine

Answer 28

parasympathetic nervous depressed or completely blocked in the entire gut

Question 29

Law of the Gut.

Answer 29

peristaltic reflex plus the anal direction

Question 30

Mixing movement:

Answer 30

keep the intestinal contents thoroughly mixed at all times

Question 31

Mixing movements differ in different parts

of the alimentary tract:

Answer 31

1.forward progression of the intestinal

contents is blocked by a sphincter→the peristaltic contractions cause most of the mixing.

Question 32

NB

Answer 32

سلايد 43