GI Tract Flashcards
1
Q
Serosa Characteristics
A
- Outer layer of CT
- Continuous with the Mesentery
2
Q
Where is most of the colonic water absorbed?
A
Proximal Colon
3
Q
Spike potentials
A
- Slow AP
- Occur automatically when Membrane pot. Is more positive than -40mv
- Channels open and close slowly
4
Q
Factors that DECREASE Saliva production
A
- Sleep
- Dehydration
- Fear
- Anticholinergic Drugs
5
Q
MOA of Peristaltic Contractions
A
- ENTERO-Chromaffin cells sense food and release SEROTONIN
- Serotonin binds to receptors on Primary efferent Neurons
- Initiation of the peristaltic reflex
6
Q
Actions of Gastrin
A
- Stimulates gastric acid secretion by the PARIETAL cells
2. Stimulate MUCOSAL growth
7
Q
Mucosa Characteristics
A
- Forms a continuous sheet lining entire GI tract
- Loose CT with sensory nerves
- Includes muscularis mucosa
8
Q
Submucosa Characteristics
A
Incorporates BLOOD vessels and submucosal plexus
9
Q
What maneuver results in an increased abdominal pressure?
A
Valsalva
10
Q
Actions of Secretin
A
Stimulates
- PEPSIN secretion
- Bicarbonate
- Pancreatic Growth
Inhibits
1. Gastric Acid secretion by Parietal cells
11
Q
Saliva is controlled by what CN?
A
- 7 (Facial)
and
- 9 (Glossopharyngeal)
12
Q
Factors that cause Depolarization and Hyperpolarization in GI
A
Dep:
- Stretching of muscle
- ACh (parasym)
- Stimulation of specific GI hormones
Hyp:
- NorEpi
- Epinephrine
(Symp)
13
Q
What are the official GI hormones?
A
- Gastrin
- CCK
- Secretin
- Gastric Inhibitory Peptide (GIP)
14
Q
Actions of CCK
- Stimulation
- Inhibition
A
Stimulates:
- Pancreatic enzyme secretions
- Bicarbonate secretion
- Grown of exocrine pancreas
- [Bile] of the gallbladder
- Relaxation of the Sphincter of Oddi
Inhibits:
- Gastric emptying
- Appetite
15
Q
Where do slow waves originate?
A
- In the Interstitial cells of CAJAL
- Pacemaker
