GI 7 Flashcards
The gallbladder stores bile needed for an entire meal
False
Defacation is triggered by
Relaxation of the Rectum
Two reflexed initiated by the distension of the rectum
Short reflex
Long reflex
Short Reflex
Local peristaltic waves
Long Reflex
Relaxation of the internal sphincter
Contracrtions from parasympathetic input
Completed by voluntary relaxation of the external sphincter (skeletal) and aided by increased abdominal pressure
Diarrhea
An increase in the frequency, volume and fluid content of the faces due to increased secretion, reduced absorption or increased motility
Types of diarrhea
Osmotic
Secretory
inflammatory
Motility
Osmotic diarrhea
When increased solute concentration in the lumen
Example: Lactose intolerant
inflammatory diarrhea
Due to bacterial infection
Secretory diarrhea
Triggered by immune cells
Example of secretory diarrhea
Cholera
C difficile
The use of penicillin based antibiotics can alter the normal bacterial flora
What does C difficile create
Colitis: Watery diarrhea, fever and abdominal pain
Vomiting
Contents of the stomach and occasionally the small intestine are forcefully expelled through the mouth
Associated with Nausea
Increased vestibular input
What does the vomiting center in the medulla cause
- Retrograde contractions in the small intestine and stomach
- Contraction of abdominal and inspiratory muscles (diaphragm). increases gastric pressure
- Relaxation of the esophageal sphincter
What’s in the GUT
Lymphoid tissue (80% of lymphocytes located in the gut)
M cells
Plays a big role in immune responses: sample lumen contents
Receptir mediated endocytosis
The primary role of the intestinal hormone is to stimulate pancreatic enzyme
CCK
The GI DOES NOT REGULATE
INTAKE
Lateral hypothalamus
Hunger center
Ventromedial hypothalamus
Satiety Center
Long term regulation of feeding behaviour
Glucostatic theory: Glucose metabolism in the hypothalamus regulates food intake
Lipostatic theory: Signals from the bodies fat stores regulate food intake
Most abundant long term regulation of the feeding behaviour
Lipostatic theory
Leptin
High levels on leptin in obese people
Response to elevated leptin
A lot fat in adipose tissue
Acts of arcuate nucleus
1. Inhibits of lateral feeding centre
2. Activation of PVN (Paraventricular Nucleus)
Increased metabolism by increasing TSH
Responses to decreased leptin
Reduce PVN
Activation of parasympathetic neurons
