Motility Flashcards
(18 cards)
4 Neuro-Endo Signals for BER to depolarize?
- Ach
- Gastrin
- Serotonin
- Substance P (tachykinin)
Peristaslsis mechanism two facts
- Behind=Contraction via Cholinergic or Tackykinin motor neuron
- In front= VIP motor neuron to hyperpolarize
Where does MMC occur?
Mid-Stomach to Terminal Ileum
How long does phase 3 MMC stay active for?
10 Minutes
Define Mass Movement
Vagus and Gastrin cranking out peristaltic contractions IN THE COLON after smoothing out the Haustra. Occurs 3-6 times a day
Define Segmentation
Mixing AND Propelling via Mid chyme Bolus Contraction
Haustrae
Pockets made from Taneia coli; holds chyme to absorbe Na+ and water. OCCURS ALL DA TIME THROGHOUT THE DAY
Segmentation mechanism
Enteric Nerves; Local/extrinsic control
LONNNNGGG areas of tract are affected
Main hormone for MMC?
Motilin
Define Peristalsis
Circular Muscle Propulsion ONLY via Law of intestines; contract behind relax ahead.
Main phase for MMC?
Phase 3
When does MMC occur? (timing)
3-4hrs after eating
- If you’re always eating then you don’t use MMC because you have that constant supply of food to keep the pushing coming
Define Segmental Propulsion
3 Bands of Longitudinal Muscle along Colon’s Taneia Coli Contracting like an accordion and make pockets called HAUSTRAE.
Whatt drives secondary esophageal peristalsis?
Enteric Nerves
Especially if something gets stuck, secretions will get cranked up
Electric Threshold of BER?
-40mV
3 Neuro-Endo Signals for BER to hyperpolarize?
- NE
- VIP (Vasoactive Intestinal Peptide)
- NO
Peristalsis vs Segmental Propulsion muscle
- Peri uses Circular
- Seg. Prop. uses longitudinal
What drives primary esohpageal peristalsis??
The PNS of Medulla’s Swallowing center
