Gut Motility Flashcards
What is the neural control of the gut motility?
All part of the enteric nervous system
Stimulating post-gang Cholinergic nerves increases contraction of gut
Stimulating non-adrenergic inhibitory nerves inhibit contractions
How do the extrinsic nerves of the gut work?
Intestino-intestinal inhibitory reflex: distension of one intestinal segment causes complete intestinal inhibition
Anointestinal inhibitory reflex: distension of the anus causes intestinal inhibition
Gastro colic and duodenocolic reflexes: stimulates motility after material has entered the stomach or duodenum
What is the process of Emesis?
Pyloric sphincter closes while the Cardia and Oesophagus relax
Gastric contents propelled by contraction of abdominal wall and diaphragm
Glottis closes with elevation of the soft palate preventing entry of vomit into the trachea and nasopharynx
What are some causes of Emesis?
Pregnancy Meds, toxins, pain and irradiation Smell Touch Increased intracranial pressure Stretching or inflammation of stomach Rotational movement of cochlear
Where is the vomiting centre of the brain?
The area postrema in the medulla
What are the preliminary signs of Emesis?
Nausea Dilated pupils Outbreak of sweat Retching Paleness
What is Domperidone?
D2 antagonist
Acts on the postrema and increases rate of gastric emptying
Used in acute nausea and vomiting
What is an ADR of Domperidone?
Stimulated prolactin release
Rare dystonia
What is Ondansteron?
Serotonin antagonist
Serotonin is usually released into the gut
Used in high dose radiation and chemotherapy and post-op
What are the ADRs of Domperidone?
Headaches
Constipation
Flushing
What is Hyoscine?
Ach antagonist
Treats motion sickness
What is Cyclizine?
H1 antagonist
Given in acute nausea and vomiting
But crosses BBB and gives a sedative effect
What are faecal softeners?
Arachis oil and glycerol act by lubricating and softening the stool
Used in
- adhesions
- anal fissures/ haemorrhoids
What non-pharm laxatives can patients use?
Bulk
Faecal softeners
Castor oil
Senna
What are non-pharm solutions for mild constipation?
Increased fluid intake
High fibre diet
Exercise
