Module 2: Pathophysiology of Vomiting Flashcards
What is the primary cause of vomiting?
Noxious stimulation of the vomiting center located in the medulla oblongata. Neural pathways are received from 4 different sites.
Name the four additional sites involved in vomiting.
- Gastrointestinal (GI) tract
- Vestibular system
- Chemoreceptor trigger zone
- Higher centers in the cortex and thalamus
Which cranial nerves are involved in transmitting neural traffic from the GI tract?
- Cranial nerve IX (glossopharyngeal)
- Cranial nerve X (vagal)
What are the targets for antiemetic drug interventions?
Their ability to block specific receptor sites
List the receptors involved in the vomiting mechanism along with their conventional ligands.
- H1 histamine (vestibular)
- M1 acetylcholine (Vestibular)
- 5-HT3 serotonin (GI tract)
- DA2 dopamine (CTZ)
- NK1 (neurokinin) substance P (CTZ)
- Mu/kappa opioids (CTZ)
Blocking these receptors can help prevent vomiting.
What is known about the transmitter mediators in the cerebral cortex and thalamus regarding vomiting?
They are poorly understood
However, cortical cannabinoid (CB1) pathways have been characterized.
What is vomiting?
Vomiting is the forceful expulsion of the contents of the stomach through the mouth.
True or False: Regurgitation involves the conscious effort to expel stomach contents.
False: Regurgitation is an involuntary process.
Fill in the blank: Retching is characterized by _____ without the expulsion of stomach contents.
the act of making the motions of vomiting
What is the primary difference between nausea and dyspepsia?
Nausea is the sensation of needing to vomit, while dyspepsia is discomfort or pain in the upper abdomen.
Multiple Choice: Which term refers to the feeling of discomfort in the stomach often associated with indigestion? A) Vomiting B) Dyspepsia C) Retching D) Regurgitation
B) Dyspepsia
Which cranial nerves are involved in the vomiting response?
5th, 7th, 9th, 10th and 12th cranial nerves to the upper GI tract, within vagal and sympathetic nerves to lower tract and within spinal nerves to the diaphragm and abdominal muscles.
What is the primary function of the chemoreceptor trigger zone (CTZ)?
The primary function of the chemoreceptor trigger zone is to detect toxins and induce vomiting.
True or False: The chemoreceptor trigger zone is located outside the blood-brain barrier.
True.
Fill in the blank: The chemoreceptor trigger zone is sensitive to _______ in the bloodstream.
chemicals
Which area of the brain contains the chemoreceptor trigger zone?
The area postrema - between the medulla and the floor of the fourth ventricle.
What type of stimuli can activate the chemoreceptor trigger zone?
Chemical stimuli, such as drugs, toxins, and metabolic changes.
