Week 2 Pre-Learning: GI Tract - Upper GI Disorders Flashcards
In the throat, swallowing is a voluntary act controlled by what neurons?
- skeletal motor neurons
thus swallowing decreases with decreased LOC
How can dysphagia occur?
- mechanical obstruction or functional impairment (nerve or muscle problem)
What are 3 common symptoms associated with upper GI disorders?
- anorexia
- nausea
- vomiting
What is anorexia? (2)
- lack of desire to eat
- non-specific symptom
Why can anorexia occur? (3)
- often associated with nausea, abdominal pain, diarrhea, and psychological stress
- Can be a side effect of medication
- Frequently accompanies diseases such as cancer, heart disease, and kidney disease
What is nausea?
- subjective feeling of discomfort in epigastrium with a conscious desire to vomit
What is vomiting, aka emesis?
- Forceful ejection of partially digested food and secretions from the upper GI tract
this is a reflex with multiple pathways that trigger it
- if we understand the trigger, we know what anti-emetic to use
Which type of patients would we see nausea and vomiting in? (6)
- Pregnancy
- Infectious diseases
- CNS disease
- Cardiovascular problem
- metabolic disorders
- allergies, stress/fear
Nausea and vomiting is controlled by what centre in the medulla?
- emetic
What role does the chemoreceptor trigger zone play in the sensation of nausea and vomiting? (2)
- lies outside the BBB
- uses receptors for dopamine, serotonin, opiate and acetylcholine
more susceptible to outside chemicals
What role does the vestibular system play in the sensation of nausea and vomiting? (3)
- sends information to the brain via cranial nerve VIII
- plays a major role in motion sickness
- rich in muscarinic receptors
What role does the enteric and vagus nervous system play in the sensation of nausea and vomiting? (2)
- inputs transmission about the state of the GI system
- Irritation of the GI mucosa by chemotherapy, radiation, distention, or acute infectious gastroenteritis activates the serotonin receptors
What role does the CNS play in the sensation of nausea and vomiting?
- mediates vomiting that arises from psychiatric disorders and stress from higher brain centers (cerebral cortex)
Nausea and vomiting sensation in the brain diagram
What causes nausea and vomiting? (3)
- Inflammation of any part of the GI
- Irritation or injury to the CNS
- Reaction to a drug
