Woman Suffering from a Stomach Pain Lying Down on Bed
Woman Suffering from a Stomach Pain Lying Down on Bed

Nausea and vomiting are common unpleasant condition that affects the quality of life of patients and can occur due to many causes causes like mechanical obstruction, gastroparesis, irritable bowel syndrome, peptic ulcer disease or pancreatitis art. Neurological processes like migraine, headache and vestibular disorders, metabolic disorders like addison disease, psychiatric causes like anxiety disorder and therapy induced like chemotherapy radiation therapy and some antibiotics are other causes like pregnancy or operative procedures. Let’s understand how nausea and vomiting are triggered inside the brain, specifically in the medulla we will find the vomiting center which coordinate motor mechanisms of vomiting, there are muscarinic receptors on the vomiting center and when they are stimulated this will trigger the vomiting reflex. Close to the vomiting center we will find the chemoreceptor trigger zone, it is located outside the blood-brain barrier, this means that it is exposed to cytotoxic agents like chemotherapy agents, it contains dopamine two receptors and the 5-ht3 receptors are the serotonin receptors when these receptors are stimulated, it will stimulate ctz which will stimulate the muscarinic receptors on the vomiting center.

Vomiting center responds to other afferent input from vestibular syste, periphery and higher brain stem so for a vestibular system, motion sickness happened because of a trigger inside the vestibular system, vestibular nuclei has histamine 1 receptors and mosconic receptors when these receptors are stimulated, it will send signals to the ctz and passed on to the vomiting center. Other reasons that trigger vomiting like emotional distress, severe pain, repulsive sight or smell, these will send signals to the higher brain stem, from that it will transmit the signals to the vomiting center, and then we can ask, what about the stomach? Well there are anterior chromophant cells that release serotonin in response to cytotoxic agents which will stimulate 5ht3 receptors on sensory nerves and lastly to the vomiting center.

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