What is the function of chemoreceptor trigger zone?
The chemoreceptor trigger zone (CTZ) is an area of the medulla oblongata that receives inputs from blood-borne drugs or hormones, and communicates with other structures in the vomiting center to initiate vomiting.
What happens when the trigger zone is stimulated?
Opioids directly stimulate the chemoreceptor trigger zone in the fourth ventricle of the brain, which in turn initiates the vomiting reflex. Dogs are more susceptible to this than cats, although both species will salivate and show signs of nausea.
What is the function of area postrema?
The area postrema, a paired structure in the medulla oblongata of the brainstem, is a circumventricular organ having permeable capillaries and sensory neurons that enable its dual role to detect circulating chemical messengers in the blood and transduce them into neural signals and networks.
What area of the brain is responsible for inducing vomiting when drinking?
The area postrema (AP) has been implicated as a chemoreceptor trigger zone for vomiting (emesis) for over 40 years. The AP is located on the dorsal surface of the medulla oblongata at the caudal end of the fourth ventricle.
Where is the chemoreceptor trigger zone located in the brain?
The chemoreceptor trigger zone (CTZ) is an area of the medulla oblongata that receives inputs from blood-borne drugs or hormones, and communicates with other structures in the vomiting center to initiate vomiting. The CTZ is located within the area postrema, which is on the floor of the fourth ventricle and is outside of the blood–brain barrier.
Why are the CTZ receptors called chemoreceptors?
These receptors in the CTZ are called chemoreceptors because they interact with different types of chemicals which are usually referred to as neurotransmitters. These neurotransmitters implement their effects on the CTZ receptors by binding to them which sets off a chain of events which produces an action potential.
What causes nausea and vomiting in the chemoreceptor?
Chemoreceptor trigger zone. There are also opioid receptors present, which may be involved in the mechanism by which opiates cause nausea and vomiting. The blood–brain barrier is not as developed here, therefore drugs such as dopamine which cannot normally enter the CNS may still stimulate the CTZ.
How does the relaying occur in the chemoreceptor?
The relaying happens by the initiation of an action potential, which is caused by the chemoreceptor causing a change in electric potential in the neuron it is embedded in, which then subsequently causes an action potential.