Basic Neurophysiology Flashcards
What receptors does glutamate act on and what does it do?
Which substances antagonize the NMDA receptor?
- AMPA, Kainate and NMDA receptors
- It is a major excitatory neurotransmitter.
- It allows the flow of cations (sodium) across cells to depolarize them
- Ketamine and Magnesium
What is the effect of agonism of the opioid receptor?
- Activation of opioid receptor causes neuronal hyperpolarization (more difficult to generate an action potential).
- It alters the resting membrane potential and NOT the threshold potential (the point of -mv that must be reached before an action potential is generated)
What is the effect of chronic hypertension on autoregulation?
Your graph becomes R shifted. This means that usually between a MAP of 50-160 you autoregulate allowing cerebral blood flow to be the same. In chronic hypertension, due to vessel wall hypertrophy you have this same regulation of cerebral blood flow and high MAPs of 80-180.
Clinical corelation: during general anesthesia you need to be aware of their baseline blood pressures. A normal MAP in a chronic hyperensive is TOO LOW = global ischemic stroke.
Relationship between CBF (cerebral blood flow) and volatile anesthesics?
CBF increases as the concentration of volatile anesthetics increases due to:
1) All volatiles act as a direct cerebral arterial vasodilator
2) All interrupt autoregulation (as MAP increases cerebral blood flow will icnrease linerarly.
