PNS and CNS Review Flashcards
Sympathetic Activity?
Fight or Flight
Parasympathetic Activity?
Discrete, finely tuned control of daily functions
Sympathetic nervous system neurotransmitters?
- Acetylcholine at ganglionic
- Norepi at receptor
Parasympathetic Neurotransmitters?
Acetylcholine at all sites
Mechanisms for
Neurotransmitter
Inactivation for the sympathetic nervous system?
COMT and MAO enzymes;
Uptake 1 & 2;
Auto-receptors
Mechanisms for
Neurotransmitter
Inactivation for the parasympathetic nervous system?
Cholinesterase enzymes
Auto-receptors
Sympathetic receptors?
Alpha, Beta, and Dopaminergic (Adrenergic)
Parasympathetic receptors?
Muscarinic and Nicotinic (Cholinergic)
Add pages slide 4 and 5 on Cholinergic and adrenergic receptor sites
Where are Nicotinic Receptors found?
Receptors are found in autonomic ganglia, neuromuscular junctions, and CNS
What does activation of Nicotinic receptors at the neuromuscular junction and CNS lead to?
- Neuromuscular = muscle contraction
- CNS (Brain) = excitation
How many Muscarinic receptors types are there?
- which two are most relevant to us?
5 receptors, M2 and M3
where are M2 receptors found and what does activation cause?
M2 are found in the heart and activation causes bradycardia
where are M3 receptors found and what does activation cause?
M3 are found on bronchial and vascular smooth muscles, mucous glands, mast cells. Activation causes:
- Bronchoconstriction
- Increased mucus production
- Mast Cell Degranulation
What are 3 types of Adrenergic receptors?
Alpha, Beta, Dopaminergic
What does activation of A1 and A2 receptors do?
- A1 = vasoconstriction of smooth muscles
- A2 = Less norepinephrine release and vasodilation
Where are A1 and A2 receptors found?
- Found on peripheral vascular smooth muscle
- Centrally located and activation causes less norepinephrine release
What are Beta 1 and Beta 2 receptors found?
- Activation?
- B1 found on the heart = Increased HR and Contractility
- B2 found on bronchial and vascular smooth muscles = bronchodilation and vasodilation
Where are Dopaminergic receptors found?
Dopamine receptors are found throughout the body
- similar to norepinephrine and can activate A and B receptors
- Dose dependant
Activation of Dopaminergic receptors?
Activation can cause multiple effects:
- Vasoconstriction
- Increased HR
- CNS excitation
What are common inotropes that would be used in the CVICU?
- Why are they selected in place of other vasopressors?
Looking for a positive increase in contraction without affecting other systems.
- Moderate dose dopamine, stimulates beta 1 receptors to contraction
- Dobutamine: selective beta 1 receptor
- Milirone: positive inotrope/vasodilator in short term management of severe CHF/low output states
Why is Norepinephrine commonly selected for refractory hypotension?
Endogenous neurotransmitter that has a moderate beta 1 stimulant with potent alpha stimulation
- Increases SVR and decreases venous return to the heart and elevate BP
what receptors get stimulated by ephedrine
- Primary use?
Antihypotensive agent
- Stimulates moderate alpha and beta 1 and 2 stimulation
When would Phenylephrine be used instead of norepinephrine or ephedrine?
Pure alpha agonist; produces intese peripheral vasoconstriction
- Increases BP and reflex bradycardia
- antihypotensive agent
