ANS I Flashcards
What is an agonist? what is an antagonist?
- agonist = activator
2. antagonist = inactivator
What do the following terms mean:
- ionotropic
- chronotropic
- dromotropic
- ligand gated
- affecting heart rate
- affects AV node- conduction of speed
What are the sympathetic effects on the heart?
- stimulation of heart rate at SA node
- stimulation of AV nodal conduction
- stimulation of myocardial contractility
What are the PNS effects on the heart?
- Inhibition of HR at SA node
- inhibition of AV nodal conduction
- inhibition of atrial contractility
Which neurons are myelinated, preganglionic or postganglionic ?
preganglionic
What transmitter do somatic neurons release? and what receptor does it bind to?
- ACh
- binds to N1 nicotinic cholinergic receptors
What transmitter do preganglionic ANS neurons release and what receptors does it bind to?
- ACh
- binds to N2 nicotinic cholinergic receptors
What transmitter does a postganglionic parasympathetic neuron release and what receptor does it bind to?
- ACh
- muscarinic cholinergic
What transmitter do postganglionic sympathetic neurons release and what receptors does it bind to?
- Norepinephrine
- alpha or beta adrenergic
What neuron activates the adrenal medulla, and how is this accomplished?
- Sympathetic preganglionic neurons release Ach to chromaffin cells
- these cells release epinephrine (80%)
Why is sympathetic stimulation of the adrenal medulla long lasting?
The hormones released are inactivated slower
When is there an exception to the receptors the sympathetic neurons usually stimulate?
Eccrine glands - muscarinic cholinergic receptors
Which type of receptors are ionotropic?
Nicotinic cholinergic - N1, N2
Na+/K+ ligand gated channel
What is the antagonist of N1 receptors?
D-tubocurarine
What is the antagonist of N2 receptors ?
Hexamethonium