ANS I Flashcards
The ANS controls […]
Visceral organs
What are the three major divisions of the ANS?
The sympathetic system, the parasympathetic system, and the enteric system.
What type of tissue does each division of the ANS innervate?
Sympathetic: cardiac and smooth muscle, glandular tissue
Parasympathetic: cardiac and smooth muscle, glandular tissue
Enteric: digestive tract
The sympathetic system is activated in […] reactions.
Emergency fight-or-flight
The parasympathetic system is activated in […] reactions.
Rest-and-digest
When are the sympathetic system and parasympathetic system active?
They are both active all the time, but in different proportions depending on the situation.
What are the two types of neurons present in the sympathetic system?
Preganglionic and postganglionic
The preganglionic cells in the sympathetic nervous system originate in the […]
Ventral roots of the thoracic and lumbar regions of the spinal cord
The postganglionic cells in the sympathetic nervous system originate in the […]
Sympathetic ganglia
What is the the sympathetic ganglia?
It is the chain that runs along either side of the spinal cord where the pre and postganglionic neurons synapse in the sympathetic nervous system.
Compare the structure of the preganglionic sympathetic neuron and the postganglionic sympathetic neuron.
Because the preganglionic sympathetic neuron synapses on the ganglia right outside of the spinal cord, its axons are quite short.
The postganglionic neuron has a long axon, because it must go from the ganglia all the way to the organ.
Sympathetic preganglionic neurons release […], which activates […] on […]
Acetylcholine, nicotinic acetylcholine receptors, postganglionic neurons
Sympathetic postganglionic neurons release […], which activates […] on […]
Norepinephrine, alpha and beta adrenergic receptors, target organs
Explain how beta blockers work.
Norepinephrine activates alpha and beta adrenergic receptors. Beta blockers for the heart prevent the sympathetic nervous system from increasing your heart rate by preventing the activation of beta adrenergic receptors.
What type of receptors are alpha and beta adrenergic?
Metabotropic receptors.