chapter 15 autonomic NS Flashcards
(53 cards)
what are the two categories of the autonomic nervous system
sympathtic and parasympathetic
what is the voluntary/somatic effector vs the autonomic effector
somatic–> skeletal muscle
autonomic–> cardiac, smooth muscle, and glands
how many motor neurons from the CNS to the effector in somatic motor division
1, lacks ventral ganglia
how many motor neurons between CNS and effector in the autonomic motor division
2 motor neurons between CNS and effector, ganglion where pre and post motor neurons connect (i.e. there is a ganglion on the anterior)
what is the excitatory neurotransmitter at the effector in the somatic motor division
ACh
in the parasympathetic system what is the neurotransmitter released and when
ACh is the only neurotransmitter involved in the parasympathetic system. It is released from the preganglionic synapse (just like in the sympathetic nervous system) and again from the postganglionic synapse
in the sympathetic nervous system what neurotransmitters are released and when
ACh is released by the preganglionic synapse (just like parasympathetic system) and norepinephrine is released from the postganglionic synapse
what makes the autonomic system excitatory or inhibitory
it depends on the types of receptors on the effector organs
what does the parasympathetic system activate
“rest and digest”
what does the sympathetic system activate
“fight or flight”
where is the cell body of the preganglionic neuron in the parasympathetic system
usually in the brainstem or sacral spinal cord (CNS)
where is the cell body of the postganglionic neuron in the parasympathetic system
usually in a ganglion near the target organ (PNS)
where are the cell bodies of preganglionic neurons in the sympathetic system
usually in the spine (CNS)
where are the cell bodies of postganglionic neurons in the sympathetic system
in a sympathetic ganglion, located next to the spinal cord (PNS); T1-L2
are there dorsal root ganglion in both voluntary and autonomic NS
yes
describe the preganglionic axon in the parasympathetic NS
thin, lightly myelinated. super long. deads ends at the ganglion, usually inside an organ or just outside of the organ it’s innervating
describe the postganglionic axon in the parasympathetic NS
very thin, unmyelinated. short
describe the preganglionic neuron in the sympathetic NS
lightly myelinated, thin, very short
describe the postganglionic neuron in the sympathetic NS
very long, from the sympathetic ganglion chain to the organ it innervates. Slow transmission so we can effectively inhibit fight or flight response if not needed
which NS has a special group of neurons that emerge from the rami comunicante, do not synapse in the ganglion chain, directly attach to the adrenal medulla (only 1 neuron, no pre or post), and initiate a rapid fight or flight response
sympathetic
which autonomic division contricts pupils, focuses lens, normal secretion of lacrimal and salivary glands, reduces heart rare, secretion of bile, GI and pancreatic motility and secretions, defication and urination, vasodilation
parasympathetic
where do preganglionic axons pass through? and where do they enter?
through the rami communicante and enter the paravertebral ganglionic chain
what is the paravertebral ganglionic chain?
location of postganglionic cell bodies
what are the 3 ways a preganglionic axon can synapse
1 synapse at same level with postganglionic neuron
2 ascent/descent and then synapse with the postganglionic neuron
3 pass through without synapsing, instead form splanchnic nerve. Then synapse in prevertebral ganglia (anterior) [some may pass through prevertebral chain and go directly to adrenal medulla]
