Module 10 - Autonomic Nervous System Flashcards
(60 cards)
What kind of contractions does the somatic nervous system cause?
voluntary (contraction of the skeletal muscles)
What kind of contractions does the autonomic nervous system cause?
involuntary (contraction of cardiac and smooth muscle as well as glandular tissue)
In the autonomic nervous system, does stimulation excite or inhibit its effector?
both
How many lower neurons does the somatic nervous system have and where does it travel?
one; travels from the spinal cord to the effector muscle
What is dual innervation?
when target effectors receive innervation from both the sympathetic and parasympathetic divisions - the situation we are in depends on which division is most active
What is the preganglionic neuron?
the first neuron in the pathway running from the spinal cord to the ganglion to synapse with the second neuron
What is the postganglionic neuron?
the second neuron in the pathway, running from the ganglion to the effector
In what nervous system division do the ganglia sit close to the spinal cord?
the sympathetic system
The sympathetic division has a short ____________ axon and a long __________
preganglionic; postganglionic
In the somatic NS, the lower motor neurons have what kind of myelination if any?
highly myleinated
Does the somatic nervous system have fast or slow conduction speed?
Fast
In the autonomic NS, the axons have what kind of myelination if any?
contains lightly myelinated or unmyelinated axons
The autonomic NS has what kind of conduction speed?
slow
Which NS division has pathways that originate from the thoracic and first two lumbar levels of the spinal cord?
The sympathetic NS
Which NS division pathways originate from the brainstem, traveling to effectors via cranial nerves, or from sacral levels S2-S4 in the spinal cord
The parasympathetic NS
The sympathetic division has a short ____________ axon and a long __________
preganglionic; postganglionic
In what NS division are the ganglia located either near or in the target organ?
the parasympathetic division
What are terminal ganglia?
cell bodies that are located near the target organ
What are intramural ganglia?
cell bodies that are located within the wall of the target organ
Which division can only have a very local effect and why?
The parasympathetic division because the postganglionic system is really short – can’t travel far from the ganglion because its so short
Which division has a more widespread effect and why?
the sympathetic; two postganglionic neurons that synapsed in the ganglion with the same preganglionic neuron can travel to effector tissues that are further from each other as well as the adrenal gland can secrete hormones into the blood stream
What is a plexus?
a web of intertwining axons and nerves traveling to their destination; a plexus will contain preganglionic parasympathetic fibers and postganglionic sympathetic fibers
What are neurotransmitters?
signaling molecules released at synapses
In the parasympathetic division, Acetylcholine is secreted in which two synapses?
-Synapse between the preganglionic and postganglionic neurons
-Synapse between the postganglionic neuron and the effector