The Autonomic Nervous System Flashcards
What are the two subdivisions of the ANS
Sympathetic
Parasympathetic
What is the main cranial nerve and what does it do?
Cranial nerve X (10) or the vagus nerve.
Supplies sympathetic control to most of the organs in the chest and abdomen
What is the ‘rest and digest’ regulation?
About reducing levels of activity over the whole body getting ready for rest
Describe the parasympathetic anatomy.
The long pre-ganglionic axon is lightly myelinated, speeding up the action potential.
When the nerve arrives at the ganglion, it releases a neurotransmitter called ACH onto the effector organ, activating the post ganglionic axon.
Explain how an axon travels in the sympathetic NS.
An axon is sent out, through the major spinal nerve.
The axon then passes through the white ramus and enters the ganglion, making chemical synapses.
The axon is sent back through the grey ramus and to the main nerve trunk
(some pass through the white ramus, branch off to control the visera that controls organs in chest and abdomen)
What are the differences of the sympathetic anatomy and the parasympathetic anatomy.
They work similar, however the sympathetic releases norepinephrine opposed to ACH
What are the two main areas of the prevertebral ganglia?
paravertebral ganglia
Prevertebral ganglia
What are the two main parts of the adrenal glands?
Medulla
Cortex
Describe the cortex of the adrenal glands.
The cortex is involved in the production of mainly cortisol but also involved with hormones that balance ions of the blood.
Describe the medulla of the adrenal glands.
The medulla contains chromaffin cells (modified neurons) which releases epinephrine and norepinephrine directly into the blood stream
How is the medulla connected to the nervous system?
The long axons pass out through the spinal nerve (the celiac ganglion) and finally out of the adrenal medulla
What is the effect of epinephrine and norepinephrine?
To increase the contractility of cardiac tissue, increase bronchodilation in the lungs and releases glucose from the liver…
Fight or flight response
What is the fight or flight response?
Physiologically getting ready and preparing the body for either fighting a source of danger or running away.
What are some physiological changes that happen during the fight or flight response?
Stroke volume increases Blood flow is redistributed Increase in heart rate Bronchodilation Salivary glands produce viscous saliva
What are the antagonistic effects of the SNS and PNS?
Heart (SNS increases, PNS decreases)
Gut (SNS decreases motility, PNS increases)
Lungs (SNS = bronchiole dilation, PNS = bronchiole constriction)
