Lecture 9: The nervous system part 1: The autonomic nervous system Flashcards
What are the two divisions of the peripheral nervous system?
Afferent and efferent
What information does the afferent division of the PNS transmit via action potentials?
Information from the sensory receptors and visceral stimuli
What are the two divisions of the efferent nervous system?
Somatic nervous system and autonomic nervous system
What is the somatic nervous system?
Voluntary control of skeletal muscles
What makes the autonomic nervous system special?
It does not require conscious regulation
What does the autonomic nervous system do?
Regulates activity of the internal organs (smooth muscle, cardiac muscle and glands)
What is another major function of the autonomic nervous system?
Homeostasis
What can the autonomic nervous system be divided into?
Sympathetic (flight or fight)
Parasympathetic (rest and digest)
What nerves are associated with the parasympathetic division of the autonomic nervous system?
Cranial nerves
Sacral nerves
What nerves are associated with the sympathetic division of the autonomic nervous system?
Thoracic and lumbar nerves
What do lumbar nerves of the sympathetic nervous system do?
Makes kidney secrete epinephrine/norepinephrine, relaxes bladder, inhibits sex organs
The ANS does not usually have single neurons connecting the CNS to organs. Instead…
There is usually an autonomic ganglion in between
What are the two ganglions in the ANS?
Neurons from the CNS to ganglia are preganglionic
Distal ones are postganglionic
In autonomic ganglia, preganglionic nerves are ________ and postganglionic fibres are ________
Myelinated
Unmyelinated
Where are sympathetic ganglia located?
Close to the CNS
Where are parasympathetic ganglia located?
Close to the target organ, or embedded in it
How many cell bodies do sympathetic preganglionic axons innervate?
> 20
How many cell bodies do parasympathetic preganglionic axons innervate?
<4