The Autonomic Nervous System Flashcards
What is the majour function of autonomic sensory receptors?
Detecting the internal environmental conditions in the body
What is the function of chemoreceptors?
assessing blood (CO2), blood pH & blood glucose
What is the function of mechanoreceptors?
detecting the degree of stretch in the walls of BV’s and organs
what is the function of nociceptors?
detecting visceral pain
Where are the motor effectors in the ANS found? (3)
- Smooth muscle
- Cardiac muscle
- Glands
Can tissue function continue if there is nerve damage to an ANS-controlled tissue?
yes.
The beart beats on its own even if nerves to it are severed or damaged.
Some glands secrete even without ANS control
Describe an ANS motor unit
2 - neuron chain
- preganglic neuron
- postganglionic neuron
Describe the functions of the preganglionic & postganglionic neurons
Impluses leave the CNS via a prehanglionic neuron, which then synapses with the postganglionic neuron which then synapses with the effector
Where are the cell bodies of postganglionic neurons found?
Outside the CNS
What is another name for cell-bodies of postganglionic neurons?
autpnomic ganglia or motor ganglia
Describe the preganglionic neuron
extends from the CNS to the autonimic ganglion.
thin & lightly myelinated
CCell body is in the CNS
Describe the axon of the prehanglionic neuron
it forms part of the spinal or cranial nerve as it lewaves the CNS
what is the neurotransmitter thats preganglionic neurons produce?
acetylcholine (Ach)
Describe the postganglionic neuron
Extends from the preganglionic neuron to the effector.
Thinner & unmyelinated.
Entirely outside the CNS
What are the 2 branches of the ANS and motor division?
- Sympathetic (thoracolumbar)
2. parasympathetic (craniosacral)
What is the majour function of the sympathetic NS?
Emergency response
When there is a real or percieved threat on homeostasis
What is the fight or flight response?
when the body is under stress it either fights or flees from this stress.
Occus because of the sympathetic NS
What are the sympathetic responses?
Higher/increased: heart rate, BP, blood sugar, BPM, sweat
Dialated pupils & bronchi
Constriction of BV’s
Slowed digestion & urine production
Stimulation of adrenal gland (release of epinephren)
Where are the preganglionic neaurons foudn in the sympathetic NS?
The dendrites & ceoll bodies are found within the lateral grey horns in the thoracis & lumbar segments of the spinaal cord
How many postganglionic neurons does one preganglionic neuron synapse to?
multiple
What does cholinergic mean?
the type of neurons found in the sympathetic NS because acetylcholine is used.
Where is the sympathetic chain ganglia found?
extend from the C2 to the coccyx
Are presympathetic neurons long or short?
short
Are the preganglionic neurons myelinated?
yes
Are the postganglion neurons myelinated?
no
Where are the cell bodies & dendrites of postganglionic neurons found?
in the sympathetic chain ganglia