ANS Flashcards
What are the functional divisions of the Nervous System
Parasympathetic
Sympathetic
Enteric
Neurohumoral component
What is the function of the Enteric NS?
It is interconnected neurons in the wall of the bowl from the oesphagus to the anus that act as an independent NS - involved in regulation of the bowl motility
What is the neurohumeral component?
A link between the CNS and the endocrine system
Describe the length of the first axons for both the sympathetic and parasympathetic systems
Sympathetic - has shorter preganglionic fibres - Ganglion is closer to the CNS
Parasympathetic - has longer preganglionic fibres - Ganglion closer to the target cell
Origin and formation of the sympathetic Ganglions
Originates in thoracolumbar region L1-S2
Forms the vertebral chain ganglia
What is the function of the vertebral chain ganglia?
Allows for nerve fibres to go above the level of T1 and below T2 to innervate target cells such as eyes and the bladder
- Allows access to all body parts all stemming from the thoracolumbar region
The preganglionic axon that leaves the mixed spinal nerve is called?
White Rami
The preganglionic axon that enters the mixed spinal nerve is called?
Grey Rami
Difference between paravertebral and prevertebral ganglions
Paravertebral occurs alongside the vertebral column
Prevertebral runs infront of the body, innervating visceral organs
Difference between a neurotransmitter and a hormone?
Neurotransmitter is if the chemical is released by an axon terminal at a synapse
Hormone is released into the blood and travels through the blood stream
What is the Adrenal Chromaffin Cell?
It recieves synaptic input from the preganglioic sympathetic axons and modify the post ganglionic cell to have no axon
They release epinephrine and noepinepherine into the blood stream as a stress response from neural stimuli - especially tissues that have weak neural stimulus
Where do Parasympathic neurons originate?
From Cranial nerves 3,7,9,10 & Sacral Nerves 2-4
Where are nicotinic receptors found?
They are found at the first synapse outside of the CNS
What receptor is the parasympathetic 2nd receptor?
Muscarinic Receptor
What are the Sympathetic receptors and where are they found?
Alpha 1 & 2 - Found in blood vessels - Mediate Vasoconstriction
Beta 1 - Found in the Heart
Beta 2 - Found in the Airways
Beta 3 - Found in the bladder and brown adipose tissue
B1 Blockers would be used for?
Hypertension / Heart Disease
- Prevent Heart Attack
B2 Agonist Would be used for?
Also called sympathomimetic drug
- Used for increasing sympathic activity do bronchodilate the airways in asthma (aka Ventolin)
What would Atropine be used for?
Hint is a blocks muscarinic receptors
Used for Brachycardia (people with low HR and blood pressure
What causes referred pain?
The merging of the visceral and somatic fibres in the dorsal horn
causing pain in certain parts of the body
Ie heart pain can be felt on the left side and down the left arm
