Divisions Of The Nervous System Flashcards
What does caudal refer to?
Bottom of nervous system
What does dorsal refer to?
Back
What does ventral refer to?
Front
What does medial refer to?
Down midline
What does lateral refer to?
Down side
What does proximal refer to?
Close to
What does distal refer to?
Far away from
What does rostral refer to?
Further forward in brain
What does ipsi and contra refer to?
Ipsi = same Contra = opposite
3 divisions of the nervous system?
Central nervous system
Peripheral nervous system
Enteric nervous system
Central nervous system contains?
Spinal cord and brain
Peripheral nervous system consists of?
Nerves and cell bodies to and from brain and Spinal cord
Enteric nervous system consists of?
Neural cells of the viscera(gut)
How many pairs of peripheral nerves in PNS?
43
What are the 2 types of peripheral nerves?
Cranial and spinal
Define peripheral nerves
What do they contain, what don’t they?
Most are…?
Some are…?
When an axon is wrapped and bundle = called a?
(what is it that bundles them?)
all surrounded by what?
Bundles of individual neuron processes (axons)
Contain axons, NOT dendrites
No neuronal cell bodies
Most are mixed = sensory input and output and have motor and sensory role
Each Axon is wrapped and bundled = FASCICLES
Some myelinated by Schwann cells
All surrounded by endoneurium
Bundled by perineurium into fascicles
What is a fascicle?
A bundle of axons, formed by perineurium
Cranial nerves
How many pairs?
Which ones run to where?
12 pairs Sensory, mainly motor or mixed 1 and 2 run from forebrain 3-12 run from brainstem 9 - connection to spinal cord 10 - vagus nerve = 80% output from PNS here
Spinal nerves
How many pairs?
Branches are called?
Define dermatomes
All nerves are mixed
5 sets of pairs
Spinal nerve branches = RAMI
dermatomes = patterns of innervation of the spinal nerves – helps to identify sites of damage
Divisions of PNS
Somatic = conscious
Afferent - pain
Efferent - skeletal muscle
Visceral = unconscious
Afferent - cardiovascular system
Efferent - autonomic nervous system = sympathetic and parasympathetic branches, enteric
Both have afferent and efferent
Autonomic vs. Somatic efferents
Somatic - motor axons go straight to muscles
Autonomic - motor Axon > ganglion > muscle/gland
Pre ganglion and post ganglion axons
-which is myelinated??
Pre- ganglion axons are myelinated
Post are not
Where Are Sympathetic ganglia?
Near spinal cord
Where are parasympathetic ganglia?
Close to targets
1 pre : 4 post ganglionic
What forms the sympathetic chain?
Paravertebral ganglia
Some ganglia are closer to the target cells. What are these called?
Prevertebral ganglia (lie between paravertebral ganglia and target organ)
What is the ratio of pre : post ganglionic for sympathetic branch??
What is the ratio for pre: post ganglionic cells for parasympathetic?
1: 20
1: 4
What is the word for direct to target??
Adrenal
Are Sympathetic pre ganglionic fibres long or short??
Short
Are paraSympathetic pre ganglionic fibres long or short??
Long
What NET and receptor do both sympathetic and paraSympathetic use?
Acetylcholine
N2 receptor
Is the sympathetic post-ganglionic adrenergic or cholinergic?
Adrenergic – adrenaline or noradrenaline
Is the parasympathetic post-ganglionic adrenergic or cholinergic?
Cholinergic – acetylcholine
So drugs affect different branches
