Nervous System Flashcards
(93 cards)
What are the structural classifications of the nervous system?
Central NS = brain and spinal cord
Peripheral NS = cranial nerves (12 pairs) and spinal nerves (31 pairs)
What are the functional classifications of the nervous system?
Peripheral NS = Sensory (afferent) and Motor (efferent) neurones
Sensory = senses and sensory receptors
Motor = Somatic and autonomic
Somatic (voluntary) = skeletal muscles
Autonomic (involuntary) = smooth muscle, glands, cardiac muscle
Autonomic = Parasympathetic and Sympathetic
Ganglion
A group of cell bodies in the PNS
Nuclei
A group of cell bodies in the CNS
How many efferent neurones does the neuron pathway, controlled by the divisions of the autonomic motor NS have?
2 efferent neurones
What are the 2 efferent neurones of the parasympathetic and sympathetic NS called?
1) Pre-ganglionic neurone = cell body will be in the CNS (anywhere apart from the cerebellum)
2) Post-ganglionic neurone = will be attached to the effector (smooth muscle, gland or cardiac muscle)
Describe the pre-ganglionic neuron of the sympathetic NS:
Cell body: In the CNS (anywhere but the cerebrum)
Axon: Extends down the anterior grey column of the spinal cord and terminates at the spinal cord between T1 and L2
Synapses with the cell body of the post-ganglionic neurone: Either in the lateral chain of sympathetic ganglia or the prevertal chain of sympathetic ganglia)
What is the neurotransmitter at the synapse between the pre-ganglionic neurone and the post-ganglionic neurone of the sympathetic NS?
ACETYLCHOLINE
Does the pre-ganglionic sympathetic neurone always synapse with the post-ganglionic neurone at the same level is terminated the spinal cord?
No it can either be on the same level or not
How does the pre-ganglionic axon of the sympathetic NS reach the prevertal chain of ganlia?
It must pass the lateral chain of ganglia before reaching the prevertal chain
Describe the post-ganglionic neurone of the sympathetic NS?
Cell body: In the lateral chain or prevertal chain of sympathetic ganglia
Axon: Attached to the effector
What is the neurotransmitter at the post-ganglionic neurone of the sympathetic NS?
Noradrenalin (however, can sometimes be acetylcholine)
Why does the post-ganglionic neurone of the sympathetic NS sometimes release acetylcholine at the synapse?
This will occur at effectors that are only supplied by the sympathic post-ganglionic neurones (Skin, sweat glands and skeletal muscles) and so ‘parasympathic’ effects can not occur.
These effectors contain NICATINE-ACETYLCHOLINE RECEPTORS - that bind to the acetylcholine from the post-ganglionic sympathetic neurones (in order for parasympathetic effects to occur)
Describe the pre-ganglionic neurones of the parasympathetic NS?
Cell body: In the CNS (anywhere but the cerebrum) or in the spinal cord
Axon: Extend down in the grey anterior column of the spinal cord and terminates the spinal cord at 2,3 or 4 sacral region.
Synapses: With the post-ganglionic neurone either in the ganglion or the effector wall
What neurotransmitter is at the synapse of the parasympathetic pre-ganglionic neurone and the post-ganglionic neurone?
ACETYLCHOLINE
Describe the post-ganglionic neurones of the parasympathetic NS?
Cell body: Ganglion or inside effector
Axon: Terminate with the effector
What neurotransmitter is at the synapse of the parasympathetic post-ganglionic neurone and the effector?
ACETYLCHOLINE
What receptors do the effectors (that are supplied by post-ganglionic parasympathetic neurones) have?
Either:
1) Nicotine-acetylcholine receptors (parsympathetic and can be sympathtic - skin, sweat glands and smooth muscles)
2) Muscarine-acetylcholine receptors (only parasympathetic)
Differences between the pre-ganglionic and post-ganglionic axons of the sympathetic and parasympathic neurones:
Sympathetic:
Pre-G: long
Post-G: short
Parasympathic
Pre-G: short
Post-G: long
What are the functions and type of reactions of the sympathetic NS?
Fight and flight
Catabolic (releases energy) reactions
What are the functions and type of reactions of the para-sympathetic NS?
Rest and Digest
Anabolic (stores energy) reactions
What are the 3 major anatomical regions of the brain?
1) Cerebrum (and lobes of the cerebral hemisphere)
2) Brain Stem (Midbrain, Pons and Medulla Oblongata)
3) Cerebellum
Cerebrum is divided into?
2 cerebral hemispheres
What joins together the 2 cerebral hemispheres?
CORPUS CALLOSUM