Session 2: Part 1 (PNS) Flashcards
What are the 2 arms of the PNS
Autonomic (unconscious) and somatic
What are the 2 autonomic branches
Sympathetic and parasympathetic
Which part of the neuron carries info the cell body
Dendrites
Which part of the nuerone carries info away from cell body and is part of a synapse with cell or another neurone
Axon and then axon terminals
What difference do neurones have in ms
Demyelinated and loss of axon
What are the cells called in axon whcih sre myelinated and the haps between
Schwann and nodes of ranvier
What does the spinal cord do
Carries information to and from the brain afferent and efferent
How many cervical nerve pairs are there (c1/c7)
There are 8 nerve pairs
How many nerve pairs in thoracic,lumbar and sacral
12,5 and 5
What is the nerve in coccyx area called
Coccygeal nerve
What are all these nerves called extending from spinal cord
Spinal nerves
What protects rhe spinal cord specifically
Vertebrae
Vertebrae canals is where spinal cord runs through
What forms the vertebrae canal
When vertebrae stack the foramen will form the vertebrae canal where spinal cord sits all the way down spinal column
What bone forms the body around the verterbal canal
Cancellous
What is the white matter outer part of the spinal cord made of
Axons from neurones ascending and descending
What forms the grey matter
Where cell bodies cluster and synapses between neurones occur
Where do nerves from body afferent enter in the spinal cord
Dorsal root/ horn. (Posterior)
What is the little bundle called on the nerves entering into dorsal horn
Dorsal root ganglia
Where do nerves exit from sc
Ventral root/ horn (anterior)
What surrounds the dorsal and bentral horns which sit in hrey matter
In white matter there is the anterior, lateral and posterior funiculus
What is the dot in middle of sc called
Central canal
What is the gap xalled in between sc
Anterior median fissure
What runs in the lateral column/funiculus of spinal cord (to the left)
Where the descending motor neurones from the cerebral cortex run to sc with info for movement (part of the corticospinal tract which are axons/white matter of these neurones)
What neurones run in the dorsal column
Sensory ascending from limbs carrying proprioceptive and fine touch info
Which nerves dont run in spinal cord
Autonomic nerves (run alongside in ganglia)
Where do ascending pain and temp sensory neurones run through in white matter
Anterolateral fasciculus / spinothalmic tract
Ventral column
Where do ANS neurones arise from after brain
Axon Synapse in ganglia forming pre and post ganglionic neurones in periphery
(Always 2 neurones)
(They DO NOT CROSS SC)
What are sympathetic and para effects on salicary flands
Symp- reduce salivation
Para - increase water salivation
Effect on cardiac muscel
Symp- increase hr and force
Para- reduce hr and force
Pupils sphincters
Symp- dilate them
Para- constrict them
Liver
Symp- increased glycogenolysis
Para- no effect
Peripheral vessels
Symp- constrict them
Para- no effect
SMall intestije
Symp- decreased motility
Para- increased motility/digestion
Stomach
Symp- reduced peristalsis
Para- increase peristalsis and secretions
Large intestine
Symp- deceeased motility
Para- increased motility/digestion and secretion
Airways/ lungs smooth muscle
Symp- dilate and relax
Para- constrict
Where are the crll bodies of sympathetic neurones on spinal column
Thoracic and lumbar segments
Explain ganglia formation in sns neurones
Wither paravertebral ganglion or individual ganglion form far from target organ (short pre,long post neurone)
What is the effect sns has on sweat glands and adrenal medulla
Increase sweat
Increwse adrenaline release
What is the effect sns has on skin and viscera/lsfge organs
Vasoconstriction eg of the GI tract = reduced motility and tight skin
Where do para sympathetic neurones arise from
Cranial nerves or at the lumbo sacral column (bottom)
How are ganglia of para symp different
Only individual jot grouped , also close to target organs (long pre neurone)
How does para symp allow motility and divestion
Vasodilation of the viscera/organs
What are the PNS neurones going to and from the cns carrying info
Afferent and efferent from cns
Somatic sensory and motor go through the spinal cord directly. Explain
Somatic sensory run in the dorsal funiculus for fine touch and proprioceptjon
Lateral column are the motor efferents from brain
Anterolateral fascucilus carries somatic sensory pain and temp fibres up
Do neurones only carry either efferent or afferent info
No it’s a combination of both
