Anatomy of the nervous system Flashcards
What muscle does the somatic nervous system control
skeletal
What muscle does the autonomic nervous system control
smooth and cardiac muscle, glands
How many neurons in the somatic pathway
often a single motor neuron
How many efferent neurons in the autonomic nervous system
2
pre-ganglion (in CNS)
Post-ganglion
What neurotransmitter is in the somatic system
acetyl choline
What neurotransmitters are in the autonomic nervous system
acetyl choline and noradrenaline
What type of impulses are in the somatic nervous system
always excitatory
What type of impulses are in the autonomic nervous system
excitatory and inhibitory
4 things the autonomic nervous system controls
Cardiovascular system
Respiratory system
Reproductive system
homeostasis
2 main sub divisions of the Autonomic nervous system
sympathetic
parasympathetic
What type of outflow is parasympathetic
craniosacral
name the parasympathetic pre-ganglionic neurons
cranial nerve 3,7,9, 10
Sacral S2, S3, S4
In the parasympathetic what size are the pre-ganglion neurons
long
Where is the ganglion situated in the parasympathetic
close to, on or in the effector organ
What size are the postganglion neurons of the PSNS
Short
Parasympathetic can be described as being
secretor motor
What are both neurotransmitters in the parasympathetic pathway (PreG-postG and PostG-effector)
acetyl choline
Whats the difference between the pre-G-postG and post-G-effector synapse parasympathetic
PreG-PostG= nicotinic receptors PostG-effector= muscarinic receptors
What are the receptors PostG-effector parasympathetic
Muscarinic
What is the difference between nicotinic and muscarinic stimulation
muscarinic is longer lasting
Where does the 3rd cranial nerve run to
pupils (PS)
Where does the 7th cranial nerve run to
submadibular and sublingual glands
lacrimal and nasal glands (PS)
where does the 9th cranial nerve run to
the parotid gland (PS)
where does the 10th cranial nerve run to
vagus (all over) (PS)
where do S2,S3,S4 sacral PS outflow supply
hind gut —> colon, kidney, bladder, sex organs
what does secretor motor mean (PS)
causes secretion to glands and has a primary motor function on muscle (apart from heart where it reduces)
Name 5 Parasympathetic effects
Constricts pupils constricts airways stimulates digestion Stimulates bladder contraction Stimulates penile erection
pre-G nerves PS do NOT travels in
spinal nerves or rami communicantes
The sympathetic nervous system is from
T1-L2 (thoracolumbar)
Sympathetic size of preG neurons
short
sympathetic size of postG neurons
Long
Where do sympathetic preG come out the spinal cord
through the ventral roots
What happens when sympathetic PreG come out the spinal cord
they synapse in the sympathetic chsin
What nerves from the white ramus (myelinated) (sympathetic)
the pre-ganglion nerves
What nerves form the grey ramus
Post ganglions , originally unmyelinated but become myelinated
What is the type of effect in the sympathetic Nervous system based on
dependant on the type of receptor and the type of neurotransmitter
Which sympathetic nerves don’t synapse through the ganglion (run as PreG)
thoracic splanchnic
Where does the greater splanchnic nerve run to supply
the celiac ganglion —> foregut
Where does the lesser splanchnic nerve run to supply
superior mesenteric ganglion
Where does the least splanchnic nerve run to supply
the inferior mesenteric ganglion
What are the vast majority of sympathetic neurotransmitters
ACh and noradrenaline (can be very varied though)
how can noradrenaline be released
locally or into the circulation
general sympathetic effect
wide spread and long lasting, fight or flight
5 sympathetic effects
dilates pupils dilates airways accelerates heart rate stimulates glucose production and release stimulates ejaculation
Horners syndrome=
disruption of sympathetic supply to eye and face
3 affects of horners syndrome
ptosis
miosis
anhydrosis
Ptosis=
lazy upper eye
miosis=
constricted pupil
anhydrosis=
lack of sweating (dry face)
Most common cause of horners syndrome
tumour in apex of lung
the pathway for horners syndrome=
ipsilateral
What nerve supplies the parotid salivary gland
auriculotemporal nerve (ultimately glossopharyngeal nerve)
Most blood vessels are innervated by the
sympathetic nervous system only
most viscera innervated by
both PS and S
In genitalia function what innervates
S and PS cooperate
How do cortical centres influence autonomic functioning
via limbic system
Bladder function is complex bc;
complex interplay of sensory, voluntary motor, involuntary motor at multiple spinal levels
What innervates pelvic floor muscles
Anterior horn cells S2-S4
UMN lesion result in a _____ bladder
spastic bladder
a LMN lesion results in a ______ bladder
flaccid
The LMN to affect the bladder occurs in the
sacral spinal cord and cauda equina
lesions affecting the bladder have to be
bilateral
Brown sequard syndrome=
hemisection
brown sequard syndrome =
ipsilateral loss of touch, proprioception, vibration (DCML)
Contralateral loss of pain and temp (spinothalamic)
A complete transection causes
loss of movement and all sensation below lesioned segment
Flaccid paralysis becoming spastic
Loss of bladder& rectal sphincter control
Lesions above T10= ineffective cough
