Session 2: Part 2 (PNS) Flashcards
What is the somatic nervous ststem
Responsible for coscoius responses to touch, proprioception,pain, temp
What are the somatic agferent nerves
Sensory nerves to sc and brain
What are somatic efferent
Motor neurones from cerebral cortex to affect skeletal muscle
Where in the brain has the nerve signal initiating movement
Precentral gyrus
What soes rhe corticospinal tract do
Mediates messages from brain to skeletal muscle
Where is the point where motor neurones innervate muscle crlls
NMJ
Where di somatic neurones synapse from cns
Mowhere. Rhey go straight to target organ
What are the somatic nerves from spinal cord called which carry info there asb from there
Spinal nerves (also carry ans)
Nerves are groups of axon bodies
What are the somatic nerves from brain
Cranial nerves
What are spinal roots
Start of spinal nerves/peripheral nerves
Where are spinal toots placed in cervixal region
Superior to each ceryebrae except c8 nerve below c7
Where do the rest of spinal toots lay
Inferior to the vertebrae levels (31 spinal roots)
What area of vertebrae has 1 spinal root
Coccyx (coccygeal nerve)
What is the membrane surrounding the spinal cord in the spinal column
Meninges
What di ventral abs dorsal root neurones form after formation
Wither a nerve plexus or carry on as individual peripheral nerves
What is a plexus
Network/tangle of nerves
Made of nerves from spinal roots at diff levels
What makes up lumbar plrcus
T12-L5 soinal nerves
What is the result of plexus forming
Nerves then have contributions from other spinal mervesy
Example femoral nerve as an extension from lumbar plexus and myltiple effects
L2,3,4 supplies muscles and skin of the leg
Give an examppe of a nerve from cervical plexus
Phrenic nerve
Give an example of a nerbe from lumbar plexus
Trigeminal
What is a lwrge nevre from sacral plexus
Sciatic
What are dermatomes and myotomes
Area of skin or muscle supplied by each spinal nerve
How is dermatome distributiok by spinal nerves diff to cutaneous distribution by peripheral nerves
Peripheral can contain pather areas than dermatomes
Which spinal nerves innervate most of thigh and leg muscle and skin
Sciatic from sacral plexus and femoral from lumbar plexus
Which motor neurone is from sciatic nerve and what area does it affect
Motor to muscles on the posterior side of the leg (hamstring to bend knee)
Where does sensory afferent supply to sciatic nerve /cns
Lateral side of leg (skin below knee and dorsum and sole of foot)
Which motor neruone from femoral nerve supplies ehrre in leg
Motor to the anterior of the thigh (quadriceps, flexing leg)
Which sensory afferents go to femoral nerve up
From anterior thigh skin and medial leg
How many cranial nerves (from brain) sre therr
12
How are cranial diff to spinal
Have special senses aswell as autonomic and somatic
Also dont have a dermatome or myotome region like sciatic and femoral
What are the speical senses by cranial nerves
Sight, smell, hearing, balance, taste
Which cranial nerve sends afferent signals for smell from nasal mucosa
I (olfactory nerve)
Which nerve is afferent for vision from retina
Optic nerve (II)
What is the somatic motor division of occulomotor nerve III
Controls eye and eyelid movement
What is the autonomic role of the occulomotor nerve III
Controls pupil constriction
Which nevrr has the somatic motor response to move 1 muscle in eye
Trochlear IV
What is the somatic division/afferent from the trigeminal nerve V
Senses touch on face and cornea from dermatomes
What motor effect does trigeminal nerve V have
For muscle movemnet for mastication/chewing
What is nerve VI wnd what is the role
Abducent: motor efferent to other muscle in eye (same as trochlear)
Which nerve senses taste from anterior palate and tongue
VII : facial nerve
Which nerve is affected if you cant control fscial expressions via myotomes
Facial VII
How does fscial VII affect salivation autonomic effect
Increases salivation except from parotid
What nerve is VIII and what does it do
Vestibulococchlear
Allows somatic sense of hearing from cochlear
Allows balance from vestibular region
What is the speical sense of the IV glossy pharyngeal nerve
Taste from posterior tongue
What sensation sends signals down IX
From external ear
Which nerve sends motor for swallowing
IX
What autonomic effect does IX have
Salication from parotid gland
What large autonomic effects does vagus X have
Innervation of gi tract, trachea, bronchi and cardiac smokth muscle from parasymp
What somatic motor effects does vagus have (mainly in swallowing)
On pharynx, larynx and palate
What afferent sensation does vagus x have
From GI, heart, airways
What is nerve XI wnd what does it do
Accesory nerve
Somatic motor effects to soft palate pharynx and 2 muscles in neck
Which nerve have motors to muscles of tongue
XII: hypoglossal nerve
Where di somwtic neurones synapse with cns
In spjnal cord
are spinal nerves both somatic and autonomic
Yes. They are just the roots going from and to spinal cord (dorsal or ventral root) but then after plexus/ near periphery end up as peripheral nerves
What is Bell’s palsy
Palsy of facial nerve which cause unilateral facial paralysis (somatic motor division for facial expression)
Eg caused by hsv
Is vagus part of the parasympathetic innervation eg of bronchi
Yes
