The nervous system

Question 1

what are cranial nerves 2 - 7

Answer 1

2 - optic nerve
3 - oculomotor
4 - trochlear
5 - trigeminal
6 - abducens
7 - facial motor

Question 2

afferent or efferent

Answer 2

afferent is sensory - impulses towards the brain from peripheral towards CNS

efferent is motor - CNS to peripheral organs to cause an effect

Question 3

optic nerve

Answer 3

sensory nerve afferent
(carries info from eye to CNS)

axon bundle exits the eye as the optic nerve, it runs nasal and posterior on the orbit towards the optic foramen and then passes through the optic canal into the sphenoid bone

Question 4

oculomotor nerve

Answer 4

controls inferior, superior, medial rectus and inferior oblique muscles and also levator muscle

somatic. motor automatic

movement of eyeballs and upper eyelids. adjusts lens for near vision. constriction of pupil

Question 5

oculomotor nerve route

Answer 5

1. nucleus
2. passes posterior cerebral, superior cerebellar and posterior communicating artery
3. into cavernous sinus
4. divides into superior and inferior branches
5. edinger westphal nucleus. parasympathetic supply to iris sphincter and ciliary muscle.
6. travels with the inferior branch then inferior oblique and into ciliary ganglion.

Question 6

trochlear nucleus

Answer 6

trochlear neurons travel backwards instead of forwards.
run on either side of aqueduct of Silvius
run parallel to ocular motor nerve

Question 7

abducens nerve

Answer 7

most lateral nerve in orbit so is most commonly associated with trauma to side of the head

lateral rectus muscle

Question 8

trigeminal nerve

Answer 8

largest and complex
mixture of motor and sensory neurons 3 sensory and 1 motor

nerve splits into three
first division - ophthalmic division
second division - maxillary division
third division - mandibular division