Neuro: CN And Pupillary Control Circuitry Flashcards
Pupillary light reflex nerves tested
In on 2 out on 3
Pupillary light reflex tests what level of the brain?
Midbrain
Voluntary eye movements access which CN?
3, 4, 6
What voluntary eye movements test which level of the brain?
Midbrain, pons
Which CN are tested in reflex eye movements?
In on 8, out on 6 and 3
Reflex eye movements test which level of the brain?
Midbrain, pons, and a little bit of medulla
Sensation in the face tests which CN?
5
Sensation in the face test which level of the brain?
Pons and medulla
Which CN does jaw movement test?
CN 5
Jaw movements test which level of the brainstem?
Pons and medulla
Facial expression test which cranial nerve?
7
Which level of th brain does facial expression test?
Pons
Corneal blink reflex tests which CN?
In on 5, out on 7
Corneal blink reflex tests which level of the brain?
Medulla and pons
Hearing reflex tests which CN?
8
Which level of the brain does hearing test?
Medulla (CN 8 nuclei located there)
Which CN does the gag reflex tests?
In on 9, out on 10
Which level of the brain does the Gag reflex tests?
Medulla
What CN do speech tests asses?
10 or 12
Which level of the brain are speech tests assessing?
Medulla
The shoulder shrug test is assessing which CN?
11
Which level of the brain does the shrug test asses?
Medulla
Tongue protrusion is checking the function of which CN?
12
Which level of the brain is the tongue protrusion test assessing?
Medulla
4 trigeminal nuclei:
-trigeminal motor
-mesencepahlic
-principal/main/chief
-spinal trigeminal
Left visual fields are processed by…
Right optic tracts, right thalamus, and right cortex
Right visual fields are processed by…
Left optic tracts, left thalamus, and left cortex
There IS a direct and consensual light response seen in eye. When the other eye is tested there is NO direct or consensual response in that eye. why?
Motor function is still intact so the muscle can still contract when light is directly shown. sensory is impaired which is preventing either eye from responding when the light is shown in the opposite eye
Possible lesion sites when there is impaired pupil dilation:
-lateral hypothalamus
-lateral brainstem
-lateral spinal cord
-sympathetic chain
-carotid plexus
-cavernous sinus
-orbit and eye
What is it called when pupils are abnormally asymmetrical in size?
Anisocoria
Benign essential anisocoria
Mild and constant unequal pupil sizes in all lighting conditions
Afferent pupillary defect:
Impaired sensory arc of reflex due to a variety of reasons
Horner’s syndrome:
Dilation lag going from light to dark, ptosis, one side sweating
Acute Adie’s pupil
Impaired constriction response to light and accommodation
Chronic Adie’s pupil:
Impaired light reflex but accommodative constriction is intact
