Neuro Flashcards
Which cranial nerve is most prominent in eye movement? What muscles does it control?
CN3 - oculomotor
Superior rectus - supraduction
Medial rectus - adduction
Inferior rectus - infraduction
Inferior oblique - extorsion, elevation
Which cranial nerve is involved in intorsion/depression of the eye?
CN4 - trochlear
Superior oblique
Which cranial nerve is involved in the abduction of the eye?
CN 6 - abducens
Lateral rectus
What cranial nerve is part of the CNS?
CN 2 - optic
Which cranial nerves contribute to the parasympathetic nervous system?
CN 3 - oculomotor
CN 7 - facial
CN 9 - glossopharyngeal
CN 10 - vagus
Injury to what cranial nerve causes Bell’s Palsy?
CN 7 - facial
Tic douloureax results from what CN?
CN 5 - trigeminal
(trigeminal neuralgia)
What is the volume of CSF?
~150 mL
What is the specific gravity of CSF?
1.002 - 1.009
Where is CSF produced and at what rate/hr?
Ependymal cells of the choiroid plexus (in all four ventricles) at a rate of 30 mL/hr
What is CSF pressure?
5-15 mmHg
How does a decrease in CSF pH affect CBF?
CBF is increased (increased PaCO2 -> decreased cerebrovascular resistance)
At what PaCO2 does maximal vasodilation occur?
80-100 mmHg
At what PaCO2 does maximal vasoconstriction occur?
~25 mmHg
What is global CBF at a PaCO2 or 40 mmHg?
50 mL/100 g brain tissue/min
What is the change in CBF for a 1 mmHg increase in PaCO2?
increased by 1-2 mL/100 g brain tissue/min
Where in the brain is the blood brain barrier NOT located?
chemoreceptor trigger zone
hypothalamus
pineal gland
posterior pituitary gland
choroid plexus
What are SS of intracranial hypertension?
headache
N/V
papilledema (swelling of optic nerve)
pupil dilation and non-reactivity to light
focal neurologic deficit
seizures
coma
What is Cushing’s triad indicative of? What are the three components?
Intracranial hypertension
1. hypertension (increased ICP -> reduced CPP -> increased BP to preserve cerebral perfusion)
2. bradycardia (baroreceptor reflex activated by hypertension)
3. irregular respirations (compression of the medulla)
What is the most common site of transtentorial herniation?
The temporal uncus
oculomotor nerve crosses near here, fixed and dilated pupil results due to ischemia
What drugs reduce CSF production?
furosemide
acetazolamide
When should steroids not be used in a brain case?
TBI
functional pituitary adenoma
What are 4 ways to reduce intracranial hypertension?
Reduce cerebral spinal fluid
Reduce cerebral blood volume
Reduce cerebral edema
Reduce cerebral mass
Discuss blood supply and skull entry to the anterior circulation:
internal carotids enter the skull through the foramen lacerum
aorta -> common carotid -> internal carotid -> Circle of Willis -> cerebral hemispheres