High Yield Must Know (Neuro)

Neuron

doesn’t divide; high metabolic rate; brain uses 20% O2 + glucose

Myelin

Insulator; saltatory conduction; Schwann (PNS) vs oligodendrocyte (CNS)

Astrocytes

Most abundant; BBB; K+ regulation

Microglia

Phagocytic; not from neural origin

Ependymal

Cilia; CSF circulation

ACh

NMJ, parasympathetic

NE

sympathetic

DA

nigrostriatal

GABA

inhibitory

Somatic

1 neuron; ACh

Autonomic

2-neuron; NE/ACh

Sympathetic

Thoracolumbar; fight/flight; NE at effector

Parasympathetic

Craniosacral; rest/digest; ACh at effector

CSF

150 mL circulating; 500 mL/day; choroid plexus; arachnoid granulation absorb

Broca’s

Expressive aphasia; frontal; 44,45

Wernicke’s

Receptive aphasia; temporal; 22

Frontal eye fields

ipsilateral gaze deviation with stroke

Thalamus

Gateway to cortex; relay center

Hypothalamus

ANS integration; oxytocin + ADH

Basal ganglia

Fine tuner; Parkinson (substantia nigra), Huntington (striatum)

Cerebellum

coordination; ipsilateral ataxia, dysmetria, dysarthria

ACA

Leg hemiparesis

MCA

Face + arm; aphasia; gaze toward lesion

PCA

visual deficits; color blindness

CPP

CPP = MAP - ICP; >70 ideal

Midbrain CN

III, IV

Pons CN

V, VI, VII, VIII

Medulla CN

IX, X, XII

Brainstem CN

I, II

Monro-Kelli

Fixed skull; blood 10%, CSF 10%, water 80%

Posterior column

fine touch/vibration/proprioception

Where does the posterior column cross?

Medulla

Spinal lesion in the posterior column

ipsilateral loss

Spinothalamic

pain/temp/crude touch

Where does the spinothalamic tract cross?

Spinal cord

Lesion in the spinothalamic tract

contralateral loss

Corticospinal Lateral

limbs

Where does the lateral corticospinal tract cross?

Medulla

Corticospinal Anterior

Axial

Where does the anterior corticospinal tract cross?

spinal column

Reflex arc

receptor → sensory → integration → motor → effector

Aphasia

inability to use or understand language due to brain lesion

Alexia

Inability to perceive written words

Agraphia

Inability to write words

Dysarthria

Slurred/stuttering speech due to motor weakness or incoordination

Apraxia

Inability to carry out a learned motor task

Ataxia

Impaired performance and coordination of movements

Dysphagia

Difficulty swallowing