Autonomic Nervous System

Question 1

Three key cortical areas for autonomic regulation

Answer 1

Insula (primary visceromotor and sensory cortex)
Amygdala (autonomic output related to emotional responses)
Anterior Cingulate (autonomic responses related to goal directed behavior)

Question 2

Subcortical areas of autonomic regulation

Answer 2

Hypothalamus and pre-optic area integrate autonomic and endocrine responses

Question 3

Brainstem regions of autonomic control

Answer 3

Nucleus of the solitary tract (medullary reflexes)
Ventrolateral medulla (nucleus ambiguus and dorsal motor nucleus of the vagus)

Question 4

Location of preganglionic neuron cell bodies and course of system

Answer 4

Intermediolateral nucleus from T1-L3. Axons exit via ventral roots to synapses in paravertebral ganglia then join peripheral spinal nerves.

Question 5

Main parasympathetic outflow

Answer 5

Vagus, sacral parasympathetics innervate pelvic organs

Question 6

Autonomic control of pupil

Answer 6

Parasympathetic constricts

Sympathetic dilates

Question 7

Horner’s Syndrome

Answer 7

Ptosis, miosis, anhidrosis. Sympathetic blowout

Question 8

CNIII Palsy

Answer 8

Eye deviated down and out, ptosis (due to the weakness of levator palpebrae) Dilated pupil

Question 9

Afferent and efferent limbs of autonomic control of blood pressure

Answer 9

Afferent: Baroreceptors in heart and major blood vessels sense pressure, chemoreceptors sensing Co2 levels, conveyed via IX and X to NST.

Efferent: Parasympathetic and sympathetics to the heart, and sympathetics to the peripheral arterioles.

Question 10

Causes of orthostatic hypertension

Answer 10

Autonomic neuropathy, parkinson’s

Question 11

Body temperature and regulation

Answer 11

In the preoptic area and anterior hypothalamus. Sweat is major means of heat dissipation.

Question 12

Segmental organization of sweating

Answer 12

Sweating is organized in segments, controlled by sympathetic fibers, can see deficits.

Question 13

Outflow incontinence

Answer 13

Due to flaccid (atonic) bladder. Because neurologic failure of detrusor Fails to empty, fills to capacity. Then overflows. Caused by conus or cauda equina syndrome.

Question 14

Detrusor hyperreflexia

Answer 14

Automatic or spastic bladder. Contracts while matient is attempting to inhibit micturition. Symptoms: frequency, urgency, nocturia

Question 15

Common causes of syncope

Answer 15

Cardiac, Neurodegenerative (parkinsons, MSA, autonomic neuropathy), Vasovagal

Question 16

Late vs early orthostatic hypertension

Answer 16

Early, there’s usually compensatory tachycardia, but late there isn’t

Question 17

Vasovagal Syncope

Answer 17

HR and BP down.

Question 18

Postural Orthostatic Tachycardia syndrome

Answer 18

Dizziness/fainting upon standing with an increase in HR, but without a change in BP

Question 19

Parkinson’s Plus

Answer 19

Tremor, bradykinesia, rigidity, but with overt autonomic dysfunction.

Question 20

Chronic causes of autonomic neuropathy

Answer 20

DM, Amyloid, hereditary, Sjogrens (connective tissue disease)

Question 21

Acute causes of autonomic neuropathy

Answer 21

Toxic (chemo), Guillain Barre, Immune mediated, Paraneoplastic (anti-hu in small cell LC)