ANS

Question 0

Anatomy of SNS preganglionic nerves

Answer 0

Arise from T1-S2, cell bodies in lateral horn
Leave through ventral root
White ramus communicans, up or down to correct sympathetic chain level (or beyond for abdominopelvic)

Question 1

All autonomic nerves are…

Answer 1

Visceral efferents
Go to smooth muscle, cardiac muscle, glands
Travel with other nerve fibers in named nerves (ie radial)

Question 2

Sympathetic chain anatomy

Answer 2

Runs from cervical ganglia (head) to coccyx
Receives input from T1-S2 (white ramus)
Output at every level (grey ramus)
Most synapses in ganglia (lateral and slightly anterior to cord)

Question 3

Route of SNS to limbs or body wall

Answer 3

Enter from T1-S2 through white ramus
Travel up or down to correct level (based on dermatomes)
Synapse in sympathetic chain
Leave through grey ramus
Travel with spinal nerves (ventral or dorsal ramus -> named nerves)

Question 4

Route of SNS nerves to head/neck

Answer 4

Enter from T1-S2, white ramus
Travel superior to cervical ganglia (inferior, middle, superior)
Synapse in ganglia, travel through internal and external carotid nerves

Question 5

Route of SNS nerves to thorax

Answer 5

Arise from T1-T4, through white ramus
Stay at same level or travel up to cervical ganglia
Synapse in chain
Travel through cardiac nerves to cardiac plexus

Question 6

Route of SNS nerves to abdomen/pelvis

Answer 6

Arive from T5-S2
Pass through white ramus, through chain without synapse!
Greater splanchnic nerve (T5-T9), lesser (T10,11), least (T12), lumbar (S1,2)
Synapse in prevertebral ganglia of aorta or pelvis

Question 7

Functions of SNS

Answer 7

Fight or flight
increasing the heart rate
dilating the pupils
increasing sweating, 
dilating the bronchial tree
diverting blood to skeletal muscles

Question 8

Rami communicantes

Answer 8

White ramus to enter sympathetic chain (only T1-S2)

Grey ramus to leave sympathetic chain (all levels, only postganglionic nerves to limbs and body wall)

Question 9

Anatomy of PNS preganglionic nerves

Answer 9

Craniosacral
Cranial nerves 3, 7, 9, 10 (nuclei in CNS)
- most travel to glands of head and neck
- 10 travels to thoracic, stomach and intestine
Sacral 2-4 (lateral horn) - “pelvic splanchnics”
- urinary and genitalia

Question 10

Anatomy of PNS

Answer 10

From cranium and sacral
Travel in cranial or “pelvic splanchnic” nerves to target organ
Synapse in organ - ex myenteric plexus within intestines

Question 11

Functions of PNS

Answer 11

Rest and digest
Increased peristalsis and digestive enzymes
Decreased heart rate
Pupil constriction