ANS

Question 1

where do presynaptic LMN originate of the sympathetic division

Answer 1

lateral/inermediate horn of the thoracolumbar spinal cord and leave the cord through the rami communicans

Question 2

spine

sympathetic division

Answer 2

• ganglia are located in the paravertebral sympathetic trunks, or the median, prevertebral ganglia in the thoracic and abdominal cavities
• postsynaptic neurons travel in spinal nerves to their target

Question 3

head

sympathetic division

Answer 3

synapse occurs in the cranial cervical ganglia

Question 4

where do presynaptic LMN originate of the parasympathetic division

Answer 4

craniosacral CNS

Question 5

where do postsynaptic nerves originate of the parasympathetic division

Answer 5

in ganglia close to the innervated organ

Question 6

what parasympathetic cranial nerves innervate the head

Answer 6

CN - III, VII, IX, X

Question 7

what does cranial nerve X innervate

Answer 7

viscera of the thorax and abdomen (travels in vagosympathetic trunk)

Question 8

what does the sacral parasympathetic nerves innervate

Answer 8

pelvic viscera

Question 9

parasympathetic innervation of head: eye - iris and lens and PLR and accomodation (origin, ganglion, and pathway)

Answer 9

origin

• PS nucleus of CN III

ganglion

• ciliary ganglion

pathway

• travels with CN III

Question 10

sympathetic innervation of the eye

Answer 10

• fibers travel from the midbrain in the tectotegmentospinal tract to synapse on presynaptic LMNs in the cranial thoracic cord (C8-T5)
• LMNs travel through the vagosympathetic trunk to synapse in the cranial cervical ganglion
• they then travel with the ophthalmic branch of CNV to the eye
• sympathetic innervation suuplies smooth muscle of the orbit, the upper eyelid and the iridal dilator muscle

Question 11

what is horner syndrome

Answer 11

damage to sympathetic innervation of the eye results in:

• miosis
• ptosis
• enophthalmosis

Question 12

other signs of horner syndrome damage may include:

Answer 12

• peripheral vasodilation
• sweating in horses

Question 13

parasympathetic innervation of the eye

Answer 13

• presynaptic neuron originates in parasympathetic nucleus of III and travels in CN III
• fibers synapse in the ciliary ganglion
• postganglionic ciliary nerves innervate the smooth muscle constrictor of the pupil

Question 14

abnormalities of the PLR may be due to either:

Answer 14

afferent (CNII) or efferent (CNIII) dysfunction

Question 15

visceral afferents of urination

Answer 15

• receptors in the bladder wall and neck are sensitive to stretch or pressure
• afferents from the urinary bladder and sphincter travel in the pelvic nerve

Question 16

somatic innervation of urination

Answer 16

somatic innervation from the pudendal nerve causes contraction of the external urethral sphincter and urinary retention

Question 17

sympathetic innervation of urination

Answer 17

• sympathetic innervation causes relaxation of the detrusor muscle and contraction of smooth muscle in the bladder neck
• fibers arise from L1-L5 synapse in the caudal mesenteric ganglion and travel in the hypogastric nerve

Question 18

parasympathetic innervation of urination

Answer 18

• causes contraction of the detrusor muscle of the bladder and passive opening of the internal urethral sphincter
• fibers arise from S1-S3 and travel in the pelvic nerve

Question 19

damage to UMN in spinal cord, cerebrum and cerebellum

urination

Answer 19

• urinary and fecal incontinence
• bladder that is full and difficult to express

Question 20

damage to LMN in sacral cord, pelvic or pudendal nerves

Answer 20

• urinary and fecal incontinence
• bladder is distended, flaccid and easy to express