Thoracic Cavity Anatomy 2

Question 1

Which neuron has a pseudounipolar

Answer 1

sensory neuron! with somas in dorsal root ganglion

Question 2

Sensory neuron overview

Answer 2

transmit impulses to the CNS.

• somatic sensory: impulses from skin, bones, muscles
• visceral sensory: impulses from visceral organs.

Question 3

Motor neuron overview

Answer 3

transmit impulses away form the CNS.

• Somatic motor: innervate skeletal muscles.
• visceral motor(autonomic motor): innervate cardiac m, smooth m, and glands.

Question 4

Interneurons…

Answer 4

conduct impulses from sensory to motor neurons.

Question 5

for sympathetic outflow, motor preganglionic neurons pass through___ ___ _____ and postganglionic neurons pass through___ ___ ____ (both in the sympathetic chain ganglion)

Answer 5

white rami communicantes
gray rami communicantes

Question 6

length of pre/post ganglionic neurons in parasympathetic system (and where does it synapse)

Answer 6

long = pre
short= post

synapse at target tissue (Ach)

Question 7

length of pre/post ganglionic neurons in the sympathetic system (and where does it synapse)

Answer 7

short = pre
long= post

synapse in ganglion or sympathetic chain (Ach or epinephrine)

Question 8

do somatic motor neurons have pre/post ganglionic neurons?

Answer 8

no lol

Question 9

What does the phrenic nerve innervate?

Answer 9

motor n to DIAPHRAGM

Question 10

Where does the phrenic nerve run in the thoracic cavity?

Answer 10

start: c5-c7
end: cardiac base of diaphragm

R phrenic runs next to caudal vena cava
L phrenic travels within L mediastinal pleura

Question 11

Intercostal nerves run…

Answer 11

caudal to the rib (with the VAN)

Question 12

Input neurons = and output neurons =

Answer 12

afferent
efferent

Question 13

Where are sympathetic neurons located in the body

Answer 13

thoracic/lumbar region of the spinal cord

Question 14

Where are the parasympathetic neurons located on the body?

Answer 14

brain/brainstem (little in sacrum)

Question 15

What autonomic system goes to the body wall (including sweat glands and smooth muscles)

Answer 15

sympathetic!

Question 16

neural crest becomes the….

Answer 16

ganglion

Question 17

Motor components of the vagus n. in the
thorax include:

Answer 17

• →heart
• →bronchial smooth musculature
• →the wall of the esophagus

Question 18

sensory components of the vagus n. in the thorax include:

Answer 18

• Visceral afferent fibers from the visceral organs

Question 19

Vagus nerve and how it branches

Answer 19

Each Rt and Lt divide into dorsal & ventral branches (dorsal and ventral to the esophagus)
• The dorsal branches of both sides join→dorsal vagal trunk
• The “ventral” branches of both sides joint→ventral vagal trunk
• The dorsal and ventral vagal trunks run with the esophagus through the esophageal hiatus.

Question 20

relationship of dorsal vagal trunk to caudal mediastinal lymph nodes in ruminants

Answer 20

If the lymph nodes enlarged→press on the esophagus & the dorsal vagal nerve trunk→ bloat (no eructation), and vagal indigestion.

Question 21

left recurrent laryngeal placement

Answer 21

curves around the aorta
• re-ascends the neck along and supplies the esophagus and trachea.

• At the level of the larynx it terminates as caudal laryngeal nerve

(to all intrinsic laryngeal muscles, except the cricothyroideus which is supplied by the cranial Laryngeal nerve)

Question 22

Which recurrent laryngeal nerve (right or left) is more commonly damaged and WHY?

Answer 22

LEFT

close to aorta (pulsing can damage it)
close to tracheobronchial lymph nodes (if enlarged-> nerve damage)

Question 23

Damage to the recurrent laryngeal n in the horse causes

Answer 23

laryngeal hemiplegia, which results in respiratory noise (roaring)

Question 24

What are autonomic plexuses

Answer 24

• are collections of sympathetic postganglionic axons and parasympathetic preganglionic axons, as well as some visceral sensory axons.

• These sympathetic and parasympathetic axons are close to one another, but they do not interact or synapse with each another.

• Although these plexuses look like disorganized masses of axons, they provide a complex innervation pattern to their target organs