Thoracic Cavity Anatomy 2 Flashcards
Which neuron has a pseudounipolar
sensory neuron! with somas in dorsal root ganglion
Sensory neuron overview
transmit impulses to the CNS.
• somatic sensory: impulses from skin, bones, muscles
• visceral sensory: impulses from visceral organs.
Motor neuron overview
transmit impulses away form the CNS.
• Somatic motor: innervate skeletal muscles.
• visceral motor(autonomic motor): innervate cardiac m, smooth m, and glands.
Interneurons…
conduct impulses from sensory to motor neurons.
for sympathetic outflow, motor preganglionic neurons pass through___ ___ _____ and postganglionic neurons pass through___ ___ ____ (both in the sympathetic chain ganglion)
white rami communicantes
gray rami communicantes
length of pre/post ganglionic neurons in parasympathetic system (and where does it synapse)
long = pre
short= post
synapse at target tissue (Ach)
length of pre/post ganglionic neurons in the sympathetic system (and where does it synapse)
short = pre
long= post
synapse in ganglion or sympathetic chain (Ach or epinephrine)
do somatic motor neurons have pre/post ganglionic neurons?
no lol
What does the phrenic nerve innervate?
motor n to DIAPHRAGM
Where does the phrenic nerve run in the thoracic cavity?
start: c5-c7
end: cardiac base of diaphragm
R phrenic runs next to caudal vena cava
L phrenic travels within L mediastinal pleura
Intercostal nerves run…
caudal to the rib (with the VAN)
Input neurons = and output neurons =
afferent
efferent
Where are sympathetic neurons located in the body
thoracic/lumbar region of the spinal cord
Where are the parasympathetic neurons located on the body?
brain/brainstem (little in sacrum)
What autonomic system goes to the body wall (including sweat glands and smooth muscles)
sympathetic!
neural crest becomes the….
ganglion
Motor components of the vagus n. in the
thorax include:
• →heart
• →bronchial smooth musculature
• →the wall of the esophagus
sensory components of the vagus n. in the thorax include:
• Visceral afferent fibers from the visceral organs
Vagus nerve and how it branches
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.
relationship of dorsal vagal trunk to caudal mediastinal lymph nodes in ruminants
If the lymph nodes enlarged→press on the esophagus & the dorsal vagal nerve trunk→ bloat (no eructation), and vagal indigestion.
left recurrent laryngeal placement
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)
Which recurrent laryngeal nerve (right or left) is more commonly damaged and WHY?
LEFT
close to aorta (pulsing can damage it)
close to tracheobronchial lymph nodes (if enlarged-> nerve damage)
Damage to the recurrent laryngeal n in the horse causes
laryngeal hemiplegia, which results in respiratory noise (roaring)
What are autonomic plexuses
• 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
