Peripheral Nervous System Of The Thorax

Question 1

Intercostal nerves

Answer 1

Ventral branches of thoracic spinal nerves; have a sensory function and a motor function (intercostal muscles are involved in respiration)

Question 2

Endothoracic fascia

Answer 2

Facia lining the inner surface of the thoracic body wall

Question 3

Intercostal muscle angel

Answer 3

Run at a right angel to each other (internal and external intercostal muscles)

Question 4

Phrenic nerve

Answer 4

Bilateral; origins in the ventral branches of C5,C6,C7, it passes through the thoracic cavity intimately associated with the mediastinum, passes ventral to hilus of lung, remains with the mediastinum as it travels to the diaphragm

Question 5

Diaphragm muscle type

Answer 5

This is a skeletal muscle under voluntary control however under mos conditions it is ultimately controlled by central pathways that can override attempt to prevents contraction

Question 6

Vagus nerves

Answer 6

Run in a slightly complex v pattern along surface of the esophagus just cranial to the diaphragm; splits into dorsal vagal trunk and ventral vagal trunk before passing through the diaphragm
Vagus nerve is cranial nerve 10, it is a peripheral nerve with origins in the head
Vagus nerve is wandering nerve of body seen in cranial cervical thoracic and abdominal regions of the body; supplies parasympathetic motor control to viscera of neck, thorax, and large portion of abdominal viscera. Also carries sensory input (85% vagal fibers are afferent)

Question 7

Intercostal nerves vs vagus nerve

Answer 7

Both peripheral nerves, intercostal nerves are spinal nerves while vagus nerve has origin in the brain

Question 8

Skeletal muscle innervation by vagus nerve

Answer 8

Innervated intrinsic muscles of the larynx and muscles of the pharynx and of the esophagus

Question 9

Recurrent laryngeal nerve

Answer 9

Innervates several laryngeal muscles, this is a branch of the vagus nerve; nerves run closely applied to surface of the trachea

Question 10

Carotid sheath

Answer 10

Connective tissue covering that envelopes the common carotid artery, vagosympathetic trunk, internal jugular vein, and tracheal lymphatic duct (not in lab guide just according to dr hermanson in lab) on each side

Question 11

Vagosympathetic trunk

Answer 11

Appears grossly as one nerve BUT functionally this contains fibers of the vagus nerve and nerve fibers of the sympathetic trunk

Question 12

Vagus nerve component of vagosympathetic trunk

Answer 12

Has parasympathetic motor (efferent) and sensory (afferent) input associated with thoracic and abdominal viscera and somatic motor (efferent) and sensory (afferent) input associated with the larynx

Question 13

Sympathetic trunk portion of vagosympathetic trunk

Answer 13

Carries sympathetic motor (efferent) innervation to the head

Question 14

Vagus nerve, thoracic inlet

Answer 14

Near the thoracic inlet the vagus nerve separates into two constituent components (vagus nerve and sympathetic trunk) (complex intersection of variety of important nerves of thorax and neck)

Question 15

Parasympathetic cardiac nerves

Answer 15

These innervate the heart, vagosympathetic trunk separates into two constituent components (vagus nerve and sympathetic trunk) then vagus nerve goes on to branch into things that innervate the heart

Question 16

Cervicothoracic ganglion location

Answer 16

Medial to dorsal end of 1st intercostal space on lateral side longus colli

Question 17

Sympathetic trunk location thorax

Answer 17

Runs longitudinally along ventral surface of neck of each rib; will see periodic enlargements which are sympathetic trunk ganglia, after branch of cervicothoracic ganglia you will feel thickening which is middle cervical ganglia

Question 18

Communicating branch location

Answer 18

Runs between sympathetic trunk and spinal nerve

Question 19

Cervicothoracic ganglion

Answer 19

Follow thoracic sympathetic trunk cranially will come to large cervicothoracic ganglion lying on surface of deep muscle at the thoracic inlet

Question 20

Ansa subclavian location

Answer 20

Pass from cervicothoracic ganglion and travel ventral to subclavian artery, sympathetic trunk will continue dorsally to subclavian artery and unite with ansa subclavian at middle cervical ganglion

Question 21

Sympathetic cardiac nerves

Answer 21

Should be able to see these coursing to heart from location of middle cervical ganglion

Question 22

Course of sympathetic trunk to the head

Answer 22

Sympathetic efferent fibers going to structures in the head continue through middle cervical ganglion to travel cranially in the neck as sympathetic component of vagosympathetic trunk

Question 23

Course of sympathetic fibers in the neck

Answer 23

Sympathetic efferent pathways innervating smooth muscles and glands in neck region of body wall synapse at cervicothoracic ganglion to travel crainailly in the neck as the vertebral nerve accompanying vertebral artery as it travels through transverse foramina of cervical vertebrea

Question 24

Thoracic duct

Answer 24

Component of lymphatic system that is present in the thorax, brings lymph from structures caudal to the diaphragm to venous side of circulation; passes through aortic hiatus travels on right side of mediastinum between aorta and esophagus and transverse to left side of mediastinum to drain left venous angle

Question 25

Left venous angle

Answer 25

Created by junction of left external jugular and left subclavian veins

Question 26

Tracheobronchial lymphnodes

Answer 26

Located at bicfurcation of the trachea and farther out in the bronchi