Aorta and more mediastinum

carotid arteries

bring blood up to the brain and face

subclavian arteries

pass under the clavicle and bring blood toward the arm

descending aorta

provides blood flow to thorax as thoracic aorta and abdomen as abdominal aorta

thoracic aorta

intercostal and esophageal branches of aorta

abdominal aorta

supplies GI organs, kidneys, pelvis, and legs

phrenic nerve

anterior rami of C3-C5

• motor and sensory innervation of the diaphragm

• sensory innervation of the fibrous and parietal pericardium

vagus nerve

cranial nerve X

• parasympathetic autonomic innervation to heart, bronchi, and esophagus

• contributes to cardiac and esophageal plexuses with sympathetic nerves

azygos system

collateral pathway between IVC and SVC, becomes life-saving when either vena cava is obstructed

thoracic duct

courses anterior to vertebrae with azygos veins

• drains lymph from abdomen and intercostal lymph nodes

• returns lymph into circulation at the junction between the internal jugular vein and the subclavian vein (venous angle)

sympathetic chain

cell bodies of postganglionic sympathetic neurons located in paravertebral ganglia

• lie against head of rib

• continue inferiorly into abdomen

• send branches to cardiac and esophageal plexuses

• send branches to form splanchnic nerves that pierce the diaphragm to innervate abdominal structures

referred pain

when the brain interprets visceral pain as the distribution of somatic sensation

• ie) sensing umbilical pain when the appendix is inflamed since these sensory axons synapse at T10 spinal level

referred pain “pathway”

peripheral axons (visceral sensory neurons) → sympathetic ganglia white ramus → visceral sensory neuron cell bodies (localized to dorsal root ganglion) → visceral sensory neurons synapse in dorsal horn with somatic sensory neurons → brain interprets visceral pain as distribution of somatic sensation

esophagus

muscular tube that conveys food bolus from pharynx to the stomach

• anterior to vertebral column

• posterior to trachea

• exits thorax through esophageal hiatus

esophageal plexus

receives branches from left and right vagus nerves and sympathetic nerves

anterior and posterior vagal trunks

exit the thorax with the esophagus