Heart & Mediastinum

• Transverse thoracic plane (T4/5 IV disc)
• Inferior mediastinum subdivided
• (anterior / middle / posterior)

• aortic arch superior to TTP (T4/5 IV disc)
• tracheal bifurcation transected by TTP
• central tendon lies at xiphisternal junction (T9)

• aortic arch transected by TTP (T4/5 IV disc)
• central tendon may fall to xiphoid process (T9/10 IV disc)

• Thymus
• SVC
• Brachiocephalic vv.
• Aortic arch (BCT / LCC / LScl)
• Vagus / Phrenic nn.
• Cardiac nerve plexus
• L. Recurrent Laryngeal n.
• Trachea
• Esophagus
• Thoracic duct
• Prevertebral mm.

• Remnants of thymus
• Lymph nodes
• Fat & CT

• Pericardium
• Phrenic nn.
• Heart / cardiac plexus
• Roots of great vessels
• Azygos arch
• Main bronchi
• Tracheobronchial lymph nodes

• Thoracic aorta
• Thoracic duct
• Tracheobronchal LN
• Azygos / Hemiazygos vv.
• Esophagus
• Esophageal plexus
• Sympathetic trunks
• Splanchnic nn.
• Vagus nn.

• Pericardiacophrenic aa.
• Pericardiacophrenic nn.
• Phrenic n.

Outer layer = fibrous pericardium

Inner layers = serous pericardium (double layer visceral & parietal)

• Anterior to SVC
• Posterior to Aorta & Pulmonary Trunk

• Continuous from left to right sides of heart
• (oblique pericardial sinus = blind pouch)

• Pericardiacophrenic a.
• (branch of int. thoracic a.)

• Pericardiacophrenic vv.
• (dumps into brachiocephalic vv.)

Phrenic n. (C3-C5)

Somatic only

phrenic n. passes anterior to root of lung

vagus n. passes posterior to root of lung

pericardiacophrenic vessels & phrenic n. superficial to fibrous pericardium

4 annuli fibrosi (fibrous rings) fuse together

• CT skeleton separates musculature of atria from ventricles
• (attachment for valves / myocardial fiber bundles)

• Sympathetics
• - postganglionic fibers (cervical ganglia) -> cardiac plexus
• - adrenergic (norepinephrine; increase HR / force)
• - visceral afferents carry pain

• Parasympathetics
• - vagus n.
• - cholinergic (ACh; decrease HR / force / constrict BV)

junction of SVC & superior crista terminalis

• posteroinferior region of interatrial septum
• (near orifice of coronary sinus)

junction of membranous / muscular parts of interatrial septum

CORONARIES

VENOUS

lymphatics form network adjacent to endo/epicardium

efferent vessels drain along coronary aa. empty into tracheobronchial nodes (lower end of trachea)

• Produces lymphocytes
• Gradually degrades post-puberty (replaced by fat)

• Internal thoracic aa.
• Superior thyroid aa.

• 3/4 = thoracic duct (left)
• 1/4 = r. lymphatic duct

• Formed by subclavian / internal jugular vv.
• L. BCV is 2x longer than R. BCV
• R/L BCV unite to form SVC (1^st costal cartilage)

R. Lymphatic Duct (1/4)

Thoracic Duct (3/4)

• Most anterior branch of aortic arch
• - Posterior to L. BCV
• - Anterior to trachea

Divides into RCC / RScl

• Middle branch of aortic arch
• Ascends post. to left sternoclavicular joint (into neck)

• Most posterior branch of aortic arch
• Ascends lateral to trachea

Lie on anterior surface of anterior scalene mm.

Lies deep to carotid sheath b/w common carotid aa. & internal jugular vv. in neck

• branches from r. vagus n. (anteromedial to RScl a.)
• wraps posteriorly around RScl a.
• ascends in tracheoesophageal groove
• innervates all intrinsic muscles of larynx except cricothyroid m.

• branches from l. vagus n. (anteromedial to aortic arch)
• wraps around aortic arch (posterolateral to ligamentum arteriosum)
• ascends similar to r. recurrent laryngeal

Inferior part of thoracic aorta

• Anterior vagal trunk arises from L. vagus n.
• Posterior vagal trunk arises form R. vagus n.

"hang a right"

• Vagus n. (motor / secretomotor / sensory)
• Sympathetics (vasomotor)

• Superior esophagus
• - recurrent laryngeal nn.
• - sympathetics (middle cervical ganglion)

• Inferior esophagus
• - esophageal plexus
• - parasympathetics (vagus nn.)
• - sympathetics (gray rami upper 4 thoracic ganglion)

Esophageal branches of thoracic aorta

Begins at cisterna chili

Empties on left side at junction of internal jugular / L. subclavian vv.