Lecture 19: Mediastinum and Respiratory Diaphragm Flashcards
Superior mediastinum structures
Trachea
Inferior mediastinum structures
Lymph nodes Phrenic nerves Pericardiacophrenic artery Heart Aorta Azygos veins
Structures found in both superior and inferior mediastinum
Esophagus Thoracic duct Sympathetic trunks Vagus nerves Thymus
Blood supply to thymus
Anterior mediastinal arteries
Inferior thyroid arteries
Esophagus passes through the diaphragm at what level
T10
Upper third of esophagus innervated by
Recurrent laryngeal nerve
Lower two thirds of esophagus innervated by
Vagus nerve and sympathetic chain
Thoracic aorta begins and ends at what levels and pierces what
Begins at T4 (sternal angle) ends at T12 (diaphragm)
Pierces diaphragm
Azygos vein is union of what veins
Right ascending lumbar and right subcostal veins
Hemiazygos vein is union of what two veins and pierces what
Left ascending lumbar and left subcostal
Pierces diaphragm
Left thoracic duct receives lymph from
Body below diaphragm
Right thoracic duct receives lymph from
Right thoracic cavity, right upper extremity, right head/neck
Vagus nerve root
Parallel to esophagus Passes posterior to root of lung Pierces diaphragm at T10 Becomes gastric nerve Right vagus--> posterior vagus trunk Left vagus--> anterior vagus trunk
Left recurrent laryngeal nerve hooks around
Arc of aorta
Right recurrent laryngeal nerve hooks around
Subclavian artery (therefore it arises in the neck, not the thorax)
Phrenic nerve route
Passes anterior to pulmonary root (only nerve to do so)
Sole motor innervation to diaphragm
Pain via phrenic nerves usually referred to base of neck and tip of shoulder
Accompanied by pericardiacophrenic arteries
Superior fascia of diaphragm
Parietal thoracic fascia
Inferior fascia of diaphragm
Transversalis fascia
The aortic opening to the diaphragm is at what level
T12
Attachments to respiratory diaphragm
Ribs
TV 12
Distal end of sternum
Central tendon
Caval foramen
Inferior vena cava pierces esophagus w/right phrenic nerve at T8
Esophageal hiatus
Esophagus pierces diaphragm with vagus nerve at T10
Aortic hiatus
Aorta pierces diaphragm w/splanchnic nerve at T12
Nerve supply to diaphragm via
Phrenic nerve
Blood supply to superior diaphragm
Pericardiacophrenic artery from internal thoracic
Musculophrenic artery from internal thoracic
Superior phrenic artery from aorta
Blood supply to inferior diaphragm
Inferior phrenic artery from aorta
Crura ligaments of diaphragm
Originate from lumbar vertebrae
Right crura swings left and forms a weak sphinctor around the esophagus
Median arcuate ligament
Around aortic opening
Bridges proximal ends of crura
Medial arcuate ligaments
Frrom deep fascia of psoas major muscle
Lateral arcuate ligaments
From deep fascia of quadratus lomborum muscle
