Thorax 4 Flashcards
Mediastinum borders
Superior - Superior thoracic aperture Inferior - diaphragm Anterior - sternum Posterior - 12 thoracic vertebrae Lateral - lungs within their flora
Sternal angle - divide superior and inferior mediastinum
Sternal angle anatomy
Second CC
4th thoracic vertebra posteriorly
Through arch of aorta - separate arch of aorta in superior and ascending aorta and descending thoracic aorta in inferior
Bifurcation of trachea
Superior mediastinum borders
Anterior - manubrium of sternum
Posterior - T1-4
Superior - superior thoracic aperture
Inferior - sternal angle
Superior mediastinum content
Thymus gland
Arch of aorta - brachiocephalic trunk, left common carotid, left subclavian
Superior vena cava - left (longer) and right brachiocephalic vein
Thoracic duct and right lymphatic duct on right.
Azygous vein
Trachea bifurcate at sternal angle.
Oesophagus - pierces diaphragm at oesophageal hiatus.
Vagus nerves and phrenic nerves
Superficial cardiac plexus
Right and left internal thoracic arteries
Vagus nerves
Right crossing over right subclavian artery where the right recurrent laryngeal nerve branches off and travels back up to the larynx
Left crossing over arch of aorta where the left recurrent laryngeal nerve branches off and travels back up to the larynx
Superior (superficial) cardiac plexus
On the arch of the aorta which is formed by branches from the left and right vagus nerves (parasympathetic), and branches from T1-T4 portions of the sympathetic trunk
Right lymphatic duct
right upper limb, right side of thorax and part of head
Anterior mediastinum content
Inferior portion of the thymus gland (a fatty, connective tissue, residual structure post puberty)
Connective tissue including the sternopericardial ligaments which anchor the anterior surface of the pericardium to to the back of the sternum
Lymph nodes including the prepericardial and parasternal lymph node groups (which drain a small portion of lymph from the breast)
Branches of the internal thoracic artery such as the perforating
Middle mediastinum content
Pericardium containing the heart
Roots of the great vessels (within the pericardium) including the ascending aorta, pulmonary trunk, SVC/IVC and pulmonary veins
Bifurcation of the trachea and therefore the right and left main (or primary) bronchi
Left and right phrenic nerves
Pericardiacophrenic artery and vein (from internal thoracic artery and vein)
Deep cardiac plexus formed by cardiac branches of left and right vagus nerves (parasympathetic) and cardiac branches from the sympathetic trunk (T1-T4)
Tracheobronchial lymph nodes lying on main bronchus and inferior trachea
Posterior mediastinum
oesophagus thoracic aorta azygous system of veins thoracic duct sympathetic trunks
Thoracic aorta
T5-T12
give off:
posterior intercostal arteries in costal groove
mediastinal branch for lymph nodes of mediastinum
pericardial branch for posterior pericardium of heart
oesophageal branch for oesophagus through the thorax
pair of superior phrenic arteries for superior aspect of diaphragm
Oesophagus
Supplied by branches of vagus nerves on left and right which form oesophageal plexus - converge at the bottom to form anterior and posterior vagal trunk
Azygous veins
Drain into superior vena cava at sternal angle
Venous shunting - crossing over of veins from left to right to reach azygous vein
Formed from right ascending lumbar vein and right subcostal vein
Crosses over hilum of right lung and leave indentation
Posterior intercostal vein drain into azygous though supreme intercostal vein drain into first intercostal space into right brachiocephalic vein
Hemiazygous vein drain intercostal spaces from ninth intercostal space down to subcostal region - cross over thoracic duct to drain into azygous vein
Accessory hemiazygous vein drain posterior intercostal veins 4 to 8 to azygous vein
Upper left intercostal spaces use superior intercostal vein into left brachiocephalic vein
Thoracic duct
Largest lymphatic duct in body
Drain all lymphatic fluid except for upper right quadrant
Begins as cisterna chyli - expansion or dilation of lymphatic tissue and formed from intestinal ducts and left and right lumbar ducts of abdo and lower limbs
Over vertebral bodies of thoracic vertebrae, move over to left and drain into junction between left internal jugular vein and left subclavian vein
Sympathetic trunk
Sympathetic ganglia and interganglionic branches
Sympathetic outflow of entire body
Arises between T1 and L2
Sympathetic efference from T1 to L2 travel up chain into cervical ganglion which supplies head and neck with sympathetic innervation or down chain to sacrum and coccygeal regions to provide pelvis and lower limbs with sympathetic innervation
Splanchnic nerves - Greater, less and least - Down through diaphragm to supply viscera of abdo with symp inn
Cardiac branch - T1-4 - supply heart with symp inn
