Middle mediastinum Flashcards
what is the anterior border of the middle mediastinum?
Anterior margin of the pericardium
what is the posterior border of the middle mediastinum?
Posterior border of the pericardium
what is the lateral border of the middle mediastinum?
Mediastinal pleura of the lungs
what is the superior border of the middle mediastinum?
Imaginary line extending between the sternal angle (the angle formed by the junction of the sternal body and manubrium) and the T4 vertebrae
what is the inferior border of the middle mediastinum?
Superior surface of the diaphragm
what does the middle mediastinum contain?
It contains several important organs, vessels, nerves and lymphatic structures
which mediastinum is the largest subdivision of the inferior mediastinum?
The middle mediastinum
what are the organs contained within the middle mediastinum?
the heart, and its protective sheath, the pericardium.
The tracheal bifurcation and the left and right main bronchi
what is the middle mediastinum also associated with?
the origins of the great vessels that run to and from the heart
which are the great vessels that run to and from the heart?
ascending aorta
pulmonary trunk
superior vena cava
what is the ascending aorta? where does it arise from?
the first part of the aorta, which arises from the aortic orifice
what is the course of travel of the ascending aorta? what does it become?
It moves upwards, exiting the fibrous pericardium and entering the superior mediastinum – where it then becomes the aortic arch
what does the ascending aorta give rise to? what are they?
gives rise to two branches; the left and right coronary arteries
what does the pulmonary trunk give rise to?
gives rise to the left and right pulmonary arteries
how is the pulmonary trunk like? why?
The trunk itself is relatively short and wide, allowing a large volume of blood to pass through it
what is the function of the superior vena cava?
returns deoxygenated blood from the upper half of the body
what is the superior vena cava formed by?
formed by the right and left brachiocephalic veins
which nerves are located within the middle mediastinum?
The cardiac plexus and the phrenic nerves
what is the cardiac plexus? what does it contain?
a network of nerves located at the base of the heart, containing sympathetic and parasympathetic fibres
where are the sympathetic nerves of the cardiac plexus derived from?
from the T1-T4 segments of the spinal cord
what is the parasympathetic nerves of the cardiac plexus supplied by?
parasympathetic innervation is supplied by the vagus nerve
what can the cardiac plexus be subdivided into?
superficial and deep components
what are the left and right phrenic nerves?
mixed nerves that provides motor innervation to the diaphragm
where do the left and right phrenic nerves arise from and where do they travel to?
They arise in the neck, and descend through the middle mediastinum to reach the diaphragm
