FIGURE 1.—_Front View of Heart and Lungs_.—Both organs are stripped
of their envelopes, the pleura and pericardium. The right lung is
drawn aside, so as to uncover the heart and large vessels. The left
lung is deeply dissected, to show the distribution and mode of
ramification of the air-tubes and blood-vessels.
[Illustration: Fig. 1]
_a_, The larynx. _b_, The trachea.—The right lung is somewhat shorter
than the left, and is divided into three lobes, _c_, _d_, _e_; while
the left lung has but two lobes, _f_, _g_. The surface of the lobes
is sub-divided into lobules, by the intersection of great numbers
of depressed lines. _h_, Right auricle of the heart. _i_, Right
ventricle. _j_, Left auricle. _k_, Left ventricle. _l_, The aorta.
_m_, The pulmonary artery. _n_, Left pulmonary veins.—These veins
are four in number, two for each lung; and they return to the heart
the blood which has been conveyed into the lungs by the pulmonary
artery. The division of the pulmonary artery into right and left
branches cannot be seen in this figure, being hidden by the aorta.
_o_, The superior vena cava. _p_, Root of the right innominate
artery, springing from the arch of the aorta. _q_, Root of the left
sub-clavian artery. _r_, Root of the left carotid artery.
[Illustration: Fig. 2]
FIGURE 2.—_Back View of the Heart and Lungs._—_a_, Larynx. _b_,
Trachea. _c_, Right bronchus. _d_, Left bronchus. _e_, Left auricle
of the heart. _f_, Left ventricle. _g_, Right pulmonary veins. _h_,
Left pulmonary veins. _i_, Left pulmonary artery. _j_, Section of
the aorta. _k_, Trunks of the brachio-cephalic veins (those which
belong to the arms and head). _l_, The opening of the inferior vena
cava.—The sub-divisions of the pulmonary arteries and veins, and of
the air-tubes or bronchi, are seen accompanying each other in the
left lung in both figures.