Having removed the blood from the heart it is next weighed. The average normal weight of the human heart is about twelve ounces in the male, and a little less in the female: its size roughly corresponding to the closed hand of the individual. Normally, the thickness of the walls of the left ventricle about its middle is five-eighths to two-thirds of an inch, and of the right ventricle one-eighth to one-quarter of an inch.
Note the condition of the aorta above the heart, whether it is dilated, atheromatous, or shows calcareous deposits. Examine the coronary arteries by opening them with a blunt-pointed scissors. Disease of these vessels with thrombosis is one of the causes of sudden death which is often overlooked.
The Lungs.—The lungs are removed by lifting them from the pleural cavity and cutting through the vessels and bronchi at their base. If a lung is very adherent it is sometimes better to remove the organ with the costal pleura attached so as not to tear the lung substance. Examine the external surface of the lung as to its shape, color, and consistency. Next open the large bronchi with a blunt-pointed scissors, and prolong the incision into the pulmonary substance along the minute bronchi. Observe the contents of the bronchial tubes, the appearance of the mucous membrane, and their relative thickness. Remember that it is very difficult to tell the condition in which the mucous membrane was during life on account of the early post-mortem changes which affect it, and also because the contents of the stomach may have been forced after death up the œsophagus and down the bronchi, giving the tubes a peculiar reddish and gangrenous appearance.
Having examined the bronchi, the lung is turned over and its base grasped firmly in the left hand. An incision is made from apex to base, which will expose at a single cut the greatest extent of pulmonary surface. Note the color of the lung substance, and whether the alveoli contain blood, serum, or inflammatory products. Blood and serum can easily be forced from the lungs by pressure between the fingers, while inflammatory exudations cannot. Examine carefully for the presence of miliary tubercles.
If a question should arise whether a portion of a lung is consolidated, this part can be removed, placed in water, and if the air cells are consolidated the portion will sink; if there is only congestion it will float. By squeezing the lung between the fingers an inflammation of the smaller bronchi (bronchitis) can be recognized by the purulent fluid which will exude at different points. It should be remembered that in normal condition the lower lobes and posterior aspect of the lungs will apparently be very much congested as a result of gravity.
Neck, Larynx, and Œsophagus.—Throw the head well backward, and place a block beneath the neck. Make an incision from the chin to the upper part of the sternum. Dissect the soft parts away on each side from the larynx and thyroid body, then cut along the internal surface of the lower jaw from the symphisis to its angle. Through this incision introduce the fingers into the mouth, and grasp and draw down the tongue. By dividing the posterior wall of the pharynx and pulling downward these parts, the trachea and œsophagus can readily be removed together, a ligature having been first placed around the lower portion of the œsophagus. Open now the pharynx and œsophagus along their posterior border. Examine the mucous membrane carefully for the evidences of inflammation, caustic poison, tumors, foreign bodies, or strictures. With an enterotome open the larynx and trachea along their posterior wall. Observe if there is any evidence of œdema of the glottis, and note the condition of the mucous membrane. Remember that redness of the larynx is very commonly the result of post-mortem changes and is also seen in bodies which have been kept cold. Dissect off and examine the thyroid gland.
Abdomen.
Having completed the examination of the organs of the thorax, we next proceed to examine those contained in the abdominal cavity. We first raise and,dissect off the omentum, noting if it is abnormally adherent.
The first organs to be removed are: