Blood Artery
The artery may be said to contain pure, and the veins impure, blood. This is true of the systemic, but not of the pulmonary, vessels, since it has been seen that the impure blood is conveyed from the heart to the lungs by the pulmonary arteries, and the pure blood returned from the lungs to the heart by the pulmonary veins. Arteries, therefore; must be defined as vessels which convey blood from the heart, and veins as vessel which return blood to the heart.
The heart and lungs are contained within the cavity of the thorax, the walls of which afford them protection. The heart lies between the two lungs, and is there enclosed within a membrane, the pleura. The skeleton of the thorax and the shape and boundaries of the cavity will be described in the section on General Anatomy.
The Cavity of the Thorax
The capacity of the cavity its apparent size does not correspond with its apparent size externally, because (1) the space enclosed by the lower ribs is occupied by some of the abdominal viscera: and (2) the cavity extends above the first rib into the neck. The size of the cavity of the thorax is constantly varying during life with the movements of the ribs and Diaphragm, and with the degree of distention of the abnomal viscera. From the collapsed state of the lungs, as seen when the thorax is opened, in the dead body, it would appear as if the viscera only partly filled the cavity of the thorax, but during life there is no vacant space, that which is seen after death being filled up by the expanded lungs.
The Upper Opening of the Thorax
The part which pass through the upper opening of the thorax are, from before backward in or near the middle line, the Sternohyroid and Sterno thyroid muscles, the remains of the thymus gland, the trachea, oesophagus, thoracid duct, the inferior thyroid veins, and the Longus colli muscle of each side: at the sides, the inominate artery, the left common carotid and left subelavian arteries, the internal mammay and superior intercostals arteries, the right and left innominate veins, the pneumogastric, cardiac, phrenic, and sympathetic nerve, the anterior branch of the first dorsal nerve, and the recurrent laryngeal nerve of the left side. The apex of each lung, covered by the pleura, also projects through this aperture, a little above the margin of the first rib.
The heart and lungs are contained within the cavity of the thorax, the walls of which afford them protection. The heart lies between the two lungs, and is there enclosed within a membrane, the pleura. The skeleton of the thorax and the shape and boundaries of the cavity will be described in the section on General Anatomy.
The Cavity of the Thorax
The capacity of the cavity its apparent size does not correspond with its apparent size externally, because (1) the space enclosed by the lower ribs is occupied by some of the abdominal viscera: and (2) the cavity extends above the first rib into the neck. The size of the cavity of the thorax is constantly varying during life with the movements of the ribs and Diaphragm, and with the degree of distention of the abnomal viscera. From the collapsed state of the lungs, as seen when the thorax is opened, in the dead body, it would appear as if the viscera only partly filled the cavity of the thorax, but during life there is no vacant space, that which is seen after death being filled up by the expanded lungs.
The Upper Opening of the Thorax
The part which pass through the upper opening of the thorax are, from before backward in or near the middle line, the Sternohyroid and Sterno thyroid muscles, the remains of the thymus gland, the trachea, oesophagus, thoracid duct, the inferior thyroid veins, and the Longus colli muscle of each side: at the sides, the inominate artery, the left common carotid and left subelavian arteries, the internal mammay and superior intercostals arteries, the right and left innominate veins, the pneumogastric, cardiac, phrenic, and sympathetic nerve, the anterior branch of the first dorsal nerve, and the recurrent laryngeal nerve of the left side. The apex of each lung, covered by the pleura, also projects through this aperture, a little above the margin of the first rib.
posted by Margi @ 1:23 AM
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