Physiology practicums : explicit directions for examining portions of the cat, and the heart, eye, and brain of the sheep, as an aid in the study of elementary physiology.

  • Wilder, Burt G. (Burt Green), 1841-1925.
Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: Physiology practicums : explicit directions for examining portions of the cat, and the heart, eye, and brain of the sheep, as an aid in the study of elementary physiology. Source: Wellcome Collection.

Provider: This material has been provided by the Gerstein Science Information Centre at the University of Toronto, through the Medical Heritage Library. The original may be consulted at the Gerstein Science Information Centre, University of Toronto.

    28/110 (page 22)
    The duct and nerve are better demonstrated upon freshly killed ani- mals ; see Anatomical Technology, Figs. 103, 107, 108. $ 34. Make a drawing of the left thorax similar to PI. VII, but shade very lightly if at all. §35. With the coarse scissors or nippers transect the sternum near the diaphragm ; also the first ribs ; then the intervening soft parts so as to remove the sternum. One or more vessels may be seen passing from the great thoracic vessels to the sternum. With the tracer tear the pleura and connective tissue so as to expose the aorta and esophagus more fully. §36. Opposite the apex of the heart slit the aorta lengthwise and in- flate it cephalad so as to demonstrate the following points : a. The aorta extends cephalad and then turns somewhat sharply to the right and then caudad to join the base of the heart. Starting from the heart, therefore, the arch so formed is to the left, and the vessel itself is at the left rather than the right of the meson ; Anatomical Technology, Fig. lor. b. With all Mammals the aortic arch is left; with all Birds it is right; see the con- trasted injected preparations in the Museum ; the matter is further discussed in the lectures. c. From the aortic arch spring two great arterial trunks carrying blood to the head and arms. d. If time permits expose them with the tracer ; the names and divisions are given in Anatomical Technology, Figs. 91, 101, 102; compare with the human arrangement as seen in the wall maps. § 37. Slit the aorta to near the diaphragm and note the orifices of the ten pairs of INTERCOSTAL ARTERIES. § 38. Cut the phrenic nerves, aorta and postcava about 2 cm. from the diaphragm ; then the precava, azygous vein and branches of the aortic arch. Pull all the parts cephalad, divide the pleural attachments with the scissors, and remove. £ 39. The Cat's Heart and Great Vessels.—If time permits a hasty examination of these may be made as follows, but the beginner will find the sheep's heart more easy to dissect. a. With the fingers tear off any fragments of fat or thymus ; then the esophagus ; then the trachea with its branches, the BRONCHI ; cut the bronchi near the lung-remnants. These latter are probably connected with the heart by the PULMONARY ARTERIES and VEINS. The veins may be full of blood. b. Cut the pulmonary vessels close to the lung-remnants so as to free the latter. § 40. Removal of the Pericardium.—a. At about the middle of the entire length of the organ pinch up a fold of the membranous sack which incloses it ; slit the sack and remove, trimming quite closely to its attach- ments at the base, but without cutting the heart itself or the vessels. a. The place and manner of attachment of the pericardium may be more easily ob- served in the sheep ; the object of this removal is to expose more fully the regions of the heart and the vessels. §41. Right Aspect of the Heart.—a. Place the heart in the posi- tion shown in PI. VII, the right side toward you, the apex toward your right. b. Recognize the RIGHT AURICLE and VENTRICLE ; both are probably quite firm to the touch on account of the contained coagulated blood. c. Note the attachments of the three great VEINS which bring blood to the auricle, the POSTCAVA and PRECAVA and the RIGHT AZYGOUS. §42. Left Aspect.—Turn the heart upon its right side and see that the vessels lie in what seems to be their natural positions.