50 LABORATORY DIRECTIONS 



Cut along the mid-dorsal line of the larynx and continue 

 the cut posteriorly for a few inches along the dorsal side of the 

 trachea. Two folds of skin, one on each side, extend from 

 the base of the epiglottis. These are t\i€^ false vocal cords. The 

 space in front of them is called the vestibule. A short distance 

 behind them is a second pair of folds, the true vocal cords. 



Survey of the Viscera. — Beginning just anterior to the 

 pelvic girdle, cut the abdominal wall on each side, being careful 

 not to injure the internal organs. Continue this cut forward 

 to the first rib, carefully loosening the body wall from the 

 diaphragm when this is reached. Cut the ribs with bone forceps. 

 To expose the contents of the body cavity it will be necessary to 

 remove this flap. In doing so observe the internal mammary 

 arteries and veins that extend onto the chest wall. Without 

 disturbing anything locate: the lungs, enclosing the heart 

 between them; the muscular diaphragm separating thorax and 

 abdomen; the liver, commonly with a portion of gall bladder 

 exposed on its right lobe; the fatty membrane, known as the 

 great omentum, covering most of the abdominal viscera; the 

 stomach, sometimes partly exposed to the left of the liver; 

 the dark colored spleen at the left of the stomach; the many coils 

 of the intestine; and the bladder, just anterior to the pubic 

 symphysis. In cats in an advanced stage of pregnancy the two 

 horns of the uterus will also be prominently in view, often greatly 

 displacing the other internal organs. The membrane lining the 

 body cavity is the peritoneum. A similar one, the pleura, lines 

 the chest cavity. 



Observe that the organs are held together and to the body 

 wall by membranes. The membranes attaching the viscera 

 to the body wall are known as mese^iteries; those connecting 

 organs with other organs are omenta (singular, omentum). 



Oesophagus. — This part of the alimentary canal is a straight 

 tube passing from the pharynx through the diaphragm to the 

 stomach. To see it, pull the left lung toward the right side, 

 but do not cut more tissues than is necessary. The oesophagus 

 is collapsed except when it contains food. 



Stomach. — The size of the stomach depends to a large extent 

 on the amount of food it contains; it also varies greatly in differ- 

 ent individuals. The cardiac end of the stomach is the region 



