HUMAN PHYSIOLOGY. 



FIG. i. DIAGRAMMATIC LONGITUDINAL 

 SECTION OP THE BODY. 



V, V. Bodies of the vertebra which divide 

 the body into the dorsal and ventral cav- 

 ities, a, a'. The dorsal cavity. C, p'. 

 The abdominal and thoracic divisions of 

 the ventral cavity, separated from each 

 other by a transverse muscular partition, 

 the diaphragm d. B. The brain. Sp. 

 C. The spinal cord. e. The esophagus. 

 S. The stomach, from which continues 

 the intestine to the opening of the pos- 

 terior portion of the body. I. The liver. 

 p. The pancreas, k. The kidney, o. 

 The bladder. I'. The lungs, h. The 

 heart. 



at the anterior extremity it is en- 

 larged and forms the cavity of the 

 skull. This cavity is lined by a 

 membranous canal, the neural 

 canal, in which is contained the 

 brain and the neural or spinal 

 cord. Through openings in the 

 sides of the dorsal cavity nerves 

 pass out which connect the brain 

 and spinal cord with all the struc- 

 tures of the body. 



The ventral cavity is confined 

 mainly to the trunk of the body. 

 Its walls are formed by muscles 

 and skin, strengthened in most 

 animals by bony arches, the ribs. 

 Within the ventral cavity is con- 

 tained a musculo-membranous tube 

 or canal known as the alimentary 

 or food canal, which begins at the 

 mouth on the ventral side of the 

 head, and, after passing through 

 the neck and trunk, terminates at 

 the posterior extremity of the trunk 

 at the anus. It may be divided 

 into mouth, pharynx, esophagus, 

 stomach, small and large intestines. 



In all mammals the ventral 

 cavity is divided by a musculo- 

 membranous partition into two 

 smaller cavities, the thorax and 

 abdomen. The former contains 

 the lungs, heart and its great 

 blood-vessels, and the anterior part 

 of the alimentary canal, the gullet 

 or esophagus; the latter contains 

 the continuation of the alimentary 

 canal that is, the stomach and 

 intestines and the glands in con- 

 nection with it, the liver and pan- 



