TABLE OF PHYSIOLOGICAL CONTENTS. . 279 



Function of red corpuscles: to carry oxygen from the lungs to the 



tissues. 



Frequency of the heart's pulsation a minute : 72 on the average. 

 Velocity of the blood movement in the arteries: about 12 inches a 



second. 

 Length of time required for the blood to make an entire circuit of 



the vascular system : about 20 seconds. 

 Amount of air passing in and out of the lungs at each respiratory 



act : from 20 to 30 cubic inches. 



Amount of air that can be taken into the lungs on a forced in- 

 spiration : no cubic inches. 

 Amount of reserve air in the lungs after an ordinary expiration ; 



100 cubic inches. 

 Amount of residual air always remaining in the lungs: about 100 



cubic inches. 



Vital capacity of the lungs: 230 cubic inches. 

 Entire volume of air passing in and out of the lungs in 24 hours : 



about 400 cubic feet. 



Composition of the air: nitrogen, 79.19; oxygen, 20.881, in 100 parts. 

 Amount of oxygen absorbed in 24 hours: 18 cubic feet. 

 Temperature of the human body at the surface: 98^ F. 

 Amount of urine excreted daily : from 40 to 50 ounces. 

 Amount of urea excreted daily: 512 grains. 

 Specific gravity of urine: from 1015 to 1025. 

 Number of spinal nerves: 31 pairs. 

 Number of roots of origin: two; ist, anterior, efferent; 2d, posterior, 



afferent. 



Rate of transmission of nerve force: about 100 feet a second. 

 Number of cranial nerves: 12 pairs. 



1. Olfactory, or first pair. 



2. Optic, or second pair. 



3. Auditory, or eighth pair. 



4. Chorda tympani for anterior two thirds 

 Nerves of special sense:^ of tongue . 



5. Branches of glosso-pharyngeal, or 

 eighth pair, for posterior one third of 

 tongue. 



Motor nerves to eyeball and accessory structures: motor oculi, or 

 third pair ; pathetic, or fourth pair ; abducens, or sixth pair. 



