448 . MAMMALIA— PHYSIOLOGY 



adrenals. Cannon ^ demonstrated the effect of increased suprarenal 

 activity on blood sugar, muscular activity, and recovery from 

 fatigue. Fear or anger enables one to fight better or run faster! 



Pineal Body {Epiphysis). — In cases of pineal tumor, causing 

 deficient secretion, there is a tendency to obesity and individuals 

 may be sexually precocious with premature ossification of the bones. 

 Pineal extract has been administered to cases of retarded mental 

 development, with reports of gratifying improvement. But we 

 really know very little about pineal function. 



Pituitary Body {Hypophysis). — The pituitary has two lobes, an 

 anterior one and a posterior one, each with distinct functions. In 

 cases of hypersecretion of the anterior lobe., acromegaly and gigantism 

 may result. The hair is excessive, teeth are widely separated, the 

 extremities are elongated and the fingers become broad and spade- 

 like. The skin is thick and wrinkled and the sweat and sebaceous 

 glands are excessively active. Glycosuria and excessive gonadial 

 development may also occur. The stimulating influence of anterior 

 lobe substance on the thyroids has already been noted (p. 445)- 



P. E. Smith and E. T. Engle (Am. Jour, of Anat., vol. 40, pp. 

 159-217, 1927) have shown that the implantation of anterior 

 hypophyseal substance in infantile female rats and mice will induce 

 sudden and extensive ripening of the Graafian follicles. After 3 

 days of implantation they induced the ripening of 48 ova in a 22- 

 day mouse. There is correlation between the sizes of rabbits and 

 the number of young. Larger breeds are thus affected in growth and 

 ovulation by the anterior hypophysis. Hyposecretion of the anterior 

 lobe results in infantilism, obesity, a thin, smooth, dry skin, scanty 

 hair, slender fingers, and dwarfism with the torso longer than the 

 extremities. The oxidative metabolism is low. 



Hypersecretion of the posterior lobe causes contraction of the 

 smooth muscles, resulting in a rise in blood pressure. Pituitrin 

 is used in obstetrics since it keeps smooth muscle contracted longer 

 than does adrenalin. Sugar tolerance is decreased in hypersecretion 

 of the posterior lobe. Hyposecretion of the postej'ior lobe results in 

 subnormal temperature, increased sugar tolerance and adiposity 

 accompanied by drowsiness (Dickens' fat boy). Epilepsy fre- 

 quently occurs. 



^ Consult Cannon, " Bodily Changes in Pain, Hunger, Fear and Rage." 



