65 



§ 3.114 VISCERAL MUSCLE 



mic lesions, parturition was not achieved, both the mother and the 

 Ktter dying in the attempt. 



It has also been suggested that oxytocin may play some part in 

 driving sperm upwards into the fallopian tubes after copulation, 



0-002 r- 



0-03 



0-5 



>2-0 



70 



20 30 40 



Days after mating 



Fig. 3-5. Graph showing schematically the sensitivity to oxytocin 

 of strips of rabbit uterus tested at various stages of pregnancy. 

 Days after mating are shown as abscissae, with the normal term for 

 parturition at P ; ordinates (on a logarithmic scale) show reactivity 

 expressed as the minimal number of units of oxytocin which causes 

 a motor effect when added to 100 ml of Ringer-Locke solution 

 (from Robson, 1933). 



by affecting the tonus differentially in different parts of the oviduct 

 (Fitzpatrick, 1957). 



3.114 Myoepithelial cells of mammary glands 



There is no known case of a hormone activating the duct 

 muscles or myoepithelial cells of a gland in invertebrates. 



Mammalia. Branched myoepithelial cells (Fig. 3-6), which 

 surround the alveoli and smaller ducts of the mammary glands, can, 

 by their contraction, drive the milk from the ductules of the gland 



