The Milk Glands and their Functions. 



85 



converge to the center of the gland where they form 

 cavities known as the milk sinuses, they used to be 

 termed lactiferous (milk-making) sinuses. 



The milk sinuses empty the lacteal secretion into the 

 teats, each of which is guarded by a sphincter muscle at 



DIAGRAM OF TEAT AND ONE QUARTER OF UDDER. 



s, sphincter muscle; t, teat; r, milk reservoir; d, the duct; o, opening of 

 a duct; Z, a lobe; ?', a lobule lined by c, epithelium; /, folds of mucous 

 membrane. 



its lower end, it is this sphincter muscle which is so hard 

 to relax in some cows, that causes them to be termed 

 hard milkers. The udder is lined with a delicate cell 

 structure known as epithelium, this cell structure extend- 

 to the alveoli (lobules). 



