MASTITIS OF THE COW 



CHAPTER I 



THE UDDER OF THE COW 



Anatomical and Physiological Review 



Anatomy. — The udder is a tubulo-alveolar gland. 

 Like other glands, it consists of a true secreting part, the 

 parench^nna, and a connective-tissue framework, called 

 the stroma. 



The parenchyma consists of extensively branched canals 

 or passages as fine as a hair, called tubuli. At their ulti- 

 mate extremities or blind end they show vesicular dilata- 

 tions (tubulo-alveolar gland type) which gradually con- 

 verge into larger collecting ducts that finally terminate in 

 cavities in the teats as large as a hen's egg, called milk cis- 

 terns. The milk cisterns empty from the ends of the teats 

 through a canal the size of a match, called the teat canal. 



The walls of the finest tubules consist of a single layer 

 of cubical epithelial cells. The collecting tubules, cisterns 

 and teat canals are lined with several layers of epithelium. 



The parenchyma is divided by the stroma into round 

 lobules as large as a pea, within which the above mentioned 

 different tubules are imbedded in a very thin, fine connec- 

 tive-tissue network called the intralobular connective tissue 

 (Fig. 1). The part of the stroma which separates the 

 single lobules is called the interlobular connective tissue. 

 From this as a framework the fine intralobular connective 

 tissue is given off. Blood-vessels and nerves lie in the 

 stroma. 



