618 



GENITAL ORGANS OF THE COW 



its wall is remarkably dense, and may be nearly an inch (ca. 2 cm.) in thickness. 

 Its lumen, the cervical canal, is spiral, and is ordinarily tightly closed and very 

 difficult to dilate. The muscular coat of the uterus is thicker than in the mare. 

 It consists of an external longitudinal layer and two circular strata. The inner 

 circular layer is about a fourth of an inch (ca. 6 mm.) thick in the cervix. The other 

 layers are continued in the vagina. The 

 mucous membrane of the horns and body 

 presents as a characteristic feature the 

 uterine cotyledons (C'otyledones uterina^). 

 These are oval prominences, about a hun- 

 dred in number, which are either irregularly 

 scattered over the surface or arranged in 

 rows of about a dozen. 



In the non-gravid uterus they average about 

 J/2 to 'J4 inch (ca. 15 to IS mm.) in length, ^ inch 

 (ca. 8 mm.) in width, and 3.8 hich (ca. 2 to 4 mm.) 

 in thickness. During pregnancy they become greatly 

 enlarged and pedunculated. The larger ones then 

 measure about 4 to .5 inches (10 to 12 cm.) in length, 

 1 to l.V^ inches (3 to 4 cm.) in width, and 1 inch (2 

 to 2.5 cm.) in thickness. The deep face has a hilus 

 at which the vessels enter. The rest of the surface 

 has a spongy appearance, due to numerous crypts 

 which receive the villi of the chorion. 



The uterine glands are long and 

 branched. The mucous membrane of the 

 cervix is pale and forms numerous folds. 

 The latter are arranged in several series 

 which obliterate the lumen. At the ex- 

 ternal orifice (os uteri) the folds (Plicse 

 palmatai) form rounded prominences ar- 

 ranged circularly, which project into the 

 cavity of the vagina. There are no glands 

 in the cervix, but a thick mucus is secreted 

 by goblet cells. 



.:"<■■ 



^ 



Fio. 413. — Utkrine Cotyledon of Cow. 

 The figure represezit.s a cotyledon of medium .size. 

 I'^llenherger, in Leisering'.s .Vtlas.) 



(After 



Fk;. 414. — Genital Organs or Cow, Dorsal 



ViKW. 



The right uterine cornu and the vagin.a and 

 vulva are ojjened up: 1, Labium vulvy; 2, ventral 

 commissure; 3, glans clitoridis; 4, glandula vesti- 

 bularis major, exposed by slit in mucous mem- 

 brane; 5, opening of duct of preceding; 6, sub- 

 urethral diverticulum; 7, extern:il urethral open- 

 ing; S, oiienings of canals of Gartner; ,9, os uteri; 

 10, cori)us uteri; //, cornu uteri; 13, cotyledons; 

 Id, Fallopian t\ibe; /4, ostium abdominale tubic; 

 75, ovary (From Leisering's .Atlas, reduced.) 



The broad ligaments are not attached in the sul)lumbar region as in the mare, 

 but to the upper part of the flanks, about a handbreadth below the level of the 

 external angle of the ilium. Tht^y contain a conspicuous amount of unstriped 

 muscle. The round ligaments are well developed, and can be traced distinctly 

 to the vicinity of the internal inguinal ring. 



The vagina is somewhat longer and more roomy than that of the mare; its 



