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FEMALE UROGENITAL SYSTEM

well, mainly the female genital and mammary system, actually.
uteri and udders!

note: picking up an animal by the scruff of the neck causes extension of 
forelimbs and flexing of hindlimbs and causes cessation of movement.

handout: uterus and udder diagrams. 

mare has uterus with horns and body more like a T, and an ovary the size 
of a hen's egg, which has an "ovulation fossa" from which the ova are 
expelled. in the cow, ova are expelled from follicles all over the 
surface of the ovary.

in the case of ruminants, the uterine horns are shaped like ram's horn, 
bringing ovary close to brim of pelvis. ovaries are smaller, almondsized. 
there is also an intercornual ligament present at the joining of the 
horns, which can be grapped when palpating the animal rectally.

recall in the rabbit there are TWO cervices - more primitive animals may 
even have a bipartate vagina with two independent cervices.

the urethral orifice: the opening of the urethra into the vestibule. in 
the cow and smaller ruminants you need to be wary of the suburethral 
diverticulum. ventral to the opening of the urethra into the vestibule is 
the suburethral diverticulum, which likes to grab catheters you're trying 
to put into the bladder. this isn't present in the horse.

horse, pig: diffuse placenta
primate, rodent: discoid placenta
ewe,cow: cotyledonary placenta
dog,cat: single zonary placenta
ferret, raccoon: double zonary placenta

note the cotyledonary type of placenta - the caruncles are present on the 
uterus all the time, even in nonpregnant animals. the cotyledons are the 
patches of special tissue on the surface of the chorion. when the 
caruncle is covered with a cotyledon, the two together are called a 
placentome.
there is in cows a predilection to have a retained placenta.
removing this is called "cleansing" the cow. it consists of peeling the 
cotyledons off the caruncles, which become fist sized in the gravid 
uterus.

recall that placenta is organ made of maternal and fetal tissues. must 
have BOTH parts.

slide: viscera of domestic animals diagram showing types of placentas.
note that in the ewe and the goat, the caruncle becomes a hollowed out 
dish, which holds within it the fetal cotyledon, which is more fistlike. 
this is the reverse situation of the cow.

UDDERS:

mammary glands of herbivores forms something called an UDDER. we don't 
talk about the udders of carnivores, just herbivores.  the lactating ewe 
has a little dome shaped udder with two teats, as does the goat. cow has 
4 teats. sow has many.

in the BITCH, the teats are not lined up symmetrically. they are in a 
staggered pattern, which gives the puppies more room :) so they don't 
have to lie on top of each other to nurse.

slide: different kinds of udders seen in dairy cows, showing normal 
variants. the "goat" type cow udder has no nice demarcation between the 
gland and the teat. sometimes there is an extra little bump caudally, 
that would be a supernumerary teat. can get in the way of a milking 
machine so usually removed when still a calf. 

WHAT IS A MAMMARY GLAND?
does a cow have one or four? does a mare have one or two or four? 

the mammary gland is the teat and all of the ducts that open into the 
teat.
the mare has 4 duct systems, but only two teats, so has only two "mammary 
glands" per se. The cow has 4 duct systems, and four teats, so has 4 
mammary glands. pig has multiple teats each with double duct system like 
the mare, and the bitch has many ducts per teat, but still only one gland 
per teat...

p 3 of handout, fig 31-5 from DYCE. note items one and two: the 
lactiferous sinus. the lactiferous sinus is in every lactating species, 
but in the ruminant it is much enlarged and divided into two cisterns or 
sinuses: the gland sinus and the teat sinus. note also the smooth muscle 
surrounding the papillary duct of the teat. also there is bacteriostatic 
activity in the papillary duct to prevent mastitis. mastitis is a problem 
in dairy cattle in particular.

when you view an engorged udder you can see the surface veins and 
lymphatics through the skin, with the lymphatics coming from the 
dorsocaudal end running cranioventrally, and the veins coming from the 
craniodorsal aspect and running caudoventrally. in animals with more 
teats, lymphatics drain in both directions. you need to think about this 
with reference to spread of cancer or infection.

mammary glands are modified sebaceous glands, NOT modified sweat glands - 
according to dr morrison.

in the case of the cow udder, there are four quarters, and the two 
quarters on one side have no clean dividing septum of any kind, although 
they are in fact totally separate with regard to communication of the 
ducts. still, if you wanted to amputate one quarter, you wouldn't know 
exactly where it ended. however, there IS a septum between the right and 
left sides of the udder, and if there were a gangrenous mastitis in a 
breeding animal, say, you could remove one half of the udder, because the 
medial suspensory laminae are running right down the middle. this is also 
called the medial ligament.

recall the prepubic tendon of the larger herbivores, which attaches to 
the rim of the pelvis -where the aponeuroses of the abdominal muscles 
come together. attacheing ventral to it is the tunica flava, aka the 
yellow abdominal tunic, which swings down to form the medial suspensory 
apparatus of the udder. it is yellow and has much elastic tissue within 
it...it also contains a contribution of collagenous tissue from the 
subpelvic tendon. also, coming from the collagenous sub pelvic or 
sympheseal tendon is the lateral suspensory lamina of the udder, which 
swings out and hugs the outer surface of the udder - see fig 31-3 on p 4 
of handout.

blood supply: the arterial supply to bovine udder comes from external 
pudendal artery, minimally from perineal artery off internal pudendal. in 
cows and heavily lactating smaller ruminants there is drainage from the 
external pudendal vein as well as the "milk" vein, aka the subcutaneous 
abdominal vein. this vein continues cranially as internal thoracic by 
going through the "milk well" which can be palpated as a defect in the 
body wall from the outside of a living cow. you could collect blood 
there, if you're careful. this vein develops during pregnancy.

there is also a perineal vein which is a potential source of infection as 
it drains blood toward the udder.

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