Page 457 - Anatomy and Physiology of Farm Animals, 8th Edition

442 / Anatomy and Physiology of Farm Animals

he organs and glands of the male repro- The remaining structures assist the sperma-
tozoa in reaching their ultimate goal (the
Tductive tract manufacture the male
VetBooks.ir gamete (spermatozoon [pl. spermatozoa]) ovum of the female) in a condition conducive
to fertilization of the ovum. These structures
and deliver it to the female reproductive
tract. Embryologically, the reproductive include the epididymis and ductus deferens,
system is closely related to the urinary sys- accessory sex glands (ampullary glands,
tem, developing the tubules and ducts of vesicular glands, prostate, and bulboure-
both interdependently. In the male adult, thral glands), the urethra, and the penis.
the urethra is a passage common to the uri- Figure 24‐1 shows the comparative anatomy
nary system and the reproductive tract. of the male reproductive organs of farm
The male reproductive system of mam- animals.
mals consists of two testes (testicles) in the
scrotum, accessory organs including ducts
and glands, and the penis. The testes produce Testis
spermatozoa (also called sperm) and testos-
terone (the male sex hormone). The scrotum The testes vary somewhat between species
provides a favorable environment for the in shape, size, and location (Fig. 24‐1). In
production and maturation of spermatozoa. the horse, the long axis of each testis is

Boar Stallion

Rectum
vs Rectum
b p dd p vs a
b dd
U
U
T

sf

Ram Bull

Rectum
Rectum b vs
Rectum
vs
p vs p p
b a a
dd
U dd
U
sf
sf

Figure 24-1. Schematic diagram comparing the reproductive anatomy of the boar, stallion, ram, and
bull. T, testicle; U, urinary bladder; dd, ductus deferens; a, ampulla; vs, vesicular gland; p, prostate; b,
bulbourethral gland; sf, sigmoid flexure.