The =spermatic cord= (Funiculus spermaticus) consists of the structures
carried down by the testicle in its migration through the inguinal canal
from the abdominal cavity to the scrotum. It begins at the internal
inguinal ring, where its constituent parts come together, extends
obliquely downward through the inguinal canal, passes over the side of
the penis, and ends at the attached border of the testicle. It consists
of the following structures:
(1) The =spermatic artery=.
(2) The =spermatic veins=, which form the pampiniform plexus around the
artery.
(3) The =lymphatics=, which accompany the veins.
(4) Sympathetic =nerves=, which run with the artery.
(5) The =vas deferens=.
(6) The =internal cremaster muscle=, which consists of bundles of
unstriped muscular tissue.
(7) The =visceral layer= of the =tunica vaginalis= or =mesorchium=.
The first four of these constituents are gathered into a rounded mass
which forms the anterior part of the cord; they are united by connective
tissue, interspersed with which are bundles of the cremaster internus.
The vas deferens is situated posteriorly, inclosed in a special fold
detached from the inner surface of the mesorchium; hence it is not
visible externally.
The term spermatic cord is to a certain extent misleading as applied
to most animals, while in man the structure is distinctly cord-like.
In the horse, when the tunica vaginalis is slit open and the “cord”
stretched out, the latter is seen to have the form of a wide sheet,
the mesorchium, which has a thick, rounded anterior edge, the
so-called “vascular part” of the cord. The posterior edge of the
mesorchium is continuous with the parietal layer of the tunic; its
inner surface presents posteriorly the deferential fold (Plica ductus
deferentis). Between the two layers of the mesorchium are bundles of
unstriped muscle (cremaster internus) and small vessels.