The vas deferens is a tubular structure in male animals that passes through the caudal bundle of the spermatic cord. Here, I will provide a concise answer to the question – what is the vas deferens in cattle?
Quick answer: The vas deferens is the tubular structure in cattle that carries sperm from the tail of epididymis to the pelvic urethra. It is also known as ductus deferens and begins from the tail of epididymis. Then, it runs on the caudal border of the testis and becomes the caudal bundle of the spermatic cord.
I will show you the origin and courses of the cattle’s ductus deferens with the proper labeled diagram. So, let’s get into the article to know the details of the vas deferens in animals.
What is the vas deferens in cattle?
The vas deferens in cattle are the continuation of the epididymal tail, passing upward along the caudal border of the testis. It is a tube-like structure and has a close association with the medial aspect of the body of the epididymis.
Then, the cattle’s vas deferens get incorporated into the caudal bundles of the spermatic cord. Finally, this tube passes through the inguinal canal with some associated structures.
You may know the detailed structure of the cattle inguinal canal from the below-mentioned article –
At the internal inguinal ring, cattle’s vas deferens separate from the other constituents of the spermatic cord. Now, the tube turns backward and inward into the cattle’s pelvic cavity.
For some distance, the vas deferens lie in the free edge of the genital fold. With the help of this fold, the vas deferens attach –
- To the inguinal part of the abdominal wall, and
- The ventral part of the lateral wall of the pelvis,
It also crosses the external iliac vessels and the corresponding ureter. Now, the vas deferens reach the caudo-dorsal aspect of the urinary bladder.
The cattle’s vas leaves the edge of the fold and inclines medially between the two layers of the fold. Finally, the vas deferens come in contact with the medial face of the seminal vesicle.
Over the neck of the cattle’s urinary bladder, two vas deferens lie very close together. Then they disappear under the isthmus of two connected prostates of the cattle.
They continue through the wall of the urethra and open in a small diverticulum just lateral to the seminal colliculus. The colliculus seminalis is the slit-like opening where the excretory ducts of the seminal vesicle open.
The terminal part of the right and left vas deferens are a little dilated and known as ampulla. Both ampullae are located side by side under the seminal vesicle and disappear under the prostate.
Summary and courses of vas deferens in bull
Let’s see the diagram where I tried to show the course of vas deferens in the cattle. It is small in caliber and possesses a thinner wall.
Most of the part of the vas deferens is covered with peritoneum, except the last several portions. The diagram shows the flexuous course of the vas deferens dorsally along the caudal border of the testis.
But, it becomes straight and lies at the caudal part of the cattle’s spermatic cord. Table 1 shows the summary and the courses of the vas deferens in the bull- –
|Vas deferens||Course of vas deferens in bull|
|Extension||Tail of epididymis to pelvic part of urethra|
|Other name||Ductus deferens|
|Origin||Continuation of the tail of bull’s epididymis|
|On testis||Pursues a flexuous course dorsally along the caudal border of the testis|
|At spermatic cord||Become straight and lie within the caudal bundle of the spermatic cord.|
|Inguinal region||Decends in the inguinal canal of cattle or bull|
|At deep inguinal ring||Separate from other constitutes of spermatic cord|
|On pelvic cavity||Turns caudally and medially into the pelvic cavity|
|Over genital fold||Lies free edge of genital fold and leaves|
|Over bladder||Inclines medially over the caudo-dorsal aspect of the bladder|
|At seminal vesicle||Come contact with the medial face of the seminal vesicle|
|At prostate||Disappears under the isthmus of the prostate gland|
|Opening of tube||The medial aspect of the seminal colliculus|
|Arterial supply||Testicular, umbilical, and pudendal arteries|
|Innervation to vas||Pelvic plexus of sympathetic nerve|
Functions of vas deferens in bull
The vas deferens in bull carries sperms from the tail of the epididymis to the pelvic urethra. The pelvic urethra of a bull is located just caudal to the neck of the urinary bladder.
Vessels and nerves in cattle’s ductus deferens
You will find the following vessels in the anatomy of a cattle’s ductus deferens –
- Testicular or urogenital artery that comes from the internal iliac artery. It supplies the ampulla of the vas or ductus deferens.
- Differential arteries that come from the umbilical artery and supply to the rest part of the vas and
- The internal pudendal artery that supplies the most of the vas,
Again, the nerves of the vas deferens come from the pelvic plexus of the sympathetic fibers.
So, the answer to the question – ‘what is the vas deferens in cattle?’ was explained perfectly. A vas deferens in the animal is a tubular structure that carries sperm and extends from the epididymal tail to the urethra.
The course and function of the ductus deferens in various animals are also similar to the cattle. It is flexuous along the caudal border of the testis but straight within the spermatic cord.