Camelid Male Anatomy - Anatomy & Physiology

Prepuce and Penis

• The prepuce is flattened from side to side and triangular in shape when viewed laterally.
• In the absence of sexual arousal, the small preputial opening is directed caudally and because of this they urinate towards the rear.
• When erect,the cranial prepucial muscles pull the prepuce, and also the penis, forward from their backward position.
• The penis is attached to the prepuce at birth and does not become free until 2 - 3 years of age.
  • Loss of adhesions is a sign of sexual maturity.
  • If castration is prior to the Testosterone peak at the beginning of puberty, then adhesions may never completely break down.
• Penis is fibroelastic.
  • In the absence of an erection, the penis is retracted into its sheath via a prescrotal sigmoid flexure not a post scrotal sigmoid flexure, as is the case in bulls.
• The length of the penis ranges from 59 - 68 cm and it is cylindrical in shape
• Process at the end of the penis is firm, composed of cartilage.
  • It has a slight clockwise curve to aid insertion of the penis through the cervix so that semen can be deposited directly into the uterine horns.
• The glans penis is curved along its vertical plane giving it a hook-shape with a definite neck between the glans and body of the penis.

Scrotum and Testes

• Scrotum is situated below the perineum, at the rear of the body (as in cats), as opposed to under it and between the hind legs (as in other domestic species).
• The scrotal skin tends to be smooth and fine during the height of breeding activity and then becomes thicker during the period of sexual inactivity because of decreased testicular size.
• Testes are oval in shape and freely mobile within the scrotum.
• 2-3 cm in length
• Usually descended at birth but are very small.
• Size is an indication of fertility (larger testes indicate greater fertility).
• Enlarge during the breeding season.

Semniferous Tubules

• Outer diameter of the seminiferous tubules varies from 113 - 250 mm and gets significantly smaller during the non-breeding season.
• The season does not however have any effect on the size of the spermatozoa although it does on their number.

Epididymis

As in other species the epididymis is composed of three distinct parts: the caput (head), the corpus (body) and cauda (tail).

• Located along the dorsal border of the testis
• Head curves around the cranial pole of the testis.

Ductus Deferens

• Very long measuring between 45 - 50 cm in length.
• Enclosed within the spermatic cord

Accessory Sex Glands

The most important feature is the absence of seminal vesicles in the Camelidae family. The accessory sex glands are: the ampullae, the prostate, the bulbo-urethral (Cowper’s glands) and the urethral glands. The size and weight of the glands are affected significantly by the age of the animal, (tending to reach a maximum between 10.5 - 15 years) and the season. They are largest during the breeding season. This is concomitant with the increased activity and size of the testis. That suggests that the activities of the accessory sex glands are regulated by androgen secretion from the testis.

The Ampulla

• The initial part of the ductus deferens is small in diameter and very tortuous but it thickens and forms the ampulla as it approaches the pelvic urethra.
• Terminal part embedded in a deep groove located on the ventral surface of the corpus prostatae.
• These glands may play the role of a sperm reserve before ejaculation.

The Prostate Gland

• This is the largest and only palpable gland.
• It has two components, a compact and a diffuse part with the two forming an L shape which lies dorsal to the pelvic urethra.

The Bulbo-Urethral Glands

• Two bulbo-urethral glands which are almond shaped structures that are located either side of the terminal portions of the pelvic urethra.

The Urethral Glands

• Located just behind the body of the prostate and extend to the level of the urethral bulb before opening into the urethral lumen via numerous ducts.
• These glands and the pelvic urethra are richly innervated.
  • Nerves are responsible for the contraction of the muscle and expulsion of glandular secretions.