The morphology and morphometry of the male reproductive system of the rufous sengi (Elephantulus rufescens).

Citation:
Kisipan ML. The morphology and morphometry of the male reproductive system of the rufous sengi (Elephantulus rufescens).. Onyango DW, Makanya AN, Oduor-Okelo D, eds. Nairobi: Kisipan, M.L.; 2009.

Thesis Type:

MSc thesis

Abstract:

The Morphology of the male reproductive system of rufous sengi was studied using light and electron microscopy while the testicular morphometry was studied using stereology. The system consisted of the cylindrical-shaped testes, genital ducts, accessory sex glands and the penis.
The testes were intra-abdominal, located just caudal to the kidneys and comprised of a parenchyma bound by tunica albuginea. The parenchyma was composed of the seminiferous tubules and the interstitial tissue; the former being more predominant than the later and exhibiting complete spermatogenesis. The interstitial tissue occurred either between the seminiferous tubules, mainly in relatively larger spaces formed when three or four seminiferous tubules approximate or beneath the tunica albuginea. The Leydig cells were mainly polyhedral with irregular nuclei and numerous lipid droplets within the cytoplasm but, in cases where the interstitial tissue made extension into a narrow space between two adjoining seminiferous tubules, the Leydig cells therein were longate with rod-shaped nuclei.
The testicular arteries branched off from renal arteries and ran caudo-laterally to the testis without convolutions or intimate association with the vein. The testicular veins also followed a straight course, without pampiniform plexuses. These animals had separate right and left caudal vena cavae which received ipsilateral testicular and renal veins. After receiving the renal veins, the left caudal vena cava crossed to the right side to join the right one to form a common caudal vena cava which then extended cranially up to the right atrium.
The genital ducts were constituted by the rete testis, efferent ductules, epididymis, and the urethra. The rete testis was made up of interconnecting channels located outside the testicular parenchyma while the efferent ductules connected the rete testis to the caput epididymis. The epididymis consisted of a highly coiled duct organized into three topographic regions; the caput, corpus and cauda epididymis. The caput epididymis was applied on dorso-lateral border, extending from cranial to the caudal pole of the testis. The corpus epididymis extended caudally from the caput to a position between the pelvic urethra and the rectum where it joined the cauda epididymis. The cauda epididymis was organized into a pear-shaped mass, located in a somewhat lateral position between the rectum and the pelvic urethra. The caput and corpus epididymis were lined by a tall pseudostratified columnar epithelium while the cauda epididymis was lined by cuboidal or low columnar epithelium. The ductus deferens was short and connected the cauda epididymis with the pelvic urethra. The urethra consisted of two parts; the pelvic and the penile urethra. The pelvic urethra, surrounded by a thick muscular coat, extended from the neck of the urinary bladder to the bulb of the penis and received the deferent ducts, uterus masculinus and the ducts of the accessory sex glands.The penile urethra extended from the bulb of penis to the tip of the penis.
The accessory sex glands consisted of the prostate and the bulbourethral glands. The prostate gland was composed of several paired lobes organized into two groups, the cranial and the caudal group of lobes, also referred to as the cranial and the caudal prostates respectively. The cranial prostate consisted of lobes organized around the neck of urinary bladder and included the ventral, laterodorsal and the medio-dorsal lobes. The caudal prostate consisted of a single pair of lobes located dorsal to the pelvic urethra.
The mean reference volume of the sengi testis was 0.089 ± 0.003 cm3, 98.3% of which was constituted by the parenchyma and the rest being contributed by the capsule. The seminiferous tubules occupied 90.94% of the testicular parenchyma, while the interstitial tissue on the other hand occupied about 9.07% of the parenchyma with 7.87% of its volume being contributed by the subcapsular interstitial tissue.

Notes:

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