MRS - Bulbourethral Glands Flashcards
What is the function of the bulbourethral glands?
These are a pair of exocrine glands located posterolaterally to the membranous urethra.
The glands produce a mucus secretion containing glycoproteins. It has three main purposes:
1) Serves as lubrication medium for the urethra and the tip of the penis.
2) Expels any residue of urine, dead cells or mucous through the urethral meatus, preparing a clean and lubricated pathway for ejaculation.
3) Helps neutralise residual acidity in the male urethra (secretions are alkaline).
These secretions are devoid od spermatozoa, as ejaculation occurs further down as the prostatic urethra level. However, occasionally these secretions (also known as pre-ejaculate) may carry spermatozoa that remain in the urethra after a previous ejaculation (keep in mind that spermatozoa in body temperature suvive for more than 48 hours).
This may obviated by urination and thus washing our the urethra. However, although rare, it may represent a cause of unintended pregnancy during unprotected sexual intercourse.
Anatomical postion and structure?
On dissection, the bulbourethral glands can be found in the deep perineal pouch of the male. They are siotuated posterolaterally to the membranous urethra and superiorly to the bulb of the penis.
The ducts of the gland penetrate the perineal membrane alongside the membranous urethra and open into the proximal portion of the spongy urethra.
The glands themselves can be described as compound tubulo-alveolar glands lined by columnar epithelium.
Embryology?
These glands are derived from the urogenital sinus, along with the bladder, prostate and urethra. Their development is greatly influenced by DHT (dihydrotestosterone).
Vasculature?
Arterial supply:
1) Arteries to the bulb of the penis
Innervation?
Nerves that arise from pelvic ganglia, sympathetic chain ganglia, the caudal mesenteric ganglion and the dorsal root ganglion innervate this gland.
They reach the gland via the hypogastric nerve and pelvic nerve or pelvic branch of the pudendal nerve.
Lymphatics?
Like the seminal vesicles, the bulbourethral glands drains into the internal and external iliac lymph nodes.
