The Bulbourethral Glands
The bulbourethral glands (also known as Cowper’s glands) are a pair of pea shaped exocrine glands located posterolateral to the membranous urethra. They contribute to the final volume of semen by producing a lubricating mucus secretion.
In this article, we shall look at the anatomy of the bulbourethral glands – their structure, vasculature and innervation.
Anatomical Position and Structure
On dissection the bulbourethral glands can be found enclosed within the fibres of the external urethral sphincter. They are situated posterolateral to the membranous urethra and superior 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.
Embryologically the bulbourethral glands are derived from the urogenital sinus, along with the bladder, prostate and urethra.
The bulbourethral glands produce a mucus secretion which serves as lubrication during sexual arousal. These secretions are also alkaline in nature and may help to neutralise residual acidity in the male urethra.
It has been theorised that this secretion can sometimes carry sperm into the female reproductive tract prior to ejaculation, resulting in failure of common contraceptive techniques such as the withdrawal method.
The arterial supply of the bulbourethral glands is derived from the arteries to the bulb of the penis.
The bulbourethral glands receive autonomic innervation derived from the prostatic plexus.
Remember Point and Shoot! The bulbourethral glands contract during ejaculation (shooting). This is therefore a sympathetic function, as opposed to the parasympathetic control of erection (pointing).
Like the seminal vesicles the bulbourethral glands drain into the internal and external iliac lymph nodes