Session 1 - The Male Reproductive System Flashcards
What are the functions of the penis?
Sexual intercourse - erection, ejaculation, remission
Micturation - contains the urethra, expels urine from the body
The penis ca be anatomically divided into what three parts?
Root - proximal, fixed part of the penis. Not visible externally.
Body - free part of the penis,suspended from pubic symphysis.
Glans - distal, has external urethral orifice
The glans is a distal expansion of what?
The corpus spongiosum
What three cylinders of erectile tissue are found in the penis?
Two corpus cavernosa
Corpus spongiosum
What are the corpora cavernosa and the corpus spongiosum called in the root of the penis?
Left and right crura (corpora cavernosa)
Bulb (corpus spongiosum)
During erection, why does the corpus spongiosum fill to a reduce pressure compared to the corpus cavernosa?
To prevent the urethra becoming occluded during erection.
What are the four muscles located in the root of the penis?
Bulbospongiosus (x2)
Ischiocavernosus (x2)
The root of the penis is supported by what two ligaments?
Suspensory ligament
Fundiform ligament
Each mass of erectile tissue has what two fascia coverings?
Deep fascia of the penis (continuation of deep perineal fascia). Binds erectile tissues together.
Tunica albuginea, forms an individual capsule around each cavernous body.
What is the prepuce?
Foreskin. Double layer of skin and fascia, located at the neck of the glans. It covers the glans to a variable extent.
What connects the prepuce to the skin of the glans?
Frenulum (a median fold of skin on the ventral surface of the penis).
What is the preputial sac?
The potential space between the glans and prepuce
What arteries supply the penis? These are all branches of what artery?
Dorsal arteries of the penis
Deep arteries of the penis
Bulbourethral artery
These are all branches of the internal pudendal artery.
What vessel does the internal pudendal artery arise from?
Internal iliac artery
Venous blood drains from the penis through what two veins?
Deep dorsal vein of the penis (drains cavernous spaces). Empties into prostatic venous plexus.
Superficial dorsal veins (drains superficial structures, e.g. skin and cutaneous tissue).
Sensory and sympathetic innervation of the skin and glans penis is supplied by what nerve?
Dorsal nerve of the penis, a branch of the pudendal nerve.
Parasympathetic innervation of the penis is supplied by what nerves?
Carried by cavernous nerves from the prostatic nerve plexus
What is hypospadia?
A congenital condition in which patients are born with the opening to their urethra on the ventral aspect of the penis. Can be corrected with surgery.
What is phimosis?
A condition where the prepuce fits tightly over the glans and cannot be retracted. It an cause irritation when smegma (oily secretions) accumulate in the preputial sac.
What is paraphimosis?
A more severe variant of phimosis, where retraction of the prepuce constricts the neck of the glans, interfering with venous and lympathic drainage. This may cause the glans to enlarge to the extent that the prepuce cannot be drawn over it.
What is Peyronie’s disease?
An abnormal curvature of the shaft of the penis caused by a build up of scar tissue. May cause pain on erection. Surgical correction needed in severe cases.
What is erectile dysfunction?
The inability to maintain an erection
What are the causes of erectile dysfunction?
Most commonly due to vascular aetiology - hypertension, hypercholesterolaemia or diabetes. Possible psychological causes include anxiety and depression.
What is priapism?
An erection that persists for more than four hours despite a lack of sexual stimulation. It is often painful and results from blood becoming trapped in the erectile bodies. If untreated may lead to scarring and erectile dysfunction.
Where in the testes does spermatogenesis occur?
Seminiferous tubules
What is the function of the testes?
Site of sperm production and hormone synthesis.
What is the function of the epididymis?
Storage of sperm
Where is the epididymis located in relation to the testes?
On the posterolateral aspect of each testicle.