Gross anatomy and histology of the male reproductive tract Flashcards
The penis is formed by structures called erectile bodies. These structures contain large vascular spaces which have the potential to become engorged with blood, in turn leading to the erection of the penis. What are these structures?
What layer of connective tissue surrounds these caverns?
Two bilateral Corpora (pl) cavernosa
One median corpus spongiosum, which lies in between the cavernous bodies
Tubica Albuginea
At the most distal portion of the penis, the corpus spongiosum expands form what structure?
Glans of penis
What structure travels through the corpus spongiosum?
Urethra
The gross sturcture of the penis can be split up into 3 components - name them
Root, body and Glans
The root is found in the perineum, and contains 3 erectile structures - two crura and one bulb. The crura are the proximal components of ??????. The bulb is the proximal component of the ?????
Corpus Cavernosum
Corpus Spongiosum
The body of the penis is located between the root and glans. It is suspended from the ??????. It is composed of three cylinders of erectile tissue. Name them
Pubic symphysis.
Two bilateral corpus cavernosa
Median corpus spongiosum
Name the opening in the glans penis
External urethral orifice
Summarise the layers of the penis - going from deep to superifical
Tunica albuginea (which surrounds both the corpus cavernousum and corpus spongiosum)
Deep fascia - Buck’s fascia - also covers all erectile bodies
Superficial fascia - Dartos fascia - again covers all erectile bodies
Covering the bulb of the penis are the bulbospongiosus muscles. This is muscle covers the bulb of the root ot penis (remember there are 2 muscles which meet), and then insert onto the corpus spongiosum. What is the function of these muscles/
helps compress the bulb of the penis and force blood into the penis.
What muscles cover the crura of the penis? Where do they originate?
Where do they originate and insert?
what is their function?
Ischiocavernousus muscles
origin: Inferior internal surface of the ischiopubic ramus and the ischial tuberosity
insert on crura of penus
push blood into muscle of pens
The superficial tranverse perineal muscles can also be in found in the superficial perineal pouch.
There are the two roots which support the root of the penis. What are they and where are they found?
- Suspensory ligament - a condensation of Buck’s fascia - connects the erectile bodies of penis to pubic symphysis
- Fundiform ligament - condensation of abdominal subcutaneous tissue - runs down from linea albea and attaches to penis like sling, attaching it to pubic symphysis
Penis arterial blood supply? (origin and branches)
- Comes from the internal pudendal artery (internal iliac artery)
- dorsal artery
- deep artery (carvnosal artery)
- Bulbourethral artery (urethral artery)
Penis venous supply?
Deep dorsal vein drains erectile bodies
Superficial dorsal veins
Both from internal pundeal vein of the interal iliac vein
Innervation of penis (roots, sensory + autonomic)
From S2-S4
Sensory and sympathetic:
Dorsal nerve of penis, branch of pudendal nerve innervates the skin and glans penis
Parasympathetic innervation is carried by cavernous nerves from the peri-plasic nerve plexus - responsible for vascular changes which cause erection
What is the scrotum? What are it’s functions?
Fibromuscular sac located between penis and anus.
protects the testes and spermatic cords. keeps testes at temperatures 2-4 lower than rest of he body.
One of the most important collection of structrues that run to testes is called the Spermatic cord. The contents of the spermatic cord are mainly bound togeher by three fascial layers - name them from superficial to deep
External spermatic fascia
Cremaster muscle and fasica
Internal spermatic fascia
Various components of the anterior abdominal wall contribue to the coverings of the spermatic cord. Study this table.
Cremaster muslce is a skeletal muscle tha runs in the spermatic cord. It contracts to raise the testis in ???
The testes are covered by tunica vaginalis - which is a serous membrane derived from the ????.
Tunica Albuginea is a deep connective tisue that sends septa throughout the testes, dividing it up into 200-300 lobules.
Each lobule contains seminiferous tubules. Sperm are produced here. The developing sperm travels through the tubules, collecting in the ??????. Ducts known as ??? transport the sperm from the ??? to the ??? for storage and maturation.
The ???? consits of a single heavily coiled duct. It can be divided into three parts - head, body and tail.
Head is the most proximal part, and is formed from the efferent tubules of testes, which transport sperm from the ??? to the ????.
The body is formed by the heavily coiled duct of the epididymis.
The tail is the most???? part of the epididymis. It markers the origin of the ????, which transports sperm to the ?? portion of the ?? for ejaculation.
Cremaster muslce is a skeletal muscle tha runs in the spermatic cord. It contracts to raise the testis in cold weather
The testes are covered by tunica vaginalis - which is a serous membrane derived from the abdominal peritoneum
Tunica Albuginea is a deep connective tisue that sends septa throughout the testes, dividing it up into 200-300 lobules.
Each lobule contains seminiferous tubules. Sperm are produced here. The developing sperm travels through the tubules, collecting in the rete testis. Ducts known as efferent tubules transport the sperm from the rete testis to the epididymis for storage and maturation.
The epididymis consits of a single heavily coiled duct. It can be divided into three parts - head, body and tail.
Head is the most proximal part, and is formed from the efferent tubules of testes, which transport sperm from the testes to the epididmyis.
The body is formed by the heavily coiled duct of the epididymis.
The tail is the most distal part of the epididymis. It markers the origin of the ductus deferens, which transports sperm to the prostatic portion of the urethra for ejaculation.
What is the innervation of testes and epididymis?
Testicular plexus - network of nerves derived from the renal and aortic plexus.
Arterial supply of the testes and epididymis?
testicular arteries, which arsie directly from abdominal aorta - pass into scortum via inguinal canal, contained within the SPERMATIC CORD.
Also cremaster artery from the inferior epigastric artery
Artery of vas deferens
This is essential in cases of obstruction of the testicular arteries, because this collateral flow will enable the testes to survive.
The scrotumn is suppled by what artery?
Internal pudendal artery (internal iliac artery)
Venous drainage of the testes?
- paminiform plexus - group of veins that surround the testicular artery,
The pampiniform plexus in the spermatic cord, wraps around the testicular artery. This is very important for ???? regulation. The veins of the plexus cool the ??? that carry warm blood before it enters the testis.
The plexus ascends through the inguinal canal, and merge into 3 or 4 veins that enter the abdomen. They then unite to form a single ??? vein. The right vein drains into the IVC, whilst the left vein drains into the left renal vein.
The pampiniform plexus in the spermatic cord, wraps around the testicular artery. This is very important for temperature regulation. The veins of the plexus cool the arteries that carry warm blood before it enters the testis.
The plexus ascends through the inguinal canal, and merge into 3 or 4 veins that enter the abdomen. They then unite to form a single testicular vein at each side vein. The right vein drains into the IVC, whilst the left vein drains into the left renal vein.
