Gross anatomy and histology of the male reproductive tract

Question 1

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?

Answer 1

Two bilateral Corpora (pl) cavernosa

One median corpus spongiosum, which lies in between the cavernous bodies

Tubica Albuginea

Question 2

At the most distal portion of the penis, the corpus spongiosum expands form what structure?

Answer 2

Glans of penis

Question 3

What structure travels through the corpus spongiosum?

Answer 3

Urethra

Question 4

The gross sturcture of the penis can be split up into 3 components - name them

Answer 4

Root, body and Glans

Question 5

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 ?????

Answer 5

Corpus Cavernosum

Corpus Spongiosum

Question 6

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

Answer 6

Pubic symphysis.

Two bilateral corpus cavernosa

Median corpus spongiosum

Question 7

Name the opening in the glans penis

Answer 7

External urethral orifice

Question 8

Summarise the layers of the penis - going from deep to superifical

Answer 8

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

Question 9

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/

Answer 9

helps compress the bulb of the penis and force blood into the penis.

Question 10

What muscles cover the crura of the penis? Where do they originate?

Where do they originate and insert?

what is their function?

Answer 10

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

Question 11

The superficial tranverse perineal muscles can also be in found in the superficial perineal pouch.

Question 12

There are the two roots which support the root of the penis. What are they and where are they found?

Answer 12

• 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

Question 13

Penis arterial blood supply? (origin and branches)

Answer 13

• Comes from the internal pudendal artery (internal iliac artery)
  
  • ​dorsal artery
  • deep artery (carvnosal artery)
  • Bulbourethral artery (urethral artery)

Question 14

Penis venous supply?

Answer 14

Deep dorsal vein drains erectile bodies

Superficial dorsal veins

Both from internal pundeal vein of the interal iliac vein

Question 15

Innervation of penis (roots, sensory + autonomic)

Answer 15

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

Question 16

What is the scrotum? What are it’s functions?

Answer 16

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.

Question 17

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

Answer 17

External spermatic fascia

Cremaster muscle and fasica

Internal spermatic fascia

Question 18

Various components of the anterior abdominal wall contribue to the coverings of the spermatic cord. Study this table.

Answer 18

Question 19

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.

Answer 19

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.

Question 20

What is the innervation of testes and epididymis?

Answer 20

Testicular plexus - network of nerves derived from the renal and aortic plexus.

Question 21

Arterial supply of the testes and epididymis?

Answer 21

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.

Question 22

The scrotumn is suppled by what artery?

Answer 22

Internal pudendal artery (internal iliac artery)

Question 23

Venous drainage of the testes?

Answer 23

• paminiform plexus - group of veins that surround the testicular artery,

Question 24

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.

Answer 24

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.

Question 25

State the contents of the spermatic cord

Answer 25

Testicular artery

Cremaster artery and vein - supply both the fascia and muscle

Pampiniform plexus of testicular veins

Genital branch of the genitofemoral nerve - supplies cremaster muscle. Autonomic nerves

Vas deferens

Processus vaginallis

Lymph vessels

Question 26

Vas deferns is a thick muscular tube that conveys sperm from the ??? to the ???. To get there, it passes through the ??? canal, through the seminal vesicle, before forming the ejaculatory duct when entering the prostate. The ejaculatory duct then merges with the ??.

Answer 26

Vas deferns is a thick muscular tube that conveys sperm from the epididymis to the ejaculatory duct. To get there, it passes through the inguinal canal, through the seminal vesicle, before forming the ejaculatory duct when entering the prostate. The ejaculatory duct then merges with the urethra.

Question 27

Seminal vesicles are a pair of glands in the male reproductive tract. They contribue ??% of the total volume of semen. They merge with the ??? just prior to the prostate (where they will be referred to as??). The type of epithelium is ???.

There are various products that are contributed to the ejaculate. This includes :

• Alkaline fluid - neutralises the ??? of the male urethra and vagina, in order to facilitate the survival of spermatozoa.
• Fructose - provides ?? for spermatozoa
• Prostaglandins - suppreses female ?????? to foreign semen
• Clotting factors - designed to keep semen in female reproductive tract post-ejaculation

Answer 27

Seminal vesicles are a pair of glands in the male reproductive tract. They contribue 70% of the total volume of semen. They merge with the vas deferens just prior to the prostate (where they will be referred to as??). The type of epithelium is pseudostratified columanr .

There are various products that are contributed to the ejaculate. This includes :

• Alkaline fluid - neutralises the acidity of the male urethra and vagina, in order to facilitate the survival of spermatozoa.
• Fructose - provides nutrition for spermatozoa
• Prostaglandins - suppreses female immune response to foreign semen
• Clotting factors - designed to keep semen in female reproductive tract post-ejaculation

Question 28

Arterial supply of the seminal vesicle?

Answer 28

Inferior vesicle, internal pudendal and middle rectal arteries (all from the internal iliac artery)

Question 29

Bulbourethral glands are also known as ??. They are found inferior to the ????>, and sit posterolaterally to the ?? urethra.

What is it;s function?

Answer 29

Cowpers gland

prostate

membranous

he bulbourethral glands function to lubricate the spongy urethra for the passage of the ejaculate. Due to the alkaline pH of the excreted fluid, they also act to neutralize residual acidic urine that remains in the spongy urethra.Upon sexual excitement, the bulbourethral glands typically secrete clear glycoproteins into the bulbous urethra (proximal part of the spongy urethra). The function of the glands and other supportive male sexual structures depend on normal testicular development and function. In addition to the glycoproteins, they also secrete other substances during sexual stimulation such as an alkaline fluid that helps in neutralizing the acidity of urine and of the vagina, and provides lubrication to for the passage of ejaculate. This fluid is known as pre-ejaculate. In a minority of men, sperm can be present in the pre-ejaculate.

Question 31

What type of epithelium can be found in the epididymis? What appendages do they have?

Answer 31

Pseudostratified columnar

Stereocilia