male

• Male Reproductive System composed of a variety of structures:

  •Testis (plural: Testes) – External

  •Epididymis – External

  •Ductus deferens – External to Internal

  •Seminal Vesicles – Gland – Internal

  •Ejaculatory duct – Internal

  •Prostate – Gland – Internal

  •Urethra – Internal to External

  •Bulbo-urethral gland – Internal

  •Penis – External (roots Internal)

  
• Males: Surface Anatomy

  A) glans penis

  B) frenulum

  C) raphe

  D) testis with scrotum

  
• Testes

  Originally develop in the abdomen and descend before birth (usually).

  Paired structures.

  
• testes In adults:

  •~4-5cm in length

  •~2-3cm in breadth

  •~3-4cm in anteroposterior diameter

  •Between 12-20g

  •Testicular volume between 15-25ml

  
• testes

  Stored within the scrotal sac (scrotum) externally.

  •Most likely for temperature regulation of sperm production.

  
• Tunica albuginea (Capsule):

  •Contains 400-600 seminiferous tubules

  •To straight tubules

  •To rete testis (in mediastinum testis)

  •To 12-20 efferent ductules

  •To epididymis

  
• Tunica vaginalis:

  •Closed sac of peritoneum

  •Processus vaginalis is a connection between scrotum and peritoneal cavity.

  •Closure after testicular descent leads to fibrous/ligamentous remnant

  Three parts:

  •Parietal layer

  •Cavity -Contains varying volumes of clear, straw-coloured fluid

  •Visceral layer

  
• Epididymis: Structure

  Runs along the posterolateral side of the testis, contained within the tunica vaginalis.

  Stores spermatozoa prior to ejaculation.

  Spermatozoa mature in the epididymis, acquiring the ability to move and fertilise an egg.

  
• Epididymis: Structure

  Convergence of efferent ductules form a coiled mass – the head of epididymis.

  •Form a single, long coiled duct – the body of the epididymis

  •Enlarges to form the tail of the epididymis

  •Continues as the ductus deferens

  
• Ductus Deferens: Overview

  Also known as the vans deferens.

  Transports spermatozoa to the ejaculatory duct and urethra during ejaculation.

  Structure that is cut during a vasectomy.

  
• Testes: Summary

  A) Ductus deferens

  B) Head of epididymis

  C) Efferent ductules

  D) Rete testis in mediastinum testis

  E) Body of epididymis

  F) Tail of epididymis

  G) Capsule - (tunica albuginea)

  H) Tunica vaginalis

  I) Parietal layer -

  J) Cavity

  K) Visceral layer

  L) Seminiferous tubule

  M) Straight tubule

  N) Ligamentous remnant of processus vaginalis

  
• Ductus Deferens: Structure

  Begins at the tail of the epididymis:

  •Tortuous for first 2-3cm

  •Runs within the spermatic cord -Posterior and parallel to the spermatic vessels

  •Moves through the inguinal canal to the anterior abdominal wall.

  •Passes through the deep inguinal ring and bends medially at the pelvic inlet to enter the pelvic cavity. -Runs over the external iliac artery and vein

  •Descends the pelvic wall, deep to the peritoneum -Crosses the ureter posterior to the bladder

  •Continues to the base of the bladder, anterior to the rectum, and almost in the midline. - Between ureter and ejaculatory duct it becomes tortuous again and expands to form the ampulla of the ductus deferens.

  •Together with the duct of the seminal vesicle it forms the ejaculatory duct - Penetrates the prostate gland to connect with the prostatic urethra.

  
• Ductus Deferens: Structure

  A) Tunica vaginalis

  B) scrotum

  C) Tail of epididymis

  D) testis

  E) Body of epididymis

  F) Head of epididymis

  G) Bulbo-urethral gland in deep perineal pouch

  H) Musculofascial pouch

  I) Ductus deferens

  J) prostate

  K) spermatic cord

  L) Superficial inguinal ring

  M) Ductus deferens

  N) Inguinal canal

  O) Deep inguinal ring

  P) Inferior epigastric artery

  Q) External iliac artery

  R) ureter

  S) Ampulla of ductus deferens

  T) Seminal vesicle

  U) Ejaculatory ducts

  
• Where does the ductus deferens begin?

  It begins at the tail of the epididymis.
• How does the ductus deferens initially appear in structure?

  It is tortuous for the first 2-3 cm.
• Within which structure does the ductus deferens run initially?

  It runs within the spermatic cord.
• What is the positional relationship of the ductus deferens to the spermatic vessels?

  It runs posterior and parallel to the spermatic vessels.
• Through which canal does the ductus deferens move to enter the anterior abdominal wall?

  It moves through the inguinal canal.
• Through which structure does the ductus deferens pass before bending medially?

  It passes through the deep inguinal ring before bending medially at the pelvic inlet.
• Over which major blood vessels does the ductus deferens run?

  It runs over the external iliac artery and vein.
• How does the ductus deferens descend in the pelvic cavity?

  It descends along the pelvic wall, deep to the peritoneum.
• What structure does the ductus deferens cross posterior to the bladder?

  It crosses the ureter posterior to the bladder.
• Where does the ductus deferens continue after crossing the ureter?

  It continues to the base of the bladder, anterior to the rectum, and almost in the midline.
• What happens to the ductus deferens between the ureter and ejaculatory duct?

  It becomes tortuous again and expands to form the ampulla of the ductus deferens.
• Which structure does the ductus deferens join to form the ejaculatory duct?

  It joins the duct of the seminal vesicle to form the ejaculatory duct.
• Where does the ejaculatory duct penetrate and connect?

  It penetrates the prostate gland and connects with the prostatic urethra.
• Seminal Vesicles: Structure

  Paired accessory glands of the male reproductive system.

  Contribute significantly to the volume of ejaculate

  
• Seminal Vesicles: Structure

  Coiled tube with numerous pocket-like outgrowths.

  •~5-10cm in length

  •~3-5cm in diameter

  •Average volume of 13ml

  •In most males it’s slightly larger on the right and both become smaller with age.

  
• Seminal Vesicles: Structure

  Contained within a dense, fibromuscular sheath and partly covered in peritoneum.

  Narrows inferiorly to form a straight duct which converges with the ductus deferens to form the ejaculatory duct.

  
• Prostate: Structure

  Non-paired accessory structure/gland of the male reproductive system.

  Surrounds the urethra in the pelvic cavity, just as it leaves the bladder.

  •Inverted, rounded cone shape

  •Inferolateral surfaces are in contact with the levator ani muscles

  
• Prostate: Structure

  Formed of about 30-40 individual independent glands that collectively form the prostate.

  •Enlarge the wall of the urethra

  •Individual ducts with drain into the prostatic sinuses

  •Empty individually into the urethra

  
• Prostate: Structure

  Together with secretions from the seminal vesicles and testes via the ejaculatory duct contribute to the formation of ejaculate.

  
• Bulbo-urethral glands: Structure

  Paired accessory glands of the male reproductive system.

  Small pea-shaped mucous glands located within the deep perineal pouch.

  Duct from each gland passes through the perineal membrane and opens into the bulb of the spongy urethra at the root of the penis.

  
• Bulbo-urethral glands: Structure

  Contribute to the lubrication of the urethra and the pre-ejaculatory emission.

  •Aided by small glands positioned along the length of the spongy urethra.

  
• Penis: Structure & Roots

  External genitalia of the male reproductive system.

  Roots of the penis contained within the urogenital triangle of the perineum – attachment is in superficial perineal pouch.

  Penis is formed of two corpa cavernosa and a single corpus spongiosum.

  
• Corpus cavernosa:

  •Proximal parts attached to the pubic arch form the root of the penis consisting of two crura

  •The free (non-tethered) proximal parts continue to form main bulk of the body of the penis.

  
• Corpus spongiosum:

  •Proximal part attaches to the perineal membrane and forms the bulb of the penis

  •Free part continues with corpus cavernosa to form the remaining body of the penis

  •Contains the urethra

  Expands at the head of the penis to form the glans penis

  
• Penis: Structure & Roots

  A) Corpora cavernosa

  B) body of penis

  C) Corpus spongiosum containing urethra

  D) glans penis

  E) External urethral orifice

  F) navicular fossa

  G) Crus of penis (attached part of corpus cavernosum)

  H) Corpus cavernosum

  I) Perineal membrane

  J) Corpus spongiosum

  K) Bulbo-urethral gland within deep perineal space

  
• Penis: Structure & Roots

  A) Fundiform ligament of penis

  B) Suspensory ligament of penis

  C) midline raphe

  D) Superficial transverse perineal muscle

  E) Ischiocavernosus

  F) Bulbospongiosus

  G) Pubo-analis

  H) External anal sphincter

  
• structures at base of penis - bulbospongiosus, perineal membrane, corpus cavernosum