MALE REPRODUCTIVE

• REPRODUCTIVE SYSTEM

  • Male and female reproductive systems develop from similar embryonic tissue.
  • First few weeks of development, male and female embryos are indistinguishable.
  • Adult reproductive systems share some functional similarities.
• FUNCTIONS OF THE MALE REPRODUCTIVE SYSTEM

  • Production of sperm cells.
  • Sustaining and transfer of the sperm cells to the female.
  • Production of male sex hormones.
• PARTS

  • Testes; a series of Ducts (Epididymides, Ductus Deferentia/Vas Deferens, & Urethra);
  • Accessory Glands (Seminal Vesicles, Prostate Gland, & Bulbourethral Gland);
  • Supporting Structures (Scrotum & Penis)
• Male reproductive system

  A) Ureter

  B) Seminal vesicle

  C) Ejaculatory duct

  D) rectum

  E) prostate gland

  F) bulbourethral gland

  G) anus

  H) ductus deferens

  I) epididymis

  J) testes

  K) scrotum

  L) urinary bladder

  M) urethra

  N) penis

  O) gians penis

  P) prepuce

  
• SCROTUM - Sac of skin that hangs outside the abdominopelvic cavity at the root of the penis
• paired Testicles – two oval-shaped glands – producing and storing

  sperm & produces hormones (testosterone)
• Scrotal Septum – divides the scrotum into two chambers.
• Perineal Raphe a line of tissue that extends from the anus, through the

  perineum, and upwards through the midline of the penis.
• SCROTUM - 3 degrees celsius lower than core body temperature
• WALL OF THE SCROTUM

  Dartos muscle – a thin layer of smooth muscle. Contractions of this muscle causes wrinkling of the skin.

  Cremaster muscle - is a thicker layer of muscle that lowers and raises the testes based on temperature.

  A) scrotal septum

  B) cremaster muscles

  C) dartos muscle

  
• TESTES/MALE GONADS - Develop internally near the kidneys and descend through the inguinal canal during the latter half of the seventh month gestation.
• Testicles — are two oval- shaped organs in the MRS.

  Importance:

  ▪ production and storage of sperm until they’re mature enough for ejaculation

  ▪ produce a hormone called testosterone (fertility, sex drive, and the development of muscle and bone mass.
• TESTES - Layers of tissues that serves as protection membranes:

  1. Tunica Vasculosa - first thin layer of blood vessels; shields tubular interior of each testicle from layers of tissue around the outer testicle
  2. Tunica Albuginea- thick, protective layer made of densely packed fibers that protect the testes.
  3. Tunica Vaginalis - a continuation of the peritoneum that lines the abdominopelvic cavity, & forms during the descent of the testes

  A) tunica vaginalis

  B) tunica Albuginea

  C) tunica Vasculosa

  
• TESTICLE

  The tunica albuginea – gives rise to septa (partitions) that divide the

  testis into lobules (about 250). Each lobule contains 3 or 4 highly coiled seminiferous tubules.
• Seminiferous Tubules – coiled tubes that make up most of each testis and responsible for spermatogenesis or the process of creating sperm
• SEMINIFEROUS TUBULES

  1. Interstitial or Leydig

  cells

  • located in the connective

  tissue surrounding the

  seminiferous tubules.

  • produce testosterone

  Testosterone

  • male sex hormone

  • responsible for the growth

  and maintenance of the cells

  of the germinal epithelium

  and the development of

  secondary sex

  characteristics.
• TESTICLE

  These converge to the rete testis which transport sperm to the

  epididymis.
• TESTICLE

  Rete Testis – helps to mix sperm cells around in the fluid secreted by

  sertoli cells.
• TESTICLE

  Sertoli cells – aid in the production of hormones that generate sperm.
• TESTICLE

  Epididymis – long, coiled tube that stores sperm and transports it from

  the testes. (head, body, and tail)
• TESTICLE

  Microvilli – millions of tiny projections in the rete testis – help

  move sperm along to the efferent tubules.
• DESCENT OF THE TESTES

  Testes - Ovoid structures about 5 cm long and 3 cm wide.

  • Located within the scrotal sac (scrotum)
  • During fetal development they are near the kidneys and slowly move inferiorly in the abdominal cavity.
  • The descent of the testes occurs during the 7th or 8th month of the fetal development, or in some cases, shortly after birth.

  A) Rete testis

  B) head of epididymis
• MEDICAL/CLINICAL RELEVANCE

  Cryptorchidism - Failure of the testes to descend into the scrotal

  sac

  • undescended testicle
  • m.c.: genital problem encountered in pediatrics.
  • a testicle that hasn't moved into its proper position in the bag of skin hanging below the penis (scrotum) before birth.
  • Treatment: Surgery (Orchiopexy)
• Inguinal Hernia - inguinal canal enlarges or ruptures. Even though After the testes descend, inguinal canals narrow permanently, but they remain as weak spots in the abdominal wall.
• SPERMATOGENESIS

  • process by which male primary sperm cells undergo

  meiosis and produce a number of cells calls spermatogonia,

  from which the primary spermatocytes are derived.

  • Each primary spermatocyte divides into two secondary

  spermatocytes and each secondary spermatocyte into two

  spermatids or young spermatozoa.

  • These develop into mature spermatozoa, also known as

  sperm cells.

  
• SPERMATOGENESIS

  • essential for sexual reproduction

  • requires optimal environmental conditions

  • starts at puberty and usually continues uninterrupted until death

  • slight decrease in the quantity of sperm produced with increase in age.
• SPERM

  1. Head :contains DNA & the nucleus with 23 highly condensed

  chromosomes (one chromatid)

  ▪ Acrosome a helmet-like containing hydrolytic enzymes that allow the sperm to penetrate and enter the egg
• SPERM

  2. Midpiece: contains mitochondria spiraled around the tail filaments
• SPERM

  3. Tail :a typical flagellum produced by a centriole
• DUCTS

   After sperm production, the sperm cells are transported

  through the seminiferous tubules and a series of ducts to

  reach the exterior of the body.

  ❖ Epididymis

  • Storage and maturation area for sperm
  • long, coiled tube that stores sperm and transports it from the testes. (head, body, and tail)

  ❖ Ductus (Vas) Deferens - Upon ejaculation the epididymis contracts, expelling sperm into ductus deferens

  ❖ Urethra

  ❖ Seminal Vesicle*

  ❖ Ejaculatory Duct*
• SPERMATIC CORD

  a bundle of fibers and tissues that form a cord-like structure that runs through the abdominal region down to the testicles in males.

  Contains the structures running from the testicles to the pelvic cavity.

  Surrounded by Cremaster muscle & connective tissues

  Contents:

  • Ductus (Vas) Deferens
  • Nerves
  • Blood Vessels

  Contractions of Vas Deferens: muscular layers propels the sperm

  cells.
• ACCESSORY GLANDS:

  SEMINAL VESICLES: Lie on the posterior wall of the bladder and secrete 60% of the volume of semen

  Seminal fluid:

  • Fructose: provides energy for the sperm.
  • Fibrinogen: helps turn semen into a bolus that can be readily propelled into the vagina.

  Join the ductus deferens to form the ejaculatory duct
• ACCESSORY GLANDS:

  PROSTATE GLAND

   Walnut-shaped gland that encircles part of the

  urethra inferior to the bladder

   Role: activation of sperm (secretes a milky substance

  that makes up around 20 to 30 percent of semen)

   Primary Function: produce the fluid that nourishes

  and transports sperm (seminal fluid)

   Enters the prostatic urethra during ejaculation

  Prostatic secretions include:

   Citrate: is a food source

   Proteolytic enzymes: acts to "decoagulate" the semen that was

  coagulated by seminal vesicle secretions, which helps the

  sperm begin their journey once inside the vagina
• POSTERIOR BLADDER

  
• BULBOURETHRAL GLANDS

  (COWPER’S GLANDS)

   Pea-sized glands inferior to the prostate

   Exocrine glands

   Produce Pre- ejaculate Fluid prior to ejaculation that neutralizes traces of acidic urine in the urethra
• PENIS

  • conveys urine and semen  body is comprised of two tissue types of erectile tissue surrounded by connective tissue
  • Corpus Cavernosum - contains spongy erectile tissue; to facilitate penile erections
  • Corpus Spongiosum - surrounds the urethra; corpus spongiosum enlarges at the tip - glans penis (sensory receptors)
  • Glans penis covered with a loose fold of skin = Prepuce or Foreskin
• URETHRA

  • Prostatic Urethra - runs through the prostate and connects to ducts from the prostate and to the ejaculatory duct (ampulla of vas deferens fuses with duct of seminal vesicle)
  • Membranous urethra - between prostate and penis
  • Spongy urethra - through the erectile tissue of the
  • penis
  • Urethra passageway for urine and male reproductive fluids.
• SPERM SUMMARY

  • Produced: Seminiferous tubules
  • Stored: Epididymis
  • Transported through epididymis by rhythmic peristaltic contractions as they mature
• • Testis→ Epididymis →Vas Deferens → Ejaculatory duct → prostate Gland →prostatic urethra (then passes the bulbourethral gland) →membranous urethra → penile urethra
• BULBOURETHRAL GLANDS (COWPER’S GLANDS)- A Pea-sized glands inferior to the prostate that produce Pre-ejaculate Fluid prior to ejaculation that neutralizes traces of acidic urine in the urethra