Male Reproductive System

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Chapter 9

• Male Reproductive System

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Anatomy

• Spermatozoan
• Male sex cell
• 1/3 the size of a red blood cell
• Composed of head and tail regions
• Head contains chromosomes (23)
• Tail consists of flagellum which makes the sperm
  motile
  
• Approximately 300 million released during a
  single ejaculation
  
• Only one can penetrate a single ovum

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Anatomy
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Anatomy
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Anatomy
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Anatomy

• Fraternal Twins
• More than one egg fertilized at one time
• Develop in utero with separate placentas
• Identical Twins
• Single egg cell is fertilized
• Fertilized egg splits forming two embryos
• Share same placenta
• Always same sex and similar in form and feature

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Anatomy

• Testes (sing. testis)
• The male gonads (where gametes sex cells are
  produced)
  
• Typically paired
• Develop in the abdomen
• Eventually descend into the scrotum
• Sac outside the body
• Testes exposed to lower temperature being outside
  the body
  
• This aids in spermatogenesis

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Anatomy

• Perineum
• Lies between the scrotum and anus
• Analogous to perineal region in female
• Seminiferous tubules
• Large mass of coiled tubules composing interior
  of testis
  
• Parenchymal tissue of testis
• Performs essential work of organ
• Interstitial cells
• Also found inside testis
• Manufactures testosterone

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Anatomy

• Once formed sperm cells move through the
  seminiferous tubules into the epididymis
  
• Epididymis
• Coiled tube running the length of each testicle
• About 16 feet long
• Spermatozoa mature and become motile here
• Temporarily stores spermatozoa
• As it turns upwards to enter the body it
  straightens out and becomes the vas deferens

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Anatomy

• Vas deferens
• About 2 feet long
• Carries sperm into pelvic region
• Merges with the ducts from seminal vesicles to
  form ejaculatory duct

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Anatomy
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Anatomy

• Seminal vesicles
• 2 glands located at base of the bladder
• Secretes a thick sugary yellowish substance
  that nourishes the sperm cells
  
• Forms most of the volume of ejaculated semen
• Semen
• Combination of fluid and spermatozoa

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Anatomy

• Prostate gland
• Located near where vas deferens enter urethra
• Secretes fluid that aids in the motility of
  sperm
  
• Urethra
• Passes through the penis to outside of body
• Discharges urine and semen from male

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Anatomy

• Penis
• Composed of erectile tissue
• Forms a soft sensitive region called the glans
  penis
  
• Is normally covered by a fold of skin called the
  prepuce (foreskin)
  
• Is visible at all times if foreskin is removed

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Anatomy
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Anatomy
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Pathological ConditionsTestes

• Carcinoma of the testes
• Tumors are typically malignant (dangerous)
• Rare except in the 15-35 year old age group
• 4 types
• Seminoma (most common)
• Embryonal carinoma
• Teratoma (terat/o monster)
• Composed of tissue such as bone hair cartilage
  and skin cells
  
• Teratocarcinoma
• Treated with orchiectomy radiotherapy and
  chemotherapy
  

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Pathological ConditionsTestes

• Cryptorchism
• Undescended testicles
• Put male at high risk of sterility and testicular
  cancer
  
• If not descended by age 2 orchiopexy performed
• Orchi/o testes testicles
• -pexy fixation put in place

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Pathological ConditionsTestes
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Pathological ConditionsTestes

• Hydrocele
• -cele
• Hernia
• Swelling or protrusion
• Generalized edema or in response to infection or
  tumors
  
• Can differentiate from testicular masses by
  transillumination
  
• Hydrocelectomy may be necessary if hydrocele does
  not resolve on its own

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Pathological ConditionsTestes
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Pathological ConditionsTestes
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Pathological ConditionsTestes

• Testicular torsion
• Twisting of the spermatic cord
• Can cut off blood supply to the testis
• Common disorder in males around the age of
  puberty
  
• Arises suddenly with acute scrotal swelling and
  severe pain
  
• Requires intervention within 6 to 12 hours

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Pathological ConditionsTestes

• Variocele
• Enlarged dilated veins near the testicle
• Often associated with oligospermia and
  azoospermia
  
• Oligospermia a lack in quantity of sperm
• Azoospermia no sperm
• Varicocelectomy is recommended
• Spermatic vein is ligated
• Segment cut out and ends tied off

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Pathological ConditionsTestes
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Pathological ConditionsProstate

• Carcinoma of the prostate
• Malignant tumor of the prostate gland
• Commonly occurs in men over 50 years of age
• Early detection method is performed by a
  physician via rectal examination with finger
  palpation
  
• Diagnosis requires a prostate biopsy
• Transrectal ultrasound is used for placement of
  biopsy needle

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Pathological ConditionsProstate

• Carcinoma of the prostate (cont.)
• Treatment consists of prostatectomy radiation
  therapy and hormonal chemotherapy
  
• Prostate-specific antigen (PSA) is a tumor marker
  that is elevated in carcinoma of the prostate
  
• Normal level is 4.0 ng/mL or less

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Pathological ConditionsProstate
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Pathological ConditionsProstate

• Prostatic hyperplasia
• Benign growth of cells within the prostate
• Common in men over 60
• Common signs symptoms (SS) include
• Urinary obstruction
• Inability to empty bladder completely
• May be treated my drugs or surgery
• Surgical treatment is called transurethral
  resection (TURP)
  
• Resectoscope is inserted into penis through
  urethra
  
• Prostatic tissue removed by electrical hot loop
  attached to resectoscope

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Pathological ConditionsProstate
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Pathological ConditionsProstate
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Pathological ConditionsPenis

• Hypospadias
• Congenital opening of the male urethra on the
  undersurface of the penis
  
• Occurs in 1 of every 300 live births
• Can be corrected surgically
• Portion of prepuce is excised
• Then wrapped around a catheter
• Sutured to distal part of urethra
• Brought to exit at the tip of the penis

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Pathological ConditionsPenis
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Pathological ConditionsPenis

• Phimosis
• Narrowing of the opening of the prepuce
• Condition can interfere with urination therefore
  causing secretions to accumulate under the
  prepuce leading to infection
  
• Treatment is circumcision

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Pathological ConditionsPenis
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Pathological ConditionsPenis
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Laboratory Tests

• PSA assay
• PSA prostate-specific antigen
• Assay test designed to see the components of a
  substance
  
• Looks for elevated levels of PSA in blood
• Associated with prostatic enlargement and
  prostate cancer

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Laboratory Tests

• Semen Analysis
• Done as part of fertility studies
• Required to establish effectiveness of vasectomy
• Specimen is collected in sterile container and
  analyzed microscopically
  
• Sperm cells are counted and examined for motility
  and shape
  
• Fewer than 20 million sperm/mL indicates
  sterility
  
• Fever or infection may cause temporary sterility
• Mumps in adult males may cause the testes to
  become inflammed and sperm cells deteriorate
  resulting in sterility
  

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Clinical procedures

• Castration
• Orchiectomy in males
• Oophorectomy in females
• If male is castrated before puberty he becomes a
  eunuch
  
• Organs remain childlike and does not develop
  secondary sex characteristics

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Clinical procedures

• Circumcision
• Removal of prepuce from the penis
• Digital Rectal Examination
• Examination of the prostate gland using finger
  palpation through the rectum
  
• Transurethral resection of the prostate (TURP)
• A resectoscope is inserted into the urethra and
  pieces of the prostate gland are removed
  

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Clinical procedures

• Vasectomy
• Both vas deferens are cut sections removed and
  free ends folded and ligated
  
• Performed under local anesthesia
• Incision is made in the scrotal sac
• Does not interfere with nerves or blood vessle
  supply to the testes and penis so hormone
  secretion sex drive and potency are not
  impaired
• A small percentage of vasectomies can be
  reversed
  

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Clinical procedures