Microscopic Structure of the Male Genital Organs

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Microscopic
Structure of the Male Genital Organs

• Dr. Sama-ul-Haque

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Objectives

• Describe the microscopic structure of the testis.
• Describe the microscopic structure of the
  epididymis and ductus deferens.
• Discuss the microscopic structure of the seminal
  vesicle and prostate gland.
• Discuss the microscopic structure of the penis.

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INTRODUCTION

• Male gonad
• Testis
• A paired duct system
• Ductuli efferentes, epididymis, ductus deferens
  and ejaculatory duct
• Exocrine glands
• Seminal vesicles and prostate gland
• Penis

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Testis

• Tunica Albuginea
• Connective tissue capsule
• Tunica Vasculosa
• Vascular layer of loose connective tissue
• Interstitial connective tissue
• Connective tissue extends inward from the
• tunica Vasculosa

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Testis

• Seminiferous tubules
• Stratified epithelium (germinal epithelium)
  contains two type of cells
• 1. Spermatogenic cells Produce Sperms
• 2. Sertoli cells (Sustentacular cells)
• For nourishment
• Fibrous Septa
• Extending from mediastinum testis towards
• the tunica albuginea
• Interstitial cells (of Leydig)
• Epithelial cells, secrete testosterone (male
  sex hormone)

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Testis
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Straight tubules, Rete testis Ductuli efferentes

• Straight tubules
• Cuboidal or low columnar epithelium
• Rete Testis
• Simple squamous to low cuboidal or low columnar
  epithelium
• Ductuli efferentes (Efferent ductules)
• Epithelium contains two group of cells
• 1. Tall columnar cells with cilia
• 2. Cuboidal cells with microvilli

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Seminiferous tubules, Straight tubules, Rete
testis Ductuli efferentes
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Spermatogenesis in Seminiferous tubules
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SPERMATOGENIC CELLS

• (1) Spermatogonia
• (2) 1ry Spermatocytes.
• (3) 2ry Spermatocytes.
• (4) Spermatids.
• (5) Spermatozoa.

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Stages of Spermatogenesis

• Spermatogonia (Immature Spermatogenic cells)
• Divide into three types
• 1. Pale Type A Spermatogonia
• 2. Dark Type A Spermatogonia
• 3. Type B Spermatogonia
• Type B Spermatogonia produces Primary
  Spermatocytes

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Stages of Spermatogenesis

• Type B Spermatogonia produces Primary
  Spermatocytes
• Primary Spermatocytes produces Secondary
  Spermatocytes (1st Meiotic Division)
• Secondary Spermatocytes produces Spermatids (2nd
  Meiotic Division)
• Spermatids differentiate into Sperms by the
  process of Spermiogeneis

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Stages of Spermatogenesis
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Seminiferous tubules
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Ductuli efferentes Tubules of the Ductus
Epididymis
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Tubules of the Ductus Epididymis

• Pseudostratified Columnar Epithelium
• Principal cells Tall Columnar epithelium with
  Stereocilia (Long branching Microvilli)
• Basal Cells
• Thin Layer of Smooth Muscle surrounds each tubule
• Tubules surrounded by Connective tissue

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Tubules of the Ductus Epididymis
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Ductus (Vas) Deferens

• Irregular lumen with longitudinal mucosal Folds
• Lumen is lined by Pseudostratified Columnar
  Epithelium with Stereocilia
• Thin Mucosa
• Thick Muscularis (Three Smooth Muscle Layers)
• 1. Inner Longitudinal
• 2. Middle Circular
• 3. Outer Longitudinal
• Adventitia

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Ductus (Vas Deferens)
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Ampulla of Vas Deferens

• Lumen is larger then vas deferens
• Numerous irregular, branching mucosal folds
• Deep Glandular Crypts
• Simple Columnar Epithelium

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Prostate Gland

• Prostatic urethra lined by Transitional
  epithelium
• Small, branched tubuloacinar prostatic glands
• Prostatic Concretions (Corpora Amylacea) Solid
  Secretory Aggregations in the Acini
• Fibromuscular Septa with Smooth muscle bundles
• Colliculus Seminalis Smooth dome-shaped
  structure of dense fibromuscular stroma (Gives
  crescent shape to prostatic urethra)

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Prostate Gland

• Prostatic sinuses (Excretory ducts of prostatic
  glands open here)
• Prostatic utricle is a sac in the middle of
  colliculus seminalis
• Ejaculatory ducts open at colliculus seminalis

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Prostate Gland Prostatic Urethra
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Prostate Gland (Glandular Acini Prostatic
Concretions)
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Seminal Vesicle

• Convoluted and Irregular Lumina
• Primary mucosal folds branch into Secondary
  mucosal folds
• Secondary mucosal folds anastomose and form
  irregular cavities called Mucosal Crypts

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Seminal Vesicle

• Lamina Propria projects into these folds
• Glandular epithelium is low columnar or cuboidal
• Two layers of smooth muscle
• 1. Inner circular layer
• 2. Outer longitudinal layer
• Adventitia

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Seminal Vesicle
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Penis

• Two Dorsal Corpus Cavernosa
• Single Ventral Corpus Spongiosum carrying urethra
  in its whole length
• Trabeculae with collagenous, elastic smooth
  muscle fibers surround form cavernous sinuses
  (veins)
• Tunica Albuginea (Thick Connective tissue
  capsule)
• surrounds Corpus Cavernosa forms Median
• Septum

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Penis

• Tunica Albuginea (Thin layer of connective tissue
  with smooth muscle fibers elastic fibers)
• surrounds Corpus Spongiosum
• Deep Penile (Bucks) Fascia (Loose connective
  tissue surrounding all)
• Dermis (Contains Smooth muscle dartos)
• Epidermis (Stratified squamous keratinized
  Epithelium)

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Penis
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Thank you