Microscopic Structure of the Male Genital Organs Dr. Sama-ul-Haque Dr Rania Gabr

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.

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

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

Testis Seminiferous tubules: Stratified epithelium (germinal epithelium) contains two types of cells 1.Spermatogenic cells: Produce Sperms 2.Sertoli cells (Sustentacular cells): For nourishment

Testis Fibrous Septa: Extending from mediastinum testis towards the tunica albuginea Interstitial cells (of Leydig): Epithelial cells, secrete testosterone (male sex hormone)

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

Seminiferous tubules, Straight tubules, Rete testis & Ductuli efferentes

Spermatogenesis in Seminiferous tubules

SPERMATOGENIC CELLS (1) Spermatogonia: (2) 1ry Spermatocytes. (3) 2ry Spermatocytes. (4) Spermatids. (5) Spermatozoa.

Stages of Spermatogenesis Spermatogonia (Immature Spermatogenic cells) Divide into three types: 1.Pale Type A Spermatogonia 2.DarkType A Spermatogonia 3.Type B Spermatogonia Type B Spermatogonia produces Primary Spermatocytes

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

Stages of Spermatogenesis

Seminiferous tubules

Ductuli efferentes & Tubules of the Ductus Epididymis

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

Tubules of the Ductus Epididymis

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

Ductus (Vas Deferens)

Ampulla of Vas Deferens Lumen is larger then vas deferens Numerous irregular, branching mucosal folds Deep Glandular Crypts Simple Columnar Epithelium

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)

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

Prostate Gland & Prostatic Urethra

Prostate Gland (Glandular Acini & Prostatic Concretions)

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

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

Seminal Vesicle

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

Penis Tunica Albuginea (Thin layer of connective tissue with smooth muscle fibers & elastic fibers) surrounds Corpus Spongiosum Deep Penile (Buck’s) Fascia (Loose connective tissue surrounding all) Dermis (Contains Smooth muscle “dartos”) Epidermis (Stratified squamous keratinized Epithelium)

Penis

Thank you