Testicle : Anatomy and function

A.  Functions

1.  Produce male germ cells (spermatozoa)

2.  Produce male hormone (testosterone)

3. Produce inhibin and estrogen, and other proteins

B.  Structure

1.  Tunica vaginalis

a.  Thin membrane

b.  Provides support

c.  From peritoneum

2.  Tunica albuginea

a.  Connective tissue

b.  Provides structure

3.  Mediastinum

a.  Connective tissue

1. Provides internal support
   4.  Seminiferous tubules
   part of the testicular parenchyma
   a.  Site of sperm production
   b. Consists of 2 cell types 
   - Germ cells (eventual sperm cells)
   - Sertoli or nurse cells which produces variety of substances including androgen binding hormone, sulfated glycoprotein, transferin, and inhibin
   - Surround developing germ cells
   - Providing structural and metabolic support to the developing spermatogenic cells
   3.  Blood-testis Barriers
   a. Cells surrounding the seminiferous tubules
   b. Prevent autoimmune reaction from destroying the developing germ cells
   5.  Interstitial or Leydig cells
   a.  Located between seminiferous tubules
   b.  Produce androgens (testosterone)
   6.  Rete testis
   a.  Collect sperm from seminiferous tubules
   7.  Vasa efferentia (efferent ductules)
   a.  Collect sperm from rete testis
   b.  Carry sperm out of testis proper