The Male Reproductive System

The male reproductive system Xu Jin Department of Anatomy Chongqing Medical University

overview Function genital

cells---sperm, to maintain the life of species sexual hormone, to maintain the 2nd sexual characteristics for male, such as, compared with female, the laryngeal prominence is higher, the muscles are stronger, the beard and hairs are highly developed.

Formation Internal genital organs The gonad---testis A series of ducts conveying the sperm: epididymis / ductus deferens / ejaculatory ducts / urethra  Accessory glands: prostate / seminal vesicles / bulbourethral gland  

External genital organs scrotum penis

The internal genital organs The gonad---tetis The external features——oval-shaped ； it has 2 extremities, 2surfaces, 2 borders

( free anterior & posterior attached by epididymis)

The structures of testis tunica vaginalis has 2 layers (viscer layer, parietal layer) tunica albuginea (dense connective tissue) enclose the testis and thickened on the post. border of testis to form mediastinum septa testis dividing the testis into the lobules each lobule of testis contains: contorted seminiferous tubules straight seminiferous tubules rete testis (in the mediastinum) efferent ductules of testis

The conveying ducts epididymis——comma-shaped having head, body, tail and duct of epididymis

ductus deferens parts testicular part: shortest part  funicular(spermatic) part: can be palpated inguinal part pelvic part: longest part ampulla of ductus deferentis 

ejaculatory duct

terminal portion of ductus deferentis and the excretory duct of seminal visicle join together to form ejaculatory duct opening to the portion of the prostatic part of urethra.

Accessory glands prostate: chestnut-shaped; between the urinary bladder and

urogeniatal diaphragm seminal vesicle: oval-shaped; lateral to the ampulla ductus deferentis  bulbourethral gland: pea-sized; inferior to the prostate

The external genital organs scrotum:pendulous sac of skin

penis   

cavernous body of penis cavernous body of urethra prepuce (neck-the skin folded upon itself)

Male urethra 3parts prostatic

part: widest; seminal colliculus / prostatic utricle membranous part: narrowest and shortest; cavernous part: longest; 2curvatures subpubic curvature prepubic curvature

3constrictions internal urethral orifice membranous part external urethral orifice

Summary 1.The passages conveying the sperm Contorted seminiferous tubules (where the sperm is produced) straight seminiferous tubules of testis epididymis

rete testis deferent duct

efferent ductucles ejaculatory duct

(terminal portion) urethra excretory duct of Seminal vesicle Out of body

2.The parts and characteristics of male urethra 3constrictions internal orifice of urethra membranous part external orifice urethra

2curvatures subpubic curvature prepubic curvature

3.The tunica vaginalis of testis and the tunical vaginalis cavity Tunica vaginalis originated from peritoneum, which can be divided into Parietal layer Visceral layer