Anatomy of Male Repro System Primary reproductive organs produce gametes Secondary reproductive organs.... Male reproductive and urinary tracts are partially shared Fig 27-1
Testes (paired glands) Develop adjacent to kidneys Descend into scrotum through inguinal canal Peritoneal lining is carried along lining of scrotum Cryptorchidism (in 3% of full-term and 30% of premature deliveries)Cryptorchidism –Significance? –Treatment? Fig month
Scrotum Function: supports and protects testes Structure: Skin & underlying superficial fascia –Dartos muscle in subcutis –Cremaster muscle deep to dermis (continuation of ___________) Involuntary contraction (cremasteric reflex) in response to ________ Scrotal sac forms 2 separate chambers Cremaster muscle
Structure of Testes Two tissue layers cover testes: –Tunica albuginea –Tunica vaginalis lobules 3 seminiferous tubules Fig 27-4/5
From Spermatocyte to Spermatozoon Spermatogenesis: Meiosis of primary spermatocytes spermatidsSpermatogenesis Spermiogenesis: Spermatid maturation into spermatozoa within Sertoli cellsSpermiogenesis Spermiation: Spermatozoon released into lumen
Sustentacular (Sertoli) Cells Maintenance of blood testis barrier »special lumen fluid »sperm specific ag Support of spermatogenesis »FSH and Testosterone work via Sertoli cells Support of spermiogenesis Secretion of inhibin Secretion of androgen-binding protein (ABP)
Anatomy of Spermatozoon Mature sperm has 3 portions 1.Head with acrosome 2.Midpiece with lots of ? 3.Flagellum (rotating in corkscrew fashion) See fig 27-6
Epididymis ~ 7 m long 1.Sperm-maturation 2.Recycling of damaged spermatozoa 3.Adjusting composition of tubular fluid (stereocilia!!) Functions:
Path of Spermatozoa from tail of epididymis: ductus (vas) deferens ampulla ejaculatory duct urethra
Capacitation Activation of spermatozoa Occurs after spermatozoa leave epididymis and come in contact with seminal fluid. Seminal fluid + Sperm = Semen Final capacitation when exposed to conditions inside female reproductive tract
The Accessory Glands. Provide for 95% of the seminal fluid 1.Seminal vesicles 2.Prostate gland 3.Bulbourethral glands
Seminal Vesicles Produce 60% of seminal fluid Tubular glands (~ 15 cm) Secretion is rich in fructose leads to sperm motility
Prostate Gland 25% of seminal fluid Single, doughnut- shaped Secretion contains: –citrate –seminal plasmin –prostate specific antigen (PSA)
Bulbourethral glands (Cowpers glands) Pea size Alkaline secretion containing lots of mucus. function??
Erectile Tissue Penis has 3 cylindrical columns: One corpus spongiosum Two corpora cavernosa Corpora cavernosa Corpus spongiosum ??