Ch 27: Reproductive System General organization Anatomy of male repro. system Anatomy of female repro. system
General Organization Gonadsgametes & hormones Ductstransport of... ? Glandssecrete fluid Perineal structures = external genitalia
Anatomy of Male Repro System Primary reproductive organs produce gametes Secondary reproductive organs.... Male reproductive and urinary tracts are partially shared Fig 27-1
Male Reproductive System
Testes (paired glands) Develop adjacent to kidneys Descent into scrotum through inguinal canal Peritoneal lining carried along lining of scrotum Cryptorchidism (in 3% of full-term and 30% of premature deliveries) –Significance? –Treatment? month
Testes Descending testis carry with them: _________________ = spermatic cord Cremaster muscle Potential for Herniation!!
Scrotum Function: support and protect testes Skin & underlying superficial fascia Dartos muscle in subcutis Cremaster muscle (continuation of ___________ Involuntary contraction in response to ________ Scrotal sac forms 2 separate chambers
Structure of Testes Two tissue layers cover testes: –Tunica albuginea –Tunica vaginalis lobules 3 seminiferous tubules Longitudinal section Fig 27-5
Testes: Histology general view sectional view
From Spermatocyte to Spermatozoon Spermatogenesis: Meiosis of primary spermatocytes spermatids Spermiogenesis: Spermatid maturation into spermatozoa within Sertoli cells Spermiation: Spermatozoon released into lumen 27-5
Spermatogonion = stem cell 1 o spermatocyte 2 o spermatocytes Spermatids Spermatozoa Spermatogenesis
Spermiogenesis Sustentacular cell (= Sertoli cells)
Spermiogenesis II
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 ÊHead with acrosome ËMidpiece with lots of ? ÌFlagellum (rotating in corkscrew fashion)
Epididymis ~ 7 m long Sperm-maturation Recycling of damaged spermatozoa Adjusting composition of tubular fluid (stereocilia!!) Functions:
Path of Spermatozoa from tail of epididymis: ductus (vas) deferens Ampulla ejaculatory duct urethra
Path of Sprmatozoa
Capacitation Activation of spermatozoa Occurs after spermatozoa leave epididymis and come in contact with seminal fluid. Final capacitation when exposed to conditions inside female reproductive tract Semen = Seminal fluid + Sperm
The Accessory Glands. Provide for 95% of the seminal fluid Seminal vesicles Prostate gland 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 (Cowper’s glands) Pea size Alkaline secretion containing lots of mucus. function??
Erectile Tissue Corpora cavernosa Corpus spongiosum Penis has 3 cylindrical columns Penis is contrary to popular believe not the primary male sex organ! Circumcision =?