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Ch 27: Reproductive System. General organization Anatomy of male reproductive system Anatomy of female reproductive system. General Organization. Gonads gametes & hormones Ducts transport of . . . ? Glands secrete fluid Perineal structures = external genitalia.
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Ch 27: Reproductive System General organization Anatomy of male reproductive system Anatomy of female reproductive system
General Organization Gonads gametes & hormones Ducts transport of . . . ? Glands secrete 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
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) • Significance? • Treatment? 4 month Fig 27-2
Cremaster muscle 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
Structure of Testes • Two tissue layers cover testes: • Tunica albuginea • Tunica vaginalis • 200-300 lobules • 3 seminiferous tubules Fig 27-4/5
From Spermatocyte to Spermatozoon • Spermatogenesis: Meiosis of primary spermatocytes spermatids • Spermiogenesis: Spermatid maturation into spermatozoa within Sertoli cells • 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 • Head with acrosome • Midpiece with lots of ? • Flagellum (rotating in corkscrew fashion) See fig 27-6
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
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 • 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??
Corpora cavernosa Corpus spongiosum Erectile Tissue Penis has 3 cylindrical columns: One corpus spongiosum Two corpora cavernosa ??