Male Reproductive System PDF

The Male Reproductive System Layne Dorrington  Components Testes Duct System Glands External Genitalia Testes Egg shaped structures which are housed in the scrotum Contain seminiferous tubules in where sperm are actually produced within the walls of these tubules. Where spermatogenesis...

The Male Reproductive System Layne Dorrington  Components Testes Duct System Glands External Genitalia Testes Egg shaped structures which are housed in the scrotum Contain seminiferous tubules in where sperm are actually produced within the walls of these tubules. Where spermatogenesis takes place. Spermatogenesis Process of sperm development 4 stages/steps 1) Spermatogonia – look like normal cells, stem cells 2) Spermatocytes 3) Spermatids 4) Spermatozoa – the developed sperm, no longer attached to the walls and enter lumen Developed sperm have three parts: tail, middle, and head Sertoli Cells Very important for sperm development Support spermatogenesis by nurturing their development: provide nutrients and chemical stimuli Stimulated by FSH and testosterone Maintain blood-testes barrier which protects the sperm cells from the bodys immune system – the immune system will kill the sperms Leydig cells In the tissue surrounding seminiferous tubules Responsible for produced Testosterone when stimulated by LH Testosterone Stimulates spermatogenesis Promotes libido establishes secondary male sex characteristics maintains male glands and organs of reproduction Hormone Flow chart FSH LH Sertoli Cells Leydig Cells Testosterone Spermatogenesis Libido, characteristics, reproductive Sperm cells tract Duct System Epididymis Ductus Deferens Ejaculatory Duct Urethra Epididymis First part of duct system Primary sperm storage Protects sperm recycles damaged spermatozoa Sperm leaving the epididymis are still immobile Think quality control Ductus Deferens Second part Also known as vas deferens Stores sperm for several months Smooth muscle in the wall Contraction propels semen (sperm and fluids) Part of spermatic cord Spermatic cord Encompasses the components after the testes including the ductus deferens, nerves, blood vessels, and surrounding layers The spermatic cord must pass through the inguinal canal which is a way out the anterior abdominal wall Ejaculatory duct Joining of the vas deferens and seminal vesicle Travels through prostate gland Empties into urethra Urethra First part travels through prostate Most travels through the penis which releases semen Semen = sperm and fluids glands Seminal vesicles produce most of the semen volume (~60%) Prostate Gland forms 20-30% of semen volume Bulbourethral glands – lubricates urethra and surface of glans External Genitalia Penis – releases urine or semen, shaft/body composed of cylindrical columns of erectile tissue, distal or end of penis is known as the glans penis Scrotum – pouch, 2 chambers with each teste in its own chamber Two muscle types: Dartos muscle – smooth muscle, causes wrinkling Cremaster muscle – skeletal muscle, spermatic cord component, temperature regulation  Male Sex Response 3 coordinated processes – order specific Erection – parasympathetic response Blood flow increased, penis stiffens Emission – sympathetic response Peristaltic movement, pushes semen into urethra Ejaculation – somatomotor response Pushes semen out of opening, accompanied by orgasm Questions?