Sexual Development Genitals for both sexes develop from 3 identical structures Genital tubercle: an anterior bud that becomes the glands or clitoris Urogenital folds: tissue folds that lie lateral to the tubercle Labioscrotal folds: larger pair of tissue that lie lateral to the urogenital folds
Sexual Development Those 3 structures start to show sexual development around week 9 and by week 12 sex is distinctive Since genitals develop from the same tissue the penis is homologous to the clitoris and the scrotum is homologous to the labia majoria Testes develop by the kidneys and are pulled into the scrotum by the gubernaculum
Male Anatomy Perineum: a diamond shaped region that contains the genitals and anus Scrotum: a divided pouch that contains the testes Median septum: marked by the perineal raphe, extends from the penis to the anus Testes cannot produce sperm at body temp, the scrotum is about 2C cooler, testes are raised or lowered for best temp
Testes Testes produce sperm Tunica albuginea: is a white fibrous capsule, protection, fight infection The testes are divided into wedge shaped lobules that contain seminiferous tubules where sperm is produced The tubules lead into the rete testis where sperm partially mature
Sperm Ducts Efferent ductules: carry sperm to the epididymis Epididymis: sperm fully matures and are stored, sperm are fertile for days then die and are reabsorbed Vas Deferens: a long muscular tube that connects the testes to the ejaculatory duct Ejaculatory duct: short tube where sperm, prostate fluid and vesicle fluid are mixed to become semen as it enters the urethra
Semen Seminal vesicles: 60% of the semen neutralizes vaginal secretions, has fructose for energy and is sticky to ensure sperm sticks to vaginal walls so they don’t fall out Prostate: 30% of semen activates sperm Cowper's gland: produces clear fluid that coats glands for entry of vagina Sperm: 10% of semen
Penis The penis function is to deliver sperm to vagina, has three parts root, shaft, glands Prepuce: layer of skin that covers the glands Erectile tissue: tissue that fills with blood to erect the penis Corpus sponginosum: single body that surrounds the urethra Corpus cavernosa: twin bodies that are inferior to the sponginosum