PSYCH 230 1st Edition Lecture 9 Outline of Last Lecture I. External Sex Organs II. The PenisIII. Penis Size and Male AnxietyIV. The Glans PenisV. The Root to the Penis VI. ErectionVII. The ScrotumOutline of Current Lecture Male Sexual Anatomy and Physiology I. The Testicles II. Testosterone ProductionIII. Spermatogenesis IV. Ejaculatory PathwayV. Pre-Ejaculatory FluidVI. Ejaculate/Semen VII. Human Ejaculate Current Lecture I. The Testicles a. 2 egg shaped glands in the scrotumb. 2 in. long 1 in. in diameterc. Typically 1 (usually the left) hangs a bit lower to allow sliding past rather than compressiond. 2 primary functions- Testosterone production- Spermatogenesis II. Testosterone Production a. Testosterone is the most important male hormone b. Interstitial, or Leydig, cells in the testicles produce testosterone out of cholesterolIII. SpermatogenesisThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.a. Seminiferous tubules produce and store sperm (uncoiled would extend over a mile)b. Sertoli cells (in the tubules) provide nutrition for the development of sperm c. This process begins with spermatogonium on the outer wall of the tubules they move toward the center during development as primary spermatocytes, then divide to form secondary spermatocytes, and divide again into spermatids d. Spermatids form the compact head covered by an acrosome that contains enzymes to penetrate the egge. The midpiece is formed and serves as the energy source f. The flagellum propels the mature spermg. Sperm production takes 72 days but is constant and each male produces about 300 million sperm a dayh. Immature sperm travel from the tubules to the epididymis; organ that rests atopthe testicle i. Epididymis is comma shaped, contains tubules that would be about 20ft uncoiledj. Old and faulty sperm are reabsorbed here k. They mature in 10-14 days in the epididymis l. Upon maturity they are transferred to the vas deferens for storagem. Can be stored for several monthsIV. Ejaculatory Pathwaya. Ejaculation- physiological process where seminal fluid is powerfully expelled fromthe penis. A spinal reflex, like erection, but seldom a “partial” ejaculation b. During ejaculation, sperm pass through the epididymis the vas deferens, the ejaculatory duct and the urethrac. Fluids is picked up from the seminal vesicles, the prostate gland, and the bulbourethral d. Pathway Organs- Vas Deferens: 18 in. tube that carries sperm from the testicles (epididymis) combines fluids from other glands and propels the sperm - Seminal Vesicles: next to the ampulla of the vas deferens; secretes a nutritional bath for travelling sperm; 60-70% of the ejaculate volume; joins the vas deferens to form the ejaculatory duct that passes into the prostate and then forms the urethra - Prostate Glands: walnut sized gland beneath the bladder; secretes a fluid thatneutralizes the acidity of the vagina that would be lethal to sperm; 25-30% of the ejaculate’s volume- Cowper’s (bulbourethral) glands: 2 pea sized glands next to urethra, under the prostate; contributes fluid that cleans the urethra of acidic urine; comprises the majority of the pre-ejaculatory fluid; may contain live spermV. Ejaculation a. Begins in the spinal cord once a threshold is reached, and proceeds until the conclusionb. Once the threshold is reached:- Epididymis, seminal vesicles, and prostate empty their fluids into the urethral bulb- A sphincter closes off the bladder- 5-15 contractions at the base of the penis squeeze the urethral bulb- Ejaculate is expelled- Orgasm- Return to flaccid stateVI. Ejaculate/Semena. 2-5 milliliters of fluid (1-2) teaspoonb. 50-150 million sperm per milliliter/ 500 million altogetherc. If less than 20 million, likely to be infertiled. Few Sperm reach ovum e. Sperm work together in order to fertilize the eggf. Many die to plug up the Os of the cervix for other spermg. The combined enzyme production of all sperm are necessary for a single spermatozoa to fertilize the ovumh. Semen coagulates upon ejaculation; this helps it remain in the vagina and travel into the uterus i. 5-20 minutes later it thins outVII. Human Ejaculate a. About 1 teaspoonb. About 15 calories c. High in proteind. No nutritional