BIOH 370 1st editionLecture 32 Outline of Last Lecture Fluid, Electrolyte and Acid-Base Balance Lecture Day 3, Reproductive System LectureI. Summary of Acidosis and AlkalosisII. Electrolyte Developmental Aspectsa. Infantsb. At Pubertyc. ElderlyIII. Reproductive Systema. Primary Sex Organsb. Accessory Reproductive Organsc. Sex HormonesIV. Male Reproductive Systema. Male Reproductive Organsi. Testesii. Spermiii. Accessory sex glandsiv. Scrotumv. Testesb. Spermatogenesisi. Sustentacular CellsThese 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.ii. Meiosis Gametesiii. Steps in Spermatogenesisc. Hypothalamic-pituitary-gonadal (HPG) AxisOutline of Current Lecture Reproductive System Day 2I. Mechanism and Effects of Testosterone ActivityII. Male Secondary Sex CharacteristicsIII. SemenIV. Testicular Cancer- Stage I- Stage II- Stage IIIV. The Four Components of the Male Duct SystemVI. The PenisVII. EpididymisVIII. Ductus Deferens and Ejaculatory DuctIX. Accessory Glands: Seminal Vesicles and Prostate GlandX. Male Sexual ResponseXI. Am I Normal?- Paper/studyXII. CircumcisionXIII. Peyronie’s DiseaseXIV. Female Reproductive System- OvariesXV. OogenesisCurrent LectureReproductive System Day 2I. Mechanism and Effects of Testosterone Activity- Testosterone and dihydrotestosterone produce several effects:o Prenatal developmento Development of male sexual characteristicso Development of sexual function o Stimulation of anabolism- A negative feedback system controls the blood level of testosterone.- Testosteroneo Synthesized from cholesterolo Transformed to exert its effects on sometarget cells Dihydrotestosterone (DHT) in theprostate Estrogen in some neurons in the brainII. Male Secondary Sex Characteristics- Features induced in the nonreproductive organs by male sex hormones (mainly testosterone)o Appearance of pubic, axillary, and facial hairo Enhanced growth of the chest and deepening of the voiceo Skin thickens and becomes oilyo Bones grow and increase in densityo Skeletal muscles increase in size and massIII. Semen- Mixture of sperm and accessory gland secretions- Contains nutrients (fructose), protects and activates sperm, and facilitates their movement (e.g., relaxin)- Prostaglandins in semen- Decrease the viscosity of mucus in the cervix- Stimulate reverse peristalsis in the uterus- Alkalinity neutralizes the acid in the male urethra and female vagina- Antibiotic chemicals destroy certain bacteria- Clotting factors coagulate semen just after ejaculation, then fibrinolysin liquefies it- Only 2–5 ml of semen are ejaculated, containing 20–150 million sperm/mlIV. Testicular Cancer- Most common form of cancer in men between the ages of 15 and 35- Two main types of testicular cancer: seminomas and nonseminomas that grow from germ cells- Symptoms:o Discomfort or pain in the testicle, or a feeling of heaviness in the scrotumo Pain in the back or lower abdomeno Enlargement of a testicle or a change in the way it feelso Excess development of breast tissue (gynecomastia), however, this can occur normally in adolescent boys who do not have testicular cancero Lump or swelling in either testicle- Treatments:o Orchiectomy: surgical removal of testicleo Radiation Therapyo Chemotherapy- Stage I: Cancer has not spread beyond the testicle- Stage II: Cancer has spread to lymph nodes in the abdomen- Stage III: Cancer has spread beyond the lymph noesV. The Four Components of the Male Duct Systemo Epididymuso Ductus Deferenso Ejaculatory Ducto UrethraVI. The Penis:- Spongy urethra and three cylindrical bodies of erectile tissue (spongy network of connective tissue and smooth muscle with vascular spaces)o Corpus spongiosum surrounds the urethra and expands to form the glans and bulb o Corpora cavernosa are paired dorsal erectile bodies - Erection: erectile tissue fills with blood, causing the penis to enlarge and become rigidVII. Epididymis:- Head: contains the efferent ductules - Duct of the epididymiso Microvilli (stereocilia) absorb testicular fluid and pass nutrients to stored sperm- Nonmotile sperm enter, pass slowly through, and become motile- During ejaculation the epididymis contracts, expelling sperm into the ductus deferensVIII. Ductus Deferens and Ejaculatory Duct:- Duct us deferenso Passes through the inguinal canalo Expands to form the ampulla and then joins the duct of the seminal vesicle to form the ejaculatory duct- Propels sperm from the epididymis to the urethra- Vasectomy: cutting and ligating the ductus deferens, which is a nearly 100% effective form of birth control- sperm doesn’t make it past ductus deferens- still will ejaculate, justejaculate without spermIX. Accessory Glands: Seminal Vesicles and Prostate Gland- Seminar Vessicleso Produces viscous alkaline seminal fluid o Fructose, ascorbic acid, coagulating enzyme (vesiculase), and prostaglandins o 70% of the volume of semen- Duct of seminal vesicle joins the ductus deferens to form the ejaculatory duct- Prostate Glando Encircles part of the urethra inferior to the bladdero Secretes milky, slightly acid fluid: Contains citrate, enzymes, and prostate-specific antigen (PSA) Plays a role in the activation of sperm Enters the prostatic urethra during ejaculation- Cowper’s Glando Pea-sized glands inferior to the prostateo Prior to ejaculation, produce thick, clear mucus Lubricates the glans penis Neutralizes traces of acidic urine in the urethraX. Male Sexual Response:- Erection:-parasympathetic reflexo Parasympathetic reflex promotes release of nitric oxide (NO)o NO causes erectile tissue to fill with bloodo Expansion of the corpora cavernosa Compresses drainage veins and maintains engorgemento Corpus spongiosum keeps the urethra open o Enlargement and stiffening of the penis from engorgement of erectile tissue with bloodo Initiated by sexual stimuli, including: Touch and mechanical stimulation of the penis  Erotic sights, sounds, and smellso Can be induced or inhibited by emotions or higher mental activity o Impotence: the inability to attain erection- Ejaculation- sympathetic responseo Propulsion of semen from the male duct systemo Sympathetic spinal reflex causeso Ducts and accessory glands to contract and empty their contentso Bladder sphincter muscle to constrict, preventing the expulsion of urineo Bulbospongiosus muscles to undergo a rapid series of contractions- Viagra/Cialis: increase