Male Reproductive System Study Guide PDF

Study Guide: Male Reproductive System 1. Define gonad and gamete. Explain the relationship between the terms. Gonad: The primary reproductive organ that produces gametes. In males, the gonad is the testes, which produce sperm. Gamete: A mature reproductive cell that unites with...

Study Guide: Male Reproductive System 1. Define gonad and gamete. Explain the relationship between the terms. Gonad: The primary reproductive organ that produces gametes. In males, the gonad is the testes, which produce sperm. Gamete: A mature reproductive cell that unites with another of the opposite sex to form a zygote. In males, the gamete is sperm. Relationship: The gonad produces the gametes. In males, the testes are responsible for producing sperm (male gametes). 2. Define male, female, sperm, and egg. Male: The sex that produces small, motile gametes (sperm). Female: The sex that produces larger, non-motile gametes (eggs or ova). Sperm: The male gamete, produced by the testes, that fertilizes the female egg. Egg: The female gamete, produced by the ovaries, that can be fertilized by sperm. 3. What are mesonephric and paramesonephric ducts? What factors determine which one develops and which one regresses in the fetus? Mesonephric ducts (Wolffian ducts): These ducts develop into male reproductive structures like the epididymis, vas deferens, and seminal vesicles. Paramesonephric ducts (Müllerian ducts): These ducts develop into female reproductive structures such as the uterus, fallopian tubes, and upper vagina. Factors determining development: The presence of testosterone promotes the development of the mesonephric ducts, while the presence of anti-Müllerian hormone (AMH) causes the regression of the paramesonephric ducts in males. In females, the absence of AMH allows the paramesonephric ducts to develop. 4. What male structure develops from the genital tubercle and urogenital folds? What develops from the labioscrotal folds? Genital tubercle and urogenital folds: The penis develops from the genital tubercle, and the urethra forms from the urogenital folds in males. Labioscrotal folds: The scrotum develops from the labioscrotal folds in males. 5. Describe the pathway taken during descent of the male gonad. The male gonad (testes) descends from the abdominal cavity into the scrotum during fetal development. This journey passes through the inguinal canal and is guided by the gubernaculum, a fibrous cord. 6. Define the wonderful word: Gubernaculum.  Gubernaculum: A fibrous cord that helps guide the descent of the testes into the scrotum during fetal development. 7. State the names and locations of two muscles that help regulate the temperature of the testes. Cremaster muscle: Found in the spermatic cord, it elevates or lowers the testes to regulate temperature. Dartos muscle: Found in the scrotal wall, it contracts to wrinkle the scrotum, helping to reduce heat loss. 8. Name three types of cells in the testes and describe their locations and functions. Sertoli cells (Nurse cells): Located in the seminiferous tubules, they nourish and support developing sperm cells. Leydig cells (Interstitial cells): Located in the spaces between the seminiferous tubules, they produce testosterone. Spermatogonia: Located in the seminiferous tubules, these are the stem cells that divide to produce sperm. 9. Name all the ducts that the sperm follow, in order, from the time they form in the testis to the time of ejaculation. 1. Seminiferous tubules (where sperm are produced) 2. Rete testis 3. Efferent ductules 4. Epididymis (where sperm mature) 5. Vas deferens 6. Ejaculatory ducts 7. Urethra (through the penis) 10. Describe the locations and functions of the seminal vesicles, prostate, and bulbourethral glands. Seminal vesicles: Located behind the bladder, they secrete a thick fluid rich in fructose that provides energy for sperm and makes up about 60% of semen. Prostate gland: Located beneath the bladder, it produces a milky fluid that neutralizes the acidity of the vaginal tract, aiding sperm survival. Bulbourethral glands (Cowper's glands): Located near the base of the penis, they secrete a clear fluid that lubricates the urethra and neutralizes traces of acidic urine. 11. Name the erectile tissues of the penis, and describe their locations relative to each other. Corpora cavernosa: Paired erectile tissues located on the dorsal (top) side of the penis. They are responsible for most of the penile erection.  Corpus spongiosum: The single erectile tissue located along the ventral (bottom) side of the penis, surrounding the urethra. It helps keep the urethra open during erection. 12. Study figure 27.16 and know the different parts of the sperm. What is contained in the acrosome and why? Parts of the sperm: ○ Head: Contains the DNA. ○ Acrosome: A cap-like structure that contains enzymes necessary for penetrating the egg. ○ Midpiece: Contains mitochondria that provide energy for movement. ○ Tail (Flagellum): Propels the sperm. Acrosome: Contains enzymes like hyaluronidase and acrosin, which are essential for breaking down the outer layers of the egg to allow fertilization. 13. State the source, target organ, and effect of GnRH. Source: Hypothalamus Target organ: Anterior pituitary gland Effect: Stimulates the release of FSH and LH, which regulate the function of the gonads. 14. Identify the target cells and effects of FSH and LH. FSH (Follicle-Stimulating Hormone): ○ Target cells: Sertoli cells in the testes ○ Effect: Stimulates sperm production. LH (Luteinizing Hormone): ○ Target cells: Leydig cells in the testes ○ Effect: Stimulates the production of testosterone. 15. List the major contributions of the seminal vesicles and prostate to the semen and state the functions of these components. Seminal vesicles: Contribute fructose, prostaglandins, and proteins that nourish sperm and promote their motility. Prostate: Contributes a milky fluid containing citric acid, zinc, and prostate-specific antigen (PSA), which help maintain sperm motility and viability. 16. Explain the process of spermatogenesis. Spermatogenesis: The process of sperm production that occurs in the seminiferous tubules. It begins with spermatogonia (stem cells) that undergo mitosis to produce primary spermatocytes, which undergo meiosis to form haploid spermatids. These spermatids then mature into sperm. 17. Explain how penile blood circulation changes during sexual arousal and why the penis becomes enlarged and stiffened. During sexual arousal, parasympathetic stimulation causes the dilation of the arterioles supplying blood to the erectile tissues. This increases blood flow into the corpora cavernosa and corpus spongiosum, causing them to expand and stiffen, resulting in an erection. 18. State the roles of the sympathetic, parasympathetic, and somatic nervous systems in the male sexual response. Parasympathetic nervous system: Responsible for initiating and maintaining an erection by increasing blood flow to the penis. Sympathetic nervous system: Controls ejaculation by stimulating the contraction of smooth muscles in the ducts and accessory glands. Somatic nervous system: Controls the contraction of the bulbocavernosus muscle to help expel semen during ejaculation.