Male Reproductive System Quiz

Male Reproductive System

• Testes: Produce sperm (spermatogenesis) within seminiferous tubules.
• Seminiferous Tubules: Long, coiled tubes where sperm are created.
• Sertoli Cells: Support developing sperm's metabolic needs.
• Interstitial Cells: Secrete testosterone.
• Epididymis: Stores sperm until mature (wraps around the testes).
• Scrotum: Keeps testes cool for optimal sperm production (outside the body).
• Ductus Deferens: Carries sperm out of the testes; mixes with seminal fluid.
• Ejaculatory Duct: Transports fluid from seminal vesicles to ductus deferens.
• Penis: Contains erectile tissue that fills with blood to become rigid.
• Urethra: Transports urine and semen. During ejaculation, a sphincter muscle closes off the bladder.
• Semen Additions:
  • Seminal Vesicles: Produce fructose-rich fluid for sperm energy.
  • Prostate Gland: Creates alkaline fluid neutralizing vaginal acidity (white). Contains prostaglandins to stimulate vaginal contractions.
  • Cowper's Gland: Produces alkaline mucus to neutralize acidity and aid sperm transport.
• Sperm: Male gametes, optimized for speed.
  • Acrosome: Enzyme-containing "hat" to penetrate the egg.
  • Head: Contains 23 chromosomes.
  • Middle Section: Contains mitochondria for movement.
  • Flagellum: Tail for propulsion.
• Androgens: Male sex hormones (e.g., testosterone).
  • Testosterone: Key androgen, initiates male sex organ development, responsible for secondary sex characteristics, essential for sperm production.
  • GnRH: Hypothalamic hormone, stimulates anterior pituitary to release LH and FSH.
  • LH: Stimulates interstitial cells to release testosterone.
  • FSH: Stimulates sperm production in seminiferous tubules.
  • Inhibin: Inhibits GnRH, LH, and FSH through negative feedback when levels of their products are high.

Female Reproductive System

• Ovary: Produces ova (eggs) within follicles. Site of egg maturation and corpus luteum formation.

  • Releases one mature ovum per month (ovulation).

• Oviduct/Fallopian Tubes: Connects ovary to uterus. Site of fertilization (look like arms).

  • Fimbriae: Finger-like structures that draw the egg into the tube.
  • Ectopic Pregnancy: Zygote implants outside the uterus (in the fallopian tube).

• Uterus: Site of zygote implantation and embryo development.

  • Endometrium: Lining that nourishes embryo.

• Cervix: Muscle band separating uterus and vagina; dilates during labor.

• Vagina: Acidic birth canal.

• Oogenesis:

  • Follicle Cells: Nourish developing ovum.
  • Corpus Luteum: Forms from ruptured follicle, secretes estrogen and progesterone. Degrades after 14 days without fertilization. Secretes for 3 months, if fertilization happens.

• Females are born with a finite number of oocytes.

  • Corona Radiata: Protective layer around the ovum.
  • Zona Pellucida: Specialized coating.

• Female Sex Hormones: Cycle through varying levels.

  • GnRH: Stimulates anterior pituitary to release LH and FSH.
  • FSH: Stimulates follicle development, releases estrogen.
  • Estrogen: Maturation of eggs, endometrium growth, secondary sex characteristics.
  • LH: Triggers ovulation, corpus luteum development.
  • Progesterone: Endometrium growth, inhibits FSH and LH.

Menstrual Cycle

• Flow Phase: Endometrial shedding, low hormone levels.
• Follicular Phase: GnRH stimulates FSH, follicle matures, estrogen released, and endometrium grows. Rising estrogen inhibits FSH.
• Ovulation: High LH triggers release of mature ovum.
• Luteal Phase: Corpus luteum secretes estrogen and progesterone (progesterone>estrogen), endometrium grows. Progesterone inhibits LH. If no fertilization = corpus luteum degenerates, and the endometrial lining is shed.

Fertilization

• Zygote travels to the uterus, undergoes cleavage (cell division).
• Forms morula and blastocyst. Trophoblast and inner cell mass layers form.
• Implantation: Blastocyst attaches to the endometrium. Successful implantation marks the beginning of pregnancy.
• hCG: Hormone that maintains the corpus luteum to keep estrogen & progesterone levels high.
• Gastrulation: Blastocyst becomes gastrula with three layers (ectoderm, mesoderm, endoderm).
• Amniotic Cavity, Notochord, and Embryo Support Systems, Placenta, and Amnion.

Parturition (Childbirth)

• Regulated by positive feedback loop (oxytocin).
• Stages of Labor: Dilation, expulsion, placental.
• C-section: Cesarean birth.
• Lactation: Prolactin and oxytocin stimulate milk production after birth.

Chromosomal vs. Anatomical Sex Determination

• Chromosomal sex at fertilization; anatomical sex around week 7.

Test your knowledge on the male reproductive system with this quiz covering its anatomy and functions. From the testes to the urethra, explore the roles of various organs and structures involved in sperm production and ejaculation. Ideal for biology students and anyone interested in human anatomy.