Reproductive System

• The vas deferens is a tube that carries sperm from the epididymis to the urethra.
• The system that is involved in the process of reproduction is essential in the creation of new individuals and the survival of the species.

  Reproductive System
• It plays a role in the formation of sex cells (egg and sperm), the development of sex organs, and the production of sex hormones.
• What are the functions of the male reproductive system?

  • Secretes male sex hormones
  • Produces sperm cells or gametes through spermatogenesis (sperm cell formation)
  • Introduce sperm cells to the female reproductive system
• Importance of Reproduction:

  • It ensures the continued existence of species
• Male Reproductive System:

  • Secretes male sex hormones
  • Produces sperm cells through spermatogenesis
  • Introduces sperm cells to the female reproductive system
• Major parts of the male reproductive system:

  • Testes: Produce sperm cells
  • Scrotum: Holds the testes
  • Penis: Deposits the sperms
  • Vas deferens: Brings sperms from storage sac to urethra
  • Urethra: Carries sperms and urine out of the body
  • Reproductive glands: Provide liquid & protection to traveling sperms
• Male Accessory Reproductive Glands:

  • Seminal vesicles: Produce a sugar-rich fluid (fructose) that provides sperm with energy
  • Prostate gland: Fluids help nourish the sperm
  • Bulbourethral gland (Cowper’s Gland): Produce a clear, slippery fluid that lubricates the urethra and neutralizes acidity
• Facts about sperm:

  • Daily sperm production by a healthy man: 10 million to 50 million
  • Contents of an average ejaculation: 50 million sperm, 25 million moving, 20 million deformed
  • Maturation time: 72 days
  • Average swimming speed of a sperm: 8 inches per hour
  • Survival time in a woman: 2 to 7 days
• Female Reproductive System:

  • Secretion of female sex hormones
  • Production of female sex cells (ova) through oogenesis
  • Sustenance of life by providing the site for fertilization
• Major parts of the female reproductive system:

  • Ovaries: Produce egg cells
  • Oviducts/Fallopian tubes: Passageway of eggs from ovaries to uterus and site of egg fertilization
  • Uterus: Site of fertilized egg implantation and development
  • Vagina: Receives the male’s external genitalia during intercourse
• External Genitalia in females:

  • Labia Majora: Enclose and protect other external reproductive organs
  • Labia Minora: Surround the openings to the vagina and urethra
  • Bartholin’s Gland: Produce a fluid secretion
  • Clitoris: Sensitive protrusion covered by a fold of skin
• Menstrual cycle is a process in which females ripen or release one mature egg
• The average menstrual cycle repeats about every 28 days, but normal cycles can range from 21 to 40 days
• Elimination of the internal lining of the uterine wall
• Formation of a mature egg by one of the ovaries
• Embryo will implant in the endometrium and release hormones to sustain the corpus luteum
• The corpus luteum degenerates
• Estrogen and progesterone levels drop, allowing the cycle to begin again
• Fertilization process
• No fertilization process
• Follicle stimulating hormone (FSH) is secreted from the anterior pituitary
• FSH stimulates growth of ovarian follicles
• The dominant follicle produces estrogen, which inhibits FSH secretion through negative feedback
• Estrogen acts on the uterus to stimulate the thickening of the endometrial layer
• Midway through the cycle, estrogen stimulates the anterior pituitary to secrete hormones through positive feedback
• This positive feedback results in a large surge of luteinizing hormone (LH) and a lesser surge of FSH
• Luteinizing Hormone (LH) causes the dominant follicle to rupture and release an egg (secondary oocyte)
• The ruptured follicle develops into a slowly degenerating corpus luteum
• Corpus luteum secretes high levels of progesterone, as well as lower levels of estrogen
• Estrogen and progesterone act on the uterus to thicken the endometrial lining
• Estrogen and progesterone inhibit secretion of FSH and LH, preventing any follicles from developing