topic 12 (reproductive system)

Question 1

Describe the structure and function of the testes, ducts, accessory glands, and penis.

Answer 1

• Testes:
  
  • Structure: Contained in the scrotum, composed of seminiferous tubules.
  • Function: Produce sperm (spermatogenesis) and testosterone.
• Ducts:
  
  • Epididymis: Stores and matures sperm.
  • Vas Deferens: Transports sperm from the epididymis to the urethra.
  • Urethra: Passage for urine and semen.
• Accessory Glands:
  
  • Seminal Vesicles: Produce seminal
    fluid rich in fructose.
  • Prostate Gland: Secretes fluid that

nourishes and protects sperm.
* Bulbourethral Glands: Secrete mucus
that lubricates the urethra.

• Penis:
  
  • Structure: Composed of erectile tissue
    (corpora cavernosa and corpus
    spongiosum).
  • Function: Delivers sperm into the
    female reproductive tract.

Question 2

Explain spermatogenesis and the hormonal regulation.

Answer 2

• Spermatogenesis: Process of sperm production in the seminiferous tubules.
  
  • Stages: Spermatogonia (stem cells) → primary spermatocytes → secondary spermatocytes → spermatids → spermatozoa.
• Hormonal Regulation:
  
  • GnRH: From hypothalamus;
    stimulates release of FSH and LH from
    the pituitary gland.
  • FSH: Stimulates spermatogenesis.
  • LH: Stimulates testosterone production from Leydig cells.
  • Testosterone: Promotes development of male secondary sexual characteristics and spermatogenesis.

Question 3

Describe the structure and function of the ovaries, tubes, uterus, vagina, and mammary glands.

Answer 3

• Ovaries:
  
  • Structure: Paired organs located in the
    pelvic cavity.
  • Function: Produce oocytes (eggs) and
    hormones (estrogen and
    progesterone).
• Fallopian Tubes:
  
  • Structure: Extend from the ovaries to
    the uterus.
  • Function: Transport oocytes; site of
    fertilization.
• Uterus:
  
  • Structure: Hollow, muscular organ.
  • Function: Houses and nourishes the
    developing fetus.
• Vagina:
  
  • Structure: Muscular canal extending
    from the cervix to the exterior of the
    body.
  • Function: Receives sperm, serves as
    the birth canal, and the outlet for
    menstrual flow.
• Mammary Glands:
  
  • Structure: Composed of glandular
    tissue and fat.
  • Function: Produce and secrete milk.

Question 4

Explain oogenesis.

Answer 4

• Oogenesis: Process of egg (oocyte)
  production in the ovaries.
  
  • Stages: Oogonia → primary oocytes
    (arrested in prophase I) → secondary
    oocytes (arrested in metaphase II until
    fertilization) → ovum (upon
    fertilization).
• Timeline: Begins before birth, pauses until puberty, and continues cyclically until menopause.

Question 5

Describe various types of contraception.

Answer 5

• Barrier Methods: Condoms, diaphragms; prevent sperm from reaching the egg.
• Hormonal Methods: Birth control pills, patches, injections; inhibit ovulation, alter cervical mucus.
• Intrauterine Devices (IUDs): T-shaped devices inserted into the uterus; prevent fertilization and implantation.
• Natural Methods: Fertility awareness, withdrawal; require precise timing.
• Sterilization: Tubal ligation, vasectomy; permanent prevention of gamete transport.

Question 6

Outline the ovarian and uterine cycles and the hormones involved.

Answer 6

• Ovarian Cycle:
  
  • Follicular Phase: Development of follicles; estrogen produced.
  • Ovulation: Release of mature oocyte; triggered by LH surge.
  • Luteal Phase: Corpus luteum forms and secretes progesterone and estrogen.
• Uterine Cycle:
  
  • Menstrual Phase: Shedding of the
    endometrial lining.
  • Proliferative Phase: Endometrial lining
    regenerates; stimulated by estrogen.
  • Secretory Phase: Endometrial lining
    prepares for implantation; maintained
    by progesterone.
• Hormones Involved: GnRH, FSH, LH, estrogen, progesterone.

Question 7

Describe male and female sex hormones and their effects.

Answer 7

• Male Hormones:
  
  • Testosterone: Promotes
    spermatogenesis, secondary sexual
    characteristics (muscle mass, deep
    voice, facial hair).
• Female Hormones:
  
  • Estrogen: Regulates menstrual cycle,
    secondary sexual characteristics
    (breast development, body fat
    distribution).
  • Progesterone: Prepares uterus for
    pregnancy, maintains pregnancy,
    regulates menstrual cycle.

Question 8

Describe the female cycle.

Answer 8

• Ovarian Cycle: Follicular phase, ovulation, luteal phase.
• Uterine Cycle: Menstrual phase, proliferative phase, secretory phase.
• Hormonal Regulation: Cyclical changes regulated by GnRH, FSH, LH, estrogen, and progesterone.