Human Reproductive Anatomy and Fertilization

Overview of How It Works

• In both M and F,– Gametes are formed in one of the organs of the

reproductive system– Gametes must travel through other organs of

reproductive system before can engage in fertilization (or attempt to)• M– for modification and to acquire “tools” to help it

reach the egg… for removal from M body• F- for implantation

Male Reproductive System

1) Form Sperm

• Occurs in the testes (singular= testis)

• Testes contained in the scrotum – Cooler temperature for

sperm production

1) Form Sperm • Seminiferous tubules = site

of spermatogenesis

2) Sperm Travel• Epididymis

(storage) vas deferens (transport) urethra (modifications) ejected from body

3) Multiple Organs Designed to Provide Sperm with Extra “Tools” To Reach Egg

• In urethra• Seminal vesicle – energy (fructose)

• Prostate gland– Alkaline fluid to protect

against acidic F• Bulbourethral gland– Mucus secretion

Prostate Problems• Prostate enlarged in most older men – not necessarily cancerous– Leads to difficulty with urination

• Cancer= Very common but easily recognized and treated (testosterone therapy)

F Reproductive Anatomy

• Ovaries= site of egg production

• Less travelling than M (more modification in ovaries– menstrual cycle)

Uterus

• Where baby lives!• Endometrium – – Inner lining– blood vessels– implantation

Signal Transduction Pathways AKA intricate and complicated

Hormone Regulation in M

• Puberty• Consistent levels

of testosterone throughout the life of the male

• LH vs. FSH• Negative

feedback • Figure 27.40 in

your books!

Negative Feedback– How Hormones Work

• Maintain consistent internal environment (homeostasis)

• What would happen if there was no negative feedback?

Menstrual Cycle

Primary oocyte secondary oocyte ovulatedFollicle corpus luteum degenerates (if no baby)

What is the Function of theCorpus luteum?

Key Points

• Involves the interaction of many hormones

• Only one follicle ovulates at a time (dominant follicle)

• When does the egg complete meiosis II?

Pregnancy vs. no pregnancy

• If no sperm, leads to menstruation• If sperm, meiosis II completed in oviduct