Reproductive Biology: Ovaries and Testes

Gonads: Ovaries and Testes

• Gonadal primordia develop into testes if a Y chromosome and TDF gene are present.
• Gonadal primordia develop into ovaries if no Y chromosome and TDF gene are present.

Male and Female Duct Systems

• If testosterone is present, the Wolffian duct system develops into the male duct system.
• If testosterone is absent, the Mullerian duct system develops into the female duct system.

Female Reproductive System

• The female reproductive system includes the uterus, fallopian tubes, ovaries, cervix, and vagina.
• Diagrams of the female reproductive system and detailed labels were included in the slide.

Ovum Maturation

• The process of ovum maturation was presented in the slide but no further details.

Menstruation

• The menstrual cycle consists of four phases: egg maturing (follicular phase), ovulation, preparation for fertilization (luteal phase), and menstruation (uterine shedding).
• Diagrams and explanations were provided for all four phases.

Ovarian Cycle

• The ovarian cycle describes follicular development, menstruation, ovulation, and luteal phases.
• Associated pituitary hormones and fluctuating hormone levels (FSH & LH) were shown graphically.
• The endometrial cycle is also depicted.

Uterine Cycle

• The uterine cycle is described as having three phases.
• The menstruation phase is the breakdown of the endometrium and the release of blood.
• The proliferative phase is the formation of a new endometrium under estrogen influence.
• The secretory phase is impacted by progesterone.
• Hormonal levels (estrogen, progesterone, FSH, LH) are depicted graphically throughout the cycle.
• Basal body temperature is tracked as an indicator throughout the cycle.

The Zygote

• Successful fertilization takes place in the oviduct.
• Successful implantation occurs in the uterus.
• The zygote embeds itself in the endometrium wall.

No Zygote, No Pregnancy

• If no fertilized ovum arrives in the uterus, the endometrium breaks down causing bleeding.

Twins

• Usually, one ovum is released per month from alternating ovaries.
• Dizygotic (fraternal) twins result from the release and fertilization of two ova.
• Monozygotic (identical) twins develop from a single fertilized ovum that splits.

Male Reproductive System

• Testes are the male reproductive organs.

Testes

• The testes are divided into interstitial cells of Leydig (testosterone production) and seminiferous tubules (spermatogenesis).