Unit 10: Reproductive and Endocrine Systems

Introduction

• Final unit in Anatomy and Physiology 12.
• Focus on male and female reproductive systems, cycles, and hormones.

Male Reproductive System

Anatomy

• Scrotum: Regulates testes temperature.
• Testes: Male gonads, site of sperm production (spermatogenesis).
  • Seminiferous Tubules: Mature sperm production.
  • Interstitial Cells: Produce testosterone.
• Epididymis: Sperm maturation and storage.
• Vas Deferens: Transports sperm to urethra.
• Urethra: Carries urine and semen.

Contributing Glands

• Seminal Vesicles: Provides nutrients (fructose) for sperm.
• Prostate Gland: Adds alkaline buffer to semen.
• Cowper's (Bulbourethral) Gland: Adds lubrication.

Sperm Anatomy

• Head: Contains nucleus and chromosomes.
• Middle Piece: Contains mitochondria for energy.
• Tail (End Piece): Enables movement.

Hormonal Regulation

• Testosterone: Development of male characteristics and sperm production.
• GnRH: Stimulates LH and FSH release.
• LH: Stimulates testosterone production.
• FSH: Stimulates sperm production.
• Negative Feedback: Regulates hormone levels.

Female Reproductive System

Anatomy

• Ovaries: Contain follicles with immature eggs.
• Oviducts (Fallopian Tubes): Transport eggs; site of fertilization.
• Uterus: Muscular organ, supports fetal development.
• Cervix and Vagina: Connect uterus to outside; allow sperm entry.
• Clitoris and Labia: External genitalia.

Hormonal Functions

• Estrogen: Promotes growth of reproductive organs, egg maturation.
• Progesterone: Prepares uterus for embryo.

Female Reproductive Cycles

Ovarian Cycle

• Follicular Phase (Days 1-13): Follicle development and estrogen production.
• Ovulation (Day 14): Release of egg from ovary.
• Luteal Phase (Days 15-28): Corpus luteum formation, progesterone secretion.

Uterine Cycle

• Menstruation (Days 1-5): Shedding of endometrium.
• Proliferation (Days 6-13): Endometrial thickening.
• Secretory Phase (Days 15-28): Preparation for fertilized egg.

Fertilization and Pregnancy

• Fertilization: Union of sperm and egg in oviduct, forming a zygote.
• Pregnancy: Implantation in uterine wall, placenta formation, hormone regulation.
• Birth: Positive feedback loop involving oxytocin for contractions.

Menopause

• Occurs between ages 45-55.
• End of ovarian and uterine cycles.

Endocrine System

Hormone Travel and Feedback

• Endocrine Cells: Release hormones into blood.
• Negative Feedback: Stabilizes body conditions (e.g., thyroxine regulation).
• Positive Feedback: Intensifies changes (e.g., childbirth).

Pituitary Gland

• Anterior Pituitary: Produces LH, FSH, TSH.
• Posterior Pituitary: Stores/releases oxytocin.

Conclusion

• Comprehensive understanding of reproductive and endocrine systems.
• Completion of Anatomy and Physiology 12 course.