Lecture on Human Reproduction and Related Topics

Introduction

• Finished first part of reproduction chapter.
• References to YouTube channel and resources available in the video description:
  • Sign up for email updates.
  • Join WhatsApp group.
  • Donate to the channel (50% proceeds go to charity).
  • Access study guides and Anki resources.
  • Lecture times on Tuesdays and Wednesdays, 6:30-9:30 PM EST.
  • Zoom link for live participation.

Human Reproduction

Physical Sex Determination

• Determined by the 23rd chromosome pair:
  • XX: Female.
  • XY: Male.
• Disorders related to X chromosome:
  • X-linked dominant disorders (e.g., Rett Syndrome affects females).
  • X-linked recessive disorders (e.g., Color blindness more common in males).

X-linked Disorders

• Explanation of carrier status and inheritance patterns.
• Example detailed family tree analysis for color blindness.

Male Reproductive Anatomy

Overview

• Testes located outside the body in the scrotum.
  • Scrotum regulates temperature for sperm production.
• Seminiferous Tubules: Produce sperm.
• Interstitial Cells of Leydig: Produce testosterone.
• Sperm path: Seminiferous Tubules → Epididymis → Vas Deferens → Ejaculatory Duct → Urethra.
• Seminal vesicles and prostate contribute to seminal fluid.

Fun Facts

• Sperm gain motility in the epididymis.
• Cowper's gland secretes pre-ejaculate fluid.
• Semen is alkaline to survive the acidic environment of the vagina.

Female Reproductive Anatomy

Overview

• Ovaries contain follicles, each with an ovum.
• Path: Ovary releases an egg into the peritoneal cavity, picked up by fimbriae, travels through the fallopian tube to the uterus.

Menstrual Cycle

Hormonal Control

• Gonadotropin-Releasing Hormone (GnRH) from hypothalamus prompts the anterior pituitary to release:
  • Follicle-Stimulating Hormone (FSH): Stimulates estrogen production in women and spermatogenesis in men.
  • Luteinizing Hormone (LH): Triggers ovulation in women and testosterone production in men.

Cycle Phases

• Follicular Phase:
  • Progesterone level drops, GnRH increases, leading to FSH and LH increase.
  • Estrogen levels rise, preparing the endometrium for possible pregnancy.
• Ovulation:
  • Occurs due to an LH spike.
  • Follicle ruptures, releasing an ovum.
• Luteal Phase:
  • Corpus luteum forms, secretes progesterone to maintain uterine lining.
• If no pregnancy occurs, corpus luteum degenerates, leading to shedding of the uterine lining.

Pregnancy and Ectopic Pregnancy

• Beta hCG: Indicates pregnancy, maintains corpus luteum to keep producing progesterone.
• Ectopic pregnancies can occur outside the uterus, leading to life-threatening complications.

Additional Stories and Experiences

• Experiences from medical rotations, including stories from Cardiology and OB/GYN.

Conclusion

• Recap of reproductive system and processes.
• Encouragement to ask questions and engage with lecture material.