Bio 30 Reproductive Systems

Reproductive Systems Overview

• Types of Reproduction:

  • Compare Sexual and Asexual Reproduction

  • Discuss Strategic Advantages of each type.

Goals for Understanding Reproductive Systems

• Male Reproductive System:

  • Structures, functions, and hormones involved in sperm production.

• Female Reproductive System:

  • Structures and hormones associated with the menstrual cycle.

• Fertilization and Development:

  • Key events, structures, hormones involved in reproduction.

• Reproductive Technologies:

  • Overview of modern reproductive methods.

Male Reproductive Anatomy

• Key Structures:

  • Scrotum: Holds testes outside for temperature control.

  • Testes: Site for sperm cell production through Spermatogenesis.

  • Epididymis: Storage and maturation location for sperm.

  • Vas Deferens: Transports sperm to the ejaculatory duct.

  • Urethra: Conveys sperm and urine.

  • Penis: Includes erectile tissue for sperm delivery.

Glands Producing Seminal Fluid

• Seminal Vesicles: Provide fructose and prostaglandins for sperm energy.

• Prostate Gland: Produces alkaline fluid for protection.

• Bulbourethral Gland: Secretes mucus for motility.

Sperm Production Process

• Spermatogenesis:

  • Meiosis occurs in seminiferous tubules of the testes.

  • Primordial Germ Cell divides and matures.

  • Maturation stages from spermatogonium to spermatid.

Structure of Sperm

• Components:

  • Head: Contains genetic material in the nucleus and acrosome.

  • Middle Piece: Contains mitochondria for energy.

  • Tail: Propels the sperm for movement.

Structure of the Testes

• Seminiferous Tubules: Site of spermatogenesis and Sertoli cell functions.

• Interstitial Cells: Produce testosterone, located outside tubules.

Reproductive Hormones in Males

• Feedback Loops:

  • GnRH, LH, and FSH regulate testosterone production and sperm development.

Testosterone Functions

• Primary Effects in Males:

  • Development of primary sex organs including penis and testes.

  • Induces secondary sex characteristics like body hair and muscle growth.

  • Contributes to sex drive and aggressive behavior.

  • Stimulates spermatogenesis.

Female Reproductive Anatomy

• Key Structures:

  • Ovaries: Produce oocytes and sex hormones.

  • Fallopian Tubes: Convey eggs and site of fertilization.

  • Uterus: Location for embryo/fetus development.

  • Endometrium: Lining that supports embryo implantation.

  • Vagina: Birth canal and passage for sperm.

  • Cervix: Separates uterus and vagina.

Menstrual Cycle Overview

• Phases:

  • Flow Phase: Menstrual bleeding.

  • Follicular Phase: Follicle development and estrogen rise.

  • Ovulation: Release of secondary oocyte.

  • Luteal Phase: Formation of corpus luteum and maintenance of uterine lining.

Hormonal Feedback in Females

• Role of GnRH, LH, and FSH in regulating hormone levels and menstrual cycle phases.

Oogenesis Process

• Development of an ovum through phases of meiosis in the ovarian follicles.

• Secondary oocyte is released; fertilization triggers meiotic completion.

Fertilization and Pregnancy

• Oocyte viability: 12-24 hours post-ovulation.

• Fertilization occurs in fallopian tubes; formation of zygote, which implants 8-10 days later in the endometrium.

Embryonic Development Stages

1. Zygote undergoes mitosis and differentiation.

2. Formation of the blastocyst and subsequent implantation into the endometrium.

3. Inner cell mass becomes embryo; trophoblast forms placenta.

Gastrulation and Tissue Formation

• Gastrula stage begins morphogenesis with three germ layers:

  • Ectoderm: Nervous system and skin.

  • Mesoderm: Skeleton and muscles.

  • Endoderm: Lining of digestive and respiratory systems.

Extraembryonic Membranes Functions

• Chorion: Becomes part of the placenta.

• Amnion: Encloses embryo; provides fluid for protection.

• Yolk Sac: Early blood cell formation and digestive tract development.

• Allantois: Contributes to umbilical cord formation.

Fetal Circulation and Placenta Role

• Placenta: Site of nutrient and gas exchange, hormone production to support pregnancy.

• Umbilical Cord: Contains vessels connecting fetus and placenta, facilitating transport of substances.

Birth and Hormonal Control

• Birth process involves cervical dilation, amniotic sac rupture, and delivery.

• Hormonal feedback loops (oxytocin and prostaglandins) stimulate contractions for labor progression.