Sexual Reproduction and Hormones

• Fertilization is the process where male and female reproductive cells join during sexual reproduction.
• General steps of fertilization involve sperm and egg cell contact/recognition, binding, fusion, and activation into a zygote.

Sexual Reproduction and Hormones

• Hormones, released by ovaries and testes, instigate sexual development during puberty.
• Puberty ranges from ages 9-15.
• Female/male reproductive systems are fully developed by the end of puberty.

Male Reproductive System

• The primary function is to produce and deliver sperm.
• Testes are located in the scrotum, which maintains a lower temperature for effective sperm flagella growth.
• Sperm needs to be slightly colder than body temperature to make flagella grow effectively
• The vas deferens is a tube-like structure that empties into the urethra.
• The shared Urethra exits for both sperm and urine (unlike females).
• The prostate produces seminal fluid containing carbohydrate-rich nutrients for sperm.
• Semen comprises seminal fluid and sperm.
• Sperm's goal is to fertilize the right egg.
• Between 20-150 million mature sperm cells are present in 1 milliliter of semen.

Male Reproductive System: Hormones

• As males approach puberty, the brain signals the body to produce luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
• LH stimulates the testes to produce testosterone.
• Testosterone stimulates the development of male secondary sex characteristics and, with FSH, stimulates sperm development.
• FSH stimulates the testes to produce sperm.
• Both FSH and LH are produced in the pituitary gland.

Female Reproductive System

• Ovaries contain follicles with a developing egg cell.
• Each ovary contains around 400,000 follicles, but only about 400 eggs will be released in a lifetime.
• Fallopian tubes provide a passageway for egg and sperm cells to meet and travel to the uterus after fertilization.
• The uterus is a hollow muscular organ where the blastocyst attaches and grows during pregnancy.
• The cervix is an opening at the bottom of the uterus that opens during labor for childbirth.
• The vagina/vaginal canal leads to the outside of the body.

Menstrual Cycle

• It is a series of events preparing the body to care for a fertilized egg, it has 4 phases
• During the follicular phase, the brain secretes FSH and LH, stimulating the follicle to develop and secrete estrogen.
• LH triggers the ovary to release the egg.
• Estrogen controls meiosis in females, signaling when the female egg is mature and ready to leave the ovary.

Ovulation

• Egg is released into the ovary.
• Egg travels into fallopian tubes where it will be fertilized (if there’s sperm cells present)
• Egg (fertilized/unfertilized) pushed toward uterus
• Ovulation occurs around day 14 of the menstrual cycle egg cell is available for fertilization.

Luteal Phase

• As the egg moves through the fallopian tubes, the ovarian follicle turns yellow and becomes the corpus luteum.
• The corpus luteum secretes progesterone, which stimulates blood vessel growth in the uterine lining to prepare for embryo implantation.

During sexual reproduction, male and female reproductive cells unite in a process called fertilization. Hormones trigger sexual development during puberty, which typically occurs between the ages of 9 and 15. By the end of puberty, the reproductive systems in males and females are fully developed.