Reproductive System Biology: Sexual Development, Functions, and Menstrual Cycle Phases

1. Chapter 39 Section 3 The Reproductive System Biology pgs. 1009-1015

2. Objectives Describe • ______________ sexual development • _________________ the functions of the male and female reproductive systems • ______________ the four phases of the menstrual cycle Explain Identify

3. sex cells • Sexual Development • In humans, the reproductive system produces, stores, and releases specialized _________________known as gametes. • These cells are released to create the fusion of sperm and egg to form a zygote, the single cell from which all cells of the human body develop. • ____________ is a period of rapid growth and sexual maturation during which the reproductive system becomes fully functional. • When puberty ends, reproductive organs are fully developed. • Puberty usually begins between the ages of 9 and 15, and usually starts one year earlier in females than in males. Puberty

4. begins • Puberty __________ when the hypothalamus signals the pituitary to produce increased levels of two hormones that affect the gonads. • These hormones are follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

5. testosterone • The Male Reproductive System • Release of FSH and LH stimulates cells in the testes to produce _____________________. • FSH and testosterone stimulate the development of ___________. • The main function of the male reproductive system is to _____________ and deliver sperm. sperm produce

6. The Male Reproductive System Head Nucleus • A sperm cell consists of: • a __________, which contains the nucleus • a midpiece, which contains energy-releasing mitochondria • a tail, which propels the cell forward Midpiece head Mitochondria Tail

7. The Male Reproductive System

8. scrotum • The testes are located in an external sac called the ______________. • The scrotum is located outside the body cavity, where it is between 1 and 3 degrees cooler than normal body temperature. The ______________ temperature helps sperm development. lower

9. Within each testis are clusters of hundreds of tiny tubules called ____________________ tubules. • The seminiferous tubules are tightly coiled and twisted together. • Sperm are produced in the seminiferous tubules. • Sperm produced in the seminiferous tubules move into the __________________, where they mature and are stored. seminiferous epididymis

10. From there, sperm move into a tube called the ___________________, which extends up from the scrotum into the abdominal cavity. • This merges with the urethra, the tube that leads to the outside of the body through the ____________. vas deferens penis

11. Glands lining the reproductive tract produce ____________________. • Seminal fluid nourishes sperm and protects them from the acidity of the female reproductive tract. • The combination of sperm and seminal fluid is called _________________. seminal fluid semen

12. ovaries • The Female Reproductive System • The primary reproductive organs in the female are the _____________________. • The ovaries are located in the abdominal cavity. • The main function of the female reproductive system is to produce _________________. In addition, the female reproductive system prepares the female's body to nourish a developing embryo. eggs

13. The Female Reproductive System Fallopian tube Ovary Uterus Cervix Urinary bladder Rectum Pubic bone Vagina Urethra

14. Puberty in females starts when the hypothalamus signals the pituitary gland to release FSH and LH. • ______________ stimulates cells within the ovaries to produce estrogen. • Egg Development  • Each ovary contains about 400,000 primary __________________, which are clusters of cells surrounding a single egg. • The follicle helps an egg mature for release into the reproductive tract, where it can be fertilized. • Eggs develop within their follicles. FSH follicles

15. ovulation • Egg Release • When a follicle has matured, its egg is released in a process called ___________________. • The follicle breaks open, and the egg is swept from the ovary into one of the two ________________________ • While in the Fallopian tube, an egg can be fertilized. • After a few days, the egg passes from the Fallopian tube into the _______________. • If the egg is not fertilized it passes through the cervix, and finally out of the _______________. • The vagina leads to the outside of the body. • Fallopian tubes. uterus vagina

16. The Menstrual Cycle • The menstrual cycle is controlled by internal feedback mechanisms between the reproductive system and the endocrine system. • The cycle takes an average of 28 days. During the _______________________, an egg develops and is released from an ovary. • The uterus is prepared to receive a fertilized egg. • If the egg is fertilized, it is implanted in the uterus and embryonic development begins. • If the egg is not fertilized, it is discharged. menstrual cycle

17. During the menstrual cycle, an egg develops and is released from an ovary. • The uterus is prepared to receive a fertilized egg. • If the egg is fertilized, it is implanted in the uterus and embryonic development begins. • If the egg is not fertilized, it is discharged. • The menstrual cycle has ___________ phases: • follicular phase • ovulation • luteal phase • menstruation four

18. The Menstrual Cycle Ovulation • Menstrual Cycle

19. The Menstrual Cycle • The follicular phase begins when estrogen levels in the blood are low.

20. The anterior pituitary secretes FSH and LH, which cause a follicle to develop to maturity. • As the follicle develops, cells surrounding the egg enlarge and produce more estrogen. • ______________________ causes the lining of the uterus to thicken. • Ovulation • This phase occurs midway through the cycle and lasts 3–4 days. • The pituitary gland produces more FSH and LH. • The release of these hormones causes the follicle to rupture, and a mature egg is released into one of the Fallopian tubes. Estrogen

21. corpus luteum • Luteal Phase  • The luteal phase begins after the egg is released. • As the egg moves in the Fallopian tube, the follicle turns yellow and is called the _______________________. • The corpus luteum continues to release estrogen but also begins to release progesterone. • Progesterone stimulates growth and development of the blood supply and surrounding tissue. • Within a few days of implantation, the uterus and the growing embryo will release hormones that keep the corpus luteum functioning for several weeks. • This allows the lining of the uterus to nourish and protect the developing embryo.

22. Menstruation • If fertilization does not occur, the corpus luteum will begin to disintegrate. • The follicle breaks down and releases less hormones, which makes the uterine lining detach. • This tissue, blood, and the unfertilized egg are discharged through the vagina. • This phase is _______________________, and it lasts 3–7 days. menstruation

23. sexually transmitted diseases • Sexually Transmitted Diseases • Diseases that spread from one person to another during sexual contact are called ________________________________ (STDs). • STDs are a serious problem in the U.S., infecting millions of people each year and accounting for thousands of deaths. • STDs caused by ______________ include chlamydia, syphilis, and gonorrhea. • STDs caused by ______________ include hepatitis B, genital herpes, genital warts, and HIV/AIDS. bacteria viruses