The Human Reproductive System The gonads-testes and ovaries-are endocrine glands that secrete sex hormones. However, the primary function of the gonads is not to produce hormones but to produce and store gametes-sperm and eggs.

THE MALE REPRODUCTIVE SYSTEM 1. Males begin to produce Sperm during Puberty. 2. At this time, the concentration of the hormone Testosterone (male sex hormone) is high enough to stimulate sperm production.

3. The TESTES develop within the Abdominal Cavity and just before birth they descend through a canal into the SCROTUM. 4. The Testes remain in the Scrotum, outside the body, where the temp is about 3C Cooler than the body internal temp.

Male Reproductive System 5. Sperm development in the Testes Requires the Lower Temperature. 6. The Testes are clusters of hundreds of Tiny Tubules called SEMINIFEROUS TUBULES. Sperm Form through Meiosis in this extensive network of tubules.

Male Reproductive System 7. As the Pituitary Gland begins to release FSH and LH, these Hormones stimulate the Testes to make the PRINCIPAL MALE SEX HORMONE TESTOSTERONE. 8. Testosterone produces a number of SECONDARY SEX CHARACTERISTICS that appear in Males at Puberty – Voice Deepens, Beard Grows, and Body Hair.

Sperm Development A Mature Sperm consists of THREE Regions: HEAD - which contains 23 Chromosomes and enzymes that help the sperm penetrate the protective layers that surround an Egg Cell. MID PIECE - packed with energy releasing Mitochondria (Energy Source) TAIL – Consists of a Single, Powerful FLAGELLUM that propels the Sperm.

Sperm remain stored in each Epididymis and then pass through the VAS DEFERENS Each Vas Deferens enters the Abdominal Cavity, where it merges with the Urethra. In the Urethra, Sperm Mix with Fluids that are secreted by Three Exocrine Glands- the Seminal Vesicles, Bulbourethral Glands, and the Prostate Gland- to produce SEMINAL FLUID -which Protects and Nourishes the Sperm.

THE COMBINATION OF SPERM AND SEMINAL FLUID IS KNOWN AS SEMEN BETWEEN 100 AND 200 MILLION SPERM ARE PRESENT IN 1 milliliter OF SEMEN OR ABOUT 5 MILLION SPERM PER DROP!

Why so many sperm cells?

Review Qs 1. List 3 male sex hormones and briefly describe their role in male reproduction. 2. Briefly describe the main hormonal and physiological events of male puberty. 3. Predict what would happen to testosterone production in a male if he were to receive an injection of a large amount of testosterone.

IN #2 Draw a diagram of the male reproductive system. Label and include functions of parts.

Female Reproductive System The Ovaries are located in the Lower Abdominal Cavity; the Ovaries USUALLY produce only ONE EGG or OVUM per month. EACH TIME AN EGG IS RELEASED, THE BODY MUST BE PREPARED TO NOURISH A DEVELOPING EMBRYO.

Female Reproductive System Puberty in females starts when FSH and LH from the Pituitary Gland. FSH (follicle stimulating hormone) stimulates cells within the Ovaries to produce the Hormone ESTROGEN. Estrogen causes the SECONDARY SEX CHARACTERISTICS - Enlargement of Breast and Reproductive Organs, Widening of the Hips, and growth of Body Hair.

Female Reproductive System Each Ovary contains about 400,000 FOLLICLES, which are clusters of cells surrounding a single egg. When a Follicle has completely matured, the Ovum (Egg) is released. THIS PROCESS IS CALLED OVULATION

Female Reproductive System During Ovulation the Follicle literally ruptures, and the Ovum is swept from the Ovary into one of the TWO FALLOPIAN TUBES. The Fallopian Tubes provide a way for an egg to travel from the Ovary to the Uterus.

Female Reproductive System IT IS DURING ITS JOURNEY THROUGH THE FALLOPIAN TUBE THAT AN EGG CAN BE FERTILIZED. An Egg must be fertilized within 48 hours of its release - after that, the egg begins to break down. Unfertilized eggs dissolve in the Uterus.

Female Reproductive System Leading from the Uterus (CERVIX) to the outside of the body is a muscular tube called the VAGINA or Birth Canal.

Menstrual Cycle THE MENSTRUAL CYCLE IS THE SERIES OF CHANGES THAT OCCUR IN THE UTERUS EACH MONTH. The Menstrual Cycle has FOUR Stages: MENSTRUATION (day 0-5), THE FOLLICULAR PHASE (day 6-14), OVULATION (day 14), and THE LUTEAL PHASE (day 14-28)

Menstrual Cycle During the THE FOLLICULAR PHASE, the Egg Matures, and the Lining of the Uterus GROWS THICKER, many tiny Blood Vessels grow into the thickened lining, in preparation for receiving a Fertilized Egg.

Menstrual Cycle OVULATION around day 14 is the release of an egg from a ruptured follicle. Following Ovulation, an egg is swept into a fallopian tube, where it travels toward the uterus awaiting fertilization. The Egg has enough stored nutrients to survive about 48 hours.

Menstrual Cycle The LUTEAL PHASE, lasts about 14 Days, the Cells of the Ruptured Follicle grow larger and fill the cavity, forming a New Structure called a CORPUS LUTEUM. The Corpus Luteum begins to secrete large amounts of PROGESTERONE and ESTROGEN. The Increase levels cause the Pituitary Gland to stop Secreting LH and FSH.

Menstrual Cycle The Lining is prepared to receive the Embryo four or five days after the Egg is released from the Ovary. An Embryo that settles into the lining of the uterus, the Corpus Luteum continues to release Hormones that causes the Uterus to maintain its thickened lining. Most of the time, no embryo arrives, and the Corpus Luteum begins to produce Less and Less Estrogen and Progesterone

Menstrual Cycle The Decrease in Levels of Estrogen and Progesterone causes the Blood Vessels in the uterine lining to begin closing and then Break. The Cells of the Uterine lining DO NOT receive adequate blood supply and come loose from the inside of the uterus The mixture of Blood and the Cells that made up the lining of the uterus is called MENSTRUAL FLUID.

Menstrual Cycle The passage of this Fluid through the Vagina and out of the body is called MENSTRUATION OR THE MENSTRUAL PERIOD IT USUALLY LASTS FROM THREE TO SEVEN DAYS. The AVERAGE Menstrual Cycle is 28 DAYS LONG.

Menstrual Period Almost ALL Women START their Menstrual Period 14 DAYS AFTER Ovulation occurs. The length of the First stage of the cycle, the period when the Follicle is growing, DIFFERS from women to women.

Review Qs What is the role of FSH and LH in female reproduction? What is the function of the corpus luteum? What is the significance of the menstrual cycle. IN #3 draw and label a diagram of the female system. Include functions of parts.