Reproductive System

Reproductive System Desi Andrade Kim Jones Sharnae Sanders Bratt Usher

Male Reproductive System

Penis • Rod-shaped organ which lies in front onf the scrotum • Base of the prostate • The two ejaculatory ducts join to form the tube within the penis called the urethra • Sperm release pass through the urethra

Testes • Two contained in bags of skin called the scrotum • Three fourths the size of a hens egg • Produce male reproductive cells and sex hormones called testosterone • Develops the male body figures such as facial hair, muscle bulk, and deepens voice

Vas Deferens • Sperm duct • continuation on the epididimus • 8 inches long (20 cm) • Carries sperm from testes to the urethra

Sperm • A sperm is a very tiny male sex cell. Under a microscope, sperm look just like tadpoles. A sperm cell is needed to fertilize a woman's egg and make a baby. Each sperm is made up of three parts. The head contains the genetic material needed for making a baby. The piece behind the sperm's head is the midpiece, which is the motor of the sperm. The sperm tail makes the sperm move so they can swim from the vagina to the uterus after ejaculation. Sperm swim about .12 inches (3mm) per hour and they need to move their tales more than 1000 times just to swim half an inch. • Sperm is made in the testes where it takes about 72 days for one sperm to grow. Sperm production needs a temperature which is three to five degrees below body temperature. • Semen is made up of sperm and other chemicals in the penis which help the sperm stay alive while they travel to the female's eggs. Every time a guy ejaculates, he releases between 400 and 500 million sperm

Female Reproductive System

External Genitals • This is made up of the fleshy tissue surrounding the vaginal and uterine opening, called the labia minor (the inner, hairless folds, closest to the body), the labia major (the outer folds which often have hair and sit on top of the labia minor) and the clitoris. The Bartholin’s glands are found just by the opening of the vagina and are responsible for producing lubricating fluid.

Vagina • This part of your body connects the external genitals with the internal reproductive organs. The vagina is a tube-like structure that ends at the cervix. It acts as the point of entry for the penis and sperm and as an exit when a child is born.

Cervix: • Sometimes referred to as the "neck" of the uterus, the cervix contains mucus that can help or hinder sperm from fertilizing an egg. When estrogen levels are high, the cervical mucus tends to be thin and slippery, thereby making it easier for sperm to travel further into the uterus. When estrogen levels are low, cervical mucus is more likely to be thick, making it difficult for sperm to navigate their way through. The cervix is positioned between the vagina and the uterus.

Uterus: • This is the part of your reproductive organs that acts as a home to your baby for nine months. It is a muscular organ made up of three layers: the outer layer is called the peritoneum; the middle, muscular layer is the myometrium while the inner lining of the uterus is referred to as the endometrium. The endometrium thickens every month in preparation for implantation of a fertilized egg. The cervix begins at the bottom, narrower part of the uterus, while the fallopian tubes are positioned near the top of the uterus, one on each side.

Fallopian Tubes: • Most women have two fallopian tubes, one on the left side and one on the right side. The fallopian tubes act as a passageway for the mature egg to travel down every month. They are also the site of fertilization. When an egg is fertilized, it stays in the fallopian tubes until it reaches the blastocyst stage, at which point it continues on to the uterus and implants itself. The fallopian tubes are connected to the uterus on one end and hover just over the ovaries on the other. This end of the fallopian tubes have 20 to 25 finger-like structures called fimbraie that help collect the mature egg into the fallopian tube each month.

Ovaries: • This is the site of your egg production. Females usually have two ovaries, one on each side of the body, and are found just outside of the uterus. The ovaries contain follicles that house immature eggs. Each month, roughly 20 follicles are stimulated and begin developing an egg. Usually, only one egg will get released although in rare instances, two or more may mature. The ovaries are also responsible for producing estrogen and progesterone, two important hormones necessary for normal reproductive function.

Ovum • An egg in the ovary of the female. This egg is called the female "gamete" or sex cell. It combines with the male gamete, called a sperm, to form a zygote. This formation process is called "fertilization."

Your Menstrual Cycle • Every woman is born with immature eggs in her ovaries. Just before birth, the number of eggs in the ovaries is roughly a few million but by the time puberty begins, this number has diminished to about 400,000. Of these, only three hundred or so will ever be released. As you age, the number of eggs in your ovaries continue to diminish, which isn’t so surprising when you remember that about 20 or so immature eggs begin to develop and then die off when the one dominant egg is released every month. • The reproductive years begin with the onset of menstruation during puberty and end when you enter menopause around age 45 or 50. A normal menstrual cycle can last for 25 to 34 days and have three to five days of bleeding. However, when discussing menstrual cycles, a 28-day cycle is the standard most professionals use. • The first day of your menstrual cycle begins on the first day of your period. This is known as Day 1. Each menstrual cycle is divided into two phases. The first phase is marked by the development and maturation of an egg while the second phase is known as the luteal phase because of the spike in LH production. These phases are separated by ovulation, which occurs about mid-way through your cycle.

Having It All Come Together • During the first few days of your cycle, your levels of estrogen decrease, signaling your body to increase its production of FSH. This helps promote the maturation of the follicles that contain the eggs. From the 20 or so eggs that are stimulated every month, one egg will manage to attract the most attention from FSH. This helps the follicle to produce more estradiol, which in turns tells the pituitary gland to stop producing so much FSH. As a result, the other follicles die off when they stop receiving enough FSH to survive. • The increase in estrogen also sends a signal to the endometrium, causing it to start thickening. Your cervical mucus will begin to change in consistency, from thick to thin and slippery. Additionally, more mucus will be produced, thereby aiding any sperm that enters your vagina in its quest to fertilize an egg.

Continued… • About a day and a half before ovulation occurs, your estrogen levels will climax, causing the pituitary to release a surge of LH. Once the follicle releases the egg, the follicle itself shrinks and gathers fatty substances known as lipids. This then becomes the corpus luteum, which is responsible for the production of progesterone. As progesterone levels in your body increase, the endometrium begins to prepare itself for implantation by a fertilized egg. • Once the ovaries have released an egg, it has approximately 72 hours to be fertilized. Since sperm can survive in your body for several days, it is usually recommended that you start to have unprotected sex before the onset of ovulation to increase your chances of fertilization.

Continued… • If the egg is fertilized, your body begins to produce human Chorionic Gonadotropin (hCG), which is often referred to as the "pregnancy hormone." HCG helps ensure that your body will continue to produce the correct amounts of estrogen and progesterone to provide the ideal conditions for implantation. If pregnancy does result, the corpus luteum will be stimulated by the placenta and continue to produce progesterone. • If the egg is not fertilized, the corpus luteum will dry up after about 14 days and become scar tissue. Your endometrium lining will shed itself as hormone levels fall, resulting in your period. Because of the drop in hormone levels, more GnRH will start to be produced and your monthly menstrual cycle will begin again.

Changes in the Reproductive System During Pregnancy • When you become pregnant, the part of your body affected first and the part that undergoes the most significant changes is the uterus. It increases to 20 times its original weight, and 1,000 times its initial capacity. The amount of its muscle, connective and elastic tissue, blood vessels, and nerves increases. Its shape changes from elongated to oval by the second month, to round by midgestation, then back through oval to elongated at term (the end of a normal nine-month pregnancy). • The uterus softens beginning at the sixth week. It changes position as it increases in size, ascending into the abdomen by the fourth month and eventually reaching to the liver. It also becomes more contractile (the tendency to decrease in size), with irregular, painless Braxton Hicks contractions beginning in the first trimester. You may feel these contractions in the last weeks of pregnancy, when they are known as false labor. • Other parts of the reproductive system change along with the uterus. The cervix and vagina have an increased blood supply, which causes a darkening in color apparent by the sixth week. The amount of elastic tissue increases to prepare the way for the stretching that will be required during delivery. Secretions increase, and a mucous plug develops in the cervix. The fallopian tubes, ovaries, and ligaments supporting the uterus all enlarge and elongate. The ovaries, of course, cease to ovulate.

Continued… • During the fourth month, the uterus grows into the abdomen, causing the abdominal wall to expand to accommodate it. The connective and elastic tissues stretch and straighten, creating thinned areas called striae (stretch marks). While the red of the striae may fade, silver remnants usually remain after delivery. In 50 percent of women, striae develop in the third trimester. Late in pregnancy, the internal pressure from the large uterus may even cause the muscles of the abdominal wall to separate (diastasis).Your breasts must undergo many changes during pregnancy to produce milk. In the first two months of pregnancy, your breasts may feel sore or full. They enlarge, and veins may become visible. Striae can develop. The nipples also increase in size and usually darken. By midpregnancy, colostrum (a thick, yellowish fluid) can be expressed, but milk is not produced until after delivery.Blood flow also changes during pregnancy, in order to satisfy your enlarged reproductive organs and feed your baby. Read about changes in the blood during pregnancy next.

Infertility • Infertility is a disease of the reproductive system that impairs one of the body’s most basic functions, the conception of children. Conception is a complicated process that depends upon many factors: • The production of healthy sperm by the man and healthy eggs by the woman • Unblocked fallopian tubes that allow the sperm to reach the egg • The sperm’s ability to reach the egg • The sperm’s ability to fertilize the egg when they meet • The ability of the fertilized egg to become implanted in the woman’s uterus • A good quality embryo

Infertilty Statistics • 1/3 of infertility cases can be attributed to male factors • 1/3 of infertility case can be attributed 2 female factors • 13% are a combination of both partners • 10% unexplained

Cause of Male Infertility • Common Causes • Azoospermia (no sperm cells are produced) • Oligospermia (few sperm cells are produce) • Genetic Disease (Cystic Fibrosis, Chromosomal Abnormality, etc.)

Causes of Female Infertility • Common causes • Blocked Fallopian Tubes • Polycystic Ovary Syndrome • Endometriosis • Repeated Miscarriages

Infertility Treatment • Surgery and Hormone Therapy • Assisted Reproductive Technology

Birth

Reproductive System