Anatomy and Physiology Junior Health Reproductive System Anatomy and Physiology Junior Health

Role of Reproductive System 1. Produce, store, nourish and transport male and female reproductive cells 2. Successfully allow meeting of sperm with ovum to produce zygote Zygote=the cell that results from fertilization. It is the union of a spermatozoon and an ovum. Gamete=A single mature egg or sperm capable of reproduction to form a zygote. Each gamete contains a single (haploid) chromosome: the double (diploid) chromosome of the resulting zygote contains the genetic information programming the growth of the new individual.

Reproductive System components Primary Sex organs Males = testes Females = ovaries Reproductive Tract Ducts that receive, store and transport gametes Accessory glands and organs Perinea structures (external genitalia)

Female Reproductive System The role of the female is not only to produce the gametes or egg cells, but her body must prepare to nurture the developing embryo. The female internal genitalia is housed in the pelvic cavity, which is part of this protection system for these organs

Principle organs of the female reproductive system Ovaries Fallopian Tubes Uterus Endometrium Vagina Cervix

Ovaries The female sex glands that house the ova and produce the female sex hormones 2 Ovaries Almond shaped and located on each side of the body in the lower abdomen At birth, a female has over 400,000 immature ova The ovaries begin the process of releasing one ova per month, this is called ovulation

Fallopian Tubes Two muscular tubes through which the egg cell moves from the ovary to the uterus. Very often the space where fertilization occurs. Each is about four inches long The tubes do not actually touch the ovaries, they kind of hover and often a egg cell is lost into the peritoneal cavity, what the tubes must do is catch the egg cell within the tube.

The uterus A small muscular, pear shaped organ about the size of a fist. Prepares each month to receive a fertilized egg Houses the fetus during pregnancy Pushes out baby during childbirth Mechanical protection Nutritional support Waste removal for the developing embryo and fetus

Cervix The lower portion of the uterus Common site of cancer in females Muscular junction that opens (dilates) during birth Cervical cancer strikes about 450,000 women each year, killing about half. the first part of the long and hazardous route which sperm must navigate to reach an ovum, but which, at fertile times, assists them by sperm-friendly modification of the secretions from its lining. In the event of pregnancy, the cervix remains a narrow channel until the final weeks: then the muscle of the wall thins out, allowing descent of the infant's head into the pelvis. During the first stage of labor the opening into the vagina enlarges; when it is ‘fully dilated’ the second stage begins, heralding descent of the fetus into the vagina. The cervix is one of the common sites for cancer, hence the advisability of regular cervical smears.

Vagina Muscular elastic tube, approximately 3-4 inches long that extends from the uterus to outside of the body. Serves as a passageway for male sperm, menstrual flow, and commonly called the birth canal.

Ovaries

External genitalia Vulva external female sex organ Mons Pubis Soft tissue that covers the pubic bone and protects the internal genitalia Labia minora and majora The outer and inner folds that surround the opening of the vagina Clitoris a small, highly sensitive organ located between the inner folds of the labia minora Breasts organs composed of fatty tissue that are sensitive and provide milk for a newborn baby Paraurethral glands Clitoris The outer and inner folds that surround the opening of the vagina Lesser and greater vestibular glands

Figure 28.22 The Female External Genitalia

Hormones of the female reproductive cycle Control the reproductive cycle Coordinate the ovarian and uterine cycles Estrogen Maintains the secondary sex characters and organs, such as mammary glands, uterus, vagina, and fallopian tubes Progesterone excreted by the ovary and placenta, acts to prepare the uterus for implantation of the fertilized ovum, to maintain pregnancy, and to promote development of the mammary glands.

Female Physiology Ovulation The release of a mature egg cell (ovum) from the ovary the usually occurs once a month. Menstruation The process by which the uterus sheds its inner lining Fertilization The union of an egg and a sperm cell. Pregnancy The process by which the zygote grows and develops in the mother’s uterus and forms a new individual Childbirth The delivery of the baby from the mother’s uterus The two ovaries typically alternate release of the egg. Menstruation- the lining of the uterus thickens in preparation fro the possibility of a fertilized egg, if not fertilized the linng breaks down and eventually blood and tissue leave the body, cycle occurs approximately every 28 days Fertilization-it is also called conception

Male Reproductive System

External Reproductive Organs Testes 2 small glands that produce sperm at the rate of 100 million per day Scrotum A sac that holds the testes and regulates temperature, which protects sperm by keeping the testes at a body temperature slightly below normal 98.6 Penis Composed of spongy tissue that contains many blood vessels. Increased blood flow to the penis causes it to become erect, and ejaculation of semen occur through the urethra

Internal Reproductive Organs Epididymus Elongated tube located at the outer surface of the testes, monitors and adjusts seminal fluid, stores and protects sperm, Vas Deferens Pair of connecting tubes that lead up the body towards the other internal ducts Ejaculatory duct joins with the seminal vesicle and distributes sperm into the Prostate Gland Urethra Passageway through which both semen and urine leave the body. Ejaculation of sperm comes from the epididymus Semen and urine do not pass through at the same time.

Male Reproductive Tract Pathway of sperm Produced in the testes Stored in the Epididymis Travels through the Vas Deferens Combines with fluid from the Seminal Vesicles Combines with fluid from the Prostate gland Combines with fluid from the Cowper’s gland Now called semen, travels through urethra in the penis Leaves the body through the opening in the penis during ejaculation

Semen Fluid containing sperm and other secretions from the reproductive organs Typical ejaculation: 2-5ml of semen Contains: Spermatozoa Seminal Fluid Enzymes

Accessory Glands Contribute close to 95% of total semen volume Glands include: Seminal Vesicles Prostate gland Cowper’s gland Major Functions: Activate spermatozoa Provide nutrients for spermatozoa mobility Protect from urethra and vaginal contents

Accessory Glands Seminal Vesicle Prostate gland Cowper’s Gland Is a gland that helps enhance sperms motility or fertilizing power Prostate gland Size of a peach pit which surrounds the urethra, it activates sperm as it travels through the ejaculatory duct into the urethra, it is then mixed with fluids from this gland Cowper’s Gland Sperm mixes with thick mucus excretions which now forms semen, and it aids in sterilization of urethra Cowpers gland is the size of a pea, the excretions neutralize acids that may have been left in the urethra from urine,

Hormones Testosterone The male sex hormone, which is released by the pituitary gland, is also responsible for the production of sperm)

Problems with the Male Reproduction System Hernia Intestines rupture through a weak spot in the abdominal wall and push into the scrotum Enlarged Prostate Occurring as a result of tumor, infection, or old age Cancer of the prostate gland Uncontrolled growth of cells in the prostate gland Prostate Cancer often occurs in older men Testicular cancer occurs most often in males between the ages of 15 and 34

Problems with the Male Reproduction System Testicular Cancer Uncontrolled growth of cells in testes Andropause Decrease in male sexual function due to diminished testosterone levels Sterility Inability to reproduce due to poor quality of sperm or too few

Causes of Male Sterility Extreme temperature changes Low sperm production Exposure to certain chemicals Contracting mumps as an adult Smoking STD’s Malformation of the Epididymus, vas deferens, Cowper’s and prostate glands