Reproductive System PDF

##### Uterus - Located between the urinary bladder and rectum - Hollow organ - Functions of the uterus: - Receives a fertilized egg - Retains the fertilized egg - Nourishes the fertilized egg ##### Support for the Uterus - Broad ligament – attached to the pelvis - Round ligament - ancho...

##### Uterus - Located between the urinary bladder and rectum - Hollow organ - Functions of the uterus: - Receives a fertilized egg - Retains the fertilized egg - Nourishes the fertilized egg ##### Support for the Uterus - Broad ligament – attached to the pelvis - Round ligament - anchored interiorly - Uterosacral ligaments – anchored posteriorly ##### Walls of the Uterus - Endometrium - Inner layer - Allows for implantation of a fertilized egg - Sloughs off if no pregnancy occurs (menses) - Myometrium – middle layer of smooth muscle - Serous layer - outer visceral peritoneum ##### Vagina - Extends from cervix to exterior of body - Behind bladder and in front of rectum - Serves as the birth canal - Receives the penis during sexual intercourse - Hymen - partially closes the vagina until it is ruptured ##### External Genitalia (Vulva) - Mons pubis - Fatty area overlying the pubic symphysis - Covered with pubic hair after puberty - Labia - skin folds - Labia majora - Labia minora ##### Oogenesis - The total supply of eggs are present at birth - Ability to release eggs begins at puberty - Reproductive ability ends at menopause - Oocytes are matured in developing ovarian follicles ##### Oogenesis - Oogonia - female stem cells found in a developing fetus - Oogonia undergo mitosis to produce primary oocytes - Primary oocytes are surrounded by cells that form primary follicles in the ovary - Oogonia no longer exist by the time of birth - Primary oocytes are inactive until puberty - Follicle stimulating hormone (FSH) causes some primary follicles to mature - Meiosis starts inside maturing follicle: - Produces a secondary oocyte and the first polar body - Meiosis is completed after ovulation only if sperm penetrates: - Two additional polar bodies are produced ##### Menstrual (Uterine) Cycle - Cyclic changes of the endometrium - Regulated by cyclic production of estrogens and progesterone - Stages of the menstrual cycle: - Menses - functional layer of the endometrium is sloughed - Proliferative stage - regeneration of functional layer - Secretory stage – endometrium increases in size and readies for implantation ##### Average menstrual cycle is about 28 days, but varies widely from person to person. - Menstrual periods usually start between the ages of 9-15. - Each month, an ovary releases an ovum, or egg, into the fallopian tube. - If the egg does not unite with a sperm within 24-48 hours, it will dissolve and be reabsorbed by the body. ##### Menstruation, or having "a period" is when the uterus rids itself of the lining (endometrium) because there was no fertilized egg. ##### Hormone Production-Ovaries - Estrogens: - Produced by follicle cells - Cause secondary sex characteristics: - Enlargement of accessory organs - Development of breasts - Appearance of pubic hair - Increase in fat beneath the skin - Widening and lightening of the pelvis - Onset of menses - Progesterone: - Produced by the corpus luteum - Production continues until LH diminishes in the blood - Helps maintain pregnancy ##### Mammary Glands - Present in both sexes, but only function in females - Modified sweat glands - Function is to produce milk - Stimulated by sex hormones (mostly estrogens) to increase in size ##### Fertilization - The oocyte is viable for 12 to 24 hours after ovulation - Sperm are viable for 12 to 48 hours after ejaculation - Sperm cells must make their way to the uterine tube for fertilization to be possible ##### The Zygote - First cell of a new individual - The result of the fusion of DNA from sperm and egg - The zygote begins rapid mitotic cell divisions - The zygote stage is in the uterine tube, moving toward the uterus ##### The Blastocyst - Ball-like circle of cells - Begins at about the 100 cell stage - Secretes human chorionic gonadotropin (hCG) to produce the corpus luteum to continue producing hormones - The blastocyst implants in the wall of the uterus (by day 14) ##### Development from Ovulation to Implantation - **Image Description:** A diagram showing the development of a fertilized egg from zygote to implantation. Images include: - Zygote - 4 cell stage - Morula - Early blastocyst - Late blastocyst (implanting) ##### Development After Implantation - Chorionic villi (projections of the blastocyst) develop: - Cooperate with cells of the uterus to form the placenta. - The embryo is surrounded by the amnion (a fluid filled sac) - An umbilical cord forms to attach the embryo to the placenta ##### Functions of the Placenta - Forms a barrier between mother and embryo (blood is not exchanged) - Delivers nutrients and oxygen - Removes waste from embryonic blood - Becomes an endocrine organ (produces hormones) and takes over for the corpus luteum: - Estrogen - Progesterone - Other hormones that maintain pregnancy ##### The Fetus (Beginning of the Ninth Week) - All organ systems are formed by the end of the eighth week - Activities of the fetus are growth and organ specialization - A stage of tremendous growth and change in appearance ##### Effects of Pregnancy on the Mother - Physiological changes: - Gastrointestinal system: - Morning sickness is common due to elevated progesterone - Heartburn is common because of organ crowding by the fetus - Constipation is caused by declining motility of the digestive tract - Urinary System - Kidneys have additional burden and produce more urine - The uterus compresses the bladder - Respiratory System - Nasal mucosa becomes congested and swollen - Vital capacity and respiratory rate increase - Cardiovascular system - Body water rises - Blood volume increases by 25 to 40 percent - Blood pressure and pulse increase - Varicose veins are common ##### Childbirth (Partition) - Labor - the series of events that expel the infant from the uterus - Initiation of labor: - Estrogen levels rise - Uterine contractions begin - The placenta releases prostaglandins - Oxytocin is released by the pituitary - Combination of these hormones produces contractions ##### Initiation of Labor - **Image Description:** A diagram showing the feedback loop between the hypothalamus, posterior pituitary, and the uterus during the initiation of labor. ##### Stages of Labor - Dilation - Cervix becomes dilated - Uterine contractions begin and increase - The amnion ruptures - Expulsion - Infant passes through the cervix and vagina - Normal delivery is head first - Placental stage - Delivery of the placenta ##### Developmental Aspects of the Reproductive System - Reproductive system organs do not function until puberty - Puberty usually begins between ages 10 and 15 - The first menses usually occurs about two years after the start of puberty - Most women reach peak reproductive ability in their late 20s - Menopause occurs when ovulation and menses cease entirely - Ovaries stop functioning as endocrine organs - There is a no equivalent of menopause in males, but there is a steady decline in testosterone ##### Diseases and Disorders of the Male Reproductive System - **Table Description:** A table describing diseases and disorders of the male reproductive system. ##### Polycystic Ovary Syndrome - Features: - Cysts in the ovaries - High levels of male hormones - Irregular or skipped periods ##### Polycystic Ovary Syndrome - Symptoms: - Irregular menstrual cycle. Women with PCOS may miss periods or have fewer periods (fewer than eight in a year). Or, their periods may come every 21 days or more often. Some women with PCOS stop having menstrual periods. - Too much hair on the face, chin, or parts of the body where men usually have hair. This is called "hirsutism." Hirsutism affects up to 70% of women with PCOS. - Acne on the face, chest, and upper back - Thinning hair or hair loss on the scalp; male-pattern baldness - Weight gain or difficulty losing weight - Darkening of skin, particularly along neck creases, in the groin, and underneath breasts - Skin tags, which are small excess flaps of skin in the armpits or neck area ##### Polycystic Ovary Syndrome - Treatment - There is no cure for PCOS, but you can manage the symptoms of PCOS. - Losing weight - Removing hair - Slowing hair growth (eflornithine HCl cream) - Hormonal birth control, including the pill, patch, shot, vaginal ring, and hormone intrauterine device (IUD) - Anti-androgen medicines - Metformin