Female Reproductive System Anatomy PDF

# Female Reproductive System The female reproductive system is composed of: 1. External genitalia 2. Internal genitalia Also, the mammary glands and bony pelvis are part of female reproductive anatomy. ## The External Genitalia The term external genitalia means the vulva. ### External Genitali...

# Female Reproductive System The female reproductive system is composed of: 1. External genitalia 2. Internal genitalia Also, the mammary glands and bony pelvis are part of female reproductive anatomy. ## The External Genitalia The term external genitalia means the vulva. ### External Genitalia 1. Mons Pubis: a mass of fatty tissue covered by skin and hair, overlies the symphysis pubis 2. Labia Majora: two folds of skin on either side of the vaginal orifice. Each labium major contains a mass of fat and the skin is covered with hair. Each labium major contains sebaceous and sweat glands. 3. Labia Minora: two thin flaps of pigmented skin lying within the labia majora on either side of the vaginal orifice. 4. Clitoris: the homologue of the penis, lies in front of the symphysis pubis and attached by a suspensory ligament. 5. Vestibule: refers to structures enclosed by the labia minora. It includes the following: - The external urethral meatus - Skene's glands: two paraurethral ducts which open in the floor of the urethra a few millimeters from the external urethral meatus. - Bartholin glands: two glands open in the floor of the vestibule. The paraurethral and Bartholin glands are each paired glands whose secretion moisten the vaginal mucosa and raise the pH of the vaginal secretions during sexual intercourse to enhance sperm motility. - Vaginal orifice: refers to vaginal introitus, located posterior to the urethral meatus, accommodates the baby at birth. 6. Hymen: a fold of mucous membrane at the introitus. Hymens can come in different shapes. The most common hymen is shaped like a half moon (annular hymen). This shape allows menstrual blood to flow out of a girl's vagina. - Imperforate hymen: a thin membrane that completely covers the opening to a young girls'. Menstrual blood cannot flow out of the vagina. This usually causes the blood to back up into the vagina and the abdomen resulting in abdominal and/or back pain. - Micro perforate hymen: a thin membrane that almost completely covers the opening to a young girl's vagina. Some menstrual blood may be able to flow out of the vagina, but the opening is very small. - Septate hymen: the thin hymnal membrane has a band of extra tissue in the middle that causes two small vaginal openings instead of one. 7. Perineum: extends from the fourchette anteriorly to the anus posteriorly. It varies in length from (2 to 5 cm). It is composed of fibrous and muscular tissues that provide support for pelvic structures. ## The Internal Genitalia The internal genital organs are: 1. Vagina (birth canal): an elastic fibro-muscular tube lined with stratified squamous epithelium. It forms the inferior portion of the female genital tract and the birth canal. It extends from the cervix to the vulva. The vagina’s location is posterior to the urinary bladder and anterior to the rectum. 2. Uterus: a hollow pear muscular organ located inside the pelvis between the urinary bladder anteriorly and the rectum posteriorly. The normal position of the uterus anteverted (rotated forward) and anteflexed (flexed forward). It measures about 7.5, 5, 2.5 cm (length, width and thickness) respectively. It weighs about 50-70 gm in the non-pregnant state: - Cervix: that connects the vagina and uterus. The cervix has external Os which open in the vagina and internal Os which open into the uterine isthmus. - Uterine isthmus: the lower portion of the uterus which connects the cervix to the main body of the uterus. During pregnancy and childbirth the uterine isthmus referred to as the lower uterine segment. - Corpus: the main body of the uterus. - Fundus: the topmost section of the uterus. The walls of the corpus and fundus are made up of three layers: 1. Perimetrium: the outer layer, the loose surrounding tissue that covers most of the uterus. 2. Myometrium: the middle layer, consists of thick smooth muscles 3. Endometrium: the inner layer, which builds a lining periodically which, if no pregnancy occurs, it is shed. Shedding is responsible for menstrual bleeding known as a woman period. ### Functions of the Uterus 1. Implantation of a fertilized ovum in the endometrium. Function of endometrium. 2. Providing nourishment for the developing fetus. 3. Expand during pregnancy and expel the fetus during labor. ## Fallopian Tubes Also known as (oviducts, uterine tubes, salpinges). They are two very fine tubes lined with ciliated epithelia leading from the ovaries to the cornua of the uterus. Tubes are about 8-14 cm long. ### Parts of the Fallopian Tubes 1. Infundibulum: the outer portion that opens into the abdominal cavity. It contains fimbriae (fingerlike projections). 2. Ampulla: the middle portion of the tube, connects the isthmus with the infundibulum. It is the widest part about 5 cm in length. 3. Isthmus: the medial portion of the tube that connects to the uterus. ### Functions of the Fallopian Tubes Provide a site for fertilization. ## Ovaries Two sex glands, located on either side of the uterus. They are similar to almonds in size and shape. The ovaries are supported by the broad and ovarian ligaments. ### Internal Structure of the Ovary 1. Cortex: Contains primary follicles in different stages of development 2. Medulla: Consists of connective tissue and is surrounded by the cortex. 3. Hilum: Gives attachment to the mesovarium and through which pass the ovarian vessels, lymphatic, and nerves. ### Functions of the Ovaries 1. Production and releasing of ova. 2. Secretion of estrogen and progesterone hormones which control the development of female body characteristics in puberty (i.e, breasts, body shape, and body hair) 3. Regulate the menstrual cycle (until menopause). ## Support Structures 1. The bony pelvis support and protects the lower abdominal and internal reproductive organs. 2. Muscle, joints, and ligaments, provide added support for internal organs of the pelvis against the downward force of gravity and the increases in intra-abdominal pressure. ## The Female Pelvis Each pelvis composed of: 1. Two hip bones 2. One sacrum 3. One coccyx ### Hip Bones In nominate bones. Each one is composed of an ilium, ischium, and pubic bone. ### Sacrum A solid bone formed from the five fused sacral vertebrae. One ilium on each side, articulates with the sacrum with a pseudo synovial joint. ### Coccyx A set of fused bones, 4-5 in number that articulate with the sacrum. ### Functions of the Pelvis 1. Supports the weight of the body. 2. Protects and supports the lower organs, including the urinary bladder, the reproductive organs, and the developing fetus in a pregnant woman. ## Pelvic Joints There are four pelvic joints: 1. One symphysis pubis: Between the two pubic bones at the front of the pelvis 2. Two sacro-iliac joints: The sacro-iliac joints between the sacrum and the ilium. A pseudo synovial joint 3. One sacrococcygeal joint: between the sacrum and the coccyx. ## Types of Pelvis 1. Gynecoid pelvis: True female pelvis, has rounded brim, well-curved, straight side walls, blunt ischial spines, wide sciatic notch, pubic arch of 90. 2. Android pelvis: Male pelvis, has heart-shaped brim, the side walls converge, narrow sciatic notch, the ischial spine are prominent, and the angle of the pubic arch is less (90). 3. Anthropoid pelvis: has long, oval brim, the anteroposterior diameter is longer than the transverse, very wide sciatic notch. 4. Platypelloid pelvis: has kidney-shaped brim, the anteroposterior diameter is reduced and the transverse increased, wide sciatic notch. ## Pelvic Floor The pelvic floor muscles are tightly slung between the tailbone (coocyx) and pubic bone, and support the bowel, bladder, uterus, and vagina. Muscular bands (sphincters) encircle the urethra, vagina, and anus as they pass the pelvic floor. ### Functions of the Pelvic Floor 1. Providing support for pelvic organs (as bladder, intestine, and uterus) 2. Maintenance of continence as part of the urinary and anal sphincters (enable emptying) 3. Reflex activity: act quickly when coughing and sneezing 4. Prevent prolapse. 5. Contact in response to abdominal pressure. ## Menstruation Menstruation means cyclic uterine bleeding caused by shedding of progestational endometrium. It occurs between (menarche (first menstrual cycle) and menopause (physiological cessation of menstruation). ### Characteristics of Normal Menstruation - Age at menarche: 10-16 years with an average of 13 years. - Duration of blood flow: 2-7 days - Length of menstrual cycle: 28+7 days. Estimated from the first day of menstruation to the first day of the next period. - Amount of menstrual blood: 30-60 mL, during the whole period. The woman is usually uses 3 pads daily (2 by day and 1 by night). If the amount of menstrual blood exceeds 80 mL it is considered to be abnormal and is known as menorrhagia - Normally, the menstrual blood does not coagulate - Menstrual discharge consists of blood rich in leucocytes, endometrial fragments, cervical mucous, desquamated vaginal epithelial cells, bacteria and enzymes. In addition to prostaglandins, enzymes as alkaline and acid phosphatase. ## Hypothalmic Pituitary Axis The hypothalamus secretes gonadotrophin releasing hormone (GnRH), which stimulates the production of both the follicle stimulating hormone (FSH) and luteinizing hormone (LH) from the acidophil cells of the anterior pituitary. The GnRH is secreted in a pulsatile manner every 60-90 minutes and reaches the anterior pituitary via the hypophyseal portal vessels. ## Menstrual Cycle The menstrual cycle is composed of two cycles, ovarian cycle, and endometrial or uterine cycle. Both cycles occur simultaneously. ### Ovarian Cycle This cycle describes the changes of the ovaries and can be further divided into three phases. 1. Follicular phase: during the first half of the menstrual cycle, the anterior pituitary secretes both FSH and LH. The FSH stimulates the growth of several primary follicles in both ovaries (100-1000). However, only one follicle reaches maturity and forms a graafian follicle which secretes increasing amounts of estrogen. The estrogen level reaches a peak about 48 hours before ovulation (day 12). This estrogen peak stimulates increased secretion LH which reaches a peak about 24 hours before ovulation (day 13). 2. Ovulation Phase: The LH peak leads to ovulation (day 14) and corpus luteum formation 3. Luteal phase: During this phase the LH maintains the growth of the corpus luteum and stimulates it to secrete estrogen and progesterone. The corpus luteum has a limited life span (14+2 days) after which it degenerates. This leads to a drop in the level of estrogen and progesterone causing separation of the endometrium and menstruation. Also the drop in the level of these hormones stimulates the hypothalamus to secrete more GnRH and thus a new cycle is started in. ### Endometrial Cycle This cycle describes the changes which occur in the endometrium every month and also it can be further divided into 3 phases. 1. Menstrual phase: about 1-5 days and during these days the superficial functional layer of the endometrium separates, leaving the basal layer which contains the basal parts of the glands to allow for regeneration of the endometrium. 2. Proliferative phase: Proliferative or pre-ovulatory phase after the end of menstruation and ends at time of ovulation. It is due to the effect of estrogen produced by the growing follicle and characterized by: - The endometrial thickness reaches 3-4 mm. - The uterine glands elongate and are increased in number but remain tubular. - Vascularity is increased. 3. Secretory phase: secretory or postovulatory phase begins at ovulation and ends at the onset of menstruation. The endometrium is under the effect of estrogen and progestrogen produced by the corpus luteum and is characterized by: - The endometrial thickness reaches 6-8 mm. - The uterine glands continue to grow and become tortuous. - Vascularity is increased greatly. If pregnancy does not occur the corpus luteum degenerates at the day 22-24 of the cycle thus secretion of estrogen and progesterone will stop and leads to break down and shedding of the lining (endometrium), called menstruation. If pregnancy occurs the corpus luteum continues to develop and function till the month 4 of pregnancy, where the placenta takes its function. The ovary will not select another follicle for ripening and no menstrual cycle will occur.