Female Reproductive System PDF

At the end of the session, the students should be able to: 1. describe the main structures and function of the external organs of female reproductive system; 2. describe the main structures and functions of the female internal genitalia; 3. explain how the oocytes produced; 4. outlin...

At the end of the session, the students should be able to: 1. describe the main structures and function of the external organs of female reproductive system; 2. describe the main structures and functions of the female internal genitalia; 3. explain how the oocytes produced; 4. outline the physiologic events in female sexual response; 5. outline the changes occur in female at puberty and menopause; 6. describe the structure and function of the mammary glands.  The major function of the reproductive is to produce offspring  The functions of female reproductive system are :  Formation of ova  Reception of spermatozoa  Provision of suitable environments for fertilization & fetal development  Parturition (childbirth)  Lactation to provide complete nourishments for the baby in its early life The organs include;  External genitalia – vulva  Internal genitalia  Vagina  Uterus  Ovaries - gonads  Fallopian tube  Mammary glands (breast)  Refers to the external genitals of female outside the vagina  Known as Vulva/pudedum  Consists of  Mons pubis  Vaginal orifice  Labia majora  Vestibule  Labia manora  Hymen  Vestibular gland’s  Clitoris (batholin’s gland) Mons pubis  It is fatty layer of skin covering pubic symphysis Labia majora  Larger, outer folds of skin  Equivalent to male scrotum Labia minora Thin, inner folds of skin The cleft in between is the vestibule – contain vaginal orifice, external uretheral orifice Vaginal Orifice  Opening of the vagina to the outside  Incompletely covered by hymen Hymen Thin layer partially closed the vagina Incomplete to allow passage of menstrual flow Clitoris Small erectile structure located in vestibule Equivalent to male penis Vestibular glands (Bartholin’s gland)  Located near the vaginal orifice  Function -secrete mucus to lubricate the vagina during sexual intercouse & moist the vulva opening Perineum It is a diamond shape extending from the base of labia minora to the anal canal  The internal organ lie in pelvic cavity  Consists of vagina, uterus, 2 ovaries & 2 fallopian tubes Structure  Extends from uterus to outside of body  Allows menstrual flow & involved in childbirth  Contains very muscular walls and a mucous membrane - that form rugae Connecting the external & internal reproductive organs  Contain lactobasilus acidophilus that secrete lactic acid to maintain pH between 4.9 & 3.5  The acidity inhibit the growth of microbes that may enter from perineum Functions  Acts as the receptacle for the penis during sexual intercourse  Passageway for spermatozoa and the menstrual flow  Provides an elastic passageway during childbirth Female reproductive organ from lateral view  The vaginal orifice is often partially covered by a thin fold of vascularized mucous membrane called the hymen. If the orifice is completely covered, this imperforate hymen must be surgically opened to permit menstrual flow  Pear sized structure  Location - pelvic cavity between the urinary bladder & rectum  Position - anteflexed (bent forward between the body & cervix & rest on top of urinary bladder) Structures  Fundus – dome-shaped portion above the entrance of uterine tubes  Body – large main portion Fundus Cervix – narrow region directed into the vagina Internal os – opening between the body & Body cervix External os – opening from cervix into the vagina Supporting structures  Broad ligament –hold the uterus in place  Round ligaments – bands of fibrous tissue between 2 layers of broad ligaments Wall of uterus  Perimetrium - outer layer  Myometrium - smooth muscle that coordinate contraction during childbirth Endometrium - innermost layer that is shed off during menstruation Contain cervical mucus - supply energy needs by the sperm A section of the uterus Functions  Pathway for spermatozoa to reach uterine tube  Source of menstrual flow  Site of implantation of a fertilized ovum  Uterine secretions nourish the ovum before it implants in the endometrium  Place for development of a fetus during pregnancy  Oestrogen & progesteron will increase uterine contractility to expel baby during labor Hysterectomy is surgical Uterine prolapse – uterus removal of the uterus due fallen from its normal to variety of reason location due to lost of muscular support  It is about 10cm long  Extend from the uterus towards oaries  Fimbriae - fingerlike projection at end of each tube - help sweep oocyte into uterine tubes Functions  Transport ova from the ovaries to the uterus  Normal place of fertilization  Ciliated cells and peristaltic contractions help move a secondary oocyte toward the uterus  Primary female reproductive organs  Homologous to the testes  Size & - 3.5cm long, 2cm wide & 1 cm thick  Location - upper pelvic cavity Functions Stored female gametes & develop prior to ovulation through process oogenesis Secrete estrogens, progesterone, inhibin & relaxin  Ovarian ligaments: hold ovaries to uterus  Suspensory ligaments: hold ovaries to pelvic cavity  Broad ligament: holds ovary in place, and is also attached to the uterine tubes and uterus Structure  2 layer of tissue - cortex (outer) & medulla (inner)  Medulla – lies in the center & consists of fibrous tissue, blood vessel, lymphatic vessel & nerves  Cortex – surrounds the medulla Female reproductive hormone and target tissue  Ovarian cyst Twisted ovarian cyst Ovarian Cysts are enlargement of ovaries with accumulation of fluid inside the functional unit of ovary  Oogenesis – process of producing eggs in ovary  Begin during fetal development  By 10 weeks gestation, mitosis occur to germ cells to form oogonia Oogonia – cell which oocytes develop Oogonia divided (Meiosis 1) to form primary oocytes Remain this state till puberty At puberty  Primary oocytes resume meiosis to complete meiosis 1 → divides into secondary oocyte & polar body  Secondary oocyte - splits into 2 cells – second polar body (discarded) and ovum (mature egg)  If no fertilization - cells degenerate  If a sperm penetrates secondary oocyte - meiosis II resumes Ovulation (puberty)  FSH and LH stimulate the resumption of oogenesis each month (resume meiosis 1)  Primordial follicle becomes primary follicles & enlarge → secondary follicle → mature ovarian follicle → ovulation  The ruptured follicles → corpus luteum → corpus albicans (if no fertilization occur)  Corpus luteum persist if fertilization occur Fertilization  Begin when sperm binds with secondary oocytes  Secondary oocyte completes meiosis II forming one polar body  Nuclei of sperm cell and ovum unite to form diploid zygote Gonadotropin-releasing hormone (GnRH)  Secreted by hypothalamus - controls ovarian and uterine cycle  Function - stimulates release of FSH & LH from anterior pituitary Luteinizing Hormone (LH)  Secreted by anterior pituitary  Functions:  Stimulate ovarian follicles to secrete estrogens  Triggers ovulation  Promotes formation of corpus luteum – produces estrogens, progesterone, relaxin and inhibin Follicle-stimulating hormone (FSH)  Initiate follicular growth  Stimulate ovarian follicles to secrete estrogens Estrogens  Secreted by ovarian follicles  Functions:  Development and maintenance of female reproductive structures & secondary sex characteristics  Inhibit release of GnRH, LH and FSH Inhibin  Function - inhibits secretion of FSH and LH Progesterone  Secreted mainly by corpus luteum in ovary  Functions:  Prepare endometrium for implantation  Prepare mammary glands for milk production  Inhibits secretion of GnRH and LH Relaxin  Produced by corpus luteum  Functions  Relaxes uterus by inhibiting contraction of myometrium  At end of pregnancy, increases flexibility of pubic symphysis and dilates uterine cervix  Typical duration 24 – 35 days  Assume a duration of 28 days  4 phases  Menstrual phase  Preovulatory phase  Ovulation  Postovulatory phase Menstrual Phase  The corpus luteum degenerate as the ovum is not fertilised (if pregnant, corpus luteum maintained due to hCG secreted by the embryo)  Progesterone & estrogen level very low  Endometrium shed in menstruation  Lost about 50–150 ml of fluids and cells  Last about 5 days of the cycle  Hypothalamus & anterior pituitary gland will resume to initiate a new cycle 1 day 14 day 28 day Preovulatory phase/proliferative phase  The time between menstruation & ovulation  Lasting from days 6 -13 in a 28-day cycle  At this stage, FSH stimulated ovarian follicle to become matured → estrogen produced → stimulates proliferation of functional layer of endometrium in preparation to accept fertilized ovum → endometrium become thicken, very vascular & rich in mucus secreting gland  Increasing level of estrogen triggered a flow of LH at mid-cycle that triggered ovulation → end of proliferative phase Secretory phase  After ovulation, LH stimulate corpus luteum to developed from the ruptured follicle → caused production of progesterone, estrogen, relaxin & inhibin  Progesterone caused endometrium to becomes edematous & secretory glands produce more watery mucus to assist the spermatozoa to pass through the uterus to the fallopian tube for fertilization  Watery mucus also increased in uterine tube & vagina  Ovum can survive for 8 hours after ovulation  The spermatozoa may able to fertilised the ovum within 24hours Secretory phase  Body changes occur during ovulation – cervical mucus becomes thin, elastic & watery; body temperature rises about 1°C immediately following ovulation; may have abdominal discomfort  After ovulation, the combination of progesterone, estrogen & inhibin suppressed the hypothalamus & anterior pituitary → FSH & LH level fall → degeneration & death of corpus luteum if no fertilization occur (menstruation) OR prevent further follicular development at 2nd half of the cycle (if pregnancy occur)  Lasts for 14 days in 28 day cycle (day 15-28) Summary of the stages of development of the ovum and associated hormones  Aged of puberty between 10 to 14 yrs old Physical changes occur at puberty 1. Internal reproductive (uterus, uterine tube & ovaries) reach maturity 2. The menstrual cycle & ovulation begin (menarche) 3. The breast develop & enlarge 4. Pubic & axillary hair begin to grow 5. Increase in height & widening of the pelvis 6. Increase fat deposited in the subcutaneous tissue, especially at the hip & breast  It is cessation of menstrual cycles  Usually occurs the aged of 45 and 55 years – marking the end of the childbearing period  Ovaries - less responsive to FSH & LH, and ovulation  Ovaries stop producing estrogen & progesterone → menstrual cycle stop  Symptoms associated with the onset of menopause occur Phenomena may occur  Short -term unpredictable vasodilatation with flushing, sweating, & palpitation, causing discomfort & disturbance of the normal sleep pattern  Shrinkage of the breast  Axillary & pubic hair become sparse  Atrophy of sex organs  Irritable, mood changes  Gradual thinning of the skin  Loss of bone mass – cause osteoporosis  Slow increase of blood cholesterol levels that increase the risk of cardiovascular disease  Menopause.  Uterine position changes and can lead to prolapse.  Uterus decreases 50% in size within 15 years after menopause.  Vaginal wall: thinner, less elastic, less lubrication.  Increased incidence of vaginal infections.  Less sexual excitement  Increased risk of breast, endometrial, cervical, and ovarian cancer.  Starts grow & develop with influence of oestrogen & progesterone after puberty  Responsible for milk production  Supported by fatty tissue & fibrous connective tissue that anchor the breast to the chest wall Each breast contains about 20 lobes Each lobes contain lobules where milk is produced  Lobules open to tiny lactiferous duct that drain milk towards the nipple  Lactiferous sinus – narrow duct opens to surface of the nipple  In lactating breast, glandular tissue proliferate to support milk production  Nipple – small conical eminence at the centre  Areola – the circular pigmented area of the skin surrounding the nipple  Alveoli - Milk-secreting cells that clustered in small compartments (lobules) within the breasts Functions  Only active during late pregnancy & after birth to produce milk (lactation)  Estrogen & progesterone stimulates the development of glandular tissue & duct in the breast  Prolactin – stimulate the production milk  Ejection of milk stimulated by hormone oxytocin in response to the sucking by infant to mother’s nipple  Batholin’s gland - secrete mucus to lubricate vagina & moist vulva  Lactic acid in the vagina inhibit the growth of microbes  Uterus walls – perimetrium, myometrium & endometrium  Endometrium will shed during menstruation  Myometrium is the muscular wall of uterus  Uterus – site for implantation fertilized ovum  Fallopian tube – place for fertilization  Ovaries - secrete estrogens, progesterone, inhibin & relaxin  Oogenesis - process formation of gametes in ovary  Estrogen - promotes development of female reproductive structures and secondary sex characteristics  Relaxin - increases flexibility of pubic symphysis and dilates uterine cervix  Aerola - circular pigmented area of the skin surrounding the nipple  Hormone prolactin stimulates milk production  Oxytocin stimulates ejection of milk  Infant sucking on mother’s nipple influence production of hormone oxytocin