Female Reproductive System PDF

The Reproductive System Part I: Female Anatomy & Physiology II BIOL2220 1 Version 09.1  The Reproductive System Female - Anatomy Basic Anatomy...

The Reproductive System Part I: Female Anatomy & Physiology II BIOL2220 1 Version 09.1  The Reproductive System Female - Anatomy Basic Anatomy The Vulva: The part of the genitals on the outside of the body — the labia, clitoris, vaginal opening, and the opening to the urethra. The Labia The labia (lips) are folds of skin around the vaginal opening. The labia majora (outer lips) are usually larger and covered with pubic hair. The labia minora (inner lips) are inside the outer lips. They begin at the clitoris and end under the opening to the vagina. The Glans Clitoris Developing Follicle (FSH) Connected to the body of the clitoris which projects upwards into the pelvis, and attaches via ligaments to the Primordial pubic bone. Follicle The clitoris (FSH) erectile tissue that swells with blood during female sexual arousal. It has contains Corpeus Albicans thousands of nerve endings — more than any other part of the human body. Corpus The Vaginal Introitus is Luteum the opening to the vagina. The vagina is a muscular canal that extends to the cervix, the opening ofCorpus Hemorrhagicum the uterus. Graafian Follicle (Mature) Mons pubis Follicle Rupture - Ovulation 2 The mons is the fleshy mound above the vulva. After puberty, it’s covered with pubic hair. It cushions the pubic bone.  The Reproductive System Female - Anatomy Basic Anatomy Developing Follicle (FSH) Primordial Follicle (FSH) Corpeus Albicans Corpus Luteum Corpus Hemorrhagicum Graafian Follicle (Mature) Follicle Rupture - Ovulation 3 The Reproductive System Female - Anatomy Schematic of the Ovary Developing Follicle (FSH) Tunica Albuginea (Capsule) Cortex (Oocytes & Follicles) Medulla (CT & Blood Vessels) Primordial Follicle (FSH) Follicle Rupture Graafian Follicle (Mature) - Ovulation Ovary Corpus Hemorrhagicum Corpeus Albicans Corpus Luteum  The Reproductive System Female - Anatomy Basic Anatomy Perimetrium (Visceral Peritoneum) Myometrium (Thick Wall Of Smooth Muscle) Endometrium - Mucous Membrane: The endometrium has three layers: Stratum Functionalis stratum compactum & stratum Stratum Basale spongiosum (which make up the stratum functionalis) - Varies With Menstrual Cycle stratum basalis The Stratum compactum and stratum spongialis develop into the stratum functionalis during the first half of the menstrual cycle (proliferative phase) 5  The Reproductive System Female – The Gonadal Axis Mainly Governed By Negative Feedback Gonadotropin Releasing Hormone (GnRH) H + P The Gonadotropins - Follicle Stimulating Hormone (FSH) Luteinizing Hormone (LH) Note: There is an + exception to Negative Feedback in the Female O The Ovarian Steroids Estradiol (E2) Cycle Progesterone (P) 6  The Reproductive System Female - Physiology Reproductive Hormones 1. Hypothalamus: Gonadotropin-Releasing Hormone (GnRH) 2. Anterior Pituitary: Gonadotropins Luteinizing Hormone (LH). Follicle-stimulating Hormone (FSH). 3. Ovary: Estrogen. Progesterone. The Hormones Secrete At Different Rates During Different Times Of The Month. 7  The Reproductive System Female – The Menstrual Cycle The Cycle Can Be Divided Into Phases Gonadal Steroids à Pituitary Gonadotropins à 8  The Reproductive System Female – The Menstrual Cycle The Cycle Can Be Divided Into Phases Follicular Phase OV Luteal Phase Pituitary Gonadotropins à éFSHà êFSHàééFSH êêFSHà êFSHà éFSH Ovaries êLHà êLHà ééLH êêLHà êLHà êLH Gonadal Steroids à éE2à éE2à ééE2 êE2à éE2à êE2 M êPà êPà éP éPà ééPà êêP M E E N Proliferative Phase Secretory Phase N S S E Growth of the Endometrium Continued Growth of the E S Mainly driven by E2 Endometrium & Increased S Uterus Secretion of Mucous Mainly driven by P, and to A lesser extent by E2 9 The Reproductive System Female – Menstrual Cycle Control of Important Events Ovulation: This “Critical Value” of E2 ééE2à Stimulates the Hypothalamusà ééFSH + ééLH +éP= Ovulation! to release a surge of GnRH Together, these three thin the wall and increase the pressure inside the follicle Menses: The crash of the two Steroids (especially P) causes the Blood The lack of LH causes theà êE2 + êêPà Flow to the Endometrium to êêLHà Corpus Luteum to Fail Constrict. The Endometrium then Dies, and is shed as Menses  The Reproductive System Reproductive Hormones Female - Physiology @ Ovaries + Rhythmic E2 Hypothalamus GnRH P - Hypothalamus Anterior Pituitary Anterior Pituitary Pulse Generator FSH LH Ovarian Target Cell Receptors Stress Starvation cAMP Exertion (2nd Messenger) Protein Kinase Reaction Phosphorylation Of Enzymes Sex Hormone P 1 Synthesis (sER) E2 Cell Growth & 11 Proliferation  The Reproductive System Female - Physiology Follicular Development Get The Follicle Ready FSH For Ovulation & Initial Uterine Preparation Follicular Maturation Follicular Maturation Proliferation Phase Granulosa Cells Thecal Cells Of Endometrium (Corona Radiata) Enclosure 1 ↑E2 1 ↑P Ovulation Corpus Luteum Secretory Phase Of Antrum Expand & (Luteinizing) Endometrium Containment Weaken LH Ovulate, Support The Development Of Corpus Luteum & Secondary 12 Uterine Preparation  The Reproductive System Female - Physiology Follicular Development FSH & E2 Get The Follicle Ready Primordial Follicle: For Ovulation Ovum Oocyte 1 Layer Of Granulosa Cells. Primary Follicle: Ovum. Oocyte Multiple Layers Of Granulosa Cells. Vesicular Follicle: Oogonium — (Oocytogenesis)—> Ovum. Primary Oocyte — Interstitial Tissue Cumulus Oophorus Oocyte Granulosa Cells. (Meiosis I)—> First Primodial Zona Pellucida Thecal Cells. Polar Body (Discarded Ova Follicle Oocyte afterward) + Follicular Fluid (Estrogens). Secondary oocyte — (Meiosis II-halted in Mature Follicle: metaphase II until fertilization)—> Ready For Ovulation. Second Polar Body (Discarded afterward) Corona Radiata + Ovum Granulosa Cells The Zona Pellucida Is A Glycoprotein Matrix (Non-Cellular). Activates Acrosome. 13 Theca Externa Theca Interna  The Reproductive System Follicular Development & Selection: Female - Physiology Typically Only One Follicle Develops Completely 6 – 12 Primordial Follicles Develop A Preferred Follicle Is Selected The follicle that grows the fastest is the one { with the most FSH receptors. ↑ E2 The one with the most FSH receptors is also the one with the highest output of E2. ↑ FSH Receptors In Preferred Follicle The E2 actually creates more FSH receptors for the follicle. Therefore, the Preferred Follicle is the one that produced Preferred Follicle Maturation the most E2, had the most FSH receptors, and bound up “all” the FSH. Literally “starving” the competing follicles. ↑ E2 ↓GnRH @ Hypothalamus As E2 rises, it suppresses both GnRH andFSH/LH, which further deprives the competing follicles. ↓FSH & ↓LH @ Anterior Pituitary As the preferred follicle matures, the competing follicles wither Other Follicles 14 Involute And are reabsorbed. The Reproductive System Female - Physiology LH& FSH Luteinizing Hormone LH Is Necessary For Final Follicular Growth And Ovulation. Two Days Before Ovulation, LH Increases 6-10 Fold. FSH Secretion Increases 2-3 Fold At The Same Time. LH & FSH Surge May Be Caused By Positive Feedback Effect Induced By Peak Secretion Of Estrogen. LH & FSH Act Synergistically To Cause Rapid Swelling Of The Follicle- àOvulation 15  The Reproductive System Female - Physiology Luteal Phase (Post Ovulation) The Granulosa Cells & Theca Cells Are Converted Into Lutein Cells After Ovulation – Luteinization. The former follicle is now called the Corpus Luteum. The Corpus Luteum secretes mainly Progesterone, but also Estrogen & Inhibin. Degenerate Corpus Luteum=Corpus Albicans. LH Stimulates The Formation Of Lutein Cells, Enhances Growth & Secretion Of The Corpus Luteum, And Extends Its Lifetime. LIF In Follicular Fluid Inhibits Luteinization. 16  The Reproductive System Female - Physiology Hormones – Estrogen & Progesterone ESTROGEN PROGESTERONE 1.Female Sex Organs: 1.Female Sex Organs: Female Genetilia Enlarge. Contributes to Ovulation Vaginal Epithelium Change – Cuboidal To Stratified. Decreases Uterine Contractions! Fallopian Cilia Increase. Increases Uterine Secretions. Endometrial Glands Proliferate. 2.Fallopian Tubes: 2.Breasts: Secretory Changes In Fallopian Tubes. Ductile Cells. Greater Fat Deposition & Stromal Tissue. 3.Breasts: 3.Skeleton: Promotes Development Of Lobules, Alveoli & Acinar. Decrease Osteoclasts. Alveolar Cells Proliferate & Become Secretory. Cause Early Growth Plate Fusing. Osteoporosis In Old Age (Post Menopause). 4.Protein & Fat Deposition: Protein To Sex Organs, Bones & Other (Less Than Men). Greater Fat Deposition & Widening Of Hips 5.Electrolyte Balance: Na+ & Water Retention. More During Pregnancy. 6.Skin: 17 Thicker In Females, More Pliant. More Vascularized.  The Reproductive System Female - Physiology Menstruation Hypothalamus Anterior Pituitary LH & FSH E2 & P Ovarian Activity ▲Estrogen ▲Progesterone ▼Progesterone Uterine Before Ovulation After Ovulation Vessels Constrict, Activity Necrosis & Shedding Basal Body Temperature 18  The Reproductive System Female - Physiology Fertilization 1 Sperm Travel From Uterus Toward The Ampulla Of Fallopian Tube Via Contractions Of Uterus (Triggered By Prostaglandins) 2 Ova Captured At Ampulla of the Fallopian Tube, and Conveyed Toward the Uterus by Peristalsis and Cilia 3 ½ Billion Sperm Deposited, 1,000 Reach Ovum & Only 1 Fertilizes 4 Zona Pellucida Is A Formidable Barrier & Permits Only 1 Sperm To Penetrate Before Changing Its Chemical Composition 5 Sperm Penetrates, Head Swells & Becomes Pronucleus 6 Female 23C + Male 23C Will Make Full 19 Complement 2N The Reproductive System Female - Physiology Pregnancy & the “Rescue” of the Corpus Luteum The Blastocyst is Comprised of an Inner Cell Mass and A Trophoblast. It Produces Human Chorionic Gonadotropin which Acts like LHà Rescues the Corpus Luteum. As long as Progesterone Is being produced, first by the Corpus Luteum, then by the Placenta, the Endometrium will be Sustained.  The Reproductive System Female - Physiology Female Fertility 1. Cycle: Ovulation Day = (Duration Of Cycle) – 14 Days. Rhythm Method? 2. Hormonal Suppression Of Fertility: ↓E2 Prior To Ovulation. Taking E2 Or P (At The Right Level) Will Prevent Steep ↑LH Increase – Ovulation. The “Pill” Contains E2 & P. Take “Pill” Creates Pseudopregnancy 3. Infertility: Slightly Higher Rate of Infertility in Females 1/6 – 1/8 Of Marriages Are Infertile. HCG or Other Fertility Drugs May Stimulate Ovulation. 21 Multiple Births Possible.  The Reproductive System Female - Physiology Placenta & Development 1. Placenta Functions: Diffusion Of Nutrients From Mother To Embryo/Fetus. Diffusion Of Metabolic Wastes From Embryo/Fetus To Mother. Permeability Increases Over Duration Of Pregnancy. O2, CO2, Etc. Diffuse Through Placenta. 2. Oxygen Diffusion O2 Diffuses Into Fetal Blood Via PO2 Pressure Gradients. Fetal Hb Has Greater Affinity for O2 Than Adult Hb. Concentration Of Fetal Hb Is 50% Greater Than Mothers. Fetal Oxyhemoglobin Higher At Low PO2. 3. CO2 & Nutrients PCO2 Greater In Embryo/Fetus – Diffuses Into Mother. Nutrients e.g. Glucose, Concentrations 22 Are Greater In Mother – Diffuses Into Fetus.  The Reproductive System Female - Physiology Key Pregnancy (Placenta) Hormones 1. Human Chorionic Gonadotropin (HCG) Trophoblast Cells Secrete HCG (Chorion). HCG Is Present In Urine 8 Days After Fertilization (sooner in blood). Prevents Involution Of Corpus Luteum. Stimulates Corpus Luteum To Secrete More P and E2 To Nourish Endometrium. Prevents Menstruation. 2. E2 ↑30x Toward The End Of Pregnancy. Secreted By Placenta Once Corpus Luteum Involutes. Synthesized (Aromatized) @ Placenta From Steroids Of Mother & Fetus’ Adrenal Glands Causes Enlargement Of Uterus & Breasts, Ductile Cells Of Breast, 3. Relaxes Ligaments (w/ Relaxin), & Enlarge Female Genitalia Progesterone P Is The Hormone Of Causes Development Of Decidual Cells In Endometrium Pregnancy (Nourishment). Prevents Contractions Of Uterus. Development Of Ovum Prior To Implantation. Prepares Breasts For Lactation – Acinar, In Conjunction w/ Prolactin. HCG Maintains Corpus Luteum 4. Human Chorionic Somatomammotropin (HCS) ↑P Development Of Breasts & Synergistic w/ Prolactin. Weak Actions Similar To Growth Hormone (Somatotropin). Affects Metabolism By Decreasing Glucose Use By Mother (Save For 1st 7 Weeks Corpus Embryo/Fetus) & Promoting Fatty Acid Extraction From Mother. Luteum 5. Other Hormonal Factors In Pregnancy ↑P Pituitary Enlarges By 50%: Increase in ACTH, TSH & Prolactin. > 7 Weeks Placenta 23 Decrease in FSH & LH. ↑P  The Reproductive System Female - Physiology Key Pregnancy (Placenta) Hormones Other Hormonal Factors In Pregnancy Adrenal Cortex SUMMARY ↑Aldosterone. HCG ↑Glucocorticoids (e.g. Cortisol). MAINTAIN CORPUS LUTEUM HORMONE Thyroid Gland Enlarges By 50% To OUTPUT Increase Production Of T4. Parathyroid Gland Enlarges – PTH Ca++ E2 Reabsorption From Mothers Bones To Facilitate Fetal Bone Development. GET MOTHER READY FOR PARTURITION Relaxin Is Released By The Placenta To Relax Ligaments & Soften Tissues For P Delivery. SUPPORT PREGNANCY BY SUPPRESSING UTERINE CONTRACTIONS HCS HELP FEED FETUS & GET BREASTS READY FOR LACTATION 24  The Reproductive System Female - Physiology Changes In Mother’s Body 1. Weight Gain Mother Puts On Weight Associated With Fetal Presence & Nutrient Storage. See Right. 2. Nutrition Greatest Growth In Fetus During Last Trimester. Mother Stores Nutrients. Need Supplemental Vitamins & Minerals. 3. Respiration O2 Usage Increases 20%. Progesterone Increases Sensitivity To CO2 Levels. 4. Amniotic Fluid Fluid Replaced Every 3 Hours. Electrolytes Replaced Every 15 Hours. 5. Renal Function ↑ In Urine Output. ↑ In Na+ & H2 O Reabsorption. ↑ In GFR. 6. Cardiac Output ↑ 30 – 40%. ↑ Blood Flow Through Placenta. ↑ BMR. 7. Blood Volume ↑ 30% Over Normal. Contingency – Expecting Blood Loss During Parturition. 25  The Reproductive System Female - Physiology Parturition 1. Increased Uterine Contractions 2. Onset Of Labor & Positive Feedback Hormonal Factors: Braxton-Hicks Contractions Prodromal Labor: Tightening of o E2/P Ratios Increase. the Uterine Muscles. o E2 Will Incite Contractions By Increasing The Oxytocin Receptors Labor Contractions. In The Uterine Myometrium. o Oxytocin Increases Contractions. o Fetal Hormones: Oxytocin, Cortisol & Prostaglandins (Softens Cervix). Mechanical Factors: o Stretch In Uterus. o Stretch Or Irritation In Cervix (e.g. Rupture Membrane To Induce Delivery). 26  The Reproductive System Female - Physiology Parturition 3. Abdominal Muscle Contractions 4. Mechanics Of Parturition Contractions Begin At Top Of Uterus & Spread Neurological Feedback. Downward – Lower Areas Are Weak. Intensity & Frequency Of Contractions Increase. Downward Force ~ 25Lbs. 1 Uterus & Birth Contractions Oscillate In Order To Permit Blood Flow. Canal Stretch 19 – 20 Births Head Expelled 1st. Cervix Is Major Obstruction To Birth. 1st Stage Of Labor Is Cervical Dilation (8 – 24 Hours). 2 Spinal Cord 2nd Stage Of Labor Is Fetus Head Through Birth Canal & Out. 5. Separation & Delivery Of Placenta Placenta Sheared From Uterine Wall During 3 Contractions. Abdominal Muscle Bleeding Ensues. Contraction Contractions & Prostaglandins Limit Blood Loss. 6. Labor Pains Hypoxia Of Uterine Muscle. Stretch Of Cervix, Perineum & Vagina. 7. Involution Of Uterus Uterus Involutes 4 – 5 Weeks. Placental Autolyses – Discharge. Endometrium Becomes Re-Epithelialized. 27  The Reproductive System Female - Physiology Breast Feeding-Summary Secretion of milk depends on certain hormones. Human Milk Colostrum Present in small volume before delivery and in Two hormones play an important role in the production first days after delivery (Prolactin) and expulsion (Oxytocin) of milk. high in the immunoglobulin IgA, which coats the PRL gastrointestinal tract. After a baby starts feeding, the maximum levels of This helps to protect the newborn until its own immune prolactin are seen in the blood after about 30 system is functioning properly along with creating a mild minutes. laxative effect, expelling meconium This helps to produce milk for the next feeding. Mature Milk The exact composition of breast milk varies from day to day, OT depending on food consumption and environment, meaning that Oxytocin is secreted faster than prolactin because it the ratio of water to fat fluctuates. is required for the current feeding as contrasted to prolactin (which is required for the next feeding). Foremilk, the milk released at the beginning of a feed, is watery, low in fat and high in carbohydrates In fact oxytocin secretion can start even before a baby starts suckling - for example when a Hindmilk is more fatty, and is released as the feed mother prepares for feed or hears the baby progresses. cry, she may start secreting oxytocin. The breast can never be truly "emptied" since milk production is a continuous biological process. If oxytocin is not produced in adequate amounts, the baby may have difficulty in Though now it is almost universally prescribed, in the 1950s the getting the feed, although there may be milk in practice of breastfeeding went through a period where it was out of mother’s breasts. vogue and the use of infant formula was considered superior to breast milk. However, today it is now recognized that there is no commercial formula that can equal breast milk. 28  The Reproductive System Female - Anatomy Other Items Of Interest Here Is An Ectopic Pregnancy In A Fallopian This Is An Adult Ovary With Two Corpora Tube That Was Excised. This Is A Medical Lutea. Emergency Because Of The Sudden Rupture With Hemoperitoneum. The Larger One At The Top Is A Hemorrhagic Corpus Luteum Of Ectopic Pregnancy Should Be Considered In Menstruation, And The Smaller One At The Differential Diagnosis Of Acute The Bottom Is Involuting From A Previous Abdominal Pain In A Woman Of Childbearing Menstrual Period. Age. If Implantation Of A Fertilized Ovum Occurs, Then The Corpus Luteum Will Persist Because Of HCG From The Placenta. Of 400,000 Ovarian Follicles Present At Birth, Only About 400 Will Mature To The Here Is The Size Of The Uterus In The Point Of Ovulation During Childbearing Third Trimester. Note How It Displaces Years. The Bowel Superiorly And Fills The Lower Abdomen. (This Unfortunate Woman Died Accidentally, And The Baby Died Too). 29  The Reproductive System Female - Anatomy Other Items Of Interest Here Is A Normal Cervix With A Smooth, Glistening Mucosal Surface. Here Is A Normal Uterus With Fallopian Tubes And Ovaries From An Maturing Follicle, So Called Because It There Is A Small Rim Of Vaginal Cuff Older Postmenopausal Woman. Contains A Definite Antrum (Or Fluid- From This Hysterectomy Specimen. filled Space) And Many Layers Of The Uterus And Ovaries Are Smaller Granulosa Cells. The Egg Is Still A The Cervical Os Is Small And Round, Than In The Preceding Picture And Primary Oocyte And Sits To One Side Typical For A Nulliparous Woman. The Have A Fairly Smooth Tan-white Os Will Have A Fish-mouth Shape After Appearance. Of The Follicle On A Mound Of Cells One Or More Pregnancies. Called The Egg Hillock Or Cumulus Oophorus. The Cells Closest To The Oocyte Will Be Expelled With It At Ovulation As The Corona Radiata. Oviduct (Fallopian Tube) With Highly Labyrinthine Mucosa. Surrounding The Granulosa Cells Of The Follicle Is The Theca Interna, A Each Piece Of Folded, Branching Rather Cellular And Vascular Mucosa Is Lined With Ciliated Simple Connective Tissue Layer, Which Columnar Epithelium. Secretes Estrogen. Outside Of This Is The Rest Of The Wall Is Rather Thin The Theca Externa A More Fibrous And Shows Interlaced Smooth Connective Tissue Layer. Muscle Bundles. 30