Female Reproductive System Lecture Notes 2024 PDF

FEMALE REPRODUCTIVE SYSTEM Lecture 1 Ovary Dr. Hana Abusaida Histology Department Faculty of Medicine, Sabha University 2024  Objectives 1. Describe the structure of o...

FEMALE REPRODUCTIVE SYSTEM Lecture 1 Ovary Dr. Hana Abusaida Histology Department Faculty of Medicine, Sabha University 2024  Objectives 1. Describe the structure of ovary & the processes of follicular development. 2. Histological features of the oviducts, uterus, cervix, and vagina. 3. Describe the structural changes in the uterus during menstrual cycle and pregnancy. 4. Cellular organization of the placenta, umbilical cord, the maternal and fetal circulations. 5. Recognize some medical applications related to the female reproductive system. Dr.Hana M.Abusaida  Female reproductive system Main organs Functions 1. Paired ovaries. 1. Produce ova. 2. Oviducts ( uterine or fallopian 2. Produce female sex hormones. tubes ). 3. Facilitate fertilization. 3. The uterus. 4. Maintain fetus. 4. The vagina. 5. Deliver fetus. 5. The external genitalia. 6. Nourish infants by lactation. Dr.Hana M.Abusaida  Female reproductive system Definitions Menarche , Time of first menses, The reproductive system monthly changes in structure and function controlled by neurohormonal mechanisms. Menopause Period where menses become irregular then disappear. In the postmenopausal period the reproductive organs slowly involute.  Fertile period: Between menarche & menopause. Dr.Hana M.Abusaida  Ovaries (the female gonads) Overview  Primary sex organ.  Are almond-shaped.  ~ 3 cm long, 1.5 cm wide, and 1 cm thick.  Attached to uterus by ovarian ligaments (mesovarium and mesosalpinx).  Mesovarium is continous with medulla of the ovary, contains vessels & nerves. Dr.Hana M.Abusaida Ovary, histological structure 1- Cortex, composed of :  A simple cuboidal epithelium, the germinal epithelium.  layer of connective tissue (tunica albuginea) just below epithelium.  Ovarian follicles in various stages of development. 2- Medulla,  The most internal part of the ovary.  Dense connective tissue containing blood vessels & nerves.  There is no distinct border between the ovarian cortex and medulla. Dr.Hana M.Abusaida Ovary, histological structure Dr.Hana M.Abusaida Ovary structure Dr.Hana M.Abusaida  Fetal ovary Early Development of Ovary  In the first month of embryonic life: primordial germ cells differentiate and developed into oogonia—immature germ cells that proliferate by mitosis. Development of ovaries  At 2–5 months,~ 600,000 oogonia divide to form ~7 million oogonia.  By 3-7 months, most oogonia die by apoptosis,  The remaining enter the first meiotic division (prophase) to produce primordial follicle that contains immature primary oocyte surrounded with pre-granulosa cells.  The immature primary oocytes remain resting (in prophase) within follicles until puberty.  Follicular Growth & Development Folliculogenesis  Beginning in puberty.  Release of (FSH) from the pituitary.  Each immature primary oocyte becomes surrounded by flattened support cells called primordial follicular cells to form an primary ovarian follicle, then form secondary follicles (antral follicles),  At this stage, FSH causes un increase in follicles growth rate.  The late mature or (pre-ovulatory follicle) ruptures and discharges the oocyte (ovulation), ending folliculogenesis. Dr.Hana M.Abusaida Phases of development (Ovarian follicles) 1. Primordial follicle One layer of squamous follicular cells surrounds primary oocyte. Present in the superficial cortex. Oocyte is ~ 25 μm in diameter, Nuclear enlargement. Mitochondria becoming more numerous. RER becoming much more extensive. Golgi complexes enlarging and migrate to the surface of the oocyte to form cortical granules. Formation of specialized secretory granules called cortical granules containing various proteases, lie just below the oocyte’s plasma membrane and undergo exocytosis early in fertilization, function is block additional sperm from reaching the egg ( polyspermy). An egg must be fertilized by a single sperm only. Distinct basal lamina between the follicular cells and stromal cells and acts as a blood-follicle barrier. Dr.Hana M.Abusaida Phases of development (Ovarian follicles) Follicular cells undergo mitosis and form a simple cuboidal epithelium around the growing oocyte. The follicle is now: 2- Unilaminar primary follicle (Early stage)  Mature oocyte: increase in size.  Surrounded by 1 layer cuboidal (follicular cells). Dr.Hana M.Abusaida Phases of development (Ovarian follicles) 3 - Multilaminar primary follicle (Granulosa). (Late stage)  Oocyte: continues to increase in size, with microvilli.  Follicular cells continue proliferate forming stratified follicular epithelium (ganulosa layer) with gap junctions.  Formation of zona pellucid, between oocyte & granulosa 5-10-μm thick and contain 4 glycoproteins ZP1, ZP2, ZP3, and ZP4 secreted by oocyte.  ZP3 and ZP4 are important for sperm penetration,  The stroma around the follicle develops to form a capsule like 'theca'  Still avascular & surrounded by a basement membrane. * Only one of the maturing follicles completes the maturation process each month. The rest degenerate into atretic follicles.  Ovarian follicles  Growing follicles including primary and secondary follicles Dr.Hana M.Abusaida  MEDICAL APPLICATION  Abnormal growing for primary follicles cause polycystic ovary syndrome (PCOS), is enlargement of ovaries, numerous cysts and an anovulatory state (no follicles completing maturation successfully).  The clinical causes are unknown, it is often a hereditary, but increased estrogen, LH production by the ovaries is involved and high levels of insulin.  PCOS is the most common cause of menstrual disorders and infertility in women. Dr.Hana M.Abusaida Phases of development Ovarian follicles 4- Secondary (antral) growing follicle The theca differentiates into two layers: 1. Theca interna, well-vascularized endocrine tissue, (rounded cells that secrete estrogen and follicular fluid). Theca interna 2. Theca externa -more fibrous with fibroblasts and spindle shaped cells (like smoothe muscle). Theca externa  Formation of antrum, a space between the granulosa layers filled with follicular fluid (liquor folliculi) adjacent to the oocyte.  Corona radiate ： follicular cell around oocyte.  Secondary (Antral follicle) Follicular fluid Contains the large GAG, hyaluronic acid, growth factors, plasminogen, fibrinogen, the anticoagulant heparan sulfate proteoglycan, and high concentrations of steroids (progesterone, androstenedione, and estrogens) with binding proteins. Phases of development (Ovarian follicles) 5- Mature or preovulatory follicle ( Graafian follicle)  The first meiotic division is completed,  the oocyte is now a secondary oocyte, and starts its second meiotic division.  Oocyte expands to a diameter of 2 cm.  visible with ultrasound imaging.  the antrum develops, rapidly accumulates more follicular fluid.  The oocyte, zona pellucida and the corona radiate are all expelled at ovulation, and enter the fallopian tube.  Graafian follicle named after 17th- century for Regnier De Graaf.  Phases of development (Ovarian follicles) 5- Mature or preovulatory follicle (or graafian follicle)  Granulosa layer becomes thinner forming membrana granulose.  Thick basement membrane between granulosa layer & theca interna.  Thick thecal layers.  The oocyte connected to the wall of the follicle through the cumulus oophorus of granulosa cells * Follicular maturation takes about 3 months. Dr.Hana M.Abusaida  Follicular Atresia 6- Atretic follicle  About 400,000 follicles are present in the two ovaries of an adult female.  Only one complete maturation and undergoes ovulation,  Other follicles undergo degenerationin (follicular cells and oocytes die) (Atresia) forming Atretic follicle.  Follicles at any stage of development, including nearly mature follicles, may become atretic.  Atresia involves: Apoptosis of granulosa cells. Autolysis of the oocyte. Collapse of the zona pellucida. Phagocytose the apoptotic materials by macrophages.  Atretic follicule takes place from before birth until a few years after menopause,  Ovulation Just before ovulation  The mature follicle detachs from the tunica albuginea, forms a whitish or translucent ischemic area, the stigma (macula pellucida) , the site for release the ovum.  Germinal epithelium → discontinuous  Cortex → thinner.  Vessels in the thecal layer disrupted, forming a blood clot.  Wall rupture at stigma → 2ry oocyte with zona pellucida and corona radiate expelled by smooth muscle contractions → released from ovary → infundibulum of oviduct where it could be fertilized by a sperm.  The stigma will heal,  the residual follicle transformed into the corpus luteum.  Ovulation & Fertilization In oviduct (fallopian tube)  If fertilization occurs, the 2nd meiotic division for oocyte produces a second polar body and an OVUM. The fusion of the 2 nuclei cannot occur until the second polar body is released, and the secondary oocyte must mature into an ootid and then an ovum, the ootid is fertilized by a sperm cell, once this fertilization takes place, the ootid mature and becomes an ovum,  Ootid is immature ovum.  If fertilization occur → Sperm + ovum → zygote (46s+2n) → cleavage → uterus in 3-5 days.  If fertilization does not occur within 24 hours after ovulation → ovum begins to degenerate forming corpus luteum without completing 2nd meiotic division. Dr.Hana M.Abusaida Oogenesis Dr.Hana M.Abusaida  Oogenesis  First polar body Is a small haploid cell formed after 1st meiotic division of primary oocyte and produces a small first polar body and a large secondary oocyte.  Second polar body Is produced after the 2nd meiotic division of secondary oocyte, produce a small haploid second polar body and ootid. Ootid (immature ovum) fertilized by sperm forms mature ovum. It does not have the ability to be fertilized. They frequently die by apoptosis and disappear, but in some cases they remain for the life cycle of the organism. Dr.Hana M.Abusaida  Corpus Luteum (yellowish body)  Is a large temporary endocrine gland.  specialized for extensive production of steroid hormones (progesterone & estrogens).  formed after ovulation from the remains of the ( granulosa & theca interna cells). Characterized by:  The cells will be named: 1. Large granulosa lutein cells (LLC), comprise 80% of the parenchyma of the corpus luteum. 2. Small theca lutein cells (SLC), which:  less than half the size of the granulosa lutein cells,  aggregated in the wall of the corpus luteum, like all endocrine glands,  well vascularized  stain darkly. Dr.Hana M.Abusaida  Corpus Luteum Types of corpus luteum: 1..Corpus Luteum of menstruation:  If pregnancy does not occur,  lives 14 days.  degenerates by apoptosis and replaced by a scar of dense C.T. called Corpus albicans. 2..Corpus Luteum of pregnancy:  if pregnancy occurs,  lives for 4 to 5 months, Functions of corpus luteum  is programmed to secrete progesterone Corpus Luteum is controlled by LH of for 10–12 days. pituitary to produce:  very large. progesterone by granulosa lutein cells. estrogen by theca lutein cells. relaxin hormone. Dr.Hana M.Abusaida  Corpus albicans Corpus albicans (CA),  is the scar of C.T. forms after degenerating of a corpus luteum after ovulation. It contains:  mostly collagen & few fibroblasts, gradually becomes very small and lost in the ovarian stroma. Dr.Hana M.Abusaida  Corpus Luteum of pregnancy  Human chorionic gonadotropin (HCG) : * (HCG) produced by the placenta trophoblast cells after implantation. * Similar to LH. * promotes growth of corpus luteum to secrete progesterone to maintain the uterine mucosa. * Progesterone stimulates secretion of uterine mucosal glands, which is important for embryonic nutrition before the placenta is functional to produce progesterone. This corpus luteum of pregnancy becomes very large and is maintained by HCG for 4–5 months, the time for placenta start produces progesterone (and estrogens) to maintain the uterine mucosa. It then degenerates and is replaced by a large corpus albicans. * detected in blood or urine pregnancy test (HCG pregnancy strip tests). Dr.Hana M.Abusaida END OF LECTURE 1 Thank you ‫قف على ناصية الحلم وق اتل‬ FEMALE REPRODUCTIVE SYSTEM Lecture 2 Oviducts Uterus Dr. Hana Abusaida Histology Department Faculty of Medicine, Sabha University 2024  Oviducts (Uterine tubes),(Fallopian tubes)  Muscular paired ducts, 10-12 cm long.  Supported by ligaments and mesenteries for mobility.  One end opens into peritoneal cavity, very close to the ovary.  The other end opens into uterus. Anatomically Composed of 4 segments: 1- Infundibulum, funnel-shaped opening with fringelike extensions called fimbriae, the fimbriae partially surround the ovary. 2- Ampulla, the longest region where fertilization normally occurs; 3- Isthmus, more narrow portion nearer the uterus; 4- The uterine or intramural part, passes through the wall of the uterus and opens into theDr.Hana interior part. M.Abusaida  Oviducts (Uterine tubes) Histologically 1. Mucosa, folded, The numerous folds are most prominent in the ampulla, in cross section it resembles a labyrinth. Mucosal folds become smaller in the regions closer to the uterus and are absent in the intramural portion of the tube. a. Epithelium, two types of cells: 1) Ciliated simple columnar (CC), the cilia wave towards the uterus to help moving of fertilized zygote to the uterus. 2) Secretory peg cells (SC),secrete glycoproteins that provides nutrients and protection for both the oocyte and the sperm during fertilization, including capacitation factors that activate sperm to fertilize an oocyte. Are nonciliated, darker staining cells. a. Lamina propria: loose C.T richly vascularized.  Oviducts (Uterine tubes) Histologically 2- Muscularis, well-defined muscularis (smooth muscle)  Inner circular layers.  Outer longitudinal layers. 3- Serosa  Connective tissue covered by visceral peritoneum with mesothelium. Functions of oviducts 1.Receive ovum. 2.Fertilization. 3.Nourish ovum & sperm. 4.Transport zygote to uterus. Dr.Hana M.Abusaida  Fertilization Defenition & Site Is the union of the female and male gametes. Occurs in the ampulla of a uterine tube. Process 1) A sperm penetrate an ovum through the corona radiata. 2) Acrosomal reaction: * Hyaluronidase & Acrosin enzymes on the acrosome, released to digest the zona pellucida, allows sperm to penetrate the zona pellucida. 35 Dr. Hana Abusaida, Faculty of Medicine, Tripoli University 3) Cortical reaction Fertilization Fusion of sperm plasma membrane with the oocyte plasma membrane. Exocytosis of proteases from the cortical granules. The proteases destroy the protein link between cell membrane and the vitelline envelope, (vitelline membrane surrounds the outer surface of the plasma membrane of the ovum) remove any receptors for other sperm have bound to. Formation of impenetrable perivitelline barrier (fertilization membrane/envelope), that prevent polyspermy fertilization. Perivitelline space, is between plasma membrane & fertilization envelop. 4) Zygote formation * Nucleus of the secondary oocyte → meiosis II, producing: I.a second polar body, II.the female pronucleus (haploid) * Nucleus of the sperm becoming male pronucleus (haploid). * Fusion of the two pronuclei → the zygote (diploid). 36  Fertilization 3) Cortical reaction Fusion of sperm plasma membrane with the oocyte plasma membrane. Exocytosis of proteases from the cortical granules. The proteases destroy and remove any receptors for other sperm have bound to. Formation of impenetrable perivitelline barrier (fertilization membrane/envelope), that prevent polyspermy fertilization. Perivitelline space, is between plasma membrane & fertilization envelop. 4) Zygote formation * Nucleus of the secondary oocyte → meiosis II, producing: I.a second polar body, II.the female pronucleus (haploid) * Nucleus of the sperm becoming male pronucleus (haploid). * Fusion of the two pronuclei → the zygote (diploid). 37  UTERUS Characters  Pear-shaped organ.  With thick, muscular walls. Anatomical 1. Body:  upper rounded part.  the largest part.  entered by the left and right uterine tubes. 2. Fundus: above dome shaped part. 3. Isthmus: the narrow part. 4. Cervix:  lower cylindrical part project into vagina.  the lumen of the cervix is cervical canal,  with openings at each end:  the internal os opens to uterine cavity,  the external os opens to vagina. Dr.Hana M.Abusaida Histological 1- Endometrium (mucosa)  Lined by simple columnar ciliated, secretory.  Lamina propria (stroma) contains: type III collagen fibers, Highly cellular (stellate cells, macrophages and lymphocytes, fibroblasts ) and ground substance. Uterine (endometrial) glands. Endometrium has two concentric zones: I. Functional zone (functionalis) outer, contains the large uterine glands. has a spongier lamina propria and highly cellular richer in ground substance. Shed during menstruation. II. Basal zone (basalis) more highly cellular lamina propria. contains the deep basal ends of the uterine glands. no changes during menstruation. Dr.Hana M.Abusaida Mucosa, surface epithelium is simple columnar ciliated and secretory cells. Stroma with many fibroblasts, ground substance, and type III collagen, but no adipocytes. Uterine Glands (endometrial glands)  lined by non- ciliated secretory columnar epithelial cells.  Secrete glycogen, store it at the base of cells. Dr.Hana M.Abusaida 2- Myometrium (muscularis )  Thickest layer,  smooth muscle fibers separated by C.T.  containing many blood vessels. Composed of: Inner: longitudinal, interwoven. Vascular: contains BV. Supravascular: oblique, many BV. Outer: longitudinal, interwoven. 3- Perimetrium, Continuous with the ligaments, Adventitia (C.T. only) in some parts. Serosa (mesothelium + C.T.) in parts inside peritonium. Dr.Hana M.Abusaida  Blood supply of uterus  BV supplying endometrium arise from uterine arteries in myometrium. 2 sets of arteries: 1. Straight arteries, supply basal zone. 2. Coiled or spiral arteries:  supply functional zone,  progesterone-sensitive.  with superfiial capillary bed and vascular lacunae. Dr.Hana M.Abusaida  Changes in uterus 1. During pregnancy: Smooth muscles:  increase size (hypertrophy).  increase number (hyperplasia).  synthesize collagen, which strengthens the uterine wall.  The well-developed uterine myometrium contracts very forcefully during parturition to expel the infant from the uterus. 2. After delivery:  the uterus returns to its prepregnancy size.  smooth muscle cells:  shrink and many undergo apoptosis.  removal of unneeded collagen. Dr.Hana M.Abusaida  Menstrual Cycle Defenition  Cyclic structural changes of endometrium.  Starts between 12-15 years (menarche),  becomes irregular and disappears between about 45-55 years (menopause). Hormonal effect  Due to ovarian hormones (estrogen & progesterone). Duration  Average 28 days. Endometrial cycle  Endometrial changes during menstrual cycle,  Divided into 3 phases: 1. Menstrual phase (first 4 days). 2. Proliferative phase (4th to 14th day). 3. Secretary phase (15th to 28th day). Dr.Hana M.Abusaida 1.Menstrual phase  Day 1 is the day when menstrual bleeding start.  The menstrual discharge (menses) consists of : 1. degenerating endometrium (necrotic tissue of functional zone). 2. mixed with blood from ruptured blood vessels. Process of menstrual phase  Degeneration of corpus luteum → rapid drop of progestron → spasm of muscle contraction, interrupting spiral arteries of functional layer, stop normal blood flow, ( vasoconstriction) → hypoxia → necrosis.  BV above constriction rupture →bleeding begins → carry with it necrotic tissue of functional zone (menses). At end of menstrual phase  endometrium reduced to a thin layer (about 0.5 mm).  is ready to begin a new cycle.  its cells begin dividing to form the mucosa. Dr.Hana M.Abusaida 2. Proliferative Phase  Also called follicular or estrogenic phase.  Rapid growth of ovarian follicles.  Depends on estrogen secreted by ovarian follicles.  Estrogens act on the endometrium, inducing proliferation of surface epithelium, glands and lamina propria.  Spiral arteries become elongated & convoluted. During proliferative phase:  the endometrial lining is simple columnar epithelium,  glands are straight tubules with narrow, nearly empty lumens. At the end of proliferative phase:  endometrium 2-3 mm thick,  glands are straight tubules. Dr.Hana M.Abusaida 3. Secretory Phase  Also called luteal phase.  Now, ovary shows corpus luteum formation so progesterone secretion.  Progesterone stimulates epithelial cells of uterine glands to secrete glycogen, lipids, stored in the base of the epithelial cells.  The gland become highly coiled. During the secretory Phase:  the endometrium reaches its maximum thickness (5 mm).  now the endometrium thickening, high secretions optimal for embryonic implantation and nutrition.  progesterone inhibits strong contractions of the myometrium that might interfere with embryo implantation. Dr.Hana M.Abusaida Ovarian cycle Hormonal cycle Endometrial cycle Dr.Hana M.Abusaida  Endometrium changes  After implantation the endometrium is called the decidua.  Decidua = Pregnant endometrium.  The endometrium increases thickness, becomes highly vascularized and its glands increase their secretions, these changes reach their maximum about 7 days after ovulation. Decidua composed of three regions: 1.decidua basalis, between the embryo and the myometrium, which becomes the major portion of placenta. 2.decidua capsularis: between the embryo and the uterine lumen, thins as the embryo gets larger. 3. decidua parietalis, on the side of the uterus away from the embryo.  Medical application Endometriosis Is a disease in which tissues lining of the uterus grows upnormally outside the uterus. Detected with laparoscope. It can cause severe pain in the pelvis and excessive bleeding during each menstruation period, make it harder to get pregnant. Endometriosis can start at first menstrual period and last until menopause. The cause is unknown. There is no known way to prevent endometriosis. There is no cure, but its symptoms can be treated with medicines or, in some cases, surgery. Dr.Hana M.Abusaida  PLACENTA Defenition  Temporary endocrine organ for physiologic exchange between the mother and the fetus and contains tissues from both.  It attaches to the wall of uterus, and baby's umbilical cord arises from it.  It expelled from the body after birth. Functions: 1. Placental barrier:  Transfer O2, nutrients, antibodies from maternal to fetal blood.  Transfer Co2 and waste products from fetal to maternal blood. 2. Endocrine organ  Fetal and maternal  Secrete estrogen, progesterone and human blood do not mix in the placenta. choroinic gonadotropins (HCG).  PLACENTA Histological Structure 1. Maternal part (Decidua basalis)  Are clusters of large round or oval cells.  Between the embryo and the myometrium.  The major portion of the placenta. 2. Fetal (embryonic) part (Chorion). Structure of chorion: A- Choroinic plate (wall), rapid proliferation give rise to chorionic villi; B- Choroinic villi.  PLACENTA Choroinic villi Are projections of the fetal chorion Provide maximum contact area with maternal blood. Undergo three stages: 1. Primary villi  appear 2 days after implantation,  as 2 (layers) cords: cytotrophoblast cells, inner syncytiotrophoblast, outer. 2. Secondary villi  form on the 15th day, extraembryonic mesenchyme. Tertiary villi  develop within a few more days, mesenchyme diffrentiates to form capillary loops (villous capillary) continuous with the embryonic circulatory system.  Intervillus spaces, is the space between chorionic villi, contains maternal blood.  PLACENTA Choroinic villi  Consists of two types of cells: 1. Cytotrophoblasts – Inner cuboidal cells with pale staining cytoplasm and euchromatic nuclei. They are absent by mid to late pregnancy. 2. Syncytiotrophoblasts – Outer multinucleated cuboidal cells with microvilli. * Maternal blood , between villi (in intervillous space).  Placental barrier  Semipermeable layer separating the maternal from the fetal blood in the placenta. Function 1. Regulating passage of substances from the maternal to the fetal blood. 2. prevents passage of harmful substances to fetus. composed of: 1. Syncytiotrophoblast 2. Cytotrophoblast 3. Basement membrane of trophoblast cells 4. Fetal loose C.T. 5. Basement membrane of decidua. 6. Fetal capillary endothelium Dr.Hana M.Abusaida Umbilical cord  The umbilical cord connects the fetus to the placenta, it is composed of:  Amniotic Epithelium – covering the surface, is a simple cuboidal epithelium.  Two Umbilical Arteries - carry deoxygenated blood from the fetus to the placenta.  Single Umbilical Vein - delivers oxygenated blood from the placenta to the fetus. The tunica media is a thick smooth muscle.  Wharton's Jelly - a matrix of embryonic mucous connective tissue.  Ground substance (primarily hyaluronic acid and chondroitin sulfate) with a low abundance of collagen or reticular fibers.  Mesenchymal Cells - are many stellate and spindle-like (fusiform).  Fibroblasts – are scattered spindle-shaped cells in the matrix.  Cleavage  Fertilization in oviduct, day 1  Cleavage: mitotic division of fertilized egg, at day 2-3  Blastomere： cells from cleavage, day 3  Morula stage：aggregation of blastomere (compaction).  Formation of blastocyst, day 4, remains in uterus about 2 days,  Blastomeres arranged themselves as: a) Trophoblast,  arranged as a peripheral layer.  Form the placenta. b) Embryoblast or inner cell mass,  will form the embryo. Dr.Hana M.Abusaida  Implantation (nidation)  Trophoblast differentiate forms: 1- Cytotrophoblast, * Cuboidal, mitotically active cells, * will surround the amnion and yolk sac. 2- Syncytiotrophoblast,  More superfiial,  Nonmitotic mass cells,  Cuboidal, multinucleated cells, with microvilli  invades the stroma.  Developing embryo embed within the stroma.  The newly implanted embryo absorbs nutrients and oxygen from the endometrial tissue and blood in the lacunae. Dr.Hana M.Abusaida  Implantation (nidation)  Formation of two cavities; the amnion and the yolk sac:  Embryoblast differentiate forming bilaminar germinal disc, which is:  all parts of the embryo develop from it,  is composed of: 1- Hypoblast  primitive endoderm.  continuous with the yolk sac. 2- Epiblast  primitive ectoderm,  continuous with the amnion Dr.Hana M.Abusaida  CERVIX Characters  Is the lower, cylindrical part of the Histological structure uterus. 1. Endocervical mucosa;  It differs histologically from the  Internal os, rest of the uterus.  Simple columnar epithelium,  does not change its 2-3 mm  Thick lamina propria, with many large, thickness during ovarian cycle, branched, mucus-secreting cervical glands;  is not shed during menstruation. their secretion depend on functional state;  lacks spiral arteries.  watery at ovulation allowing penetration by sperms.  viscid at pregnancy prevent penetration of microorganisms. 2. Exocervical (Ectocervical) mucosa  External os,  is lined with stratified squamous Dr.Hana M.Abusaida nonkeratinized epithelium, CERVIX Dr.Hana M.Abusaida Transformation zone CERVIX  Is the junction between the two types of epithelium,  The squamocolumnar junction: marks the boundary between the squamous-lined exocervix and the columnar-lined endocervix  Periodic exposure of this zone to the vaginal environment leads to intraepithelial neoplasia. Medical application Squamous cell neoplasia,  the most common type of cervical cancer, occurs in metaplastic cells of the transformation zone. Dr.Hana M.Abusaida  Deeper wall of the cervix consists:  Mainly dense connective tissue,  Less smooth muscle than the rest of the uterus.  Cervix becomes rigid during pregnancy to helps retain the fetus in uterus. Before parturition A process of cervical changes (cervical effacement) occurs;  Connective tissue remodeling,  Collagen removal, mediated by macrophages.  As a result the cervix softens, the cervical canal dilates, birth occurs more easily. Dr.Hana M.Abusaida END OF LECTURE 2 Thank you FEMALE REPRODUCTIVE SYSTEM Lecture 3  Vagina  Mammary glands Dr. Hana Abusaida Histology Department Faculty of Medicine, Sabha University 2024 Characters VAGINA  Fibromuscular canal, about 10 cm.  From cervix to external genitalia.  No submucosa.  Lacks glands. Histological structure 1.Mucosa a. Epithelium  Is stratified squamous non-keratinized.  Thickness is 150-200 μm in adults.  Synthesize and accumulate glycogen, presence of vaginal flora (Lactobacillus).  Bacteria metabolize glycogen to lactic acid, causing a low pH in the vagina to provide protection against pathogenic microorganisms. b. Lamina propria  Is rich in elastic fibers,  With numerous papillae projecting into the epithelium.  Contains lymphocytes and neutrophils in large quantities.  No glands, mucus in the vagina is Dr.Hana produced by cervical glands. M.Abusaida  VAGINA 2. Muscularis  Smooth muscle fibers arranged in:  Inner circular.  Outer longitudinal. 3. Adventitia  Dense connective tissue.  Is rich in elastic fibers, making the vaginal wall strong and elastic.  Contains extensive venous plexus, lymphatics, and nerves. Dr.Hana M.Abusaida  EXTERNAL GENITALIA (Vulva) The female external genitalia, or vulva, include several structures, all covered by stratified squamous epithelium: 1) The vestibule, A space whose wall includes: the vestibular glands produce lubricating mucus and paired of Bartholin glands, which are homologous to the male bulbourethral glands. 2) The paired labia minora, folds of skin lacking hair follicles but with numerous sebaceous glands. 3) The paired labia majora, homologous and histologically similar to the skin of the scrotum. 4) The clitoris, An erectile structure homologous to the penis with paired corpora cavernosa. The mucosa of these structures, abundantly supplied with sensory nerves and tactile receptors, is important in the physiology of sexual arousal. Dr.Hana M.Abusaida  MAMMARY GLANDS  Are modified apocrine sweat glands.  Derived from ectoderm,  Are 2 tubuloalveolar glands covered by skin.  Persists on each side of the chest.  Function is to secrete nutritive milk for newborns. Each gland:  15-25 lobes.  with a surface elevation (nipple). Each lobe:  can be considered a gland.  it has its own lactiferous excretory duct.  separated from other lobes by dense and much adipose C.T. Dr.Hana M.Abusaida  MAMMARY GLANDS The nipple:  is a skin elevation,  has 15–25 pore-like openings of lactiferous duct.  Conical, brown color.  richly supplied by sensory nerve endings.  covered by stratified squamous keratinized epithelium. Areola:  light brown skin around nipple.  is thin skin with sebaceous glands.  Lactiferous duct emerge in the nipple,  contains more melanin, darkens  Lactiferous ducts aggregate as 15-20 during pregnancy. lactiferous sinuses.  rich in smooth muscle, contract to  Milk stored in lactiferous sinus until produce nipple erection. released at tip of nipple. Dr.Hana M.Abusaida  The histological structure of the mammary gland varies according to sex, age and physiologic conditions: 1- Before puberty In both sexes Flat gland. In both sexes are composed only of lactiferous sinuses near the nipple, with very small, branching ducts emerging from these sinuses. 2- During puberty In females due to ovarian estrogen, breasts increase in size by:  increase in adipose tissue.  increase in C.T.  elongation and branching of duct system.  nipple enlarges. 3- In adult  Resting inactive nonpregnant mammary gland.  Lactating mammary gland.  Post-lactational mammary gland.  Post-menopausal mammary gland Dr.Hana M.Abusaida 1) Resting inactive mammary gland In nonpregnant adult women:  Each gland lobe consists of many lobules, called terminal duct lobular units (TDLU).  Each lobule has several small, branching ducts.  Lactiferous sinuses are lined with stratified cuboidal epithelium.  Lactiferous ducts and terminal ducts lined with simple cuboidal epithelium with many myoepithelial cells.  Sparse of smooth muscle fibers encircle the larger ducts.  Composed of large connective tissue separates the lobes. Dr.Hana M.Abusaida 2) Changes in mammary glands during Pregnancy  Alveoli develop and begin to grow as a result of the action of hormones estrogen, progesterone, prolactin, and the placental lactogen.  The spherical alveoli are composed of cuboidal epithelium, with myoepithelial cells.  The stroma becomes less prominent, lymphocytes and plasma cells becoming more numerous late in pregnancy. 3) Late pregnancy  Alveoli and ducts are dilated by an accumulation of colostrum, is the first form of breast milk that is released by the mammary glands after giving birth, it is rich with proteins.  Immunoglobulin A (IgA) antibodies are synthesized by plasma cells and transferred into colostrum, from which passive acquired immunity is conferred on the breast-fed newborn. Dr.Hana M.Abusaida 4) At parturition and during lactation,  Secretory alveoli lined by simple cuboidal epithelium surrounded by myoepithelial cells.  Large amounts of milk protein are secreted by exocytosis or merocrine mode.  Lipids secreted by apocrine mode (with part of apical cell membrane).  Milk is acidophilic.  The intralobular connective tissue is sparse and difficult to seen.(only septa).  Adult mammary gland Adult,inactive nonpregnant women Active during pregnancy, Active during lactation  (Milk ejection reflex)  Is an automatic natural reaction that happens in body when the baby starts to breastfeed.  There are nerves in the nipples that are triggered by baby’s sucking. These nerves cause two hormones to be released into the bloodstream. Prolactin is responsible for making more breast milk. Oxytocin causes the let-down reflex so the milk flows. 5) After weaning, The alveoli and ducts cells die with apoptosis. Myoepithelial cells & basal laminae persist for next pregnancy. Changes of mammary glands Dr.Hana M.Abusaida 6) Post-menopausal mammary gland Reduction in size. Atrophy of alveoli, ducts and interlobular C.T. Caused by absence of ovarian E & P.  MEDICAL APPLICATION  Most breast cancers (mammary carcinomas) arise from epithelial cells of the lactiferous ducts.  Cell spreading via the circulatory or lymphatic vessels to critical organs such as the lungs or brain are responsible for the mortality associated with breast cancer.  Axillary lymph nodes are removed surgically and examined histologically for the presence of metastatic mammary carcinoma cells.  Early detection (e.g, through self-examination, ultrasound, and other techniques) early treatment have significantly reduced the mortality rate. Dr.Hana M.Abusaida  END OF FEMALE LECTURES Thank you ‫قف على ناصية الحلم وقاتل‬