The Reproductive System Lecture PDF

The Reproductive System Cellular Pathology and Imaging ASC_4_498_23_24 Alison Alvarez  The Female Reproductive Tissue Objectives Recognise sections of ovary in relation to its function. Describe and recognise the changes to the d...

The Reproductive System Cellular Pathology and Imaging ASC_4_498_23_24 Alison Alvarez  The Female Reproductive Tissue Objectives Recognise sections of ovary in relation to its function. Describe and recognise the changes to the developing ovarian follicles Describe the histological arrangement of the oviduct and uterus and explain how its structure is adapted to its function. Describe the structure of breast tissue (mammary gland) and the changes that occur during pregnancy and breast-feeding.  The Female Reproductive System Ovaries produce 2nd oocytes & hormones Uterine tubes transport fertilized ova Uterus where fetal development occurs Vagina & external genitalia Vulva Mammary glands produce milk  The Ovary cortex region just deep to tunica, containing ovarian follicles Ovarian follicles lie in the cortex consist of oocytes in various stages of development germinal epithelium simple cuboidal epithelial covering over the ovary tunica albuginea capsule of dense connective tissue Medulla deeper region composed of connective tissue, blood vessels & lymphatics rete ovarii - solid networks of irregular channels lined by cuboidal epithelium.  Follicular Stages primordial primary secondary Graafian OVULATION Corpus luteum Corpus albicans  Primordial Follicles Structure primary oocyte surrounded by a single layer of squamous epithelial cells Location – just beneath the tunica albuginea Size ~25 μm diameter arrested in prophase stage of meiosis I  Primary Follicles Structure surrounded by a layer of cuboidal epithelial cells If more than one layer of cuboidal cells (multilaminar) they are called granulosa cells and form the granulosa layer cortical granules secretory vesicles contained in the oocyte Zona pellucida – Secreted by the oocyte glycosaminoglycans and glycoproteins Theca interna – layer of cuboidal cells Size (100-250 μm diameter)  Secondary Follicles Early Secondary Follicle Structure fluid filled cavities containing liquor folliculi rich in hyaluronic acid Cumulus oophorus – thickened area of granulosa cells that contains the oocyte and projects into the antrum Theca interna – inner, highly vascular layer of cuboidal cells Steroid producing cells Have receptors for luteinizing hormone (LH) Late Secondary Follicle Theca externa – outer layer of connective tissue cells, smooth muscle cells and bundles of collagen fibers Corona radiata – cells of the cumulus oophorus immediately surrounding the oocyte and released with the oocyte at ovulation http://www.ndvsu.org/images  Graafian (Mature) 10 mm diameter Follicle primary oocyte spherical with centrally located nucleus prominent nucleolus. Zona pellucida Corona Radiata Cumulus oophorus The granulosa cells that surround the oocyte, and project into the antrum Antrum Single space of follicular fluid Membrana granulosa Cuboidal epithelial cells that surround the antrum Stratum granulosum Granulosa cells Thecalayers Theca interna (inner vascular layer) Theca externa (outer fibrous layer). http://www.ndvsu.org/images  Corpus Luteum Function produce and release hormones Structure Corpus hemorrhagicus central blood clot that goes on to form the corpus luteum. Granulosa lutein cells formerly the granulosa cells, now folded. centrally located, ~30 μm in diameter secrete progesterone, convert androgens into estrogens Theca lutein cells formerly the theca interna cells Located in the periphery and are smaller in size (~15 μm) secrete progesterone, some estrogen, and androgens Corpus luteum of pregnancy Persists throughout pregnancy but its functions are taken over by the placenta by 8th week of pregnancy Corpous luteum of menstruation – remains active for 14 days; it’s degeneration forms the corpus albicans  Corpus albicans Structure fibrous connective tissue slowly disintegrates after several months  Oviducts / Fallopian tubes Function transmit ova from ovaries to uterus environment for fertilization Structure paired structures extend from the uterus to the ovaries approximately 12 cm long Four regions Infundibulum – funnel-shaped region adjacent to the ovary. The end of the infundibulum has fringed extensions known as fimbriae Ampulla – longest segment. Usual site of fertilization Isthmus – narrowest portion Uterine/intramural region –opening to uterine cavity Arrow indicates Pseudo- stratified columnar epithelium with motile cilia. http://www.ndvsu.org/images  Walls of the oviduct- Layers Mucosa with mucosal folds folds which project into the lumen of the oviducts and are most pronounced in the ampulla – Epithelium – simple columnar with two types of cells Peg cells – non-ciliated. Secretory- secretions: -facilitates capacitation of spermatozoa -provides nutrition for the ovum and early embryo -inhibits movement of microorganisms to the oviducts Ciliated cells – cilia: -beat toward the uterus -propell the ovum toward the uterus – Lamina propria – loose connective tissue Muscularis inner thick circular layer and longitudinal layer Serosa mesothelium and thin layer of connective tissue http://www.ndvsu.org/images  Uterus Function receives the morula from the oviduct Location of fetal development Structure hollow pear-shaped organ. consists of three regions: – Body – large upper portion – Fundus – upper, rounded part lying above the attachment of the oviduct – Cervix – lower portion. Connects the uterus to the vagina.  Layers of the uterine wall Perimetrium – covers the posterior surface of the uterus and part of the anterior surface; remaining is covered by adventitia Myometrium – thickest layer of uterine wall. Consists of three muscle layers: inner and outer longitudinal layers oriented parallel to the long axis of the uterus middle circular layer highly vascularized. known as the stratum vasculare. http://www.ndvsu.org/images  Layers of the uterine wall Endometrium – mucosa lined by simple columnar epithelium contains secretory and ciliated cells cyclic changes during the menstrual cycle Parts: – Stratum functionalis – thick part of the endometrium sloughed off during menstruation – Stratum basale – part which is retained during menstruation and serves as a source of regeneration of the functionalis – Lamina propria – contains simple branched tubular glands http://www.ndvsu.org/images  Cervix Structure terminal end of the uterus Thick walled muscular tube rich in elastic fibres- dense connective tissue Internal communicates with the uterine cavity External communicates with the vagina Portio vaginalis – protrusion into the vagina, lined by stratified squamous epithelium Fornix – extension of the vagina around the portio vaginalis Secretions- Mucosa – Epithelium – lined by mucus-secreting columnar epithelium except at the portio vaginalis where it is lined by stratified squamous epithelium Glandular secretions – two types of secretions: – Serous – produced during ovulation – Viscous produced at other times and during pregnancy. The viscous secretion forms a mucus plug http://www.ndvsu.org/images  Vagina Structure – muscular tube, 8-9 cm in length, extending from the cervix to the external genitalia Three layers of the vaginal wall: Mucosa epithelium - stratified squamous epithelium supported by a fibroelastic, richly vascularized connective tissue. no glands Lamina Propia / Muscularis rich in elastic bundles of smooth muscle cellsouter longitudinal bundles Adventitia thin layer of dense to loose connective tissue joins the vagina to the urethra and bladder anteriorly and rectum and anal canal posteriorly http://www.ndvsu.org/images  Mammary Glands Function Production and excretion of milk Structure secretory lobes (15-25) embedded in adipose tissue -tubular acinar gland Ducts -lined with cuboidal epithelial cells -Surrounded by myoepithelial cells Nipple Ducts surrounded by smooth muscle cells  The Male reproductive system Objectives Recognise sections of the testes in relation to its function Describe and recognise the changes to the developing sperm Identify and explain the role of cells within the testes that promote the development of sperm. Describe the histological arrangement of the testes and seminal passage and explain how its structure is adapted to its function.  Sperm (About 65 µm long) Head Nucleus: tightly-packed 23 chromosomes. Acrosome: Flattened sac containing digestive enzymes. Tail Central core is a typical flagellum (9+2=axoneme). Dense fibers. Middle piece: Helically wound mitochondria. Principal piece: Fibrous sheath (for support). End piece: End of flagellum. Plasma membrane. LadyofHats, wikimedia commons Bloom and Fawcett Histology, 11th ed, fig 31-20, p 813 Fawcett 1975, Dev Biol, 44:394, fig 3, p 397 Male reproductive organs Elf Sternberg, wikimedia commons  Testis Diagram of testis and epididymis The testis has about 250 lobules, each containing 1-4 seminiferous tubules. Seminiferous tubule Germ cells: Develop into sperm. Sertoli cells: Somatic cells, support, nutrition, hormone receptors. Seminiferous tubule and interstitial tissue Boundary layer (flattened fibroblasts). Interstitial tissue Leydig cells produce testosterone (a steroid hormone). Gray’s Anatomy, answers  Spermatogenesis Development of germ cells into sperm. Stem cells: Spermatogonia With 23 pairs of chromosomes (normal amount of DNA). Meiosis Steps of spermatogenesis Meiosis: Primary and secondary spermatocytes Primary spermatocyte: Chromosome pairs fuse, crossing over. Long prophase (about 20 days). First meiotic division, where each daughter cell receives one chromosome from each pair. Secondary spermatocyte: Prompt second meiotic division, which is a normal mitotic division. Spermiogenesis: Spermatids With 23 chromosomes (half of DNA, for fertilization). Remarkable differentiation into sperm. Heller and Clermont, 1964  Seminiferous tubule, LM A.K. Christensen  Primary spermatocytes, spermatids, Sertoli cells Lumen Older spermatid head Young spermatid nucleus A.K. Christensen Secondary spermatocyte, division figures A.K. Christensen  Spermatid, acrosome, flagellum, EM Spermiogenesis, diagram A.K. C  Sertoli cells Cell trunk extends from basement membrane to lumen. Supports and nourishes germ cells. All germ cells are surrounded by Sertoli processes or lie in Sertoli surface invaginations. Main endocrine target cell in the seminiferous tubule. Testosterone receptors. Follicle stimulating hormone (FSH) receptors. Blood-testis barrier (Sertoli-Sertoli tight junctions). Blocks entrance of extraneous proteins, etc., into seminiferous tubules between Sertoli cells (must go through Sertoli cell). Special fluid inside tubule (high K+) made by Sertoli cell. Possible protection of germ cells from immune system. Sperm first arise at puberty, when immune system already set. Sperm surface antigens may be seen as foreign. Fawcett, Handbook of Physiology,1975  Leydig cell Leydig cells in the interstitial tissue, testis, LM Source of the male sex hormone testosterone, a steroid hormone synthesized from cholesterol. Testosterone secretion is regulated by pituitary LH. EM of Leydig cell cytoplasm, showing abundant smooth ER A well-developed smooth endoplasmic reticulum (SER)  Testis of a rat from which pituitary removed (= hypophysectomy), LM A.K. Christensen  Sperm pathway through the male tract Mediastinum of the testis. Straight tubules. Rete testis. Efferent ducts. Passageway from testis to epididymis. There are 15-30 efferent ducts. Epididymis. Head, body, tail. Single long coiled duct (~6 m long). Sperm mature during passage, and are stored in the tail of the epididymis (for ejaculation). Ejaculation Ductus deferens conducts sperm from epididymal tail. Seminal vesicles usually furnish most of seminal fluid. Seminiferous tubules, rete testis (channels), LM Efferent duct, epididymis, LM Prostate gland contributes to seminal fluid. Semen passes through prostatic and penile urethra. Ross and Pawlina, 5th ed, 2007, fig 22.4a, pg 732.  Efferent duct (star-shaped lumen) Smooth muscle Cilia A.K. Christensen  Epididymis (pseudostratified columnar epithelium) Microvilli (“stereocilia”) Sperm Basal cell A.K. Christensen  The Female Reproductive System Pathology Cervix- Cervical cancer chronic inflammation Fallopian Tube- Ectopic pregnancy Uterus – Endometriosis Adenomyosis endometrial carcinoma leiomyosarcoma Ovary – Haemorrhage carcinoma GTD https://doctorlib.info/  Diseases and disorders of the female reproductive system Disease/disorder Description Breast cancer Second leading cause of cancer death. BRCA 1& 2 Cervical cancer Slow to develop, PAP smear detects abnormal cervical cells Cervicitis Inflammation of the cervix usually due to infection Dysmenorrhea Condition with severe menstrual cramps limiting normal activities Endometriosis Fibrocystic breast disease Abnormal cystic tissue in the breast. Common in women in their 30-40s Ovarian cancer Detection difficult – often spreads before detection (CA125)  Fertility Many cancer treatments can affect a girl’s or woman’s fertility. Whether or not fertility is affected depends on factors such as: baseline fertility age type of cancer and treatment Dose, length of treatment, time passed since treatment personal health factors Females can be diagnosed as infertile if: The ovaries don’t contain healthy eggs Hormones that are needed to help with egg release are disrupted A tumor or other problem might press on the ovaries or uterus (womb) and cause them not to work properly Damage to other parts of the reproductive system prevents eggs from being released, fertilized, or implanted A fertilized egg cannot grow inside the uterus Something happens that won't allow a fetus (unborn child) to be carried through the full pregnancy, causing a miscarriage Jeruss, Jacqueline & Woodruff, Teresa. (2009). Current Concepts: Preservation of Fertility in Patients with Cancer.. The New England journal of medicine. 360. 902-11. 10.1056/NEJMra0801454. Male reproductive tract Elf Sternberg, wikimedia commons  Spermatic cord: ductus (vas) deferens, testicular artery and veins, cremaster muscle, LM Ductus deferens Veins Artery Cremaster Countercurrent heat exchange Kirkman slide colle  Semen Normally about 3.5 ml per ejaculate in humans. Sperm About 100 million sperm per ml. Concentrations lower than about 20 million/ml may cause fertility problems. Seminal fluid Mainly from seminal vesicle (usually about 70%), prostate and epididymis.  Seminal vesicle The secretion includes fructose, ascorbic acid, prostaglandins. Kirkman histological slide collection  Seminal vesicle, LM Secretory epithelium Smooth Mucosal folds muscle From Japanese 35mm histological slide set (Mizoguti), slide 689  Prostate Gland The glands are organized into three zones: Mucosal (or urethral) glands. Main (or peripheral) glands 70% of prostate volume. Submucosal (or median) glands located anteriorly between the mucosal and main glands. © Cambridge.org  Detail of prostate glands, LM Smooth muscle Gland A.K. Christensen  Prostate gland, concretions Concretion Gland Smooth muscle Kirkman histological slide collection  Penis erectile tissues urethra, surrounded by tunica albuginea and skin. corpus cavernosum penis erectile tissues ( dorsally) corpus cavernosum urethrae (corpus spongiosum) erectile tissues located ventrally and surrounds the urethra. At its end it dilates, forming the glans penis. Gray’s Anatomy, wikibooks  The Male Reproductive System Cancer Prostate – Carcinoma Testis – Testicular Cancer embryonal carcinoma Seminoma Penis- Penile Cancer  Disease of male reproductive system Disease/ disorder Description Benign prostatic hypertrophy Non malignant enlargement of prostate gland; common in older men Epididymitis Inflammation of epididymis – usually starts with UTI Impotence or erectile dysfunction Disorder in which erection cannot be achieved or maintained – increases by age >50 Prostatitis Inflammation of prostate gland  Fertility Nearly 1 in 7 couples is infertile In up to half of these couples, male infertility plays at least a partial role. Male infertility can be caused by low sperm production abnormal sperm function blockages that prevent the delivery of sperm. I llnesses, injuries, chronic health problems lifestyle choices and other factors https://www.everydayhealth.com/ https://www.mayoclinic.org/diseases-conditions/male-infertility/symptoms-causes/syc-20374773