Female Reproductive System PDF

Specific Learning Objectives 1. Describe the microscopic arrangement of the ovary 2. Understand the arrangement and function of cells that form an ovarian follicle 3. Explain and recognize the differences between primordial, primary, secondary, tertiary and mature follicles 4....

Specific Learning Objectives 1. Describe the microscopic arrangement of the ovary 2. Understand the arrangement and function of cells that form an ovarian follicle 3. Explain and recognize the differences between primordial, primary, secondary, tertiary and mature follicles 4. Understand the physiological events in developing follicles 5. Describe follicular atresia 6. Describe the microanatomy and function of the CH, CL and CA 7. Describe the microanatomy and function of the oviduct 8. Describe the microanatomy and function of the uterus 9. Describe the microanatomy of the vagina 10. Explain the differences between epitheliochorial, endotheliochorial and hemochorial placentas  i Female reproductive system what'sin Femalereproductivesystem 1. Ovaries (Bilateral) iii msn.at 2. Oviducts (Fallopian/Uterine tubes) 3. Uterus 4. Cervix 5. Vagina 6. External genitalia (vestibule, vulva) 7. Associated glands 8. Mammary gland (covered in integumentary system)  2 Major functions Production of the female gametes (ova oogenesis) Endocrine function Production of sex hormones (mainly estrogens and progesterone) Reception of male gametes (spermatozoa) and provision of a suitable environment for fertilization Provision of a suitable environment for fetal development (uterus) Nutrition of the newborn – what structure? mammarygland  3 Ovaries Two major functions: Produce the female gametes Produce the sex hormones Ovary from a sow- Ovaries from a cow – monotocous: polytocous single follicle usually  Ovaries Ovaries in mammals all have a similar basic structure 1. Cortex Broad peripheral zone containing follicles in various stages of development 2. Medulla contains connective tissue, nerves, blood and lymph vessels M C  s Species differences In the mare, these areas are reversed, and the cortical tissue is focused around the ovulation fossa  u Ovary- Cortex E surface is lined by a low cuboidal epithelium (germinal/surface epithelium) TA Tunica albuginea: connective/fibrous tissue (stains blue in picture)  Ovary- Cortex Under the tunica albuginea numerous follicles that contain oocytes in different stages of development  8 Follicular development Folliculogenesis upon sexual maturity, one or more primordial follicles (present at birth) undergo maturation during each reproductive cycle Follicular growth and maturation is dependent on follicular stimulating hormone (FSH) from the adenohypophysis (pituitary gland)  a Ovarian follicles Ovarian follicle structure containing an oocyte surrounded by specialized epithelial cells - the size, content and wrapping of the follicle vary depending on the stage of development  10 Primordial follicles Primary oocyte in primordial follicle enclosed by flattened, simple squamous follicular cells Retained in a resting stage since formation in the fetal ovary  Primary follicles A primary oocyte enclosed by a simple cuboidal layer of follicular cells - Start forming after puberty (FSH,LH) r  13 Secondary follicles Oocyte enclosed by several layers of follicular cells Oocyte completes meiosis secondary oocyte (most species) Follicular cells proliferate through mitosis and are called granulosa cells  µ Secondary follicles Zona pellucida thick glycoprotein layer located at the interface between the oocyte and the granulosa cells Theca interna cells large, pale staining, spindle-shaped cells that are steroid producing/metabolizing cells Granulosa cells acquire receptors for follicle stimulating hormone (FSH), important in the development of the follicle  is Tertiary follicles Follicle becomes larger, small liquid-filled areasappear between the granulosa cells (antrum) Antrum  µ Tertiary follicles The antrum enlarges, the oocyte is surrounded by a layer of follicular cells (corona radiata) and sits on an aggregate of granulosa cells (cumulus oophorus) Corona radiata The structure in green is called…? Cumulus oophorus  n Mature (Graäfian) follicle Secondary oocyte detaches from the cumulus oophorus and floats free in the follicular fluid; now ready to ovulate Follicular cells acquire luteinizing hormone receptors (LH) necessary for the development of the corpus luteum  Corpus luteum (CL) Ovulation blood into antrum corpus hemorrhagicum Capillaries from stroma invade and convert it into a temporary endocrine organ called the corpus luteum (CL) CL is vital to maintaining pregnancy – secretes progesterone say simple squamous FernandaCastillo  no Corpus luteum (CL) Luteinization is the process by which the granulosa and theca cells transform into luteal (lutein) cells (hypertrophy and hyperplasia) growinsize growin  H Corpus luteum (CL) In response to follicle stimulating hormone (FSH)and luteinizing hormone (LH), lutein cells produce progesterone and estrogens  w Corpus luteum (CL) Yellow pigment (lutein) appears in the luteal cells of carnivores, mares and cows (“corpus”, body; “luteum”, yellow) sheep Pigment is not present in the corpus luteum of sows, ewes and goats  whitescar Corpus albicans (CA) Involution of the corpus luteum results in a fibrous scar called corpus albicans (albicans = white)  µ Follicular atresia Majority of follicles do not ovulate degenerate Oocyte, zona pellucida and follicular cells degenerate and are resorbed G M GlassyMembrane  as Oviduct (uterine tube) Muscular tube from ovary to uterus 3 sections: Infundibulum with fimbriae Ampulla Isthmus thickestmuscularlayer smaidinPeristalsis  26 Functions 1. Receive the ovum ovum is picked up by fimbriae of the infundibulum and directed into oviduct lumen 2. Provide favorable environment for fertilization (ampulla) epithelial secretions promote capacitation of sperm 3. Transport zygote to uterus for implantation cilia assist transport  n Oviduct (uterine tube) Tunica muscularis inner circular and an outer longitudinal smooth muscle layers Serosa contains blood vessels and nerves Broad ligament (mesentery)  Oviduct (uterine tube) Mucosa Epithelium is columnar with motile cilia on most cells Non-ciliated have secretory granules in the cytoplasm; secretion provides nutrients to the ovum toovary close  a Uterus - Functions Inian 1. Sterile and inert environment for development of conceptus iiiii serosa this know 2. Nutrient/oxygen/waste exchange via placenta 3. Muscles of uterus contribute to birth of offspring Endometrium =mucosa Mesometrium =mesentery Myometrium Perimetrium =muscularis = serosa  30 Endometrium Columnar epithelium with tubular glands  a Endometrium Glandular mucosa divided into 2 zones 1. Functional zone (F) superficial layer that degenerates after pregnancy or estrus (hormonally dependent) 2. Basal zone (B) layer that remains after pregnancy orestrus Myometrium Smooth muscle Inner circular Outer longitudinal needed expel muscles  Cervix FernandaCastillo FernandaCastillo Thick-walled, muscular structure Endocervix – faces uterus Ectocervix – faces vagina  m Function Provides a seal that prevents organisms and substances entering from the cranial vagina Functions as a gatekeeper by holding the products of conception within the uterus until parturition  as Endocervix Epithelium simple columnar with mucus-secreting cells Mucosa may have prominent primary, secondary and tertiary folds Muscularis inner circular and outer longitudinal smooth muscle layers (continuous with uterus and vagina) Serosa  we Ectocervix Lined by stratified squamous epithelium  m Vagina Fibro-muscular tube with three layers: mucosa, muscularis and serosa (cranial)/adventitia (caudal) Mucosa numerous folds (rugae) separated by channels of variable depth mostly stratified squamous epithelium with patches of simple columnar epithelium and mucus producing cells Muscularis Smooth muscles are arranged circularly (inner) and longitudinally (outer)  38 Cyclical changes in vaginal epithelium Height of epithelium and degree of keratinization vary with hormonal fluctuations during the estruscycle Changes monitored by examining stained vaginal smears (routinely done in bitches) cells cornified displayed being http://www.medvet.umontreal.ca/clinpath/banq-im/menuE.htm#Keratocytes Period of sexual Period of high follicular activity. Superficial cells and anuclear 80-100% of parabasal and arrest. Cytology varies between early squames accounting more intermediate cells plus The uterus and late phase here. Cyto: RBC, than 80% of the total vaginal neutrophils and metestrus involution is numerous parabasal, small and cells and often reaching cells. produced large intermediate vaginal cells, 100%. No neutrophils and red neutrophils are common, blood cells are not usually bacteria. presents. notreceptiveanymore The female attracts the males but is Estrus starts with this allowing and ends not receptive when she no longer accepts the male tests cheap relatively Foetal membranes and placenta formation ñ Chick embryo Zygote embryo + foetal membranes 9 days Foetal membrane = yolk sac, amnion, chorion, allantois Functions: - Viviparous animals - form the placenta - Supply and storage of nutrients Canine midterm - Respiratory exchange embryo - Excretion - Mechanical protection - Transfer of IgG/passive immunity (humans>K9/fel>>>equine/bovine) - In mammals, also hormone production Placenta 40 chorion allantois Amnion Chorion layer that contacts the mother; in most species fused with the allantois (chorioallantois/allantochorion) exchange of blood and gases between mother and fetus and develops into the fetal aspect of the placenta Allantois contains fetal urine and other fluids arising from the membrane itself collect liquid waste from the embryo, as well as to exchange gases used by the embryo smooth translucent membrane that surrounds the fetus and holds amniotic fluid providing a cushion against Equine mechanical injury  Horse, pig, ruminant not basically much blood upon delivery Placenta types Carnivore Human theftgig adof Bleeding invaded be Montiel et al. (2013). Maternal-fetal unit interactions and eutherian neocortical development and evolution. Frontiers in neuroanatomy. 7. 22. 10.3389/fnana.2013.00022.