The Female Reproductive System

University:
Texas A&M University
Course:
BIOL 319 | Integrated Human Anatomy and Physiology I
Academic year:

2024
Views:

73

Pages:

92
Author:

Athena Harrison

The Female Reproductive System Ovary Objective To learn the structure of the ovary, fallopian tube, uterus, cervix, and vagina To learn how these organs contribute to the many functions of the female reproductive system To learn how hormones regulate and/or orchestrate the female reproductive processes Functions of the female reproductive system • Ova production • Ova and sperm transportation • Microenvironments for fertilization • Implantation and fetal-placental growth • Nourishment and support of offspring • Postnatal repetition Female Reproductive System Female Reproductive System Ovary General structure • • • • Germinal epithelium Tunica Albuginea Medulla Cortex Functional overview Origin of germ cells Germinal epithelium Cortex Ovary Primary Follicle Follicle Maturation Primordial follicles • Oocyte • Follicular (granulosa) cells Follicle Maturation Primary follicle • Zona pellucida • Stratum granulosum • Thecal folliculi • Call-Exner bodies Follicle Maturation Secondary (antral) follicle: Follicular fluid Membrana granulosa Cumulus oophorus Corona radiata Theca interna Theca externa Follicles Follicle maturation Graafian follicle Graafian follicle egg Primordial Follicle Primordial Follicles Primary Follicle Zona Pellucida Primary Follicle Primary Follicles Primary follicle - Secondary (antral) Follicle Secondary (antral) follicle Graafian follicle Graafian follicle Ovulation Ovulation Rupture of follicle – Mechanism unknown collagenase, protease, plasmins – Not pressure related Oocyte surrounded by zona pellucida & corona radiata – Lost at ovulation in cow – Lost after sperm penetration in most species After ovulation, the corpus luteum develops from remains of the follicular wall after ovulation. Corpus Luteum - yellow body Corpus hemorrhagicum – transitory structure caused by hemorrhage into ruptured follicle Corpus Luteum - yellow body Luteinization of granulosa and theca cells to luteal cells Corpus Luteum - yellow body Granulosa lutein cells - granulosa cells proliferate, hypertrophy, and transform – (Yellow lipid pigment - lutein marks transitory membrana granulosa cells into granulosa lutein cells) Corpus Luteum - yellow body (Invasion of stromal cells and vasculature removes clot, deposition of reticular fibers, highly vascularized) Theca lutein cells - lipid producing cells formed from theca folliculi interna Fate relates to pregnancy – If not pregnant: slow regression  corpus albicans – If pregnant: active for all or to various time during pregnancy Ovary Atresia – Glassy membrane Ovary Corpus Luteum – Granulosa lutein cells – Theca lutein cells Corpus Luteum Corpus Luteum Corpus luteum – Corpus albicans Hormones orchestrate the process Ovarian Hormones Androgens – LH stimulation causes theca interna cells to produce androgens (androstenedione and testosterone) Estrogens – FSH stimulation causes membrana granulosa cells to produce estrogens (estradiol - 17b) • Granulosa cells aromatize androgens from theca interna cells to produce estrogens • Estrogens - induce further proliferation of granulosal cells Ovarian Hormones Inhibition of FSH – Folliculostatin - inhibitory substance has negative feedback on FSH – Steroidsthemselves work through negative feedback Progesterone - granulosa lutein cells of corpus luteum – Uterine gland development – Maintenance of pregnancy Relaxin - produced by corpus luteum – Causes relaxation of ligaments associated with pubic symphysis before partarition Oogenesis - formation and development of ova Mitosis (oocytogenesis) – oogonia – Prenatal development (ruminants, rodent, swine, human) – Postnatal development (carnivores) Oogenesis - formation and development of ova Meiosis – oocytes Early development Maturation arrest (dictyate step of meiotic prophase) Later development synchronized with development and maturation of follicles Division • First meiotic division – reduction division – first polar body • Second meiotic division – equational division – second polar body Fertilized 1n Meiosis Zygote Meiosis (only in spermatogenesis and oogenesis) Exchange of genetic material in homologous chromosomes (leptotene, zygotene, pachytene, and diplotene steps of development) Produces haploid condition of gametes Meiosis (only in spermatogenesis and oogenesis) Produces haploid condition of gametes Species difference in time of polar body formation Polar body extrusion many mammals horse and dog First preovulation postovulation Second zona penetration zona penetration of sperm of sperm First polar body Birth Follicular development - synchronized with gamete development Type Description Germ cell type Primordial cells flattened follicular primary oocyte Primary follicular cells low cuboidal primary oocyte Secondary zona pellucida yolk formation primary oocyte theca interna theca folliculi externa Follicular development - synchronized with gamete development (cont’d) Type Vesicular follicle (tertiary follicle) Mature follicle secondary of ovary Description Germ Cell type - Call-Exner bodies primary oocyte (precursors of liquor folliculi) - Formation of follicular antrum - Cumulus oophorus- mound of cells - Corona radiata- adjacent to oocyte nutrients - Stratum granulosum - preovulatory primary/ (graafian follicle) largest, extend from cortex to surface oocyte Fallopian tube (oviduct or uterine tube) Segments • Infundibulum with fimbriae • Ampulla • Isthmus • Intramural segment Fallopian tube (oviduct or uterine tube) Wall structure and Variation Epithelium • Ciliated cells • Secretory cells Oviduct Oviduct Oviduct Oviduct Normal Lack of estrogen Oviduct Oviduct Acrosome reacted Intact Uterus General structure: Perimetrium Myometrium Endometrium • Zona basalis • Zona functionalis - spiral arteries Zona Functionalis Spiral arteries Proliferative Phase Phases of the Menstrual Cycle Overview Menstrual phase: days 1-4 Proliferative phase – Early: days 4-7 – Late: days 7-14 Secretory phase: – Early: days 15-21 – Late: days 21-28 Menstruation Decidual reaction Hormones Orchestrate the Process Menstruation Phases of the Menstrual Cycle Implantation and Fetal-Placental Growth Implantation and Fetal-Placental Growth Slide 272 Implantation and Fetal-Placental Growth Decidual Reaction Cervix Vagina Endocervix – Cervical mucus External os Ectocervix Vagina Structural components Epithelium Endocervix Cervical Mucus Endocervix ends in the vagina which has no mucus glands - - - Vagina Nourishment and protection of offspring Nourishment and protection of offspring Other glands of epidermal origin – mammary gland Gland for which our class, mammalia, was named. Mammals are characterized by hair on skin, special ear bones, and in females, milk-producing mammary glands for nourishment of young. Leiomyoma Ovary Ovary Primordial follicles Primary follicle Corpus luteum Female Reproductive System

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