BSC2086 A P II Final Exam Study Guide Lesson 22 Lesson 22 The Reproductive System Part II Female Reproductive System Produces sex hormones functional gametes Protects supports developing embryo Nourishes newborn infant Structures include o Ovaries Female gonads Release one immature gamete oocyte per month Produce hormones estrogen progesterone o Uterine Fallopian Tubes Oviducts Carry oocytes to uterus If sperm reaches oocyte fertilization begins Oocyte matures into ovum o Uterus Encloses supports developing embryo o Vagina Connects uterus with exterior Ovaries Small almond shaped organs near lateral walls of pelvic cavity o Three 3 Main Functions Production of immature female gametes oocytes Secretion of female sex hormones estrogens progestins Secretion of inhibin involved in feedback control of FSH released from the anterior pituitary Oogenesis Ovum production o Begins BEFORE birth Oogonium completes mitotic division to produce primary oocyte Primary oocyte development stops at prophase I until puberty o Accelerates at puberty 1 BSC2086 A P II Final Exam Study Guide Lesson 22 Some primordial follicles each containing a primary oocyte will become activated each month One will release a secondary oocyte ovulation Other activated follicles will degenerate atresia o Ends at menopause Process of Oogenesis o Primary oocytes remain in suspended development until puberty o At puberty Rising FSH triggers start of ovarian cycle o Each month thereafter Some primary oocytes are stimulated to develop further Differences between Oogenesis Spermatogenesis o Cytoplasm of primary oocyte divides unevenly Produces ONE secondary oocyte with original cytoplasm 2 BSC2086 A P II Final Exam Study Guide Lesson 22 o Contains most of the nutrients energy o If there are two secondary oocytes both are fertilized can be fraternal twins 2 3 smaller polar bodies will disintegrate o Ovary releases secondary oocyte not mature ovum Suspended in metaphase II Meiosis is completed upon fertilization by ONE sperm cell Polyspermy Fertilization of one secondary oocyte by more than one sperm cell Is prevented Ovarian Cycle o Begins after sexual maturation puberty A different group of primordial follicles is activated each month One of the primordial follicles will develop into a tertiary follicle and release a secondary oocyte ovulation Other activated follicles will degenerate o Divided into Follicular Phase Preovulatory Phase Luteal Phase Postovulatory Phase o Follicular Phase initiated by FSH from anterior pituitary Ovarian Follicles Specialized structures in cortex of ovaries where oocyte growth meiosis I occur Primordial Follicle Primary oocyte surrounded by follicle cells Primary Follicle Activated primordial follicles o Follicle cells divide become granulosa cells produce estrogens Secondary Follicle Inner follicular cells secrete follicular fluid which separates inner outer follicle layer o Few of the primary follicles mature into this Tertiary Mature Graafian Follicle Contains secondary oocyte o Primary oocyte continues from prophase I produces secondary oocyte that stops at metaphase II o Usually 1 2 secondary follicles develop this each month 3 BSC2086 A P II Final Exam Study Guide Lesson 22 Three 3 Segments of the Uterine Tubes 5 2 in long o Infundibulum An expanded funnel near the ovary Has fimbriae finger like projections that extend into pelvic cavity Inner surfaces lined with cilia that beat toward middle segment o Ampulla Middle segment Smooth muscle layers in wall become thicker approaching the uterus o Isthmus Short segment between ampulla uterine wall Epithelium lining uterine tube contains mucin secreting cells peg cells Uterine Tube Oocyte Transport Involves ciliary movement peristaltic contractions in walls of uterine tube o o A few hours before ovulation sympathetic parasympathetic nerves Turn on beating pattern Initiate peristalsis Uterine Tube Fertilization o For fertilization to occur o Travel from infundibulum to uterine cavity takes approximately 3 4 days 4 BSC2086 A P II Final Exam Study Guide Lesson 22 Secondary oocyte must meet spermatozoa during first 12 24 hours of ovulation o Fertilization typically occurs near boundary between ampulla isthmus o Uterine tube provides nutrient rich environment by secretions from peg cells Peg cell secretions Contain lipids glycogen Supply nutrients to developing pre embryo sperm Completes capacitation of sperm Uterus Pear shaped muscular organ bends anteriorly near base o Provides mechanical protection nutritional support waste removal for Developing embryo weeks 1 8 Developing fetus week 9 delivery o Structures Body Largest portion of uterus Fundus Rounded portion of body superior to uterine tubes Cervix Inferior portion Distal end projects 0 5 in into vagina Cervical Canal Constricted passageway connecting the uterine cavity to the vagina o Uterine wall consists of Perimetrium Incomplete serous membrane continuous with peritoneal lining Myometrium Thick outer muscular layer Thickest part of uterus 90 of its mass Has longitudinal circular oblique layers of muscle o Used for child delivery Endometrium Mucosa Thin inner glandular layer Has uterine glands vascular tissue to support growing fetus 10 of uterine mass Estrogen causes uterine glands blood vessels and epithelium to change with phases of monthly uterine cycle 5 BSC2086 A P II Final Exam Study Guide Lesson 22 Two 2 Divisions of Endometrium o Functional Zone closer to uterine cavity Contains most of the uterine glands Contributes most of endometrial thickness Undergoes dramatic changes in thickness structure during menstrual cycle Blood supplied by spiral arteries o Basilar Zone Attaches endometrium to myometrium Remains relatively constant Blood supplied by straight arteries Uterine Cycle Menstrual Cycle A repeating series of changes in endometrium o Lasts from 21 35 days average 28 days o Responds to hormones of ovarian cycle interrelated o Menses proliferative phase occur during ovarian follicular phase o Secretory phase occurs during ovarian luteal phase o 1 Menses The degeneration of the functional zone Occurs in patches Caused by constriction of spiral arteries reduces blood flow oxygen nutrients Basilar zone not affected supplied by straight arteries Weakened arterial walls rupture releasing blood into connective tissues of functional zone Degenerating tissues break away enter uterine lumen Menstruation Entire functional zone is lost expelled through vagina Lasts 1 7 days 35 50 mL blood
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