The Reproductive System PART 3 The Reproductive System

The Ovarian Cycle Follicular phase Days 1 – 13 of the ovarian cycle 6 – 12 primordial follicles stimulated to develop Growth stimulated by FSH from anterior pituitary Primordial follicle becomes a primary follicle Zona pellucida – glycoprotein coat surrounding oocyte Theca folliculi – internal layer secretes hormones Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Follicular phase (continued) Antrum forms The Ovarian Cycle Follicular phase (continued) Antrum forms A fluid filled cavity between granulose cells Primary follicles become a secondary follicle Corona radiata – coat of granulosa cells surrounding oocyte Secondary follicle enlarges and becomes Visicular (Graafian) follicle – ready to be ovulated Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

The Ovarian Cycle Ovulation Occurs about halfway through each ovarian cycle (Day 14) One mature oocyte exits from one ovary Enters peritoneal cavity Swept into uterine tube Sudden increase in LH is signal for ovulation PLAY Ovulation Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

The Ovarian Cycle Luteal phase Occurs after ovulation – days 15 – 28 Remaining follicle becomes a corpus luteum Secretes progesterone Acts to prepare for implantation of an embryo If no implantation Corupus luteum dies and becomes a corpus albicans Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Takes many years to complete Oogenesis Takes many years to complete Primordial follicles are arrested (stalled) in meiosis I Surge of LH also causes primary oocyte to compete meiosis I Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Oogenesis produces only one ovum and three polar bodies Polar bodies do not contribute to developing embryo Meiosis II is completed only is sperm penetration occurs Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Oogenesis Figure 24.15 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Receive ovulated oocyte Parts of the uterine tube The Uterine Tubes Receive ovulated oocyte Parts of the uterine tube Infundibulum – distal end of uterine tube Surrounded by fimbriae Ampulla – middle third of uterine tube Usual site of fertilization Isthmus – medial third of uterine tube Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

The Uterine Tubes Figure 24.12 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Lies anterior to rectum – posterior to bladder The Uterus Lies anterior to rectum – posterior to bladder Anteverted (anteflexed) usual position of uterus Parts of the uterus Fundus – rounded superior portion Cervix – “neck” of uterus Cervical canal – communicates with vagina inferiorly Internal os – opening connecting with uterine cavity External os – inferior opening of cervix Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

The Uterus PLAY Female Reproductive Anatomy Figure 24.11 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

The Uterine Wall Figure 24.18b Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Series of cyclic phases of the endometrium The Uterine Cycle Series of cyclic phases of the endometrium Phases coordinate with the ovarian cycle Endometrial phases directed by FSH and LH Phases of uterine cycle Menstrual phase – days 1 – 5 Stratum functionalis is shed Proliferative phase – days 6 – 14 Secretory phase – days 15 – 28 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Series of cyclical changes to endometrium The phases of uterine cycle The Uterine Cycle Series of cyclical changes to endometrium The phases of uterine cycle Menstrual phase (days 1– 5) Proliferative phase (days 6 – 14) Secretory phase (days 15 – 28) Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Structural and hormonal changes The Menstrual Cycle Structural and hormonal changes Figure 24.19a, c Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

The Menstrual Cycle Figure 24.19b, d Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Consists of three coats The Vagina Consists of three coats Adventitia – fibrous connective tissue Muscularis – smooth muscle Mucosa – marked by transverse folds Consists of lamina propria and stratified squamous epithelium Hymen – an incomplete diaphragm Fornix – recess formed at the superior part of the vagina Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

The Vagina Figure 24.12 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

The Vagina Figure 24.11 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings