Female Reproductive Overvie · 2008-06-26 · Female Reproductive Overview • Primary reproductive...

7/11/02 Mr. Davenport 1

Female Reproductive System

Copyright 1999, Stephen G. Davenport, No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form without prior written permission.


Female Reproductive Overview• Primary reproductive organs - ovaries

– produce oocyte and hormones (estrogens and progesterone)

• Accessory ducts - uterine tubes (Fallopian tubes or oviducts), uterus, vagina

• External genitalia - include the vestibule, the labia minora and majora, clitoris, vestibular glands, and paraurethral glands


• 1 Ampulla• 2 Infundibulum• 3 Fibriae• 4 Ovary• 5 Cervix• 6 Vagina• 7 Vestibule• 8 Uterine (Fallopian) tube• 9 Uterus• 10 Urinary bladder• 11 Symphysis pubis• 12 Mons pubis• 13 Urethra• 14 Clitoris• 15 Urogenital diaphragm• 16 Labium minora• 17 Labium majus

Female Pelvis


Ovaries• Site of oocyte and hormone

production (estrogens and progesterone)

• Anchored by – ovarian ligament - attaches medially to

uterus– broad ligament - peritoneal fold that

supports uterus, uterine tubes, and vagina– suspensory ligament- part of broad

ligament, attaches laterally to pelvic wall• Organized into an outer cortex and

inner medulla.– Cortex houses follicles– medulla houses blood vessels and nerves


Follicles of Ovary• Ovarian follicles located in cortex

– follicle contains an oocyte surrounded by one or more layers of cells.

• Follicular cells - applies to cells in a single layer• Granulosa cells - applies to cells in more than one layer• Primordial, primary, and secondary follicles

• Corpus luteum is not a follicle. It functions as an endocrine gland

• Corpus albicans is scar tissue formed from corpusluteum.


Follicles of Ovary• primordial follicle - oocyte

surrounded by a single layer of cells

• primary follicle - oocytesurrounded by two or more layers of granulosa cells

• secondary follicle - oocytesurrounded by layers ofgranulosa cells and has a fluid filled cavity

• mature secondary follicle (Graafian or vesicular) -follicle ready for ovulation (release of the oocyte from the follicle)


Corpus luteum and albicans

• Corpus luteum is not a follicle. It functions as an endocrine gland

• Corpus albicans is scar tissue formed from corpusluteum.


Structure of Ovary• 1 Medulla• 2 Cortex• 3 Oocyte• 4 Primordial follicle• 5 Primary follicle• 6 Secondary follicle• 7 Ovulation• 8 Corpus luteum• 9 Corpus albicans


Uterine tubes• Uterine tubes (fallopian or oviducts)

– first tube of duct system– receives ovulated oocyte– provides a site for fertilization– oocyte moved by peristalsis and cilia

• Structure– ampulla - expanded area curves around ovary and usual

site of fertilization

• Infundibulum (in-fun-dib-u-lum)- open funnel-like structure (with fimbriae) which covers the ovary

• Fimbriae (fim-bre-e)- ciliated extensions from infundibulumwhich drape over the ovary. Aid in “capturing” the oocyte.


Uterus• Second component of duct system• Located anterior to rectum and

posterosuperior to bladder• Divided into

– body; major central portion– fundus; superior to entrance of uterine

tubes– cervix; narrow outlet projecting to

inferior vagina– cervical canal; cavity of cervix. Contains

cervical glands which produce mucus which blocks entrance to cervix, except at mid-uterine cycle


Wall of Uterus• Divided into three layers

– perimetrium; serous membrane which covers outside of uterus

– myometrium; thick middle smooth muscle layer

– endometrium; innermost layer which consists of blood vessels and uterine (endometrial glands). Layer is divided into two regions:

• stratum basalis– maintains endometrial layer

• stratum functionalis– cycles in relationship to uterine

cycle (controlled by ovarian hormones)


Vagina• Third portion of duct system Located

between bladder and rectum; extends from cervix to exterior

• Functions include– provides passageway for delivery (often called

birth canal)– female organ of copulation


External Genitalia• Structures external to vagina which include

– mons pubis; area over pubic symphysis– labia majora; outer skin folds (homologous to scrotum)

– labia minora; inner skin folds (homologous to ventral penis)

– vestibule; area that contains openings of urethra and vagina

– greater vestibular glands; open next to vaginal opening and produce mucus (bulbourethral glands)

– clitoris; contains erectile tissue (homologous to penis) and located just anterior to vestibule


Mammary Glands

• Structurally modified sweat glands (integumentary system)

• Structure– areola; pigmented area around nipple– nipple; projection of breast which contains lactiferous

ducts from lobes of gland– lobes (15 -25); structural units of gland which radiate

around and open to nipple– lobules; structural units of lobes which contain alveoli– alveoli; units which consist of cells that produce milk.

Ultimately merge to form lactiferous ducts


Oogenesis• Production of oocyte• Female is born with oocytes. Release starts at

puberty and continues until menopause• Oogenesis begins in fetal development

– oogonia (2n); produce primary oocytes which are located in primordial follicles (have one cell layer)

– primary oocytes; meiosis is arrested and female is born with about 400,000 primary oocytes

– from puberty “selected” primary follicles /oocytes (one per month) begin development. Only one functional gamete produced. Fertilization is required for completion of meiosis.


Ovarian Cycle• Monthly (28 day) cycle of

the ovary• May be divided into two

phases - follicular and luteal– follicular phase; period of

follicular development (days 1 to 14, ovulation on day 14)

– luteal phase; period of corpus luteum (functional endocrine gland (14 days from ovulation; days 14-28)


Ovarian Cycle- Follicular Phase• Primordial follicle

– oocyte surrounded by a single layer of squamous cells (follicular cells)

– develops into primary follicle

• Primary follicle– oocyte surrounded by two or more layers of cuboidal cells

(granulosa cells)– granulosa cells begin to produce fluid which begins to

accumulate in follicle


Ovarian Cycle - Follicular Phase• Secondary follicle

– follicle has a fluid filled cavity (antrum) with many layers of granulosa cells.

– oocyte becomes positioned on a “stalk” of granulosacells

– follicle continues to enlarge until day fourteen, (reaches a diameter of about one inch and bulges from surface)

• Vesicular follicle (Graffian follicle)– a mature secondary follicle (day 14) ready for ovulation

• Ovulation– rupturing of follicular wall and release of oocyte into

peritoneal cavity– triggered by a surge of LH


Ovarian Cycle - Luteal Phase• Corpus luteum forms from ruptured vesicular

(Graffian) follicle– functions as an endocrine gland– produces progesterone and estrogen– if pregnancy does not occur it degenerates and

forms corpus albicans (scar tissue)– if pregnancy occurs it remains (about three

months) until placenta becomes dominate hormone producer


Ovarian Hormonal Regulation• Hypothalamus begins to release GnRH at

puberty• GnRH stimulates anterior pituitary to release

FSH and LH which target the ovaries• Menarche (me-nar-ke), first menstrual period

occurs about four years after GnRH starts regulation (gonadotrophins reach adequate levels to promote ovarian cycle).


Ovarian Hormonal Regulation• GnRH (hypothalamus) stimulates increased

production of LH and FSH from anterior pituitary• FSH (and LH) causes increased production of

estrogens and promotes follicle maturation• High estrogen levels promote positive feedback on

hypothalamus causing surge-like release of LH (and FSH) on/around day fourteen - ovulation results


Ovarian Hormonal Regulation

• LH transforms ruptured follicle into corpus luteum• Corpus luteum begins production of progesterone

and estrogen


Ovarian Hormonal Regulation• Progesterone and estrogen

– have negative feedback on anterior pituitary release of LH and FSH declines. Thus, ovulation cannot occur again

– decline in LH promotes the degeneration of the corpus luteum(if pregnancy occurs developing embryo produces an LH-like hormone to maintain corpus luteum)

– low levels of hormones triggers hypothalamus to release GnRHand FSH and LH start new cycle


Uterine (Menstrual) Cycle

• Cycles in response to ovarian hormones• Most receptive to implantation about 7 days

after ovulation• Three phases

– menstrual phase; days 1 - 5– proliferative phase; days 6 - 14– secretory phase; days 15- 28


Menstrual Phase

• Days 1 - 5• Uterus sheds surface layer of

endometrium (stratum functionalis)


Menstrual Phase

• 1 Stroma• 2 Uterine glands


Proliferative Phase• Days 6 - 14• Endometrium rebuilding (stratum functionalis)

under influence of rising levels of estrogens. Glands enlarge and arteries proliferate

• Cervical plug of uterus becomes porous for passage of sperm.

• Ovulation occurs on day 14 in response to LH surge from anterior pituitary.

• LH also promotes development of corpus luteum from ruptured follicle


Secretory Phase• Days 15 - 28• Endometrium prepares for implantation of

embryo – (14 + 7 = day 21)

• Glands secrete glycoproteins to maintain embryo until implantation and arteries continue to develop

• LH levels increase and cervical plug is maintained


Secretory Phase• Rising levels of progesterone (corpus luteum)

inhibit GnRH, LH and FSH levels begin to drop, corpus luteum degenerates (unless pregnancy occurs then embryo produces an LH-like hormone and corpus luteum is maintained)

• Progesterone levels drop and endometrium(stratum functionalis) loses hormonal support -arteries constrict, cells die, autolysis, and menstrual cycle starts again


Secretory Phase• 1 Uterine glands• 2 Stroma

Female Reproductive Overvie · 2008-06-26 · Female Reproductive Overview • Primary reproductive...

Documents

Transcript of Female Reproductive Overvie · 2008-06-26 · Female Reproductive Overview • Primary reproductive...