Copyright © 2006, Elsevier Inc. All rights reserved C HAPTER 2 The female reproductive system

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-1 S IDE VIEW OF THE FEMALE PELVIC REGION SHOWING SOME MAJOR COMPONENTS OF THE REPRODUCTIVE SYSTEM.

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-2 ( A ) A DIAGRAMMATIC SECTION THROUGH THE UTERUS AND OVIDUCTS. ( B ) A N ENLARGEMENT OF THE BOX IN ( A ) SHOWING THE STRUCTURE OF THE UTERINE WALL.

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-3 S ECTION THROUGH THE OVARY SHOWING ITS COMPONENT PARTS.

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-4 P HOTOMICROGRAPH OF A REGION FROM A HUMAN TERTIARY FOLLICLE SHOWING THE OOCYTE SURROUNDED BY FOLLICULAR ( GRANULOSA ) CELLS. T HE LOWER LEFT CORNER SHOWS SOME CELLS OF THE THECA.

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-5 S TEROIDOGENESIS WITHIN THE OVARY. C ONVERSION OF PREGNENOLONE TO DHEA, THEN FURTHER SYNTHESIS OF OTHER ANDROGENS AND ESTROGENS, IS THE 5 PATHWAY, PREDOMINANT IN OVARIAN FOLLICLES. C ONVERSION OF PREGNENOLONE TO PROGESTERONE AND THEN TO ANDROGENS AND ESTROGENS IS THE 4 PATHWAY, PREDOMINANT IN THE CORPUS LUTEUM. S PECIFIC ENZYMES ARE REQUIRED FOR EACH ARROW. D OUBLE ARROWS MEAN THAT CONVERSION CAN GO IN EITHER DIRECTION

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-6 C HEMICAL STRUCTURES OF THREE STEROID HORMONES. N OTE THAT ALTHOUGH THESE MOLECULES ARE ALL DERIVED FROM CHOLESTEROL AND DIFFER ONLY SLIGHTLY IN STRUCTURE, THEY HAVE QUITE DIFFERENT ACTIONS ON TISSUES

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-7 S TEROIDOGENESIS IN THE TERTIARY AND PREOVULATORY FOLLICLE AND IN THE CORPUS LUTEUM AFTER OVULATION. N OTE THAT THE TERTIARY FOLLICLE FOLLOWS THE 5 PATHWAY, PRODUCING MOSTLY ESTRADIOL IN THE BLOOD. I N CONTRAST, THE PREOVULATORY FOLLICLE ( I. E., A G RAAFIAN FOLLICLE AFTER THE LH SURGE BUT BEFORE OVULATION ) AND THE CORPUS LUTEUM PRODUCE A LARGE AMOUNT OF PROGESTERONE AND SOME ESTRADIOL, AND THUS FOLLOW THE 4 PATHWAY OF STEROIDOGENESIS.

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-8 T HE PROCESS OF OOGENESIS, WHICH IS NOT COMPLETED UNTIL A SPERM PENETRATES AN OVULATED EGG.

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-9 D IAGRAMS ILLUSTRATING OVULATION. T HE STIGMA ( A ) RUPTURES ( B ) AND THE OVUM IS EXPELLED ALONG WITH FOLLICULAR ( ANTRAL ) FLUID ( B AND C ). T HE OVULATED OVUM IS ARRESTED IN THE SECOND MEIOTIC DIVISION ( D ) UNTIL IT IS PENETRATED BY A SPERM

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-10 U SUAL AND UNUSUAL POSITIONS OF THE UTERUS. ( A ) T HE UTERUS IS IN THE USUAL ANTEFLEXED POSITION, WHEREAS ( B ) THE UTERUS IS TILTED BACKWARD IN A RETROFLEXED POSITION.

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-11 T HE FEMALE EXTERNAL GENITALIA, OR VULVA

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-12 S ECTION THROUGH THE ADULT FEMALE MAMMARY GLAND.

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-13 D IAGRAMMATIC VIEW OF A SINGLE MAMMARY ALVEOLUS. M ILK IS SECRETED BY EPITHELIAL SECRETORY CELLS INTO A CAVITY ( LUMEN ) WITHIN THE ALVEOLUS. F ROM HERE, THE MILK IS CARRIED TO THE NIPPLE THROUGH A SERIES OF DUCTS. T HE BLOOD SUPPLY TO THE ALVEOLUS IS IMPORTANT BECAUSE OF ITS SUPPORT OF ALVEOLUS GROWTH AND SECRETION. A LSO, THE BLOOD CARRIES HORMONES TO THE ALVEOLUS THAT STIMULATE ITS SECRETION AND CAUSE CONTRACTION OF THE MYOEPITHELIAL CELLS, LEADING TO MILK EJECTION.

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-14 I NFLUENCE OF TIMING OF FIRST BIRTH AND NULLIPARITY ON INCIDENCE OF BREAST CANCER. W OMEN WHO FIRST GAVE BIRTH BEFORE AGE 30 HAVE A LOWER RATE OF BREAST CANCER THAN NULLIPAROUS WOMEN.

Copyright © 2006, Elsevier Inc. All rights reserved F IGURE 2-15 H OW TO EXAMINE THE BREASTS AS A METHOD TO DETECT ABNORMAL LUMPS AND OTHER CHANGES. (M ODIFIED WITH PERMISSION OF THE A MERICAN C ANCER S OCIETY.)