FEMALE REPRODUCTIVE SYSTEM Kristina C. Erasmo, M.D.

Female reproductive system External genitalia Clitoris Labia majora Labia minora Vestibular glands Internal genitalia Ovaries Oviducts Uterus Vagina

OVARY Paired, slightly flattened, ovoid organs Produce ova and hormones Simple squamous or cuboidal epithelium (“germinal epithelium”) Tunica albuginea – layer of dense CT beneath the epithelium

OVARY Cortex Medulla Thick peripheral zone Stroma – CT substance of cortex, Fibroblasts, collagenous fibers surrounded by amorphous intercellular substance Ovarian follicles Medulla Vascular inner zone, pale-staining Loose CT, abundant blood vessels

Ovarian cycle Refers to structural and physiological changes that the ovarian follicles and the stroma that surrounds them undergo during the menstrual cycle Hormonal control: FSH LH

Oviduct (fallopian tubes) Pair of muscular tubes Passageway for ovum on its way to the uterus and the sperms on their way to fertilizing the ovum 4 parts: Infundibulum Ampulla Isthmus Pars interstitialis

Oviduct (fallopian tubes) Infundibulum Funnel-shaped area related to the ovary and opens into peritoneal cavity Fimbriae Ampulla Expanded intermediate portion (2/3 of length) Isthmus Narrow, slender part w/c connects the FT to uterus Pars interstitialis Part of the tube within the uterine wall

Oviduct: layers Mucosa Muscular layer (OLIC) Serosa Forms numerous folds Simple columnar epithelium Ciliated cells Non-ciliated cells Lamina propria Muscular layer (OLIC) Serosa

OVIDUCT Thickness and specific characteristics of histologic layers vary with the segments Infundibulum and ampulla: Tunica mucosa: thick, highly developed. Isthmus: Tunica mucosa: thinner Tunica muscularis: thicker

uterus Pear-shaped, hollow pelvic organ Receives fertilized ovum and nourishes the embryo throughout its dev’t 2 parts: Corpus uteri (body) Fundus Cervix Portio vaginalis

UTERUS: LAYERS Endometrium Myometrium Serosa/Adventitia Innermost (mucosa) Myometrium Middle, thickest Smooth muscles Serosa/Adventitia Serosa: over fundus, posterior aspect of uterus

endometrium Simple columnar epithelium Lamina propria: CT, endometrial glands Functional layer – superficial 2/3 Basal layer – deeper 1/3

MYOMETRIUM Thickest layer of the corpus uteri Smooth muscle cells arranged in bundles separated by CT

UTERINE CYCLE a.k.a. endometrial cycle, menstrual cycle Refers to continuous sequence of morphological and physiological changes that the endometrium undergoes in response to ovarian hormones Proliferative (follicular) phase Secretory (luteal) phase Menstrual phase

Proliferative phase Governed by estrogen (ovarian follicles) Coincides with ovarian follicle growth (under the influence of FSH in first ½ of menstrual cycle) Epithelial and stromal cells undergo mitosis Glands in lamina propria Blood vessels Ground substance Thickness

Secretory phase Governed by progesterone (from corpus luteum, under LH influence) Occurs during the 15th day of menstrual cycle Glands become tortuous and secretory Blood vessels Thickest endometrium (due to glandular secretion and edema of stroma)

Menstrual phase 2 weeks after ovulation (no fertilization) Decrease in ovarian hormones No glandular secretion Blood vessels constrict → close → open Functional layer exfoliates Basal layer intact

CERVIX Cylindrical inferior portion of uterus Parts: Cervical canal Internal os External os Portio vaginalis (ectocervix)

CERVIX: LAYERS Histologically different from uterus Mucosa: Forms folds Simple columnar epithelium (external os: stratified squamous) Lamina propria: cervical glands Wall contains very few smooth muscle Abundant collagenous and elastic fibers

vagina Fibromuscular tube Extends from vestibule of external genitalia to the cervix Normally, collapsed (anterior and posterior walls are in contact with each other)

Vagina: layers Mucosa Muscularis (OLIC) Adventitia Thrown into folds (rugae) Stratified squamous non-keratinized epithelium Lamina propria: dense CT, no glands Muscularis (OLIC) Adventitia Thin CT Nerve bundles, venous plexus

External genitalia Clitoris Labia minora Labia majora Vestibular glands Major vestibular glands (Bartholin’s glands) Minor vestibular glands

EXTERNAL GENITALIA Description Epithelium Clitoris Homologue of male penis, 2 erectile cavernous bodies (corpora cavernosa) Stratified squamous with specialized nerve endings Labia minora Form the lateral walls of the vestibule Stratified squamous epithelium with highly vascular CT underneath Numerous sebaceous glands, no hair follicles Labia majora Cover the labia minora Homologue of the male scrotum Stratified squamous epithelium

EXTERNAL GENITALIA Description Major vestibular glands (Bartholin’s) Pair of larger glands in the lateral walls of vestibule, open on the inner surface of labia minora Mucus-secreting Minor vestibular glands Located under the urethral opening and near the clitoris

Mammary gland Modified sweat gland Provide nourishment for offspring Enlarge markedly in females during puberty Attain highest degree of development during and immediately after parturition

Mammary gland: lobes 15-20 lobes/mammary gland divided by interlobar CT Intralobular ducts → interlobular ducts → lactiferous duct and sinus Stratified cuboidal epithelium

Mammary gland: areola and nipple Lactiferous ducts open into nipple Skin of nipple: highly pigmented, dermis contains many smooth muscle Areola – surrounds nipple, contains sweat and sebaceous glands, hair, glands of Montgomery