Female Reproductive System

Objectives

At the end of this lecture, student will be able to

• List the parts of female reproductive system

• Describe the functions of female reproductive organs

• Describe the histology of ovaries and uterus

• List the functions of mammary glands

FEMALE REPRODUCTIVE SYSTEM

Female reproductive organs and their functions include-

Anatomy of female reproductive system

Ovaries

• Female gonads; Paired glands; resemble unshelled almonds in size and shape

• Homologous to the testes

• Ovaries produce

– Gametes, secondary oocytes  à develop into mature ova (eggs) after fertilization

– Hormones – Progesterone; Estrogens (the female sex hormones)

                     Inhibin

                     Relaxin

Histology of the Ovary

Each ovary consists of

•   Germinal epithelium (germen sprout or bud)

– A layer of simple epithelium (low cuboidal or squamous)

– Covers the surface of the ovary

•   Tunica albuginea

– A whitish capsule of dense irregular connective tissue

– Located deep to the germinal epithelium

•   Ovarian cortex

– A region just deep to the tunica albuginea

– Has ovarian follicles surrounded by dense irregular connective tissue, contains stromal cells.

•   Ovarian medulla

– Deep to the ovarian cortex

– Has more loosely arranged connective tissue, blood vessels, lymphatic vessels, and nerves

• Ovarian follicles (folliculus little bag)

–  Present in the cortex

–  Consist of oocytes in various stages of development

– Surrounding cells   – form a single layer- follicular cells

                                    – Form several layers- granulosa cells

                                    – secrete estrogens

• Mature (graafian) follicle

– A large, fluid-filled follicle

– Ready to rupture and expel its secondary oocyte by ovulation

• Corpus luteum (yellow body)

– Remnants of a mature follicle after ovulation

– Produces progesterone, estrogens, relaxin, and inhibin à until it degenerates into fibro car tissue, corpus albicans (white body)

Arrows indicate the sequence of developmental stages that occur as part of the maturation of an ovum during the ovarian cycle.

(Hemisection)

Uterine Tubes

• Females have two uterine (fallopian) tubes, or oviducts

• Extend laterally from the uterus

• Lie between the folds of the broad ligaments of the uterus

• Provide a route for sperm to reach an ovum

• Transport secondary oocytes and fertilized ova from the ovaries to the uterus

Parts of uterine tube

Infundibulum – Funnel-shaped portion of each tube

Fimbriae – A fringe of fingerlike projections called

Ampulla – Widest, longest portion

Isthmus – More medial, short, narrow, thick-walled portion, joins the uterus

Relationship of the uterine (fallopian) tubes to the ovaries, uterus,
and associated structures

Histology of uterine tube

Composed of three layers:

• Mucosa – Epithelium (ciliated columnar)- “ciliary conveyor belt” lamina propria (areolar connective tissue)

• Muscularis – Inner- thick, circular ring of smooth muscle, Outer- thin region of longitudinal smooth muscle

• Serosa – Serous membrane; outer membrane

Uterus (womb)

• Pathway for sperm deposited in the vagina to reach the uterine tubes

• Site of implantation of a fertilized ovum

• Development of the fetus during pregnancy, and labor

• Source of menstrual flow when no implantation

• Situated between the urinary bladder and the rectum

• It is the size and shape of an inverted pear

Anatomy of uterus

• Subdivisions of uterus:

– A dome shaped portion superior to the uterine tubes, the fundus

– A tapering central portion, the body

– An inferior narrow portion, the cervix that opens into the vagina

• Between the body of the uterus and the cervix is the isthmus

• Interior of the body of the uterus is the uterine cavity

• Interior of the cervix is the cervical canal

Histology of uterus

Uterus consists of three layers of tissue:

• Perimetrium- outer layer

• Myometrium- middle layer

• Endometrium- inner layer

Endometrium

Endometrium is divided into two layers

• Stratum functionalis (functional layer)

– Lines the uterine cavity

– Sloughs off during menstruation

• Stratum basalis (basal layer)

– Permanent

– gives rise to a new stratum functionalis after each menstruation

Vegina

• Tubular, 10-cm long fibromuscular canal

• Lined with mucous membrane

• Extends from the exterior of the body to the uterine cervix

• Receptacle for the penis during sexual intercourse

• Outlet for menstrual flow; Passageway for childbirth

Vulva

–   Collective term for the external genitals of the female

Consists of –

• Mons pubis – An elevation of adipose tissue covered by skin

– Coarse pubic hair, cushions the pubic symphysis

• Labia majora – Two longitudinal folds of skin

– Covered by pubic hair

– Contain an abundance of adipose tissue, sebaceous (oil) glands, and apocrine sudoriferous (sweat) glands

– Homologous to the scrotum

• Labia minora – Two smaller folds of skin

– Devoid of pubic hair and fat

– Have sudoriferous and sebaceous glands

– Homologous to the spongy (penile) urethra

• Clitoris – Small cylindrical mass

– Composed of two small erectile bodies

– Numerous nerves and blood vessels

– Homologous to the glans penis in male

Vestibule

• Region between the labia minora

Consists of

• Hymen (if still present)

• Vaginal orifice – opening of the vagina to the exterior

• External urethral orifice – opening of the urethra to the exterior

– 3 sets of glands- The paraurethral (Skene’s)

                                Greater vestibular (Bartholin’s)

                                Lesser vestibular

Mammary Glands

• Modified sudoriferous (sweat) gland that produces milk

• Lie superficial to the pectoralis major muscles

• Consists of 15 to 20 lobes, separated by adipose tissue

• Each lobe have several smaller compartments called lobules

• Each lobule have grapelike clusters of milk-secreting glands termed alveoli

• Synthesize, secrete and eject milk (lactation)

• Development depends on estrogens and progesterone

• Milk production is stimulated by prolactin, estrogens, and progesterone

• Milk ejection is stimulated by oxytocin

Summary

• Female organs of reproduction include the ovaries (gonads), uterine (fallopian) tubes or oviducts, uterus, vagina, and vulva

• Mammary glands are part of the integumentary system and also are considered part of the reproductive system in females

• Ovaries produce secondary oocytes, discharge secondary oocytes (the process of ovulation), and secrete estrogens, progesterone, relaxin, and inhibin

• Uterine (fallopian) tubes transport secondary oocytes from the ovaries to the uterus and are the normal sites of fertilization

• Uterus helps in menstruation, implantation of a fertilized ovum, development of a fetus during pregnancy, and labor

• Layers of the uterus are an outer perimetrium (serosa), a middle myometrium, and an inner endometrium

• Vagina is a passageway for sperm and the menstrual flow, the receptacle of the penis

• Vulva, a collective term for the external genitals of the female

Reproductive cycle, Pregnancy and labor