Female Reproductive System

Anatomy and Physiology II

BIO 232

Overview of Female Reproductive System

The Ovaries

• Paired and flank the uterus on each side

• Held in place by ligaments

• Ovarian ligament - anchors the ovary medially to the uterus

• Suspensory ligament - anchors it laterally to the pelvic wall

• Mesovarium - suspends it in between

• Broad ligament - suspensory ligament and the mesovarium are parttof this - tents over the uterus and supports the uterine tubes, uterus and vagina

The Ovaries

• Served by ovarian arteries & ovarian branch of the uterine artery

• Supported on the outside by tunica alburginea - covered by germinal epithelium

• Ovarian follicles - are embedded into the cortex

• Composed of an oocyte (immature egg) and a single layers of follicular cells or several layers of granulosa cells

Structure of the Ovary

Female Duct System

• Uterine tubes (fallopian tubes or oviducts)

• They receive the ovulated oocyte - also typical cite of fertilization

• Each is 10 cm or 4 inches long - extending from the ovary to the superolateral region of the uterus

• Connect to the uterus via the isthmus

• Each tube ends in an infundibulum (funnel-like opening)

• Finger-like projections, fimbrae drape over the ovary

Female Duct System

• The uterus - size and shape of an inverted pair

• Body of the uterus - main portion

• Fundus - rounded area superior to the entrance of the uterine tubes

• Cervix - narrow neck or outlet

• Cavity - cervical canal

• External os (mouth) - vaginal side

• Internal os - uterine body cavity side

Female Duct System

• Uterine wall - three layers

• Perimetrium - outermost layer

• Myometrium - bulky middle layer - interlacing bundles of smooth muscle

• Endometrium - mucosal lining - simple columnar epithelium underlain by a thick lamina propria of highly cellular connective tissue

• Stratum functionalis - undergoes cyclic changes in response to blood level of ovarian hormones

• Stratum basalis - forms a new functionalis after menstruation ends

Female Duct System

• The vagina - thin walled - birth canal

• Lies between the bladder and rectum

• Extends from the cervix to the outside

• Urethra embedded in the anterior wall

• Highly distensible wall of the vagina - three layers

• Outer adventitia - fibroelastic connective tissue

• Smooth muscle - muscuilaris

• Mucosa - transverse ridges called rugae - stimualte penis during intercourse

Ø Epithelium is stratified squamous adfapted to stand up to friction

• n virgins - mucosa of the distal vaginal orifice forms an incomplete partition called hymen

Posterior View of Female Reproductive Organs

External Genitalia

• Also called the vulva or pudendum

• Mons pubis - fatty, rounded area overlying the pubic symphysis

• After puberty it is coverd with hair

• Labia majora - from the mons pubis are two elongated, hair-covered fatty skin folds

• Counterpart of the male scrotum

• Labia minora - two thin hair-free skin folds enclosed by the labia majora

• These enclose a a recess called the vestibule

• Contains theurethra opening and vagina opening

External Genitalia

• Clitoris - small protruding structure - made of erectile tissue

• Richly innervated by sensory nerve endings sensitive to touch

• Becomes swollen with blood and erect during tactile stimulation

• Contributes to female sexual arousal

• Perineum - diamond shaped region located between the pubic arch anteriorly and the coccyx posteriorly

External Genitalia

Mammary Glands

• Present in both sexes - normally only functional in females

• Developmentally they are derived from sweat glands

• Really part of the skin

• Contained within a rounded skin-covered breast anterior to the pectoral muscles of the thorax

Mammary Glands

• Slightly below center of each breast is a ring of pigmented skin, the areola - this surrounds a central protruding nipple

• Large sebaceous glands in the areola make it slightly bumpy & produce sebum that reduces chapping and cracking of the skin of the nipple

• Autonomic NS controls smooth muscle fibers in the areola and nipple cause the nipple to become erect when stimulated by tactile or sexual stimuli & when exposed to the cold

Mammary Glands

• Internally - they consist of 15 to 25 lobes that radiate around and openat the nipple

• Lobes are padded & separated from each other by fibrous connective tissue and fat

• The connective tissue forms suspensory ligaments that attach the breast to the underlying muscle fascia

Mammary Glands

• Each lobe is composed of smaller lobules- these contain alveoli that produce milk when a women is lactating

• The foregoing description applies to nursing women

• In on-pregnant women - glandular structure is undeveloped - hence breast size is largely due to the amount of fat deposits

Mammary Glands

Oogenesis

Female Hormone Levels

• Hypothalamus - gonadotropic releasing hormone (GnRH)

• Ant. Pituitary - Follicle Stim. Hormone (FSH) & Luteinizing hormone (LH)

Female Hormone Levels

• Ovaries - Estrogen and progesterone

• Estrogen

• Puberty- stim growth of uterus and vagina

• Necessary for egg maturation

• Responsible for secondary sex characteristics

• Responsible for onset of uterine cycle, body hair & fat distribution

The Ovarian Cycle

• Lasts @ 28 days

• Day 1-13 (Follicular Phase)

• FSH secreted by ant. pituitary

• Promotes development of follicle

• Follicle secretes estradiol

• Estradiol level - neg feedback - anterior pituitary - stops FSH release

• Day 14 - Ovulation

The Ovarian Cycle

• Day 15-28 (Luteal Phase)

• Ant. pituitary produces LH

• LH promotes develop corpus luteum

• Secretes progesterone

• Negative feedback of FSH &LH secretion

• As luteal phase ends - menstruation begins

Overview: Ovarian Cycle

Uterine Cycle

• 28 day cycle

• Day 1-5

• Low level sex hormones

• Uterine lining disintegrates blood vessels rupture

• Flow of blood - menses - from vagina during menstruation

Uterine Cycle

• Day 6-13

• estrogen by ovarian follicle

• Endometrium thickens - Proliferation phase

• Day 14 - Ovulation

Uterine Cycle

• Day 15-28

• Increased progesterone production - corpus luteum

• Endometrium doubles in thickness

• Uterine glands produce mucoid secretion - Secretory phase

• Endometrium now prepared for developing embryo

Uterine Cycle

• No pregnancy - corpus luteum degenerates

• Low level of sex hormones

• Cause uterine lining to breakdown - Menstrual discharge (Menstrual phase)

• Even during menstruation - ant. pituitary - FSH - new follicle matures

Anterior Pituitary and Ovarian Hormones

Ovarian Cycle and Uterine Cycle

Pregnancy

• Occurs when developing embryo embeds into endometrium

• Starts 5th day - finished by 10th or 11th

Pregnancy

• Implanted embryo - human chorionic gonadotropic hormone (hCG)

• Prevents degeneration of corpus luteum

• Increases production of progesterone

• Inhibits motility of uterus

• Declines by 10th day - only needed for 5 or 6 days

• Progesterone and estradiol prepare breasts for lactation

Placenta

• Both maternal and fetal tissue

• Region of exchange of molecules between fetal and maternal blood

• No mixing of blood

• Produces hCG & estradiol and progesterone

• Shut down anterior pituitary - no new follicles

• Maintains lining of uterus - corpus luteum no longer needed

Female Sexual Response

• Similar to that of males

• During sexual excitement

• Clitoris,vagina mucosa, and breasts engorge with blood

• Nipples erect

• Increased activity of vestibular glands - lubricates vestibule

• These events are analogous to erection in the male

• Same autonomic pathways for sexual excitement as in males

• Final phase is orgasm - muscle tension increases throughout the body, pulse rate and BP: rise and uterus begins to contract rhythmically - accompanied by intense feelings of pleasure and then relaxation