Female reproductive system - slides

Gonads

Ovaries

• oogenesis

• hormones

Organs

Uterine(fallopian) tubes/oviducts

Uterus

Vagina

External organs- vulva/pudenum

Mammary glands

Ovaries

produce games and hormones

• held by ovarian, broad and suspensory ligament

• consist of : germinal epithelium, tunica albuginea, ovarian cortex, ovarian medulla

Primordial follicle

baby follicles that develop into primary follicles during ovarian development. They consist of an oocyte surrounded by a single layer of follicular cells.

Follicles

ovarian follicles contain oocytes in various stages of development, and their supporting cells (follicular cells/granulosal cells)

6 types'

• Primordial follicle

• Primary follicle

• Secondary follicle

• Tertiary (Mature/Vesicular/Graafian) follicle

• Corpus luteum

• Corpus albicans

Oogenesis

Formation of gametes in the ovaries

• begins before birth

• primordial germ cells migrate from the yolk sac

Uterine tubes (fallopian tubes)

Histology

• mucosa- simple ciliated columnar epithelium

• muscularis

• serosa

Anatomical parts

• infundibulum

• ampulla

• isthmus

Uterus major areas

• body

• fundus

• isthmus

• cervix

• cervical canal

Uterus interior parts

• uterine cavity

• cervical canal

• internal os

• external os

Uterus Histology

3 layers

• perimetrium(serosa): visceral peritoneum

• myometrium: 3 layers of smooth muscle

• endometrium: mucosal lining of uterine cavity - stratum functionalis and stratum basalis

Endometriosis

Growth of endometrial tissue outside of uterus

• causes pain, scarring and infertility

• exact cause: unknown

Vagina function

Passageway for birth, menstrual flow and intercourse

Vagina layers

3 layers (outer to inner)

• mucosa

• muscularis (smooth muscle layer)

• Adventitia

External genitalia (vulva)

Mons pubis

• rounded mass of fatty tissue, overlying pubic symphysis

Labia majora (like scrotum)

Labia minora (like spongy penile urethra)

Clitoris (like glans penis)

Vestibule

• external urethral orifice, openings of several ducted glands and vaginal orifice

Bulb of vesibule

• elongated masses of erectile tissue on either side of vaginal orifice

• homologous to erectile tissue of penis

Paraurethral(skene’s) glands

• like erectile tissue of penis

• secrete mucus

• homologous to prostate gland

Mammary glands

Modified sweat glands that produce milk (lactation)

• lobes (15-20) → lobules → alveoli

• lactiferous ducts

• areola

• suspensory ligaments

Ovarian cycle hormones FSH

hypothalamus releases gonadotropin-releasing hormone (GnRH) that stimulates the anterior pituitary to secrete follicle-stimulating hormone (FSH), promoting ovarian follicle development.

• stimulates growing follicles (initial development of ovarian follicles)

• stimulates further development of ovarian follicles and their secretion of estrogen and inhibin

-Inhibin: inhibits release of FSH and to a lesser extent LH

-Estrogen: promotes development of secondary sexual characteristics, moderate levels inhibit release of GnRH, FSH, and LH

Ovarian cycle hormones LH

hypothalamus releases gonadotropin-releasing hormone (GnRH) that stimulates the anterior pituitary to secrete luteinizing hormone (LH), which triggers ovulation and promotes the formation of the corpus luteum.

• stimulates OVULATION(further development of ovarian follicles and their secretion of estrogen and inhibin)

• stimulates CORPUS LUTEUM (stays until the cycle ends, if fertilized it can stay up to 3 months for fetus growth and nourishment)- secretion of progesterone, estrogens, relaxin, and inhibin

Ovarian cycle

• follicular phase

• ovulation

• luteal phase

• The ovarian cycle encompasses the series of hormone-controlled events during which ovarian follicles mature and ovulation occurs, followed by the luteal phase where the corpus luteum develops.

Uterine cycle

• menstruation

• proliferate phase

• secretory phase

• The uterine cycle consists of three main phases: the menstruation phase, where the uterine lining is shed; the proliferative phase, during which the lining thickens and regenerates; and the secretory phase, where the lining prepares for potential implantation of an embryo.

Follicular phase

pituitary hormone effect: LH and FSH stimulate several follicles to grow

Ovarian hormone effect: dominant follicle produces estradiol → Inhibits GnRH, FSH, and LH production causes endometrium thickening

Ovulation

Pituitary hormone effect: LH and FSH stimulate maturation of one of the growing follicles

Ovarian hormone effects: Growing follicle continues to produce estradiol→ stimulates GnRH, FSH, LH production and LH surge triggers ovulation

• The process in which a mature ovarian follicle releases an egg, typically around the midpoint of the menstrual cycle, influenced by a surge of luteinizing hormone (LH).

Luteal phase

Pituitary hormone effect: LH stimulates formation of a corpus luteum from follicular tissue left behind after ovulation

Ovarian hormone effects: the corpus luteum secretes progesterone which

• inhibits GnRH, FSH, and LH production

• Maintains the endometrium: as the corpus luteum degrades, progesterone declines, initiating sloughing of the stratum functionalis

Perimenopause

• time near menopause

• may have irregular or skipped periods

Menopause

• stopped having monthly menstrual cycles for one year

• typically between 45-55 years

• some atrophy of reproductive organ and breasts (no remaining follicles to stimulate estrogen secretion

• Decrease in vaginal wall thickness and uterus shrinking

• hot flashes with periodic elevation in body temperature (skin blood vessels undergo intense vasodilation)

• possibly thinning scalp hair and increased facial hair- coarse (due to relatively high testosterone levels)

• Increased risk of osteoporosis and heart disease

• sx are sometimes treated with hormone replacement therapy