1 / 18

Ovaries

Ovaries. Each ovary is about the size and shape of an almond. In young women ovaries are the size of an almond; after menopause they tend to shrink. They produce eggs (also called ova); every female is born with a lifetime supply of eggs

nona
Télécharger la présentation

Ovaries

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Ovaries • Each ovary is about the size and shape of an almond. • In young women ovaries are the size of an almond; after menopause they tend to shrink. • They produce eggs (also called ova); every female is born with a lifetime supply of eggs • They also produce hormones: Estrogen  & Progesterone

  2. Oogenesis • Before birth at 4 months oogonia form • At birth- some oogonia degenerate, the rest go through mitosis forming more oogonia & primary oocytes • 2 million 1˚oocytes @ birth by puberty only 300,000- 400,000 exist • Puberty primary oocytes finish developing • Primary oocytes grow & go through Meiosis I  secondary oocytes & polar bodies • Ovulation  release of 2˚oocyte • 2˚oocyte go through Meiosis II only if fertilization occurs

  3. Fallopian tubes [uterine tubes] • Tubes stretch from the uterus to the ovaries • 8 -13 cm in length; an in. wide near the ovary to the diameter of spaghetti • Cilia line the tubes • Cilia beat in waves catching the egg at ovulation & move it through the tube to the uterine cavity. • Fertilization typically occurs in the fallopian tube

  4. uterus • Pear-shaped muscular organ in the upper female reproductive tract. • Fundus = upper portion of the uterus where pregnancy occurs • Cervix = lower portion of the uterus connecting to the vagina • serves as a sphincter keeping the uterus closed during pregnancy until delivery • The uterus expands during pregnancy growing 10 to 20x its normal size during pregnancy.

  5. uterus • Body= firm outer coat of muscle (myometrium) and an inner vascular/glandular layer (endometrium) • Endometrium thickens during the menstrual cycle for implantation of a fertilized egg. • Pregnancy occurs when the fertilized egg implants in the endometrial lining. • If fertilization does not occur, the endometrium sloughs off and is expelled as menstrual flow.

  6. The Cervix • Neck of the uterus. • Lined with mucus, the quality and quantity depends on estrogen & progesterone. • Low estrogen levels= mucus is thick and sparse, hindering sperm from reaching the fallopian tubes. • High estrogen levels= mucus is thin and slippery, offering a “friendly environment” to sperm • At the end of pregnancy, the cervix= gateway to the vagina. • Cervical canal expands 50x its normal width for birth

  7. The Vagina • A muscular, ridged sheath connecting to the uterus • Two Functions: • Accepts the penis and sperm during intercourse • Avenue of birth

  8. External genetalia • The urethral orifice (external urinary) opening is below the clitoris on the upper wall of the vagina and is the passage for urine • The introitus or opening of the vagina is separate from the urinary opening (unlike males) and located below it. • The hymen is a thin cresentic fold of tissue which partially covers the opening of the vagina. • medically it is no longer considered to be a 100% proof of female virginity.

  9. Menstrual Cycle • Menstrual Cycle- cyclic changes in the uterus (includes hormone secretion in the uterus and ovaries) • 28 days long (btw. 18-40 days)

  10. Phases of Female Reproductive Cycle • Menstrual Phase- discharge of the blood & the uterine mucous membrane which is sloughed & expelled (menses) • First day of menstrual cycle; lasts 4-5 days • Preovulatory Phase- time btw. the ending of menses & ovulation • Lasts from days 6-13 in a 28 day cycle • rapid production of uterine mucosa/ lining • Ovulation- release of a secondary oocyte • Occurs on day 14 of 28 day cycle • Postovulatory Phase- period after ovulation & before next menses • Maturation of follicles • Lasts 14 days in a 29 day cycle

  11. Ovarian Cycle- events in the ovaries that occur during and after maturation of an oocyte • Oocyte matures erupts from ovary travels down oviduct uterus • Horomones from the hypothalmus & pituitary gland stimulate: • 1stmeitoic division of an oocyte • Development of the uterine wall

  12. Uterine Cycle- the endometrium of the uterus prepares for the fertilized ovum • Lining of uterus grows & prepares for embryo to implant if fertilization occurs • If fertilization has not occurred lining of uterus sloughs off in menstruation

  13. External genetalia • Vulva— runs from the pubic area downward to the rectum. • Labia majoraor "greater lips" are the part around the vagina containing • Labia minoraor "lesser lips" are the thin hairless ridges at the entrance of the vagina (anteriorly they split to enclose the clitoris) • Hymen- a thin fold of tissue partially covering the vagina • Urethral orifice or external urinary opening is below the clitoris

More Related