Ovaries and the Fertility Cycle

By: Louise, Sarah, and Rebecca

OVARY STRUCTURE

● Located on either side of the uterus, below the opening of the fallopian tubes

● Within are small groups of cells called follicles

● Follicles are made up of two types of cells Primary Oocyte Cells: they contain the genetic

makeup and undergo meiosis to be transformed into a mature oocyte

Granulosa Cells: they provide nutrients to the oocyte

OVARY STRUCTURE

● At puberty, each ovary contains about 400,000 follicles

● Many follicles develop during each fertility cycle, but only a single follicle reaches full maturity

● The other follicles deteriorate and develop into the corpus luteum, a yellow endocrine tissue that forms in the ruptured follicle Releases hormones necessary during pregnancy If pregnancy does not occur, the corpus luteum will

disintergrate after ten days

THE OVARIES

OVARY FUNCTION

● Produces egg cells

● Produces estrogen and progesterone Estrogen is secreted to thicken the walls of the

uterus, and it also activates the development of other female sex characteristics

Progesterone maintains the uterine lining during pregnancy

STOP THE FLOW

THE FERTILITY CYCLE

● The Ovarian cycle occurs at the same time as the menstrual cycle - each cycle lasts about 28 days

● Menstrual cycle means the changes that occur in the uterus

● Ovarian cycle is the changes that occur in the ovaries

PHASE ONE…FLOW PHASE

● Days 1 - 5

● Only phase that can be determined externally

● The uterus lining (endometrium) is broken down and excreted out the vagina

● Continues until the endometrium is completely excreted

PHASE TWO... THE FOLLICULAR PHASE

● Days 6 - 13

● The follicles in the ovaries begin to develop

● The egg cell enlarges and becomes multi-layered

● One of the follicles goes on to enlarge and mature whiles the others disintegrate

HORMONES DURING THE FOLLICULAR PHASE

● GnRH (Gonadotropin - releasing hormone) is released from the hypothalamus and stimulates the pituitary gland to secrete FSH (Follicle Stimulating Hormone)

● The release of FSH stimulates the follicle development

● The follicles then secrete estrogen, which stimulates endometrium production

OVULATION OCCURS

The outer surface of the ovary wall bursts and the egg is released

PHASE THREE... OVULATORY PHASE

● FYI: The uterus always prepares for possible pregnancy before ovulation

● The rising estrogen levels during phase two causes increased LH secretion, which results in ovulation

● The ovary ruptures and the egg is released

● The follicle remains in the ovary and it develops into the corpus luteum

PHASE FOUR... LUTEAL PHASE

● Days 15 - 28

● The Corpus Luteum secretes estrogen and progesterone

● Prepares the uterus for a fertilized egg by gradually building up the endometrium lining (also known as the poliferative phase)

● The cycle starts over with the flow phase unless the woman becomes pregnant

HORMONES DURING THE LUTEAL PHASE

● After ovulation, the high levels of LH stimulate the follicular tissue to develop a corpus luteum which then secretes estrogen and progesterone

● These hormones stimulate endometrium production by supplying blood to the uterine lining

● When LH levels become too low, the corpus luteum disintergrates

● When the woman is not pregnant, estrogen and progesterone levels drop, which then restarts the flow phase (causes endometrium lining to shed)

THE MENSTRUAL CYCLE

EVENTS OF THE FERTILITY CYCLE

Information and Quiz:http://www.sumanasinc.com/webcontent/animations/

content/ovarianuterine.html

Video:http://www.blinkx.com/video/how-the-body-works-the-

menstrual-cycle/66APAaQqDuC_M73r_Xqzwg http://www.teenwire.com/interactive/movies/do-040707-

period.php

HOMEOSTATIC REGULATION OF THE FERTILITY CYCLE

● The Hypothalamus-Pituitary Complex regulates the hormones of the ovaries

When female puberty occurs, the gonadotropin-releasing hormone (GnRH) is released from the hypothalamus

This stimulates the pituitary gland - the storage site for the gonadotropins LH (luteinizing hormone) and FSH (follicle - stimulating hormone)

A negative feedback loop is then developed to regulate both the gonadotropins and the ovarian hormones during the fertility cycle

NEGATIVE FEEDBACK LOOP

POLY-CYSTIC OVARIAN SYNDROME

● What is PCOS?● How common is it?● What causes it?● Symptoms?● Treatment?

WHAT IS PCOS?

● Ovaries are larger than normal, and follicles appear in clumps. (May not affect fertility)

● Cysts cause a hormonal imbalance and symptoms develop, which makes it a syndrome.

● PCOS = Women who have Polycystic Ovaries with symptoms

● “Metabolic" disorder (many factors cause this)

HOW COMMON IS IT?

● Most common hormonal disorder occurring in women during their reproductive years

● 4% to 10% of all women have the disorder

● Many women don’t know that they have PCOS so the number is probably higher than 10% (Mis- diagnosis)

● Symptoms start to show shortly after puberty

CAUSES

Combination of 2 or more of these factors:

● Genetics● Insulin resistance or hyperinsulinism (high blood levels of

insulin)● Obesity ● Hyperandrogenism (excessive production of male hormones)● Abnormality of the hypothalamic-pituitary-gonadal axis

(organ/hormonal disorder)● Environmental chemical pollution (hormonal disruptors) ● Food adulterantion (excitatory amino acids, for example) ● Chronic inflammation

SYMPTOMS

● Multiple ovarian cysts● Irregular or absences of menstruation ● Obesity/inability to lose weight● Infertility● High blood pressure● Excessive body or facial hair● Polycystic ovaries that are 2-5 times larger than

healthy ovaries● Multiple hormone imbalances (estrogen levels,

insulin, thyroid hormones)

TREATMENT OPTIONS

● Birth control pills

● Metformin (Glucophage) - increases insulin efficiency

● Weight Loss

● Ovarian Drilling

● Surgical removal of Cysts

REFERENCEShttp://science.jrank.org/pages/2478/Endocrine-System-ovaries.html

http://www.umm.edu/endocrin/reproduct.htm

http://www.sumanasinc.com/webcontent/animations/content/ovarianuterine.html http://www.fertilityfriend.com/HelpCenter/FFBook/ff_menstrual_cycle.html http://womens-sexual-health.suite101.com/article.cfm/the_phases_of_the_menstrual_cycle http://www.homehealth-uk.com/medical/ovulationandmenstrualcycle.htm http://science.jrank.org/pages/4950/Ovarian-Cycle-Hormonal-Regulation.html http://www.merck.com/mmhe/sec22/ch241/ch241e.html

http://www.kcl.ac.uk/teares/gktvc/vc/medical/year2/ssm/menstweb/Web/kate/main.htm