ob power point ch 3

Ovulatory

(day 14)

Follicular Phase

(days 1-14)

Luteal Phase

(days 15-28)

LH: luteinizing hormone

* Follicular maturation * Corpus luteum * Progesterone

how many week until its called an embyro

8 weeks

Usual cause is lack of ovulation, but hormonal imbalance in the pituitary-ovarian axis may be a factor. Menorrhagia Increased amount and duration of flow Metrorrhagia Bleeding between cycles Polymenorrhea Short cycles of less than 3 weeks Oligomenorrhea Long cycles of more than 6 weeks

Abnormal Menstrual Bleeding

Partial fusion failure Complete duplication of uterus Either: bicollis (1 vagina, 2 cervices, & 2 uterine horms) unicollis (1 vagina, 1 cervices, & 2 uterine horns)

Bicornuate Uterus

Produces progesterone until placenta takes over around week 10. Placenta produces hCG

Corpus luteum

Endometrium undergoes histologic and cytologic changes that culminate with menstrual bleeding when the corpus luteum ceases to secrete progesterone. The basal layer (stratum basale) of the endometrium then regenerates the functional layer (stratum functionale). The functional layer is shed during menstruation. Endometrial glands proliferate under the influence of estrogen, and the mucosa thickens. In the luteal phase, the glands become coiled and secretory, with increased vascularity and edema of the tissue. When estradiol and progesterone decline, the endometrium blood vessels necrose and bleeding ensues.

Cyclic changes in target organs

Ovulation

DAY 14

Oocytes exist in follicles Primordial or primary follicles exist in ovary Primary follicle development: Size increases, granulosa cells increase Zona pellucida forms around follicle Follicle full size, antrum develops Maturation or graafian follicle matures; others undergo atresia

Development of follicles

Helped increase favorable outcomes for an at risk pregnancy Daughters showed increased Vaginal cancer Breast cancer T-shaped uterus

Diethylstilbesterol (DES) Exposed Uteruspg. 46

Affects musculoskeletal and cardiovascular systems Affect brain Increased levels of estrogen suppress FSH Inhibit ovulation Mechanism of contraception High levels of estrogen - negative feedback on LH and FSH, inhibiting their secretion Low levels of estrogen - positive feedback on LH and FSH, increasing their levels

Estrogen

Steroid hormone Main source from ovaries Also synthesized by CL and placenta Estradiol, estriol, and estrone Estradiol - ovarian follicles Estriol - placenta Estrone - widespread; only estrogen present after menopause Development of secondary sex characteristics Estrogen stimulates the endometrium to thicken before ovulation Promote clotting Minimize loss of calcium from bone

Estrogen

* Stimulates follicular growth * Follicles secrete estrogens

FSH: follicle stimulating hormone

Originate at upper portion of the uterus Sections Isthmus Ampulla Infundibulum

Fallopian Tube

Controlled by Negative feedback loop Positive feedback loop

Female Reproductive Endocrine Glands

Follicular Ovulatory Luteal

Follicle Phases

After early follicular phase, FSH levels fall and LH levels rise slowly. About 7 days before the preovulatory LH surge, estradiol and estrone increase until the day before the LH surge. The divergence in LH and FSH levels may be related to the secretion of inhibin B, which inhibits the release of FSH. Progesterone does not increase until just before the LH surge onset.

Follicular phase

Follicles begin to grow under influence of FSH Usually 5-8 follicles in active ovary One follicle usually becomes "dominant"

Follicular phase

Primitive oocyte Developing follicle Mature follicle

Follicular phase

Begins with day 1 of menstrual cycle Day 1 is first day of bleeding Bleeding occurs with fall of estrogen and progesterone Endometrium sloughs Lasts from day 1 until LH surge and ovulation - typically day 14 Main purpose to develop follicle capable of surviving ovulation When estrogen levels decrease, positive feedback triggers secretion of GnRH, FSH, and LH. When FSH starts to rise, ovarian follicles develop. Follicle produces estrogen (estradiol). Estrogen levels peak near end of follicular phase Then exerts positive feedback on LH causing LH surge

Follicular phase or preovulatory phase

Self - perpetuating monthly cycle GnRH FSH estrogen production in follicles (androgen estrogen) High estrogen suppresses GnRH, FSH, and LH LH surge occurs when follicle reaches mature stage and begins to produce a higher level of estrogen, the opposite effect occurs. Positive feedback activates the pituitary to secrete large burst of LH. LH surge stimulates ovulation from follicle. The remaining cells become CL and secrete progesterone. LH and FSH levels decline. CL secretes progesterone and estrogen until it starts degenerating. Becomes corpus albicans if no pregnancy Low levels of estrogen and progesterone initiate positive feedback on hypothalamus and pituitary and its starts all over.

Hypothalamic - pituitary - ovarian axis

Maintains homeostasis Part of diencephalon, below thalamus Directly above pituitary Floor of third ventricle Hypothalamus contains centers to control temperature, breathing, appetite. Secretes releasing hormones that stimulate the release of hormones from pituitary. Hormones are secreted directly into the hypophyseal portal system.

Hypothalamus

Näegele's Rule

In developing this numerical relation, Dr. Naegele assumed that the menstrual cycle lasted for 28 days and ovulation occurred on the 14th day of the cycle. He also believed that the average duration for human gestation was 266 days from conception or 280 days from the LMP.

how does progesterone finish off endometrial preparation

Induces progestational effects in endometrium Causes rise in BBT at ovulation (> 0.5-1.0° F) Causes breast changes

During this phase, the ovum is released from the mature graafian follicle about 32 to 34 hours after the preovulatory LH surge. Some women experience unilateral pelvic pain near the time of ovulation, termed mittleschmerz, which occurs before or after ovulation. During the ovulatory phase, a rapid rise in plasma LH in response to positive estrogen feedback leads to ovulation. As peak LH levels are reached, estradiol levels drop, but progesterone levels increase.

Ovulatory phase

Uterine Layers

Perimetrium Myometrium Endometrium

Rests in sella turcica (Turkish saddle) Size of a pea Connects to hypothalamus by a stalk Two separate tissues Anterior (adenohypophysis) Posterior (neurohypophysis) Anterior pituitary GH, ACTH, TSH, FSH, LH, Prolactin Posterior pituitary ADH and oxytocin

Pituitary or hypophysis

"finishes off" endometrial preparation for implantation

Progesterone

Prepares the endometrium for implantation Decreases contractility of myometrium Blocks development of new follicles Inhibits LH, inhibits ovulation Thickens cervical mucus (impenetrable to sperm) Increases basal body temperature

Progesterone

Stimulated by corpus luteum LH stimulates the CL LH surge triggers ovulation; follicle ruptures Residual cells form the corpus luteum Corpus luteum secretes progesterone and estradiol Progesterone prepares the body for pregnancy and maintains it till birth

Progesterone

Stimulates growth of uterine wall and uterine blood vessels If implantation occurs, the placenta will secrete progesterone near end of first trimester until end of pregnancy. If there is no implantation, estrogen and progesterone levels drop, CL degenerates, endometrium breaks down, and menstruation occurs.

Progesterone

Increasing estrogen levels result in regeneration of surface and glandular epithelium. Endometrial thickness increases as phase continues.

Proliferative Phase days 6-14

Increasing thickness of endometrium Progesterone induces maturational changes Maximal stromal edema at ~day 22

Secretory phase

Follicle becomes the corpus luteum and produces progesterone. Vascularization of endometrium in preparation for implantation (12 to 14 days prior to the onset of next menstruation) If implantation does not occur: Corpus luteum atrophies Uterine muscle contracts → ischemia Endometrium is shed as the menses

The Menstrual Cycle

UTERINE CIRCULATION

Uterine artery a. ascending branch b. descending branch 2. Arcuate arteries 3. Radial arteries a. straight arteries b. spiral arteries

Complete midline failure of mullerian duct fusion Resulting in 2 hemiuteri each with their own vagina and endometrium Each hemiuteri is associated with one fallopian tube No communication between endo cavities Asymptomatic Diagnosis may come when tampon doesn't prevent flow Commonly associated with renal agenesis

Uterus Didelphys

Complete failure of one müllerian duct elongation while other develops normally Contralateral rudimentary horn Associated with renal anomalies Ispilateral Renal agenesis Pelvic kidney Horseshoe kidney (pg 39)

Uterus Unicornis

when is an embryo called a fetus

at 12 weeks

Menstrual Phase

days 1-5

Secretory Phase

days 15-28

Proliferative Phase

days 6-14

steroids that prepare endometrium for implantation

estrogen

what are the ovarian hormones that prepare the endometrium for implantation

estrogen and progesterone

when will you see the three line sign

in late proliferative phase

Three phases: follicular, ovulatory, and luteal Oogenesis Primitive germ cells or oogonia go through mitosis only in fetal life Most oogonia die, the remaining 1 - 2 million begin meiosis I, and are arrested in meiosis I. Meiosis I is completed just before ovulation

ovarian cycle

Almond-shaped Located lateral to the uterus Size varies

ovaries

Develop from different tissues, making agenesis rare Not associated with the formation of the mesonephric and paramesonephric ducts Malposition common with uterine malformations

ovaries

In late luteal phase, another dominant follicle develops and a new menstrual cycle begins. The potential to produce a dominant follicle stops at menopause.

ovary

Produce a single dominant graafian follicle that grows and develops to the preovulatory stage during the follicular phase. This process is brought about by combined action of FSH and LH on the follicle to increase estradiol synthesis. LH acts on the preovulatory follicle to cause the secretion of the mature fertilizable oocyte. After ovulation, the follicle wall transforms into the corpus luteum, which produces progesterone and estradiol. If implantation does not occur, the CL will involute and stop hormone production.

ovary

Midpoint in the menstrual cycle, the preovulatory surges of LH and FSH act on the preovulatory follicle to initiate the events leading to ovulation. Luteogenesis Ovulation leads to changes in the granulosa and theca cells of the ovulated follicle that result in increased production of progesterone and estradiol during the first week of the luteal phase. This event, termed luteinization, is important for the formation and development of a secretory endometrium

ovulation

what is the hormone that finishes off endometrial preparation

progesterone

how does estrogen prepare the endometrium for implantation

stimulates glandular growth, endometrium becomes highly vascular, estrogen levels increase 24 hours prior to ovulation

Occurs 24-36 hours after onset of LH surge

Ovulation

FALLOPIAN TUBES (UTERINE TUBES OR OVIDUCTS):

. Interstitial portion 2. Isthmus portion 3. Ampulla portion 4. Infundibulum portion 5. Fimbriae

The luteal phase is about 14 days long and ends with the onset of menses. This phase includes the lifespan of the corpus luteum, which supports the released ovum by secreting progesterone. Progesterone secretion increases up to 8 days after the LH surge. Progesterone decreases before menses unless the ovum is fertilized and pregnancy results. Progestins increase basal morning body temperature so that an increase of more than 0.3 degrees C indicates ovulation.

Luteal (postovulatory) phase

Early corpus luteum Mature corpus luteum Corpus albicans

Luteal phase

Follicle becomes corpus luteum (yellow body) Corpus luteum produces progesterone Begins to regress if implantation does not occur

Luteal phase

Decreasing hormone levels result in tissue necrosis Basal layer remains Functional or decidual layer is sloughed off

MENSTRAL PHASE DAYS 1-5

Menstrual abnormalities Amenorrhea (absence of menstruation) May be primary or secondary Primary may be genetic. Secondary is usually hormonal imbalance. Dysmenorrhea Painful menstruation due to excessive release of prostaglandins as a result of endometrial ischemia Usually begins a few days prior to menses and lasts a few days after onset NSAIDs offer relief.

Menstrual Disorders

Premenstrual syndrome Begins approximately a week before onset of menses Pathophysiology not completely known; may be several forms Breast tenderness, weight gain, abdominal distension or bloating, irritability, emotional liability, sleep disturbances, depression, headache, fatigue Treatment is individualized and may include exercise, limiting salt intake, use of oral contraceptives, diuretics, or antidepressant drugs.

Menstrual Disorders

what is the uterine response

Menstrual Phase (days 1-5) Proliferative Phase (days 6-14) Ovulation (day 14) Secretory Phase (days 15-28

Expression of the coordinated interactions of the hypothalamic-pituitary-ovarian axis with associated changes in the target tissues (endometrium, cervix, vagina) of the reproductive tract. A menstrual cycle begins with the first day of genital bleeding and ends just before the next menstrual period. Menstrual cycles vary most in the years immediately after menarche and preceding menopause, partly because of an increase in anovulatory cycles. Irregularities in menstrual cycle length may be caused by changes in diet, exercise, emotional disturbances, parturition or abortion.

Normal menstrual cycle

According to this rule, pregnancy due date is determined by adding seven days to the first day of the LMP and subtracting three months from the sum result. Example: 1st day of the LMP: January 1, 2010 EDD or EDC: October 8, 2010.

Näegele's