MENSTRUAL CYCLE

menstrual cycle

regular shedding of the uterine lining in response to hormonal changes

menstrual cycle

main purpose is to mature and egg and prepare the uterus in case of pregnancy

menarche

first period and can start as early as 9 yeard old

menstruation

episodic uterine bleeding in response to cyclic hormonal changes (conception and implantation)

12-13 years old

average onset of menarche

9-17 years old

average range of menarche

28 days normal but it can range from 23-25 days

average cycle

4-6 days but 2-9 days can be still normal

menstruation usually last

30-80 mL

average amount of menstrual flow

menopause

permanent cessation of menstruation

polymenorrhea

having menstrual cycles that are too short thats why the person gets their period more often than normal

oligomenorrhea

having menstrual cycles that are too far apart thats why the person has fewer periods than normal

amenorrhea

temporary absence of menstruation

menorrhagia

abnormally heavy bleeding or bleeding that lasts longer than 7 days

metrorrhagia

irregular bleeding or spotting between menstrual periods

hypothalamus

starts the menstrual cycle by releasing GnRH, which signals the pituitary gland to send hormones to the ovaries to produce estrogen

additional info

high estrogen = less cycle — thats how birth control works

pituitary gland

produces the FSH and LH under the influence of GnRH

follicle stimulating hormone (FSH)

active early in the cycle that helps control the menstrual cycle and egg production in ovaries and responsible for maturation of the ovum

lutenizing hormone

most active at mid cycle and responsible for ovulation and growth of the uterine lining during the second half of the cycle

gonadotropic hormones

FSH AND LH ARE CALLED — BECAUSE THEY CAUSE GROWTH IN THE GONADS

graafian follicle

the growing follicle moves to the ovary surface and become visible

follicular fluid

rich in estrogen and some progesterone

oocyte

FSH activate this to grow

day 14

ovum divides completes meiotic division and ovulation occurs due to LH surge and prostaglandins

day 14

ovum enters the fallopian tube

14 days before the cycle ends

ovulation happens when

until day 24

basal temperature drops before ovulation and rises after and stays high until

16-20 weeks

if fertilized the corpus luteum remain for how many weeks

corpus albicans

if not fertilized the corpus luteum will become

uterus

also illustrates uterine changes that occur monthly as a result of stimulation from the estrogen and progesterone produced by the ovaries

proliferative (first phase)

first 4-5 days after menstrual flow the endometrium is thin (one cell layer)

up to eight fold by day 14

under FSH and rising estrogen the endometrium proliferates increasing up to

proliferative, estrogenic, follicular, post-menstrual phase

name of first phase

secretory (second phase)

after ovulation, LH triggers progesterone formation in the corpus luteum which causes endometrial glands to become twisted, filled with glycogen and mucin giving s spongy velvet look

progesterone

main hormone of secretory phase produced by corpus luteum

secretory phase

the endometrium thickens even more and glands become coiled and start secreting nutrients (prepares the uterus to receive fertilized egg)

additional info

if no fertilization corpus luteum degenerates after 8-10 days and progesterone drops which leads to the ischemic phase and menstruation follows

ischemic phase

by 24-25 days the endometrium degenerates, capillaries rupture, and sloughing begins (no oxygen)

menstruation (fourth phase)

contains blood, mucin, endometrial fragments, and the unfertilized ovum

menstruation (fourth phase)

it marks the end of one cycle and beginning of the next cycle

77 mg

iron loss in menstruation

cervical change

when estrogen is low, cervical mucus is thick, and scant (poor sperm survival)

fern test

high estrogen before ovulation causes mucus to form a fernlike pattern when dried

additional info

after ovulation, with progesterone, ferning disappears. no ovulation may show constant or absent ferning

spinnbarkeit test

at estrogen peak, mucus stretches into long strands with progesterone it is thick

spinnbarkeit test

this test confirm high estrogen and ovulation; done with fingers or on a slide

excitement, plateau, orgasm, resolution

sexual response cycle

excitement

begins with stimulation causing parasympathetic response, vaso congestion and muscle tension

plateau

just before orgasms clitoris retracts vagina congests, nipple elevate, penis distends and heart rate increase

orgasm

pelvic muscles contracts, blood / fluid released

resolution

last 30 minutes, genitals returns to normal