Menstrual Cycle
Dr. Hazrat Bilal Malakandi
DPT (IPM&R KMU)
Menstrual Cycle
• Rhythmic cyclic changes in mucous membrane
(endometrium) of uterus, associated with
cyclic production of estrogen and
progesterone is called menstrual cycle
• Period
– 28 days (20-45 days)
Significance
• These cyclic changes in uterus are for
preparation of uterus for implantation and
nutrition of the embryo and for pregnancy.
• But when fertilization fails to occur, uterine
epithelium sheds off and blood vessels necrosis
occurs as a result which blood and mucus along
with degenerated epithelium oozes out
through vagina, each month in a cyclic fashion
Phases
Three phases
• Menstruation phase
• Proliferative phase
– (also called postmenstrual or estrogen phase)
• Secretary phase
– (also called premenstrual or progesterone phase)
• Menstruation phase
– During this phase all superficial layers of
endometrium are desquamated through vagina
• Proliferative phase
– Estrogen in first ½ of ovarian cycle causes rapid
proliferation of stromal and epithelial cells
– Endometrium (that was desquamated during
menstruation) is thus reepithilialized within 3-7
days
– Endometrium increase in thickness (3-5 mm) due to
increase no. of stromal cells and endometrial glands
and blood vessels
Hormonal Fluctuation
• After bleeding is over or during last days of
menstruation, hypothalamus releases follicle
releasing hormone (FRH) which stimulate ant.
Pituitary gland to secrete FSH.
• This in turn causes excessive growth of follicles.
The follicle estrogen, which is responsible for the
proliferation of endometrium and makes it thicker.
• Just before (2-3 days) ovulation, LH appears which
causes ovulation and formation of corpus luteum.
This corpus luteum secretes progesterone.
• Secretary phase
– Progesterone in last ½ of ovarian cycle causes
marked swelling and secretary development of
endometrium
– Glands become tortous
– Secretary substance accumulate in glandular
epithelium
– Cytoplasm , lipid and glycogen increase in stromal
cells
– Blood vessels increase and become tortuous
– Endometrium increase in thickness (5-6 mm)
• Causes of menstruation
– Cessation of estrogen and progesterone secretion
two days before menstruation
• Menstrual fluid
– Volume = 70 ml
• Characteristic
– Does not clot due to presence of fibrinolysin
Preovulatry LH surge
• One or two days prior to ovulation, LH
secretion increase due to positive feedback
effect of estrogen, this is called preovulatry LH
surge.
• Importance
– Preovulatry LH surge is essential for ovulation to
occur
Anovulatory Cycles
Female sexual cycles in which ovulation does not
occur are called anovulatory cycles.
• Causes by
– Insufficient preovulatry LH surge.
• Anovulatory cycles occur:
– Few cycles after puberty
– Several cycles before menopause
• Menarche
– Onset of menstruation is called menarche.
Menopause
Cessation of menstruation in old age is called
menopause.
• Caused by
– Cessation of female sex hormones secretion
• Age : 45-50 years
• Symptoms
–
–
–
–
–
Hot flushes
Psychic sensation of dyspnea
Irritability
Fatigue
Anxiety
Amenorrhea
• Cessation of menstruation at any age is called
amenorrhea.
• Two types
A. False Amenorrhea
B. True Amenorrhea
A. False Amenorrhea
– (also called hidden menstruation or crypto menorrhea)
– In this menstruation takes place but patient is unaware
of it because outflow of menstrual fluid is blocked at
level of cervix, vagina or vulva.
B. True amenorrhea
– In this menstrual function is suppressed so that
there is no menstrual fluid.
• Two subtypes
1. Physiological
2. pathological
a. Primary
b. secondary
1. Physiological
– Before puberty
– During pregnancy
– During lactation
– After menopause
2. Pathological
– Amenorrhea is a clinical symptom not a disease and
has a variety of causes. This can be divided into:
a. Primary
– It means failure of menstruation to occur at puberty
– Types
•
•
•
•
Hypothalamic amenorrhea
Pituitary amenorrhea
Ovarian amenorrhea
Uterine amenorrhea
• Hypothalamic amenorrhea
– Failure of hypothalamus to secrete LHRH
• Pituitary amenorrhea
– Failure of anterior pituitary gland to secrete LH and
FSH.
• Ovarian amenorrhea
– Failure of ovaries to secrete estrogen and
progesterone
• Uterine amenorrhea
– Absence of disease of uterus
b. Secondary
– It means cessation of menstruation after it has
once occurred at puppetry.
• Causes
– Endocrinal disease
– Chronic diseases
– Malabsorption syndromes
• Endocrinal disease
– Hypo or hyperthyroidism
– Diabetes mellitus
– Cushing’s syndrome
• Chronic diseases
– Pulmonary tuberculosis
– Lymphoma
– Crohn’s disease
• Malabsorption diseases
– Starvation
– Anorexia nervosa
– anemia
• Dysmenorrhea
– Painful menstruation is called dysmenorrhea
– May be due to psychology
– Enzyme fibrinolysin is absent so dry clots appears,
causing pain.
• Polymenorrhea
– Abnormal frequent menstruation is called
polymenorrhea
– Bleeding continues for more than 6 days.