Hormonal Control of the Menstrual Cycle

Inside the ovary of females there are large sac like structures called Graafian follicles

Each follicle contains a maturing ovumThe growth of he ovum inside the Graafian

follicle is controlled by follicle stimulating hormone (FSH)

Secreted by anterior lobe of the hypophysis or pituitary gland

These are produced by the germinal epithelium

Hormonal Control of the Menstrual Cycle

Between day 11 and 16, ovulation takes place

During ovulation, a single graaffian follicle ruptures and sets free an ovum

The ovum is collected by the funnel of the fallopian tube and passes down toward the uterus

Hormonal Control of the Menstrual CycleLuteinising hormone (LH),

also produced by the anterior lobe,

helps convert ruptured follicle into a structure called corpus luteum

Hormonal Control of the Menstrual Cycle

If the ovum is fertilized by a sperm cell

Corpus luteum secretes hormone progesterone

Makes certain that the embryo remains attached to the uterus wall

Ensures pregnancy remains

Hormonal Control of the Menstrual CycleIf the ovum is not fertilized, the corpus luteum

is destroyed

Little progesterone is secreted and menstruation occurs

During menstruation, the endometrium lining of the uterus comes off as the menstrual period

Hormonal Control of the Menstrual CycleThis is accompanied by bleeding

Menstruation takes place about 14 days after ovulation

The next egg is then released about 14 days after menstruation

Hormonal Control of the Menstrual CycleThere are 2 separate sub-cycles during

the menstrual cycle

The ovarian cycle

The uterine cycle

Hormonal Control of the Menstrual CycleThe ovarian cycle describes what happens in

the ovary

The uterine cycle describes the changes that are made in the uterus lining

A graafian follicle, at different stages, produces oestregen and progesterone

Hormonal Control of the Menstrual CycleThese hormones control what happens ti the

uterine wall

The cycles are closely related

The entire menstrual cycle is controlled by hormones produced by anterior lobe of hypophysis