the menstrual cycle Flashcards
Which two hormones control the ovarian cycle?
Follicle Stimulating Hormone (FSH) and Luteinising Hormone (LH).
Which two hormones control the uterine cycle?
Oestrogen and Progesterone.
What is the function of FSH?
Stimulates the development and maturation of a follicle in the ovary.
What is the function of LH?
Triggers ovulation (release of the egg).
What is the role of oestrogen in the menstrual cycle?
Thickens the endometrium and stimulates the release of LH.
What is the function of progesterone?
Maintains the endometrium and inhibits FSH and LH.
What happens if the ovum is not fertilised?
The corpus luteum breaks down, progesterone levels drop, and menstruation occurs.
What happens if fertilisation occurs?
The corpus luteum remains active and continues secreting progesterone, preventing ovulation.
On which day does ovulation usually occur?
Around day 14 of the menstrual cycle.
What hormonal change causes ovulation?
A sharp increase in LH around day 13-14.
What happens when progesterone levels remain high?
It indicates pregnancy and inhibits ovulation.
What happens when progesterone levels drop?
The endometrium breaks down, leading to menstruation.
What type of feedback mechanism occurs between progesterone and FSH?
Negative feedback—progesterone inhibits FSH, preventing new follicle development.
Where does fertilisation occur?
In the fallopian tube.
What happens when a sperm fertilises an ovum?
A diploid zygote forms.
What is the function of the sperm’s acrosome?
It releases enzymes to penetrate the jelly layer of the ovum.
What type of cell division occurs after fertilisation?
mitosis
What is a morula?
A solid ball of cells formed by mitosis of the zygote.
What is a blastocyst?
A hollow fluid-filled ball of cells that forms around day 5.
What happens after the blastocyst forms?
It implants into the uterine lining.
