hormones Flashcards
What are hormones?
Chemical messengers in the body that travel through the bloodstream and coordinate different functions in the body.
Where is the pituitary gland located in the body?
Below the hypothalamus.
What is the function of the pituitary gland?
To secrete hormones that stimulate other endocrine glands to release hormones for growth, metabolism, and reproduction.
Name some examples of endocrine glands. (4)
Testes, ovaries, pituitary, and adrenal cortex.
What is the role of sex hormones in the body?
affect the growth and functioning of the reproductive organs and the development of secondary sex characteristics.
What are the male endocrine glands?
Testes/gonads
What are the female reproductive glands?
The ovaries
Which gland is responsible for secreting hormones to stimulate other endocrine glands
The pituitary gland
What are secondary sex characteristics?
Physical traits that develop during puberty that distinguish males from females, such as deepened voice, facial hair, breast development, and widened hips.
What are androgens?
Androgens are hormones that are responsible for controlling the development and functioning of male sex organs, as well as for the development of secondary sex characteristics.
Which hormone is the main androgen secreted by the testes?
The main androgen secreted by the testes is testosterone
What is the role of androgens in spermatogenesis?
testosterone is responsible for the production of sperm (spermatogenesis).
Do males or females have higher levels of androgens?
Males have higher levels of androgens than females.
Where are androgens produced?
Androgens are mainly produced by the testes in males.
What is the role of oestrogen in males?
Along with testosterone, it is responsible for the maturation of sperm
What are the roles of oestrogen in females? (overall)
Plays a key role in the functioning and development of female reproductive organs and systems, as well as secondary sex characteristics.
Where is oestrogen produced in females?
ovaries and placenta during pregnancy
What is the main function of oestrogen in the menstrual cycle?
Thickens the lining of the endometrium in preparation for potential pregnancy and triggers ovulation.
Where is progesterone produced?
mainly produced in corpus luteum, and placenta
What is the function of progesterone?
- known as the “pregnancy hormone”
- responsible for the maintenance and thickening of the endometrium for implantation after ovulation.
- stimulates the secretion of cervical mucus to create a favourable environment for implantation
- prevents muscle contractions from happening in the uterus to support implantation and foetal development during pregnancy
- stimulates the production of milk in mammary glands (lactation).
What triggers the release of progesterone?
The release of progesterone is triggered by the luteinising hormone (LH) which is produced by the anterior pituitary gland.
What is the role of progesterone in preparing the breast for lactation during pregnancy?
helps in the development of milk ducts in the breast to grow in size.
What happens to progesterone levels if pregnancy does not occur?
- progesterone levels in the body will begin to decline
- lining of the uterus begins to break down and is shed through the cervix and vagina.- menstruation
What is the role of progesterone in supporting a healthy pregnancy?
- thicken the endometrium
- prevent contractions of the uterus that could lead to premature delivery
- promote the growth of blood vessels in the uterus to provide nutrients and oxygen to the fetus.
What happens to progesterone levels after delivery?
Drecreases
How does progesterone prepare the uterus for implantation?
- thickening of the lining of uterus
- preventing contractions by relaxing muscles to ensure egg is implanted
Where is progesterone primarily made?
- corpus luteum (first ten weeks of pregnancy)
- placenta (later stages of pregnancy)
Where is Luteinising (LH) hormone made?
pituitary gland in the brain
What is the role of LH in ovulation?
- Surge in LH levels is responsible for ovulation
How does LH affect t he corpus luteum?
- if pregnancy does not occur, low levels of LR will cause the break down of the corpus luteum
What happens once corpus luteum breaks down?
significant drop in progesterone which results in menstruation
drop in oestrogen levels
What is the role of follicle-stimulating hormone in the female reproductive system?
stimulating the maturation of ovarian follicles, which contain the immature egg cells
Where is FSH produced?
pituitary gland
What are the two main phases of the menstrual cycle?
Follicular phase and luteal phase
What happens during ovulation in the menstrual cycle?
a mature egg is released from the ovary and travels down the fallopian tube towards the uterus.
What happens during the follicular phase of the menstrual cycle?
- hypothalamus releases GnRH, which stimulates the pituitary gland to release FSH and LH.
- FSH stimulates the maturation of ovarian follicles
- as the follicle grows, it produces estrogen.
- High levels of estrogen inhibits FSH production to prevent other follicles from maturing
- high levels of oestrogen thickens endometrium and stimulates production of LH
- surge in LH results in ovulation
What is the role of the corpus luteum in maintaining pregnancy during the few months?
- secretion of progesterone which helps maintains endrometrium
What are the main hormones that are secreted by the placenta during pregnancy?
- progesterone
- oestrogen
- hcG
What is the function of human chorionic gonadotropin (HCG) during pregnancy?
hormone stimulates the corpus luteum to produce progesterone
What is the function of the umbilical cord in pregnancy?
transports oxygen and nutrients and removes wastes
What are the potential consequences if the placenta fails to function properly during pregnancy?
- affect development and growth of foetus
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How does the placenta maintain pregnancy after the corpus luteum breaks down?
- secretes progesterone
- transport oxygen and nutrients to foetus via umbilical cord and removes wastes
During the luteual phase, when oestrogen and progesterone levels are high, they can inhibit the secretion of which two key hormones that regulate the menstrual cycle?
FSH AND LH
What happens to the corpus luteum after few months of pregnancy?
breaks down and is replaced by the placenta who takes over role
What is role of prolactin?
stimulates milk production in the breasts by enlarging mammary glands
When do levels of prolactin start to rise during pregnancy?
second trimester
What is lactation?
Lactation is the production of milk by the mammary glands in the breasts
What is the corpus luteum
It is a temporary endocrine structure in the ovary that is from the ovarian follicle after ovulation
