Sex Hormones

Question 1

What are sex hormones and where are they synthesised from?

Answer 1

These are steroid hormones and they are synthesised by cholesterol

Question 2

What hormones do both genders have?

Answer 2

In both males and females all sex hormones are present however, in lesser amounts.

1.the females body contains low levels of testosterone and other androgens.

2.the male body contains low levels of oestrogen

Question 3

What are the male sex hormones?

Answer 3

These are androgens, e.g. testosterone

Question 4

What are male sex hormones responsible for?

Answer 4

They are responsible for:
1.foetal differentiation
2/development of the urogenital system
3.have some effects of the brain

Question 5

what cells does FSH act on and what do they go on to do?

Answer 5

Works on the Sertoli cells, these are somatic cells within the testes:
They work to stimulate spermatogenesis

Question 6

How does testosterone inhibit luetinzing hormone secretion?

Answer 6

1. Acts on the hypothalamus to decrease the GnRH being released- long negative feedback mechanism
2. Acts directly on the interior pituitary gland to decreases the LH response to any given amount of GnRH - short negative feedback mechanism

Question 7

What is inhibin and what does it do?

Answer 7

This is a major inhibitory signal that has a direct effect on the anterior pituitary gland and inhibits or controls the secretion of FSH. Inhibin is a protein hormone that is secreted by the serotonin cells, it is important to note that the follicular stimulating hormone stimulates the serotonin cells to increase both spermatogenesis and inhibin production, this decreases the FSH release by acting on the interior pituitary.

Question 8

Why is testosterone essential in males and what effects do they have?

Answer 8

• required for initiation and maintenance of spermatogensis
  -decrease GnRH secretion via the action of hypothalamus
  -inhibits LH secretion via a direct action on the anterior pituitary gland
  -induce differentiation of male accessory reproductive organs and maintains their function
  -induces male secondary sex characterises: opposes action of opestorgen on breast growth
  -stimulates protein anabolism, bone growth and cessation of bone growth
  -required for sex drive and may enhance an aggressive behaviour
  -stimulates erythropoietin secretion by the kidneys

Question 9

What is the female sex hormones?

Answer 9

Oestrogens and progesterones

Question 10

Why are the female sex hormones important?

Answer 10

These are important for:
-foetal development
-infancy and childhood
-sex hormone is low

Question 11

What function does the sex hormone have during puberty and menopause ?

Answer 11

The hormone production surges during puberty, triggering sexual maturation and development of secondary sex characteristics

From puberty to menopause the sex hormones control the menstrual cycle and produced cyclically

Question 12

When are female sex hormones produced in larger quantities?

Answer 12

During pregnancy by the placenta to inhibit ovulation

Question 13

Where are the androgens produced in females?

Answer 13

They’re produced in small quantities by the ovaries and adrenals

Question 14

What are the effects of progesterone?

Answer 14

-converts the oestrogens primed endometrium to actively secrete tissue suitable for implantation of an embryo.

-induces thick, sticky cervical mucus

-decreases contraction of follaopian tubes and myometrium

-decreases proliferation of vaginal cells

-stimulates breast growth

-inhibits milk inducing effects of prolactin

-has feedback effects on hypothalamus and anterior pituitary

-increases in body temperature

Question 15

What is the menstrual cycle?

Answer 15

This is regular changes in the uterine lining resulting in monthly bleeding

Question 16

What is menarche?

Answer 16

This is the first menstrual period

Question 17

What is menopause?

Answer 17

This is the termination of the cycle due to normal aging of the ovaries

Question 18

What are the 4 main hormones that are involved in the menstrual cycle?

Answer 18

-follicle stimulating hormone (FSH)

-luteinising hormone (LH)

-oestrogen

-progesterone

Question 19

What are the two phases of the menstrual cycle?

Answer 19

Two phases are 14 days long each
1. Follicular phase
-this is called this due to the egg is inside a follicle that is developing

2.luteal phase( always 14 days)
-because the egg has exited the ovary during ovulation and what is left inside the ovary is called the corpus luteum.

Question 20

What’s is the endometrium?

Answer 20

This is the lining of the uterus where the foetus grows, has a good blood supply thus able to fully support a child.

This is broken down every month and is renewed, giving a period.

Question 21

What is the main function of FSH and LH ?

Answer 21

FSH=This is to stimulate the development of follicles

LH= causes ovulation

Question 22

In the ovaries there are __________ and FSH stimulates around ________ of them to start developing within the ovaries and the _____________ develop the cells surrounding them called the _________ secreting an increasing amount of oestrogen

Answer 22

1. Primordial follicles
2. 15-20

3.follicles

4. Granulosa cells

Question 23

What is the main function of oestrogen?

Answer 23

They are female sex hormones that work to acts on tissues with an estrogen receptor to promote female secondary sexual characterises, stimulates the development of breast tissue and other female sex organs. they stimulate the blood vessels in the uterus and the development of the endometrium, they cause the mucus in the cervix to become thinner so that the sperm are able to penetrate it a round the time of ovulation.

Question 24

How does oestrogen cause negative feedback?

Answer 24

As the oestrogen levels rise, it suppresses the release of FSH and LH from the anterior pituitary

Question 25

Why is there a decrease in oestrogen just before ovulation and when ?

Answer 25

This is because the follicles are getting ready to release the eggs