Hormones - Biology edexcel IGCSE

Where is Insulin secreted from?

The pancreas (acts as an endocrine gland)

Insulin controls _____ _________ ______

blood glucose levels

What does insulin stimulate?

It stimulates the muscles, liver and stomach to take up glucose from blood and store as glycogen

Where is adrenaline secreted from?

The adrenal gland

What is the role of adrenaline?

It prepares the body for action

4 effects of adrenaline

• It increases heart rate

• it diverts blood flow towards muscles

• dilation of blood vessels

• breaking down of stored glucogen

Where is testosterone produced/sourced?

The male testes

What is the role of testosterone?

It stimulates the development of male sexual characteristics

Give 4 examples of male sexual characteristics

• Production of sperm

• Facial, body and pubic hair

• Sexual organs develop

• Voice breaks

Where is oestrogen sourced?

The female ovaries, in the developing follicle

What is the general role of oestrogen?

It stimulates growth of femal sexual characteristics

Give 3 examples of female sexual characteristics

• Breasts

• Pubic hair

• Beginning of menstrual cycle

Where is progesterone stored/sourced?

Female ovaries - in the corpus luteum

What is the role of progesteron/ it’s effect generally

To maintin the uterine lining during pregnancy

ADH stands for…

Antiduretic hormone

ADH is sourced from the

pituitary gland - the brain

ADH’s role is to…

detect the increase or decrease of blood water levels

If the blood is at a low water level ADH will ____ __________

be released

If ADH is released, when urine passes through the collecting duct it will _______ _____ ______

reabsorb more water

ADH determines the ____-_____ levels and conc. of _____

blood water, urine

Oestrogen in the menstrual cycle stimulates

repair and thickening of the uterus lining

A drop in levels of oestrogen triggers…

Loss of uterus lining

Progesterone in the menstrual cycle…

maintains the uterus lining

Levels of progesterone drop if….

no fertilisation occurs

FSH and LH are produced by the…

pituitary gland

LH in the menstrual cycle stimulates the ovaries to produce what hormone?

progesterone

LH in the menstrual cycle stimulates…

the release of the egg, ovulation

FSH in the menstrual cycle causes the

maturation of the egg in the ovary

FSH in the menstrual cycle stimulates the ovaries to start releasing which hormone?

Oestrogen