The endocrine system

Question 1

What is the endocrine system?

Answer 1

A network of glands throughout the body that manufacture and secrete hormones

Question 2

What does secrete mean?

Answer 2

Produce and discharge

Question 3

What are the major glands in the endocrine system?

Answer 3

Pituitary
Adrenal
Reproductive organs

Question 4

How is the endocrine system regulated similarly to a thermostat which regulates room temperature?

Answer 4

A signal is sent from the hypothalamus to the pituitary gland (‘releasing hormone’) - causes the pituitary to secrete a ‘stimulating hormone’ which signals the target gland to secrete its hormone - as the levels of this hormone rises the hypothalamus shuts down secretion of the stimulating hormone - slows it down resulting in stable concentrations of hormones

Question 5

What do hormones do?

Answer 5

They travel through the bloodstream and affect the activity of specific target organs or cells - timing of release + levels of hormones released is critical for normal functioning

Question 6

What is the role of the pituitary gland?

Answer 6

The ‘master gland’ whose primary function is to influence the release of hormones from other glands - regulating many of the bodily functions

Question 7

What is the pituitary gland controlled by?

Answer 7

The hypothalamus (receives information from many sources about the basic functions of the body then uses the information to help regulate these functions)

Question 8

What are the two parts of the pituitary gland? and what are examples of the hormones they release?

Answer 8

The anterior pituitary (front)
- releases ACTH as a response to stress (stimulates the adrenal glands to produce cortisol)
- releases LH and FSH (stimulates ovaries to produce oestrogen + progesterone/stimulate testes to produce testosterone + sperm)
The posterior pituitary (back)
- releases oxytocin (stimulates contraction of uterus during child birth + important for infant-mother bonding

Question 9

What are the two parts of the adrenal glands? and what do they release?

Answer 9

Adrenal cortex (necessary for life)
- cortisol in response to stress
- aldosterone to maintain blood volume/pressure
Adrenal medulla
- adrenaline + noradrenaline which prepare body for fight or flight