8 - HORMONAL SYSTEM

Question 1

What is the hormonal system made up of?

Answer 1

Glands and hormones

Question 2

What is a gland?

Answer 2

A gland is group of cells that are specialised to secrete a useful substance, such as a hormone

Question 3

What is a hormone?

Answer 3

Hormones are chemical messengers. Many hormones are proteins or peptides.

Question 4

How are hormones secreted?

Answer 4

Hormones are secreted when a gland is stimulated and a gland is stimulated by a change in concentration of a specific substance or by stimulus of electrical impulses.

Question 5

Explain the process of hormones triggering target cells (the effectors)

Answer 5

1) stimulus detected by receptors
2) The appropriate hormone is released in response
3) The target cells detect the hormone and a response is given

Question 6

Differences between hormonal and nervous control (communication):

Answer 6

1) NC uses electrical transmissions by nerve impulses and chemical transmission at synapses whereas HC uses chemical transmissions through the blood
2) NC is faster acting
3) NC has a localised response as the neurones carry electrical impulses to specific cells, whereas the HC has a widespread response as the target cells can be all over the body
4) NC has a short-lived response as the neurotransmitters are removed quickly, whereas the HC has a long-lived response as the hormones aren’t broken down very quickly