5.3.1 Human endocrine system

Question 1

How do the endocrine and nervous systems differ?

Answer 1

Nervous system - faster
Endocrine system - slower

Nervous system - acts for a very short time
Endocrine system - acts for longer

Nervous system - act on a very precise area
Endocrine system - act for longer

Question 2

What is the endocrine system?

Answer 2

The endocrine system is composed of glands which secrete chemicals called hormones directly into the bloodstream. The blood carries the hormone to a target organ where it produces an effect.

Question 3

What are hormones and what do they do?

Answer 3

• chemical molecules released directly into the blood
• Carried in the blood to other parts of the body but only affect particular cells in particular organs (target organs)
• Hormones control things in organs and cells that require constant adjustment
• Hormones are produced in and secreted by various glands, called endocrine glands. The glands make up your endocrine system.
• Hormones tend to have relatively long lasting effects

Question 4

The pituitary gland

Answer 4

Found in the brain
Sometimes called the ‘master gland’ because it secretes several hormones into the blood in response to body conditions. These hormones act on other glands to stimulate the release of other hormones to bring about effects.

Question 5

Thyroid

Answer 5

• in the neck
• produces thyroxine - involved in regulating things like rate of metabolism, heart rate and temperature

Question 6

Adrenal glands

Answer 6

• above the kidneys
• produces adrenaline - used to prepare the body for a ‘fight or flight’ response

Question 7

Pancreas

Answer 7

• belly
• produces insulin - used to regulate blood glucose levels

Question 8

Ovaries (female)

Answer 8

-either side of the uterus
- produce oestrogen - involved in the menstrual cycle

Question 9

Testes (male)

Answer 9

• beneath the penis
• produce testosterone - controls puberty and sperm production