4.5.3.1 Human Endocrine System

Question 1

Differences between nervous system and endocrine system:

Answer 1

• nervous system signalling is extremely fast and effects of nervous system are short lived
• endocrine system effects are much slower but act for longer
• nervous system uses electrical impulses carried down neurones but endocrine system controlled by chemicals called hormones that are carried in the blood stream

Question 2

What does the endocrine system consist of?

Answer 2

• composed of glands which secrete hormones (chemicals) directly into the bloodstream
• the blood carries the hormone all around the body
• but each hormones only acts on specific target organs where it produces an effect

Question 3

How are hormones transported in the human endocrine system?

Answer 3

blood transports the hormone to a target organ or tissues where it has an effect

Question 4

Diagram of glands in the endocrine system:

Answer 4

Question 5

Function of pancreas in the endocrine system:

Answer 5

• pancreas releases hormones involved in controlling the concentration of glucose in the blood
• secretes insulin

Question 6

Function of ovaries in the endocrine system:

Answer 6

• release hormones involved in puberty and in reproduction
• secretes oestrogen
• involved in the menstrual cycle and the development of female secondary sexual characteristics (different features that develop during puberty that distinguish a female from a male)

Question 7

Function of testes in the endocrine system:

Answer 7

• secretes testosterone
• involved in the production of sperm and the development of male secondary sexual characteristics

Question 8

Function of thyroid gland in endocrine system:

Answer 8

• produces hormones (thyroxine) involved in growth and in regulating the body’s basal metabolic rate (how rapidly the body’s reactions take place)
• controls heart rate and temperature

Question 9

Function of adrenal gland in endocrine system:

Answer 9

secretes the hormone adrenaline which is produced in times of fear or stress - ‘fight or flight’ response

Question 10

Function of pituitary gland in endocrine system:

Answer 10

• located in the brain
• scientists call the pituitary gland a “master gland” which secretes several hormones into the blood depending on the body conditions
• pituitary hormones act on other glands to stimulate other hormones to be released
• by acting on other glands, the pituitary hormone can trigger a range of different effects in the body