Topic 5- Homeostasis & Response

• What is Homeostasis?

  The body's ability to maintain a stable internal environment despite external conditions changing.
• What types of things does Homeostasis do?

  Maintains body temperature, blood glucose levels and water content
• What is a stimulus?

  A change in the environment.
• What are receptors? Give an example of types of receptors:

  They are cells that detect a stimulus.

  Taste receptors on the tongue and sound receptors in the ears.
• What does the coordination centre do? Give examples of coordination centres in the body:

  receives information from receptor cells, processes it and then organises a response.

  the spinal cord, brain, or a gland
• What does an effector do? Give examples of what happens:

  An effector carries out a response or action in response to a stimulus and restores the optimum condition.

  Muscles contracting, glands releasing a hormone
• what does the nervous system do?

  it detects and reacts to a stimulus
• what is the central nervous system (CNS)?


  the part of the nervous system that includes the brain and spinal cord- it is only in vertebrates.
• what are sensory neurons? how do they carry information?

  Neurons that transmit sensory information from the receptors to the CNS.

  they carry information as electrical impulses.
• what are motor neurons?

  Neurons that control muscle movement and carry electrical impulses from the CNS to effectors.
• what is the flow of the reflex arc?

  stimulus, receptors, sensory neurons, coordinator, motor neurons, effector, response
• what is a synapse? how does it work?

  A synapse is the connection between two neurons.

  An electrical signal is transferred by chemicals which diffuse across the gap
• What are reflexes for?

  To help prevent injury.
• What are reflexes?

  Automatic and rapid responses to stimuli, they don't involve the conscious part of the brain.
• Give an example of a reflex:

  When a bright light is shone in the eyes, the pupils will get smaller to stop the eyes from getting damaged.
• What is the practical that measures the time it takes for the body to respond to a stimulus?

  Reaction time experiment- ruler drop test.
• How can you speed up a person's reaction time?

  Give them caffeine
• What is another way to measure reaction time?

  By using a computer and having the user press a key when there is a change in stimulus.
• What is the endocrine system?

  A system of glands that produce and secrete hormones into the bloodstream to regulate various bodily functions.
• What is the pituitary gland and where is it found?

  The pituitary gland is a gland that produces many hormones located at the base of the brain.
• What does the adrenal gland do and where is it found?

  The adrenal gland produces adrenaline hormones and is located on top of the kidneys.
• What does the thyroid gland do and where is it found?

  The thyroid gland produces hormones that regulate metabolism, heart rate and temperature and is located in the neck.
• What hormones does the ovaries produce?

  Oestrogen which is involved in the menstrual cycle.
• Which hormone does the pancreas produce and what does it do?

  Produces insulin which regulates the blood glucose levels.
• What do the testes produces and what does it control?


  They produce testosterone and it controls puberty and sperm production.
• How nerves carry messages:

  Very fast, act for a short time in a precise area.
• How hormones carry messages:

  Slow, act for a long time in more wider range in the body.
• What is hormone is added if the blood glucose level is too high?

  Insulin.
• What hormone is added if the blood glucose level is too low?

  Glucagon.
• What is type 1 diabetes? Treatment?

  Where little or no insulin is made.

  Insulin injections, changing diet and more exercise.
• What is type 2 diabetes? Treatment? Cause?

  Where the body becomes resistant to the insulin produced.

  Changing diet, regular, exercise.

  Being overweight.
• What happens in the 4 stages of the menstrual cycle?

  Menstruation starts, the uterus lining builds up, egg developed and is released, wall is maintained.
• What does FSH stand for?

  Follicle-stimulating hormone
• What is the purpose of the FSH? Where is it produced?

  Causes the egg to mature in the ovaries and stimulates the ovaries to produce oestrogen.

  In the pituitary gland.
• What does oestrogen do and where is it produced?

  It causes the uterus lining to grow and stimulates the release of LH.

  Produced in the ovaries.
• What doe LH stand for?

  Luteinizing Hormone
• What is the function of LH and where is it produced?

  Stimulates the release of an egg.

  Produced in the pituitary gland.
• What is the function of progesterone and where is it produced?

  Maintains the lining of the uterus in 2nd half of the cycle.

  Produced in the ovaries after ovulation.
• What hormones can be taken in a pill (contraceptive)?

  Oestrogen and progesterone
• What other ways are there to avoid pregnancy?

  Sterilisation(cutting of fallopian tubes/sperm ducts), natural methods, abstinence