By the end of this module you should know / be able to:
• Explain the roles of thyroxine and adrenaline in the body
• Adrenaline is produced by the adrenal glands in times of
fear or stress. It increases the heart rate and boosts the
delivery of oxygen and glucose to the brain and
muscles, preparing the body for ‘fight or flight’.
• Thyroxine from the thyroid gland stimulates the basal
metabolic rate. It plays an important role in growth and
development.
NEGATIVE FEEDBACK:
Maintaining a steady state.
If a factor in the internal environment
increases, changes take place to
reduce it and restore it to the original
level.
If a factor in the internal environment
decreases … a change takes place to
increase it and restore it to the orginal level
THYROXINE
Underline or highlight the key points from the information below, based on the
phrasing of the specification:
• The thyroid gland uses iodine from your diet to produce thyroxine
• Thyroxine stimulates the basal metabolic rate of
your body (rate of all your chemical reactions and
oxygen use in respiration)
• Thyroxine plays an important role in growth and
development in children
• In adults, the level of thyroxine should remain
stable due to negative feedback mechanisms
Extension: What happens if you don’t get enough iodine in your diet
(can be a problem in third world countries)?
• Explain the roles of thyroxine and adrenaline in the body
• Adrenaline is produced by the adrenal glands in times of
fear or stress. It increases the heart rate and boosts the
delivery of oxygen and glucose to the brain and
muscles, preparing the body for ‘fight or flight’.
• Thyroxine from the thyroid gland stimulates the basal
metabolic rate. It plays an important role in growth and
development.
NEGATIVE FEEDBACK:
Maintaining a steady state.
If a factor in the internal environment
increases, changes take place to
reduce it and restore it to the original
level.
If a factor in the internal environment
decreases … a change takes place to
increase it and restore it to the orginal level
THYROXINE
Underline or highlight the key points from the information below, based on the
phrasing of the specification:
• The thyroid gland uses iodine from your diet to produce thyroxine
• Thyroxine stimulates the basal metabolic rate of
your body (rate of all your chemical reactions and
oxygen use in respiration)
• Thyroxine plays an important role in growth and
development in children
• In adults, the level of thyroxine should remain
stable due to negative feedback mechanisms
Extension: What happens if you don’t get enough iodine in your diet
(can be a problem in third world countries)?
