AdrenalineSpec 14.3.3, 14.3.6
Adrenaline is the hormone secreted by the adrenal glands in ‘fight or flight’ situations. These are moments of danger or stress when the body must get ready to fight or run away.
- Increased breathing rate
- Increased heart rate
- Increased pupil diameter
These changes get more oxygen and glucose to the muscles quickly, and let more light into the eyes so the person can see the danger better.
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanAdrenaline and metabolic activity
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanAdrenaline also controls metabolic activity. It increases the blood glucose concentration and increases heart rate.
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels mean- Adrenaline increases the blood glucose concentration, so more glucose is available to the muscles.
- Adrenaline increases heart rate, so this glucose, and oxygen, reach the muscles more quickly.
- The muscle cells use the glucose in respiration to release energy for movement.
Adrenaline is spelt with an e at the end. Do not write that it ‘gives you energy’. It raises blood glucose so cells can release energy by respiration.
Quick check
Which gland secretes insulin?
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The pancreas.
Name the hormone made by the testes.
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Testosterone.
Which type of control has the longer-lasting effect, nervous or hormonal?
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Hormonal.
Supplement State two ways adrenaline affects the metabolic activity of the body.
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It increases blood glucose concentration and increases heart rate.