Endocrine system and Fight or Flight response

function of the pituitary gland

‘master gland’, situated at the base of the brain

function of the thyroid gland

produces thyroxine

function of the pancreas

produces insulin

function of the adrenal glands

produces adrenaline

function of the testes

produces testosterone

function of the ovaries

produces oestrogen

function of the pineal gland

produces melatonin

function of the fight or flight response

allows us to act quickly to escape life-threatening situations

The process of the fight or flight response

1. Threat processed by hypothalamus

2. activation of sympathetic branch of ANS

3. nerve message to adrenal gland

4. adrenaline released into bloodstream

5. fight or flight response

   → when threat ceases, parasympathetic branch of ANS returns body back to normal

Effects of adrenaline

• Increase in heart rate to supply blood to the muscle cells at a faster rate

• more blood means more oxygen and glucose available for muscle cells → increases the rate of aerobic respiration

• more energy is provided to deal with the situation

  → increases impulses travelling along sympathetic neurons → quickening heart rate

  → blood vessels to less important organs (e.g. digestive system and skin) constrict so that more blood can be diverted to organs used in fight or flight response

Fight or flight response effects

• increased heart rate

• dry mouth

• increased sweating

• dilated pupils

• increased breathing rate