Hormones While coordination by the nervous system produces an immediate response, a different kind of coordination is brought about by the endocrine system. This system depends on chemicals called hormones, which are released from special glands called endocrine glands, into the bloodstream. The hormones circulate round the body in the blood and eventually reach certain organs called target organs. Hormones speed up or slow down or alter the activity of those organs in some way. …showed first 75 words of 589 total…

…showed last 75 words of 589 total…of glycogen to glucose Glucose available in blood for energy production No sensation Fat depots Conversion of fats to fatty acids Fatty acids available in blood, for muscle contraction No sensation All these effects make us more able to react quickly and vigorously in dangerous situations that might require us to run away or put up a struggle. However in some situations where physical activity is not required, adrenaline makes us feel tense or anxious.