Nervous and hormonal coordinationSpec 8.13
In short
Coordination in animals uses two systems. The nervous system sends rapid electrical impulses along neurones to specific effectors, giving short-lived responses. The endocrine system releases hormones into the blood, which act more slowly on target cells and last longer. The hypothalamus links the two systems.
Coordination means that different parts of an animal work together in response to stimuli. It is brought about by the nervous system and by hormones released by the endocrine system. The two work together: the hypothalamus is part of the brain but controls the pituitary gland.
| Feature | Nervous control | Hormonal control |
|---|---|---|
| Signal | Electrical impulses (action potentials) and neurotransmitters | Chemicals (hormones) |
| Transmitted by | Neurones | Blood (plasma) |
| Speed | Very fast (milliseconds) | Slower (seconds to hours) |
| Target | Specific effectors, usually one muscle or gland | Target cells with the complementary receptors, which may be widely spread |
| Duration | Short-lived, stops when the stimulus stops | Longer-lasting, because the hormone remains in the blood |
| Example | Withdrawal of a hand from a hot object | Adrenaline released from the adrenal glands |
Many responses use both. In the ‘fight or flight’ response, nervous impulses from the hypothalamus stimulate the adrenal glands to release adrenaline. The nervous system gives a very fast response, and adrenaline then prolongs and widens it by raising heart rate, ventilation and blood glucose. The hypothalamus also detects changes in the blood and controls the pituitary gland, which secretes hormones that control other endocrine glands.
In compare questions use matching features: ‘nerves are fast, hormones are slower’ and ‘nervous effects are short-lived, hormonal effects longer-lasting’. Give a statement for both sides.
Written and checked against the Edexcel International A Level Biology (YBI11) specification · Updated October 2026