Revise: Control and communicationStructure of the brain
Communication between cells in a multicellular organism occurs by use of nerve impulses or hormones. The central nervous system produces electrical impulses for rapid response.
The cerebrumThe large folded part of the brain that controls conscious responses, memory, thought and intelligence is the large folded area of the brain and is responsible for conscious thoughts, reasoning, memory and emotions.
The cerebellumThe part of the brain that controls balance and co-ordination is found at the rear of the brain below the cerebrum and controls balance and coordinated movement.
The medullaThe part of the brain controlling breathing, heart rate and peristalsis. is found at the top of the spinal cord and contains groups of neurons that transmit electrical impulses to the heart and lungs to control heart rate, breathing rate and peristalsis.
Reflexes
A reflex action is a rapid automatic response to a stimulus (anything an organism can detect). Reflex actions are involuntary and do not necessarily involve the brain.
Reflex actions protect the body from further damage by allowing it to react quickly to stimuli, such as high temperatures, that may be harmful.
Reflex actions are quick because there is a direct link in the spinal cord called an inter neuron (between the sensory neuron and a motor neuron) that causes a muscle to make the protective response.
The circuit of the neurons that act to produce the reflex action is called the reflex arcThe pathway of information from a sensory neuron through an inter neuron to a motor neuron..