BMAT Biology - Nervous System Review Questions and Answers

Job: nervous system Allows the body to respond rapidly to changes in the environment What is a stimulus? A change in the internal or external environment How is a stimulus is detected? By specialised cells called receptors that are located in sense organs. Stimuli examples (5) Touch, pressure, light, sound, pain, chemicals or changes in position and temperature. What do receptors do? turn energy from stimuli into electrical impulses, which are rapidly transmitted to the central nervous system via neurons What does the CNS comprise of? spinal cord & brain What does the CNS do?(3) coordinate responses, reflexes and actions Motor neurons (2) Many *short* dendrites carry nerve impulses from the CNS to the cell body 1 *long* axon carries nerve impulses from the cell body to effector cells (in muscles or glands). Sensory neurons(2) 1 *long* dendrite carries nerve impulses from receptor cells to the cell body . 1 *short* axon carries nerve impulses from the cell body to relay neurons in the CNS Relay neurons (2) Many *short* dendrites carry nerve impulses from sensory neurons to the cell body Many *short* axons carry nerve impulses from the cell body to motor neurons Neuron diagram Effectors Produces a response e or gland