The Nervous system

-A complex network that transmits nerve impulses between different parts of the body

-They receive stimuli from: The body + the environment -These stimuli are turned into impulses to the brain and spinal cord

-Located in the skull -Part of the central nervous system -Sends messages to the whole body

-Runs from the brain through the vertebral column -A bundle of nervous tissue

-An enclosed bundle of nerve cells (Neurons) -They work together to carry impulses throughout the body -They make up the peripheral nervous system

-Carry impulses from the central nervous system to muscles -They send messages to muscles and tell them to contract

-Carry impulses from sense organs to the central nervous system

-The cells responsible for receiving sensory input from the external world -They send motor commands to muscles -They relay electrical signals

-Dendrites -Call bodies (Soma) -Axon

-A long, tail-like structure -Joins the cell body at the axon hillock -Insulated with a fatty substance (Myelin) -Myelin helps to conduct electrical signals

-Where a neuron receives inputs from other cells

-The neurons core -Carry genetic info -Maintain the neuron’s structure -Provides energy to drive activities

-Axon endings that are enlarged and club-shaped - They make synaptic connections with other nerve cells

-Microscopic gaps that separate the terminal buttons of one neuron from the receptors of another -Located on the dendrites

-An insulating layer that forms around nerves -Found in the brain and spinal cord -Allows electrical pulses to transmit quickly and effectively along nerve cells -If damaged, these impulses slow down

• Period gaps in the myelin sheath -On the axon of neurons that facilitate the rapid conduction of nerve impulses

-Blood flow to the brain is stopped -Brain cells begin to die within minutes without oxygen -Parts of the brain stop working

-Drugs like cocaine and heroin change the way that nerves in the brain pass messages to each other -They damage the nerves in the brain responsible for: Memory and learning -They can cause permanent brain damage

-Can easily fool someone to believe they are smarter or good fun to be with -Makes it harder to judge your own behaviour