the cns, neurons, synaptic transmission

• central nervous system = the brain + spinal cord
• the CNS is the central processing and control point for all human behaviour
• the cells in the CNS are known as neurons
• the cell body of the neuron contains the nucleus which houses the genetic material
• the cell body contains mitochondria which provide energy for the neuron
• dendrites receive messages from other neurons
• the axon hillock attaches the axon to cell body
• around the outside of the axon are layers of fatty deposits called myelin sheath that provide an insulating layer to the axon and help to speed up the rate of message transmission
• nodes of ranvier are breaks between the cells along the myelin sheath
• nodes of ranvier are breaks between the cells along the myelin sheath
• at the end of the axon are axon terminals, and at the ends of these are terminal buttons. this is at the end of the neuron where the electrical impulse becomes chemical message to be passed on to other neurons.
• action potential is the electrical trigger that passes along the axon and stimulates the neuron to activate and release neurotransmitters as a result of synaptic transmission
• the neuron sending the message is the presynaptic neuron
• the neuron receiving the message is the post synaptic neuron
• when the electrical message reaches the axon terminal, the neuron can pass on its chemical message to further neurons across the synaptic cleft
• each neuron is responsible for producing its own kind of chemical or neurotransmitter
• receptors on the post synaptic neuron are designed to bind to a specific neurotransmitter, and when they detect it the neurotransmitter molecule will then be absorbed by the postsynaptic neuron
• any neurotransmitter molecules that have not been absorbed by the receptors of the postsynaptic neuron will be destroyed by enzymes in the synaptic cleft or will be absorbed again by the presynaptic neuron in a process known as reuptake
• reuptake is where the molecules are reabsorbed by the presynaptic neuron and will be destroyed by enzymes
• acetylcholine


  stimulates muscle contractions and has a key function in motor control and movement. it is necessary for memory and other cognitive functions such as attention and alertness
• acetylcholine = stimulates muscle contractions and has a key function in motor control and movement. it is necessary for memory and other cognitive functions such as attention and alertness
• noradrenaline


  associated with emotion particularly with mood control. involved in functions like sleeping, dreaming and learning
• noradrenaline =associated with emotion particularly with mood control. involved in functions like sleeping, dreaming and learning
• dopamine

  chemical precursor to noradrenaline. related to emotion and cognitive functions as well as posture and control of movement and has also been associated with reinforcement in learning as well as dependency such as addictions
• dopamine = chemical precursor to noradrenaline. related to emotion and cognitive functions as well as posture and control of movement and has also been associated with reinforcement in learning as well as dependency such as addictions
• serotonin

  associated with mood control particularly in the limbic system and is also involved in functions like feeling pain, sleep, regulating body temperature and hunger
• serotonin = associated with mood control particularly in the limbic system and is also involved in functions like feeling pain, sleep, regulating body temperature and hunger
• limbic system

  a set of structures in the brain associated with mood, drives and emotion
• limbic system = a set of structures in the brain associated with mood, drives and emotion