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Topic 1 - Neural Organisation - Coggle Diagram
Topic 1 - Neural Organisation
Neural Transmission
Presynaptic neuron
Neuron before the synapse
Postsynaptic neuron
Neuron after the synapse
Synapse
Where two neurons meet
Neurotransmitters
Chemical messengers that transport an action potential across the synapse, a nerve impulse is an electro chemical signal
Transmission across the synapse
Action potential arrives at the axon terminal of the presynaptic neuron
Vesicles located in the axon terminal release neurotransmitters into the synapse
Neurotransmitters diffuse across the synapse and bind to receptors on the dendrites of the synaptic neuron
An action potential is established in the post synaptic neuron
Central Nervous System (CNS)
Consists of the brain and spinal cord
Spinal cord
Connects the brain to the PNS
Transmits messages from sensory receptors in the PNS to the brain
Transmits motor messages from the brain via the PNS activating muscles or glands
Contains interneurons that transmit messages from sensory neurons to motor neurons
Peripheral Nervous System (PNS)
Sensory neurons transmit messages to CNS
Motor neurons transmit messages away from CNS
Neurons are nerve cells
Nerves connect to the CNS
Somatic nervous system
Messages from motor neurons activate voluntary skeletal muscles for conscious responses to the external environment
Messages from sensory neurons convey information to the CNS
Autonomic nervous system
Contains motor neurons that activate involuntary responses via involuntary effectors (heart rate, digestive tract, secretions from glands)
Sympathetic nervous system
Produces the involuntary/automatic fight or flight stress response to external stimuli
Increased heart and breathing rate, increased blood glucose levels, dilated pupils
Stimulates secretion of the hormone adrenalin into the blood stream which strengthens the fight or flight response
Parasympathetic nervous system
Decreases/returns heart rate and breathing rate to normal levels
Dampens the stress response returning the body to the rest and digest state
Neurons
Nerve cells that conduct electrochemical impulses called action potentials
Structures
Axon terminal
Axon endings containing vesicles that house neurotransmitters
Dendrites
Receives nerve impulses from other neurons and transmits them to the cell body
Axon
Transmits nerve impulses away from the cell body towards effectors (muscles or glands)
Myelin sheath
Fatty covering of the axon that Protect and Insulates the axon, and Speeds up action potential transmission
Cell body
Contains nucleus and other organelles
Types
Motor neurons
Transmit nerve impulses from the CNS to effectors (muscles or glands)
Interneurons
Located in the CNS, transmit nerve impulses from sensory to motor neurons
Sensory neurons
Transmit nerve impulses from receptors to the CNS