Biopsychology - 3) Neurons and Synaptic Transmission Flashcards
What do dendrites do?
Receive messages from other cells
What is the cell body?
The cells life-support centre
What does the axon do?
Passes messages away from the cell body to other neurons, muscles or glands
What is the neural impulse?
The electrical signal travelling down the axon
What does the myelin sheath do?
Covers the axon of some neurons and helps speed neural impulses
What do the terminal branches of axon form?
Junctions with other cells
What do sensory neurons do?
Carry nerve impulses from sensory receptors to the CNS
Structure of sensory neurons
Long dendrites and short axons
What do relay neurons do?
Carry information across spinal chord or the brain from sensory neurons to motor neurons
Structure of relay neurons
Short dendrites and short axons
What are motor neurons responsible for?
Directly or indirectly controlling muscles
What do the motor neurons do?
Carry impulses from CNS to effector
Structure of motor neurons
Short dendrites and long axons
What do neurotransmitters allow?
The transfer of signalling messages between brain cells
Where are neurotransmitters located?
In a part of the neuron called the axon terminal
Where are neurotransmitters stored?
Within thin-walled sacs called synaptic vesicles
What are neurotransmitters?
Molecules used by the nervous system to transmit messages between neurons or from neurons to muscles
What happens in the synaptic cleft?
Communication between two neurons
What are the two main neurotransmitters?
Serotonin and dopamine
What are low levels of serotonin associated with?
Depression
What can high levels of dopamine be found within people with?
Schizophrenia
What is synaptic transmission?
The process by which one neuron communicates with another
What results in not enough binding of neurotransmitters?
Too few or too many receptors
What results in the brain being flooded with that neurotransmitter?
Enzymes being transported away either too much or too little
What is excitation?
A neuron which increase likelihood that an excitatory signal is sent to the post-synaptic cell, making it more likely that the signal will ‘fire’
What is inhibition?
A neuron which decreases likelihood of a neuron ‘firing’
What is summation?
The sum total of excitatory and inhibitory neurotransmitters that bind to the receptor
