Biopsychology
Neurons and synaptic transmission
Key assumptions of biopsychologists
Biopsychologists assume that behaviour and experiences are caused by activity in the
nervous system
The nervous system transmits signals for communication via the billions of nerve cells
(neurons) it houses
These nerve cells communicate with each other, through electrical and chemical messages,
within the body and the brain.
Neurons
Cells that conduct nerve impulses are called neurons
Key Features of a neuron:
Nucleus, the control centre of a cell, which contains the cell's chromosomal DNA
Dendrite, Receives the nerve impulse or signal from adjacent neurons
Axon, Where the electrical signals pass along.
Myelin sheath, Insulates /protects the axon from external influences that might effect the
transmission of the nerve impulse down the axon.
Nodes of ranvier, these speed up the transmission of the impulse by forcing it to ‘jump’
Terminal buttons, Terminal buttons send signals to an adjacent cell.
Different types of neurons
The knee-jerk reflex
In a reflex arc, like the knee-jerk reflex, a stimulus, such as a hammer hitting the knee, is detected by
sense organs in the peripheral nervous system, which conveys a message along a sensory neuron.
The message reaches the central nervous system where it connects with a relay neuron. This then
transfers the message to a motor neuron. This then carries the message to an effector such as a
muscle, which causes the muscle to contract and, hence, the knee to move or jerk.
Neurons and synaptic transmission
Key assumptions of biopsychologists
Biopsychologists assume that behaviour and experiences are caused by activity in the
nervous system
The nervous system transmits signals for communication via the billions of nerve cells
(neurons) it houses
These nerve cells communicate with each other, through electrical and chemical messages,
within the body and the brain.
Neurons
Cells that conduct nerve impulses are called neurons
Key Features of a neuron:
Nucleus, the control centre of a cell, which contains the cell's chromosomal DNA
Dendrite, Receives the nerve impulse or signal from adjacent neurons
Axon, Where the electrical signals pass along.
Myelin sheath, Insulates /protects the axon from external influences that might effect the
transmission of the nerve impulse down the axon.
Nodes of ranvier, these speed up the transmission of the impulse by forcing it to ‘jump’
Terminal buttons, Terminal buttons send signals to an adjacent cell.
Different types of neurons
The knee-jerk reflex
In a reflex arc, like the knee-jerk reflex, a stimulus, such as a hammer hitting the knee, is detected by
sense organs in the peripheral nervous system, which conveys a message along a sensory neuron.
The message reaches the central nervous system where it connects with a relay neuron. This then
transfers the message to a motor neuron. This then carries the message to an effector such as a
muscle, which causes the muscle to contract and, hence, the knee to move or jerk.
