Neurons
What is the basic unit of the nervous system?
a neuron/ nerve cell
What is the largest part of the brain?
Cerebrum
What does CNS and PNS stand for?
Central Nervous System, peripheral Nervous system
What is a reflex action?
A rapid, automatic response to a stimulus.
What is the name of the junction between two neurons?
A synapse
What is the function of dendrites?
Dendrites receive impulses/signals from other neurons or receptors.
Which part of the brain is responsible for balance and coordination?
Cerebellum
What is the main function of the spinal cord?
The spinal cord carries information between the brain and the rest of the body and is also involved in reflex actions.
What type of neuron carries information from a receptor to the CNS?
Sensory neuron
What chemical is released at a synapse to transmit a signal to the next neuron?
A neurotransmitter
What is the function of the axon?
The axon carries nerve impulses away from the cell body towards the axon terminals.
Which part of the brain controls breathing and heart rate?
Medulla Oblongata
Explain the difference between the CNS and PNS.
CNS: brain and spinal cord.
PNS: nerves outside the brain and spinal cord that connect the CNS with the rest of the body.
A person touches a hot object. Which structure detects the change in temperature?
A receptor in the skin
What is the difference between a nerve and a neuron?
A neuron is an individual nerve cell, whereas a nerve is a bundle of nerve fibres/axons.
What is the function of the myelin sheath?
The myelin sheath insulates the axon and increases the speed of nerve impulse transmission.
Which part of the brain is responsible for interpreting sensory information and producing voluntary responses?
The cerebrum
What is the difference between the grey matter and white matter of the spinal cord?
Grey matter contains mainly cell bodies and synapses, while white matter contains mainly myelinated nerve fibres/axons.
Why does a reflex arc involve the spinal cord rather than requiring the brain to initiate the response?
The spinal cord can process the information and produce a rapid response without waiting for the brain to initiate the movement, reducing reaction time.
Why is communication between neurons described as being unidirectional at a synapse?
The signal passes from the presynaptic neuron to the postsynaptic neuron; neurotransmitters are released from the axon terminal and detected by receptors on the next cell.
Explain how the structure of a neuron allows it to transmit impulses efficiently. (At least 4 points)
What is meningitis?
Swelling of the meninges
Explain how information travels between the brain and the rest of the body through the spinal cord.
The spinal cord acts as a major communication pathway between the brain and the peripheral nervous system. Sensory information travels towards the CNS, while motor information travels from the CNS towards effectors.
A student touches a hot surface and withdraws their hand before consciously experiencing the pain. Explain the steps on how this is possible.
The heat acts as a stimulus, detected by receptors in the skin. An impulse travels along a sensory neuron to the spinal cord, where it passes to a motor neuron. The motor neuron carries the impulse to a muscle (effector), causing the hand to withdraw. The brain receives information about the stimulus at the same time, allowing the person to become consciously aware of the pain.
A drug blocks neurotransmitter receptors at a synapse. Predict what effect this would have on the transmission of a nerve impulse.
The neurotransmitter would be unable to bind effectively to receptors on the next cell, so transmission of the signal across the synapse would be reduced or prevented.