Sensory Systems PN1002 Exam Questions and Answers Already Passed Latest Update 2025-
2026
What is an action potential? - Answers Rapid increase in positive charge in a nerve fibre (axon)
that travels down the fibre (nerve impulse/spike)
What is bottom-up processing? - Answers perceiving information through the senses
(stimulation of receptors), rather than using prior knowledge. Data based processing.
What is top-down processing - Answers uses existing knowledge to interpret new information.
Afferent vs Efferent neurons - Answers Afferent- carry action potentials towards CNS
Efferent- neurons that carry action potentials away from CNS to effectors (muscles)
What is the homunculus - Answers a map of the body in the brain
What is a neuron? - Answers One of two cell types in the nervous system (also glial cells).
Responsible for processing sensory, motor, cognitive, and affective information
What is the receptive field of a neuron? - Answers the area on the receptor surface (e.g., the
retina for vision or the skin for touch) that, when stimulated, affects the activity of that neuron.
The blind men and the elephant - Answers Each was partly right but all were in the wrong. We
perceive things differently.
What does a transducer do? - Answers Converts a signal in one form of energy to another
Action potentials - Answers look basically the same in all neurons. Begins at axon hillock and
travels along axon to axon terminal near synapse.
anterior vs posterior - Answers front vs back
what is the cerebral cortex? - Answers Outer layer of cerebrum and is responsible for higher-
level functions like language, memory, and thought. It is divided into two hemispheres, each
containing four major lobes
What is the CNS? - Answers brain and spinal cord.
what is the peripheral nervous system? - Answers nerves outside CNS. Contains autonomic and
somatic nervous system.
Autonomic nervous system - Answers interaction with internal environment. Sympathetic and
parasympathetic nervous system.
, Somatic nervous system - Answers interaction with external environment. 12 pairs of cranial
nerves and 31 pairs of spinal nerves.
brain development - Answers CNS begins as a hollow neural tube. Head part expands to form
three primary brain vesicles which then grow and separate into further parts
Four lobes of the cerebral cortex - Answers frontal, parietal, occipital, temporal
grey vs white matter - Answers grey surrounds hollow central cavity whilst white is exterior to
grey matter.
Grey- contains primarily neuronal cell bodies.
white- contains millions of melinated axons
What is the reticular theory? - Answers proposed that the nervous system single interlinking
network
What is the neuron doctrine? - Answers proposed that the nervous system is composed of
discrete, individual cells called neurons
How is neuronal activity generated? - Answers by action potentials which are triggered by
changes in membrane potential caused by flow of ions across the cell membrane
concentration gradients of the membrane - Answers 3 sodium ions pumped out and 2
potassium ions pumped in. Inside of the cell is more negative (resting potential).
why does the action potential happen? - Answers Opening of voltage-gated ion channels leads
to a short-lived reversal of relative membrane permeability
myelination - Answers increases the speed of action potentials
how do neurons communicate with each other? - Answers synaptic transmission.
Steps:
Action Potential arrival
Neurotransmitter release
Neurotransmitter binding
post-synaptic potential
signal termination
What do some tastants contain? - Answers small, charged particles that directly change the
membrane potential of the receptor cells
2026
What is an action potential? - Answers Rapid increase in positive charge in a nerve fibre (axon)
that travels down the fibre (nerve impulse/spike)
What is bottom-up processing? - Answers perceiving information through the senses
(stimulation of receptors), rather than using prior knowledge. Data based processing.
What is top-down processing - Answers uses existing knowledge to interpret new information.
Afferent vs Efferent neurons - Answers Afferent- carry action potentials towards CNS
Efferent- neurons that carry action potentials away from CNS to effectors (muscles)
What is the homunculus - Answers a map of the body in the brain
What is a neuron? - Answers One of two cell types in the nervous system (also glial cells).
Responsible for processing sensory, motor, cognitive, and affective information
What is the receptive field of a neuron? - Answers the area on the receptor surface (e.g., the
retina for vision or the skin for touch) that, when stimulated, affects the activity of that neuron.
The blind men and the elephant - Answers Each was partly right but all were in the wrong. We
perceive things differently.
What does a transducer do? - Answers Converts a signal in one form of energy to another
Action potentials - Answers look basically the same in all neurons. Begins at axon hillock and
travels along axon to axon terminal near synapse.
anterior vs posterior - Answers front vs back
what is the cerebral cortex? - Answers Outer layer of cerebrum and is responsible for higher-
level functions like language, memory, and thought. It is divided into two hemispheres, each
containing four major lobes
What is the CNS? - Answers brain and spinal cord.
what is the peripheral nervous system? - Answers nerves outside CNS. Contains autonomic and
somatic nervous system.
Autonomic nervous system - Answers interaction with internal environment. Sympathetic and
parasympathetic nervous system.
, Somatic nervous system - Answers interaction with external environment. 12 pairs of cranial
nerves and 31 pairs of spinal nerves.
brain development - Answers CNS begins as a hollow neural tube. Head part expands to form
three primary brain vesicles which then grow and separate into further parts
Four lobes of the cerebral cortex - Answers frontal, parietal, occipital, temporal
grey vs white matter - Answers grey surrounds hollow central cavity whilst white is exterior to
grey matter.
Grey- contains primarily neuronal cell bodies.
white- contains millions of melinated axons
What is the reticular theory? - Answers proposed that the nervous system single interlinking
network
What is the neuron doctrine? - Answers proposed that the nervous system is composed of
discrete, individual cells called neurons
How is neuronal activity generated? - Answers by action potentials which are triggered by
changes in membrane potential caused by flow of ions across the cell membrane
concentration gradients of the membrane - Answers 3 sodium ions pumped out and 2
potassium ions pumped in. Inside of the cell is more negative (resting potential).
why does the action potential happen? - Answers Opening of voltage-gated ion channels leads
to a short-lived reversal of relative membrane permeability
myelination - Answers increases the speed of action potentials
how do neurons communicate with each other? - Answers synaptic transmission.
Steps:
Action Potential arrival
Neurotransmitter release
Neurotransmitter binding
post-synaptic potential
signal termination
What do some tastants contain? - Answers small, charged particles that directly change the
membrane potential of the receptor cells
