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Chapter 11 Sensory Physiology - Anatomy & Physiology

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Termini in questo insieme (23)

  • Define transduce

    Transduce means to convert one form of energy into another, such as converting a sensory stimulus into an electrical signal in a neuron.

  • What initiates membrane potential change in sensory receptors?

    A sensory stimulus initiates a change in membrane potential by activating receptor proteins that open ion channels.

  • What is a modality in sensory physiology?

    A modality is the type or form of a stimulus, such as touch, temperature, or pain.

  • What are the two types of neural receptors? Are they myelinated?

    The two types are myelinated and unmyelinated receptors; myelinated receptors conduct signals faster.

  • What type of information do nonneural receptors receive?

    Nonneural receptors receive chemical or physical stimuli and generate receptor potentials without generating action potentials themselves.

  • Define adequate stimulus

    The adequate stimulus is the specific type of stimulus a receptor is most sensitive to and can detect effectively.

  • Define threshold in sensory receptors

    Threshold is the minimum stimulus intensity required to generate a receptor potential that triggers an action potential.

  • Define receptor potential

    A receptor potential is a graded change in membrane potential in a sensory receptor in response to a stimulus.

  • Define receptive field

    The receptive field is the specific area or region where a sensory neuron detects stimuli.

  • What are the four major groups of sensory receptors?

    They are mechanoreceptors, thermoreceptors, nociceptors, and chemoreceptors.

  • What does 'receptive field size determines sensitivity' mean?

    Smaller receptive fields allow for greater sensitivity and better spatial resolution of stimuli.

  • How does sensory information travel to the brain?

    Via ascending pathways in the spinal cord or through cranial nerves directly to the brain.

  • What are perceptual thresholds and habituation?

    Perceptual threshold is the minimum stimulus intensity perceived consciously; habituation is decreased perception after repeated stimuli.

  • How do neurons determine sensory modality?

    Neurons determine modality by the type of receptor activated and the specific brain region where they terminate.

  • How does lateral inhibition help distinguish stimuli?

    Lateral inhibition enhances contrast by inhibiting neighboring neurons, sharpening stimulus location via primary, secondary, and tertiary neurons.

  • How is stimulus intensity coded by receptors?

    Intensity is coded by the number of receptors activated and the frequency of action potentials generated.

  • How do moderate and longer stimuli affect action potentials and neurotransmitter release?

    Stronger or longer stimuli increase action potential frequency and neurotransmitter release amplitude.

  • Explain tonic and phasic receptor adaptation

    Tonic receptors adapt slowly and respond continuously; phasic receptors adapt quickly and respond mainly to changes.

  • Trace the somatic sensation pathway to the somatosensory cortex

    Signals travel from receptor → primary neuron → secondary neuron in spinal cord/brainstem → tertiary neuron in thalamus → somatosensory cortex.

  • What are nociceptors and where are they located?

    Nociceptors detect pain stimuli and are located in skin, muscles, joints, and some internal organs.

  • How do fast and slow pain differ?

    Fast pain is sharp and carried by myelinated fibers; slow pain is dull and carried by unmyelinated fibers.

  • Examples of stimuli for mechanical, thermal, and chemical receptors

    Mechanical: pressure or stretch; Thermal: temperature changes; Chemical: pH or irritants.

  • What is referred pain?

    Referred pain is pain perceived at a location different from the stimulus origin, often due to shared neural pathways.