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Ch. 15 Sensory Pathways and the Somatic Nervous System
Martini - Fundamentals of Anatomy & Physiology 11th Edition
Martini, Nath, Bartholomew11th EditionFundamentals of Anatomy & PhysiologyISBN: 9780136874089Not the one you use?Change textbook
Chapter 15, Problem 1

The larger the receptive field, the
(a) Larger the stimulus needed to stimulate a sensory receptor
(b) Fewer sensory receptors there are
(c) Harder it is to locate the exact point of stimulation
(d) Larger the area of the somatosensory cortex in the brain that deals with the area
(e) Closer together the receptor cells

Verified step by step guidance
1
Understand what a receptive field is: it is the specific physical area where a sensory receptor can detect stimuli.
Recognize that a larger receptive field means that one receptor covers a bigger area of the body surface or sensory space.
Consider how the size of the receptive field affects stimulus detection: a larger field means the receptor integrates signals over a wider area, so a stronger or larger stimulus is generally needed to activate it.
Think about spatial resolution: with larger receptive fields, it becomes more difficult to pinpoint the exact location of a stimulus because multiple points within the field activate the same receptor.
Relate the size of receptive fields to the density of receptors and cortical representation: larger receptive fields usually correspond to fewer receptors in that area and less cortical area dedicated to processing that input.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Receptive Field Size

A receptive field is the specific area where a sensory receptor can detect stimuli. Larger receptive fields cover more surface area, meaning a stimulus must be bigger to activate the receptor. This affects how precisely the location of a stimulus can be identified.
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Spatial Resolution and Localization

Spatial resolution refers to the ability to distinguish two separate stimuli close together. Smaller receptive fields allow for better localization of stimuli, while larger receptive fields reduce this precision, making it harder to pinpoint the exact stimulus location.
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Somatosensory Cortex Representation

The somatosensory cortex processes sensory information from the body, with the size of its cortical area related to the density of receptors and the precision needed. Areas with smaller receptive fields and higher receptor density have larger cortical representation.
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