2. When touching the surface of a flask with water, thetemperature of which is +40oC, with the bundles of fingers, aperson first feels the smooth surface of the flask, and only then- heat. Explain the reasons for such a sequence of the formationof sensations. Name which pathways transmit information fromthe tactile, thermal receptors of the skin of the bundle of fingersto the sensory area of the cortex.

Answered: 2. When touching the surface of a flask…

Human Anatomy & Physiology (11th Edition)

11th Edition

ISBN:9780134580999

Author:Elaine N. Marieb, Katja N. Hoehn

Publisher:Elaine N. Marieb, Katja N. Hoehn

Chapter1: The Human Body: An Orientation

Section: Chapter Questions

Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...

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Related questions

Question

2. When touching the surface of a flask with water, the
temperature of which is +40oC, with the bundles of fingers, a
person first feels the smooth surface of the flask, and only then
- heat. Explain the reasons for such a sequence of the formation
of sensations. Name which pathways transmit information from
the tactile, thermal receptors of the skin of the bundle of fingers
to the sensory area of the cortex.

Expert Solution

Step 1: Reason for such sequence of sensations:

Touch sensations are carried by A group of nerve fibres, i.e. A- beta nerve fibres, which are myelinated. Myelin acts as electric insulator and thus speeds up the conduction of the action potential upto velocity of 150m/s, whereas, heat sensations are carried by C-group of nerve fibres which are unmyelinated and so they have a low conduction velocity upto a maximum of 10m/s. Therefore, touch sensations are always felt early compared to heat sensations.