By Billy Hammond (Copyright AELS)

December 29, 2020

The skin is invested with three kinds of temperature receptors: cold receptors, heat receptors and pain receptors. There are three to ten times more cold receptors than heat receptors in various spots, so your perception of cold is far more likely to be more rapid and stronger than your perception of heat. The pain receptors only kick in when there are temperature extremes, so they’re active in cases of “freezing cold” or “burning heat.”

When the free nerve ending temperature receptors perceive cold or heat, they send it to the brain via one of two pathways: the neospinalthalamic tract (fast pain) or the paleothalamic spinal tract (slow pain). Most cold receptors transmit their signals through the fast pain pathway through Aδ nerve fibers at a speed of about 20m/sec. Cold receptors tend to be somewhat adaptable with a lot of signaling going in the first few seconds after they’re first exposed to the cold and the signaling progressively slowing down over the next 30 minutes or so. This is why you feel so cold when you first leave a heated room in the winter.

ReferenceHall, John E.. Guyton and Hall Textbook of Medical Physiology Chapter 48; II: Somatic Sensations:”Thermal Sensations”

感じる寒さ

皮膚には疼痛受容体がある:冷受容器 、熱受容器 及び痛覚受容体。場所により 熱受容器よりも310倍の 冷受容器があるので寒さを感じる確率は暑さよりも高い。痛覚受容体は極端の温度差にしか作動しないので『凍るほどの寒さ』または『火傷する暑さ』にしか脳へ信号を送らない。

皮膚の自由神経終末温度受容器が熱か寒さを感じる時、新脊髄視床路(速い経路)または旧脊髄視床路(遅い経路)を通じて信号を脳に送信する。殆どの 冷受容器は神経線維を通じて速い経路で20m/1秒の速度で脳に神経信号を伝達する。 冷受容器の適応性は高く、寒さにさらされる最初の数秒間には数多くの神経信号を送信するが、その後の30分間には徐々にゆっくりになる。これによって、真冬に暖房が効いた部屋から外に出る瞬間に急に寒さを感じる。

参考:Hall, John E.. Guyton and Hall Textbook of Medical Physiology Chapter 48; II: Somatic Sensations:”Thermal Sensations”

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English novels by Billy Hammond published by AELS

(AELS出版英語書籍リスト)

 

I. Majoh Gakuin and Hikari Juku – Japanese Witch Schools Trilogy

1. Majoh Gakuin & Hikari Juku – Japanese Witch Schools

2. Lost Witch (The second book)

3. Fate & Magic (The final book in the trilogy)

II. Brindle – Scryer Extraordinaire Trilogy

1. Brindle – Scryer Extraordinaire

2. Brindle – Scryer Extraordinaire – Returns

3. Brindle – Scryer Extraordinaire – Challenges (The final book in the trilogy)

III. Fantasy fiction set in Japan

1. 21st Century Ninja

2. Regressed

3. Japanese Woman

IV. Fantasy fiction set outside of Japan

1. Dimension Jumpers

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