Halata Z
Department of Functional Anatomy, University of Hamburg, Germany.
J Invest Dermatol. 1993 Jul;101(1 Suppl):75S-81S. doi: 10.1111/1523-1747.ep12362877.
The sense of touch develops early in phylogeny and is one of the most important senses for the survival of the animal. Touch organs of hairy skin in mammals include the so-called "Haarscheiben" (also Pinkus corpuscles) and all types of hair follicles with their nerve endings. The touch organs of the skin consist of a mechanical transducing component and the sensory component. The epithelium and its derivatives like hair follicles and sebaceous glands are the mechanical transducing component transmitting the mechanical forces like pressure or touch to the second component--the sensory nerve endings. In mammalian hairy skin all sinus and guard hairs and many vellus hairs are touch organs. The sinus hair is a typical example of a touch organ. All mammals except humans are equipped with these highly differentiated touch organs. The hair follicle is almost completely embedded in a blood sinus and equipped with more than 2,000 sensory nerve endings. All sinus and guard hairs are equipped with free nerve endings (nociceptors), Merkel nerve endings (slowly adapting [SA I] mechanoreceptor units-pressure detectors), palisades of lanceolate nerve endings (velocity detectors), and pilo-Ruffini corpuscles (tension receptors). In most of the sinus hairs lamellated corpuscles of Pacini type could be found (rapidly adapting receptors-acceleration detectors). Most vellus hairs are equipped with free and lanceolate nerve endings. Some of the vellus hairs of the upper portion of the body (head, upper extremity) are innervated by Merkel nerve endings. The presence of pilo-Ruffini nerve endings in vellus hairs is very unusual.
触觉在系统发育中很早就出现了，是动物生存最重要的感觉之一。哺乳动物多毛皮肤的触觉器官包括所谓的“Haarscheiben”（也称为平库斯小体）以及所有带有神经末梢的毛囊类型。皮肤的触觉器官由机械转导成分和感觉成分组成。上皮及其衍生物如毛囊和皮脂腺是机械转导成分，将压力或触摸等机械力传递给第二个成分——感觉神经末梢。在哺乳动物的多毛皮肤中，所有的窦毛和触毛以及许多毳毛都是触觉器官。窦毛是触觉器官的一个典型例子。除人类外的所有哺乳动物都配备有这些高度分化的触觉器官。毛囊几乎完全嵌入血窦中，并配备有2000多个感觉神经末梢。所有的窦毛和触毛都配备有游离神经末梢（伤害感受器）、默克尔神经末梢（慢适应[SA I]机械感受器单元——压力探测器）、柳叶状神经末梢栅栏（速度探测器）和毛-鲁菲尼小体（张力感受器）。在大多数窦毛中可以发现帕西尼型环层小体（快适应感受器——加速度探测器）。大多数毳毛配备有游离和柳叶状神经末梢。身体上部（头部、上肢）的一些毳毛由默克尔神经末梢支配。毳毛中存在毛-鲁菲尼神经末梢是非常不寻常的。
