Elementary anatomy and physiology : for colleges, academies, and other schools . elementaryanato00hitc Year: 1869 AND PHYSIOLOGY. 299 the skin with the finest needle, when a drop of blood is sure to follow. The nerves of sensation too are very abundant, as we know by the insertion of a pin into any part of the body, which invariably pains us, because we have wounded a nerve, and not an expanded surface, like a membrane. 524. Sebaceous or Oil Glands.—The Sebaceous Glands are small elongated sacs which are generally gathered in clusters about each of the hairs of the body, varying Fig. 290. in
Elementary anatomy and physiology : for colleges, academies, and other schools . elementaryanato00hitc Year: 1869 AND PHYSIOLOGY. 299 the skin with the finest needle, when a drop of blood is sure to follow. The nerves of sensation too are very abundant, as we know by the insertion of a pin into any part of the body, which invariably pains us, because we have wounded a nerve, and not an expanded surface, like a membrane. 524. Sebaceous or Oil Glands.—The Sebaceous Glands are small elongated sacs which are generally gathered in clusters about each of the hairs of the body, varying Fig. 290. in number from four to twen- ty. They pour their secre- tion into the hair-canals near their orifices, and are most abundant in the parts of the body most exposed, as in the skin of the nose. Their se- cretion in most places resem- bles fat, although in the pas- sage of the external ear a substance resembling wax (cerumen) is poured out. 524a. Parasite in the Sebaceous Glands.—It is a fact curious, if not at first sight revolting, that there is very constantly found in the outlets to many of the sebaceous glands a parasitic animal, as represented by the cut. (Fig. 291, p. 300.) The occurrence of this animal in almost every individual has led one anat- omist to call it a ' denizen' of the human body. 525. Sweat Glands.—Length of Sweat Tube in the Human Body.—The Sudoriparous or Sweat Glands essen- A View of the Cerumen Gland formed by the Contorted Tubes. 1, 1; The Tubes. 2, The Excretory Duct. 3, The Vessels supplying it. What of the nerves in the corium ? 524. What are the sebaceous glands ? Where are they the most abundant ? What is their secretion ? 524 a. What is said of the parasite in the skin?
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