Human anatomy, including structure and development and practical considerations . of the blood-vessels. Surfaces hij^hly endowed with general and tactilesensibility are ])rovided with a generous supply of twigs containing meduUated the latter pass towards their ultimate destination (for convenience assuming thatall are peripherally directed) they lose their medullated character and, as naked axis-cylinders, form the suhcpilhclialplexuses, from which delicate filaments pass into thepapillcnt\ where they terminate either as free club-shaped or special sensory is probable tha
Human anatomy, including structure and development and practical considerations . of the blood-vessels. Surfaces hij^hly endowed with general and tactilesensibility are ])rovided with a generous supply of twigs containing meduUated the latter pass towards their ultimate destination (for convenience assuming thatall are peripherally directed) they lose their medullated character and, as naked axis-cylinders, form the suhcpilhclialplexuses, from which delicate filaments pass into thepapillcnt\ where they terminate either as free club-shaped or special sensory is probable that in places the nerves penetrate between the epithelial cells formingthe layers next the basement epithelium and terminate in varicose free endings. GLANDS. Certain of the epithelial cells lining the mucous membranes of the body becomemodified to assume the role of secretion-forming organs or glands, the products ofwhich are poured out upon the free surface and keep the latter moist. The latterpurpose is secondary in the case of many important glands, as the parotid, pancreas,. Diagram showing^ types of glands, a-e, tubular; y-/, alveolar or saccular, a, simple; b, coiled; c-d, increasinglycomplex compound tubular; e, tubo-aiveolar ; f, simple; g-h-i, progressively compound alveolar. or li\-er, since these organs supply special secretions for particular ends. Aggrega-tions of the secreting elements vary greatly in size, form, and arrangement, as wellas in the character of their products. The simplest type is the jaucelhilar gland ionnd in the lower forms; in principlethis is represented in man and the higher animals by the goblet-cells seen in pro-fusion in mucous membranes covered with columnar epithelium. The secretionpoured out by these goblet-cells serves to protect and lubricate the surface of themucous membranes in which they occur. The term gland, however, usuallyimplies a more highly developed organ composed of a collection of secreting epithe-lial elements. Gl
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Keywords: ., bookauthormc, bookcentury1900, bookdecade1910, booksubjectanatomy
