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The Science of Homeopathy – page 53

vision. As this process advances, three different layers of cells develop and become the primordial structures from which the rest of the or- ganism grows. These three levels are called: ectoderm, mesoderm, and endoderm. From each layer, specific organs and systems develop, as follows:

Ectoderm

The skin and its appendages. (Specifically, the epithelium of skin, hair, nails, epithelial cells of sweat, sebaceous glands, and mammary glands.)

Epithelium of the beginning and end of the gastrointestinal tract. (Specifically, epithelium and glands of lips, cheeks, gums, part of the floor of the mouth and of the palate, and mucous membranes of nasal cavities and paranasal sinuses, as well as epithelium of the lower part of the anal canal, and terminal parts of the genital and urinary tracts.)
Tissues of the nervous system. (Specifically, the entire central ner- vous system including the retina; the peripheral nervous system, in- cluding sympathetic nerve cells and fibers, the medulla of the adrenal gland, and the neurilemmal sheath cells; and the sensory epithelium of the olfactory and auditory organs.)
Anterior part of the pituitary.
Lense of the eye, anterior epithelium layer of the cornea, muscles of the iris, and the outer layer of the eardrum.

Endoderm

Epithelium of the gastrointestinal tract, except its terminal parts, and the parenchyma of glands derived from it (liver, pancreas, thyroid, parathyroid, and thymus).

The lining epithelium of the Eustachian tube and of middle ear cav- ity, including inner layer of eardrum and lining of the mastoid air cells.

Lining epithelium of the larynx, trachea, bronchi, and alveoli. Epithelium of the bladder, of most of the female urethra, and part of the male urethra, plus the glands derived from them (e.g., prostate), and lower part of the vagina.

Mesoderm

Epithelial derivatives:

Visceral and parietal linings of the peritoneal, pleural, and pericardial cavities.