Thymus

thymus

Pyramid-shaped lymphoid organ (see lymphoid tissue) between the breastbone and the heart. Starting at puberty, it shrinks slowly. It has no lymphatic vessels draining into it and does not filter lymph; instead, stem cells in its outer cortex develop into different kinds of T cells (see lymphocytes). Some migrate to the inner medulla and enter the bloodstream; those that do not may be destroyed to prevent autoimmune reactions. This process is most active during infancy. If a newborn's thymus is removed, not enough T cells are produced, the spleen and lymph nodes have little tissue, and the immune system fails, causing a gradual, fatal wasting disease. Thymus removal in adults has little effect.

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thymus

a glandular organ of vertebrates, consisting in man of two lobes situated below the thyroid. In early life it produces lymphocytes and is thought to influence certain immunological responses. It atrophies with age and is almost nonexistent in the adult

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Thymus 

(thyme), a genus of plants of the family Labiatae. The plants are subshrubs with herbaceous branches and with woody stems that are often decumbent. The small leaves are opposite and, for the most part, petioled. The flowers, which are usually lilac in color, are gathered in a head or some other type of inflorescence. The fruit consists of four nutlike lobes.

There are about 400 species, distributed in the temperate zone of Eurasia and in North Africa. Of the more than 150 species found in the USSR, the most common are wild thyme (T. serpyllum) and T. marschallianus. The former is found in the forest zone, where it grows in pine forests and in arid, sandy places. The latter is encountered on slopes, along forest margins, and in glades in the forest-steppe and steppe zones. The leaves of both species contain a number of essential oils, mainly thymol, which is used as an anthelmintic, a disinfectant, and an analgesic. The liquid extract and tea from the leaves are used as expectorants. Common thyme (T. vulgaris), which grows in the Mediterranean region and is cultivated in the USSR, is used the same way as the above-mentioned species. Thyme leaves are used as a seasoning and flavoring in cooking and by the canning and alcoholic beverages industries.

REFERENCE

Alias lekarstvennykh rastenii SSSR. Moscow, 1962.

T. V. EGOROVA