• Hilum

    Pronunciation

    • IPA: /ˈhaɪ.lÉ™m/

    Origin

    From Latin hilum ("a trifle; a spot on a seed").

    Alternative forms

    Full definition of hilum

    Noun

    hilum

    (plural hila)
    1. (botany) The eye of a bean or other seed; the mark or scar at the point of attachment of an ovule or seed to its base or support.
      • 1913, Washington Academy of Sciences, Journal of the Washington Academy of Sciences, Volume 3, page 141,The hilum is very prominent in some species and nearly flat in others.
      • 2005, David Feldman, Do Elephants Jump?, page 24,On the tip of each corn kernel is a hilum, collectively known as the “black layer,” where it is attached to the cob. While corn is growing, nutrients are being transferred from the rest of the cob to the kernels through the hilum.
    2. (botany) The nucleus of a starch grain.
      • 1916, William Mansfield, Histology of medicinal plants, page 188,In central hilum starch grains the grain is laid down around the hilum in the form of concentric layers.
    3. (anatomy) A depression or fissure through which ducts, nerves, or blood vessels enter and leave a gland or organ. Also called porta.
      • 1998, Robert Matthew Hay McMinn, R. T. Hutchings, B. M. Logan, The Concise Handbook of Human Anatomy, page 145,pancreas is a hook-shaped gland, about 15cm long, that lies transversely across the upper abdomen, with the head in the C-shaped curve of the duodenum (6.9, 6.13), extending to the left as the body behind the stomach and ending as the tail lying against the hilum of the spleen.
      • 2010, Emmanuel E. Coche, Benoit Ghaye, Johan De Mey, Comparative Interpretation of CT and Standard Radiography of the Chest, page 166,The shadows of the hila on chest X-ray are mainly formed by the pulmonary arteries (PAs) and some of their main branches and the upper pulmonary veins (PVs).
      • 2010, W. Richard Webb, Charles B. Higgins, Thoracic Imaging: Pulmonary and Cardiovascular Radiology, page 161,In the large majority of normal patients, the hila appear equal in size on frontal radiographs; comparison of the two hila is helpful in patients with a unilateral abnormality.

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