The innermost part of an organ or other body structure; for example, the adrenal medulla is the central region of an adrenal gland. The term “medulla” is also sometimes used to refer to the medulla oblongata.
The inside part of an organ or tissue that is distinct from the outer part – for example, the marrow in the centre of a long bone, or the inner portion of the kidneys or adrenal glands.
n. 1. the inner region of any organ or tissue when it is distinguishable from the outer region (the cortex), particularly the inner part of the kidney, adrenal glands, or lymph nodes. 2. see medulla oblongata. 3. the *myelin layer of certain nerve fibres. —medullary adj.
The hindmost part of the BRAIN, continuing into the SPINAL CORD. In it are situated several of the nerve centres which are most essential to life, such as those governing breathing, the action of the heart and swallowing.... medulla oblongata
The inner part of the adrenals, derived embryonically from spinal nerve precursors, they secrete epinephrine, norepinephrine and dopamine; used locally as neurotransmitters, sensitive receptors can be mobilized totally by the adrenal medullas.... adrenal medulla
a tumour whose consistency was thought to resemble that of bone marrow. Medullary carcinoma of the thyroid has associations with tumours of other organs (multiple endocrine neoplasia; see MENS) and is often familial: it arises from the *C cells of the thyroid and produces calcitonin, which can often be used as a *tumour marker.... medullary carcinoma
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