hemosiderin
Học thuậtThân thiện
Definition
Noun: A granular, brownish-yellow, iron-storage complex found within cells, particularly in the liver, spleen, and bone marrow. It is composed of partially denatured ferritin (an iron-protein complex) and other materials, and represents a storage form of iron that is less readily available than ferritin. Its presence in excess can indicate disorders of iron metabolism or breakdown of red blood cells.
Usage
Hemosiderin is a medical and biological term used to describe an abnormal or excessive accumulation of iron in tissues, which is often a sign of disease. - It is typically observed under a microscope in tissue samples (biopsies). - It is discussed in the context of diagnosing conditions like hemochromatosis, hemosiderosis, or chronic bleeding.
Examples
- Noun:
- The liver biopsy revealed significant hemosiderin deposition, confirming the diagnosis of hereditary hemochromatosis.
- In patients with chronic venous stasis, hemosiderin can leak from broken-down red blood cells and stain the skin, causing a brownish discoloration.
- The pathologist identified hemosiderin-laden macrophages in the alveolar spaces, a finding consistent with pulmonary hemorrhage.
Advanced Usage
- Hemosiderin staining: Refers to the visible brownish discoloration of skin, often on the lower legs, caused by the deposition of hemosiderin from broken-down red blood cells leaking from capillaries. This is common in chronic venous insufficiency.
- Hemosiderin-laden macrophages: Immune cells (macrophages) that have phagocytosed (engulfed) and contain hemosiderin granules. Their presence is a key histological finding in conditions involving hemorrhage or iron overload.
Variants and Related Words
- Hemosiderosis (noun): A condition characterized by the excessive accumulation of hemosiderin in tissues, often without the associated tissue damage seen in hemochromatosis. It can be systemic or localized.
- Hemochromatosis (noun): A hereditary disorder causing excessive absorption and accumulation of iron in the body, leading to organ damage. Hemosiderin deposition is a hallmark of this disease.
Synonyms
- Iron pigment: A general term for pigments containing iron, including hemosiderin.
- Ferritin aggregate: While not a perfect synonym, as ferritin is a different molecule, hemosiderin is partially composed of aggregated and degraded ferritin.
Related Phrases and Concepts
- Iron storage: The biological process of retaining iron for future use. Hemosiderin is one form of stored iron.
- Hemoglobin breakdown: The process by which old red blood cells are destroyed, releasing iron which can be stored as ferritin or hemosiderin.
- Prussian blue stain: A special histological stain used in laboratories to detect the presence of iron, which turns hemosiderin granules a bright blue color for easy identification under a microscope.
Noun
- a granular brown substance composed of ferric oxide; left from the breakdown of hemoglobin; can be a sign of disturbed iron metabolism