Glossary of Terms and Definitions
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| Autoimmune Hypophysitis |
Response of the immune system against the hypophysis.
It is also called Lymphocytic Hypophysitis because lymphocytes are the
main cells infiltrating the hypophysis. It has been increasingly recognized
in the last 20 years, due to a better understanding of its clinical,
radiological and pathological features of the disease.
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| Autoimmunity |
Response of the immune system against components (antigens) of the
host itself (rather than against invading parasites, bacteria
or viruses). This autoimmune attack is mediated by antibodies
or hematopoietic cells (usually lymphocytes).
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| Bitemporal
Hemianopsia |
A type of visual defect characterized by loss of vision
in the lateral (temporal) half of the two visual fields. Typically caused
by an enlarged hypophysis, which compresses the optic chiasma.
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| Choroid Plexus |
A network of capillaries located in the walls of the
four brain ventricles. These plexuses are the production sites of the
cerebrospinal fluid, a colorless liquid that protects the
brain and the spinal cord against chemical and physical injuries.
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| Endocrine |
Endocrine refers to the fact that a gland secretes
its products into the bloodstream. Other glands instead, such as the
lacrimal glands, secrete their products outside the body (exocrine). For example, the lacrimal glands secrete tears and are therefore exocrine glands.
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| Hormone |
Substance produced by an endocrine gland and transported
in the bloodstream to a target tissue, where it carries on its function
(stimulatory or inhibitory).
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| Hyperplasia |
An increase in the size of an organ or a tissue as a result
of increased numbers of cells.
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| Hypertrophy |
An increase in the size of an organ or a tissue as a result
of increased size of the individual cells.
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|
Hypophysitis |
Inflammation of the hypophysis, which be an acute or chronic.
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| Hypopituitarism |
Clinical condition characterized by a deficiency of one or more
of the hormones produced by the hypophysis. Autoimmune hypophysitis
can result in hypopituitarism.
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| Hypothalamus |
Part of the brain located above the pituitary, to which
it is anatomically connected. It contains specialized nervous cells
which regulate the production and release of pituitary hormones.
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| Optic
Chiasma |
Part of the visual tract where the fibers of the left and right
optic nerve meet and partially cross. The chiasma is located in
front of and above the hypophysis, so it may be compressed when
the hypophysis is enlarged.
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| Sella
Turcica |
A deep depression of the sphenoid bone, at the base of the skull,
which surrounds the hypophysis.
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| Visual
Field Defect |
A loss of vision in a particular area of the visual
field. Bitemporal hemianopsia is an example of visual field defect.
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