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− | ==Anatomy and Physiology==
| + | #REDIRECT[[:Category:Pituitary Gland - Pathology]] |
− | Anatomy and Physiology of the pituitary gland can be found [[Pituitary Gland - Anatomy & Physiology|here]].
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− | ==General Pathological Principles==
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− | Two major changes can occur in an endocrine gland:
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− | *'''Failure of hormone production''':
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− | **Destruction or lack of cells.
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− | **Lack of trophic drive.
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− | *'''Overproduction of hormone''':
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− | **Hyperplasia or neoplasia.
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− | **Excessive trophic drive.
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− | ==Pituitary Hypofunction==
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− | ===[[Congenital Panhypopituitarism]]===
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− | ===[[Pituitary Cysts]]===
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− | ===Pituitary Neoplasia===
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− | Tumours within the pituitary fossa may be functional and sectrete trophic factors. However, more commonly they are non-functional and are space-occupying lesions.
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− | Pressure on neighbouring structures causes clinical signs, for example:
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− | *Pressure on the optic chiasma produces ocular signs.
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− | *Pressure on the hypothalamus may lead to [[Frohlich's Adiposogenital Syndrome - Pathology|Frohlich's adiposogenital syndrome]].
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− | *Pressure on the neurohyposphysis may lead to failure of ADH secretion. This will allow large volumes of water to be lost form the kidney; [[Diabetes Insipidus]].
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− | [[Image:Pituitary tumour.jpg|right|thumb|125px|<small><center>'''Pituitary neoplasia'''. Courtesy of A. Jefferies</center></small>]]
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− | Neoplasia may be derived from:
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− | *Pituitary itself.
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− | *Surrounding brain tissue.
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− | *Ependyma.
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− | ====Pituitary neoplasia in the horse====
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− | Neoplasia usually occurs in the ''pars intermedia'' of the anterior pituitary and compresses the hypothalamus.
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− | ''Clinical signs'':
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− | *Polyuria and polydipsia.
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− | *Increased appetite reulting in increased food intake and downregulation of insulin receptors. This leads to a hyperglycaemia.
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− | *Somnolence.
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− | *Muscle wekaness.
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− | *Hirsutism.
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− | *Hyperhidrosis.
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− | [[Category:Pituitary Gland - Pathology]]
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− | [[Category:Neoplasia]]
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− | ==Pituitary Hyperfunction==
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− | [[Gigantism]]
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− | ===[[Acromegaly]]===
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