Term
| Components of the endocrine system |
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Definition
| Hypothalamus, Posterior/Anterior Pituitary, Thyroid, Parathyroid, Adrenal, Pancreas, Gonads |
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Term
| What is TSH, where is it made, and what does it do? |
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Definition
Thyroid stimulating hormone
Anterior Pituitary
Stimulates release of thyroid hormone |
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Term
| What is ACTH, where is it made, and what does it do? |
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Definition
Adrenocorticotropic hormone
Anterior Pituitary
Stimulates adrenal hormone release |
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Term
| What is ADH, where is it made, and what does it do? |
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Definition
Antidiuretic hormone
Posterior Pituitary
Concentrates urine by causing kidneys to conserve and resorb water |
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Term
| What is T3 and what does it do? |
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Definition
Triiodothyronine
Active form of hormone responsible for metabolism and growth |
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Term
| What is T4 and what does it do? |
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Definition
| Storage form of hormone responsible for metabolism and growth |
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Term
| What is PTH and when is it released? |
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Definition
Parathyroid hormone
Released when blood calcium levels are too low. |
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Term
| Where is Calcitonin made, and when is it released? |
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Definition
Made in the thyroid
Released when blood calcium levels are too high. |
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Term
| Why is T3 not clinically useful for detecting thyroid disease? |
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Definition
| Doesn't decline in early or mild hypothyroidism |
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Term
| How is a T3 suppression test done, and what can it diagnose? |
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Definition
T4 measured before and after T3 administration.
Dx hyperthyroidism (no change in T4 levels) |
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Term
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Definition
| Baseline measure of resting thyroid, includes both bound and unbound hormone. |
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Term
| What does Free T4 testing detect? |
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Definition
| Feline hyperthyroidism in cats with normal or slightly increased T4 |
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Term
| Why is free T4 testing useful? |
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Definition
| Less sensitive to medications and disease processes than T4 |
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Term
| What does elevated TSH indicate? |
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Definition
| Lack of negative feedback on the pituitary and hypothalamus |
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Term
| Chemical indications of hypothyroidism |
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Definition
Increased TSH
Decreased TT4
Decreased Free T4 |
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Term
| Chemical indications of hyperthyroidism |
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Definition
Increased TT4
OR
Increased Free T4 |
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Term
| Which disease process commonly accompanies hyperthyroidism? |
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Definition
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Term
| Lab results for hyperthyroidism |
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Definition
T3 suppression: No change in T4
TRH stim: T4 does NOT increase by 50% |
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Term
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Definition
CNS triggers hypothalamus to release CRH
CRH tells pituitary gland to release ACTH
ACTH stimulates adrenal gland |
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Term
| Causes of primary hypoadrenocorticism |
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Definition
Immune system destroys adrenal glands
Adrenal tumor
Hemorrhage
Infarction
Overdose of mitotane |
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Term
| What three things can be causes of secondary hypoadrenocorticism? |
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Definition
Decreased production of ACTH leading to glucocorticoid deficiency
Iatrogenic (caused by sudden termination of steroids)
Lesion destroying hypothalamus or pituitary gland |
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Term
| Clinical signs of Addison's Disease |
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Definition
- Depression, lethargy, weight loss, GI upset, PU/PD, shaking
- BUN/CREAT increased
- Hyponatremia/hyperkalemia (dt fluid loss)
- Dilute urine |
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Term
| Causes of hyperadrenocortism |
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Definition
- Pituitary tumor (causing adrenaocortical hyperplasia)
- Adrenal tumor
- Excessive or prolonged exogenous steroids |
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Term
| What does Low-Dose Dex Suppression test? |
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Definition
| Screens for Cushings (both pituitary and adrenal) |
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Term
| What does High Dose Dex Suppression test? |
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Definition
| Distinguishes pituitary and adrenal Cushings |
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Term
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Definition
Extracellular Cation
Maintains osmolality (with Cl) |
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Term
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Definition
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Term
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Definition
Extracellular Anion
Maintains osmolality (with Na)
Maintains electro-neutrality |
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Term
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Definition
Vomiting
Anorexia/malnutrition
Diabetes insipidus |
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Term
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Definition
Intracellular cation
Important in cardiac and neuromuscular function |
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