Test 3 Flashcards
(56 cards)
What are the 4 primary glands of the endocrine system?
Adrenal glands, Thyroid glands, Parathyroid glands, Pituitary gland
Where are the adrenal glands located?
Above the kidneys
What does ACTH stand for?
Adreno cortico tropic Hormone
Where is ACTH produced?
Pituitary Gland
What does ACTH stimulate the adrenal cortex to produce?
Cortisol
Describe the cortisol feedback mechanism?
A negative feedback loop, with CRH secreted from the hypothalamus, positively stimulating the anterior pituitary to release ACTH, which acts on the adrenal glands to stimulate release of cortisol. High levels of cortisol negatively impacts CRH and ACTH secretion.
What does Hypoadrenocorticism mean? What is the common name?
Decreased production of hormones (cortisol) from adrenal cortex; Addison’s Disease
List some symptoms and causes of hypoadrenocorticism.
- Lethargy
- Anorexia
- Vomiting
- Weight loss
- Diarrhea
- PU/PD
- Dehydration
- Hypothermia
- Slow CRT
- Melena
- Bradycardia
- Painful abdomen
- Weak pulse
- Alopecia
What does Hyperadrenocorticism mean? What is the common name?
Increased production of hormones from the adrenal cortex; Cushing’s Disease
List some symptoms and causes of hyperadrenocorticism.
- PU/PD
- Polyphagia
- Pendulous abdomen
- Hepatomegaly
- Hair loss
- Lethargy
- Muscle weakness
- Anestrus
- Obesity
- Muscle atrophy
- Panting
- Testicular atrophy
- Hyperpigmentation
- Thin skin
- Bruising
At what age are most dogs affected by these diseases?
4 years (middle age)
List and briefly describe the 3 types of Hyperadrenocorticism.
- Adrenal dependant (primary) Hyperadrenocorticism: Regular amount of ACTH being produced, excessive cortisol being released
- Pituitary dependant (secondary) Hyperadrenocorticism: Pituitary releasing excessive ACTH, causing release of more cortisol
- Iatrogenic: Caused due to prescribed medications (steroids)
What does iatrogenic mean?
Of or relating to illness caused by medical examination or treatment.
Suddenly stopping corticosteroid treatment can cause iatrogenic what?
Hyperadrenocorticism
How is Cushing’s disease diagnosed?
- ACTH Stim Test
- Low Dose Dexamethasone Test
- High Dose dexamethasone Test
- Radiographs
- Clinical Signs
What are two electrolyte abnormalities you may see when there is a hormonal imbalance?
- Hyperkalemia
- Hyponatremia
What other diagnostic test, besides blood work, can be used to check the adrenal glands?
Radiology
List and describe the 3 most common blood tests for diagnosing endocrine disease.
- ACTH Stimulation Test: Tests for both hypoadrenocorticism and hyperadrenocorticism
- Low Dose Dex Test: Used to confirm or replace ACTH test for diagnosis of Cushing’s disease
- High Dose Dex Test: Used to determine between pituitary dependent or adrenal dependent Cushing’s
How many blood samples are taken from a patient having an ACTH Stim test?
3 (1 pre sample, 2 post samples)
Which test helps distinguish if cause is iatrogenic, or ‘true’ adrenal dysfunction?
ACTH Stimulation Test
Which test differentiates between the types of Cushing’s (pituitary or adrenal dependent)?
High Dose Dex Test
Which test/s is/are used in cats?
- ACTH Stim Test
- High Dose Dex Test
After running a high dose dex test, what would you expect the results to be if the dog has Pituitary-dependent Cushing’s disease? Adrenal-dependent Cushing’s disease?
- Pituitary dependent - Normal test results (no effect)
- Adrenal dependent - High test results
What is the difference between primary Hyperadrenocorticism and secondary Hyperadrenocorticism? Briefly explain.
- Primary: Adrenal dependent, normal amount of ACTH, excessive Cortisol
- Secondary: Pituitary dependent, excessive amount of ACTH, excessive Cortisol secondary to excessive ACTH
