Term
| The hypothalamus sends signals to the anterior pituitary via a ____________ connection. |
|
Definition
|
|
Term
| The hypothalamus sends signals to the posterior pituitary via a ____________ connection. |
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Definition
|
|
Term
| T/F: both the anterior and posterior pituitary cause systemic effects. |
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Definition
|
|
Term
| T/F: the HPA sends signals directly to the autonomic nervous system. |
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Definition
|
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Term
| The anterior pituitary is also known as the ___________, is made up of the pars ___________ and pars ____________, and secretes 3 main hormones: _____________, _____________, and _________________. |
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Definition
Adenohypophysis
Intermedia
Distalis
ACTH
TSH
GH |
|
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Term
| The posterior pituitary is also known as the _____________, is made up of the pars ____________, and secretes one main hormone: ________________. |
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Definition
Neurohypophysis
Nervosa
ADH |
|
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Term
| Growth hormone is also known as __________. |
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Definition
|
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Term
| What are the actions of GH? |
|
Definition
Anabolic
Lipolytic
Diabetogenic |
|
|
Term
| List the 4 diabetogenic hormones: |
|
Definition
GH
Cortisol
Glucagon
Epinephrine |
|
|
Term
| The primary function of GH is to promote _______________. |
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Definition
|
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Term
| GH is under positive control by _________ from the hypothalamus, negative control by _____________ released from the hypothalamus, and GH's effects are mediated by ______________ which is produced in the ______ as a result of stimulation by GH. |
|
Definition
GHRH
Somatostatin
Insulin-like growth factor (IGF-1)
Liver |
|
|
Term
| What are the four effects of IGF-1 production on the body? |
|
Definition
1. increased chondrogenesis
2. skeletal growth
3. increased protein synthesis
4. increased cell proliferation |
|
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Term
| T/F: GH levels differ between dogs based on their breed/size, but IGF-1 levels remain constant between dogs. |
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Definition
| False: GH remains constant, while IGF-1 is highly variable. |
|
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Term
| The catabolic effects of GH are mediated by _________ (hormone) and include what two effects? |
|
Definition
Cortisol
Lipolysis
Hyperglycemia |
|
|
Term
| The anabolic effects of GH are mediated by ________ and _________ (hormone) and result in what systemic effects? |
|
Definition
IGF-1
Thyroid hormone
Increased chondrogenesis/skeletal growth
Increased protein synthesis
Increased cell proliferation |
|
|
Term
| Hyposomatotropism is also known as _____________, GH levels will be low/high, and IGF-1 levels will be low/high, with little to no response to GH stimulation tests. |
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Definition
|
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Term
| T/F: hyposomatotropism usually involves a deficiency of GH alone, resulting in _________________ dwarfs, or can be in combination with a deficiency of ________ and results in a _____________ dwarf. |
|
Definition
Proportionate
TSH
Disproportionate |
|
|
Term
| T/F: most dogs with hyposomatotropism retain normal ACTH. |
|
Definition
|
|
Term
| What two breeds have an autosomal recessive inheritence of hyposomatotropism? |
|
Definition
German Shepherd
Carnelein Bear Dog |
|
|
Term
| When dogs with hyposomatotropism are evaluated, what are some clinical observations? |
|
Definition
Evaluated in first year of life
Smaller than unaffected littermates (runts)
Retain puppy coat--retain secondary hairs but lack guard hairs
Normal mentation/attitude |
|
|
Term
| While the MDB for animals with hyposomatotropism is generally WNL, what one factor may be seen and why? |
|
Definition
| Mild azotemia due to concurrent glomerular maldevelopment. |
|
|
Term
| Basal levels of ________ are better correlated with hyposomatotropism than taking basal _____ levels. |
|
Definition
|
|
Term
| What is the current recommended method of diagnosis for dogs with hyposomatotropism? |
|
Definition
GH stimulation testing
Note: xylazine stimulation test is the preferred test, though others exist (clonidine, GHRH) |
|
|
Term
| T/F: baseline TSH levels are the method for thyroid stimulation testing. |
|
Definition
False--cannot do baseline TSH
Must do TRH testing |
|
|
Term
| Treatment for hyposomatotropism involves replacement of GH. ________ GH can't be used because it is not commercially available, _____ GH is not recommended because it is antigenic, so _______ GH is currently recommended because it is genetically identical to canine GH. |
|
Definition
|
|
Term
| What is the goal of GH therapy for hyposomatotropism? |
|
Definition
| Normal plasma IGF-1 levels |
|
|
Term
| T/F: thyroid supplementation is warranted as a therapy for hyposomatotropism. |
|
Definition
| True--especially if concurrent TSH deficiency but may be of benefit if the patient is just GH deficient. |
|
|
Term
| T/F: progestins/progesterone are the current recommended therapy for hyposomatotropism. |
|
Definition
| False--controversial due to numerous side effects |
|
|
Term
| What is the prognosis for a patient with hyposomatotropism? |
|
Definition
Dermatologic improvement should be seen in 6-8 weeks
Body stature may not change
Untreated, most will die or be euthanized within 5 years |
|
|
Term
| What are the two iatrogenic sequellae of GH therapy for hyposomatotropism? |
|
Definition
|
|
Term
| Hypersomatotropism is also known as _______________. In the canine, this condition is most commonly a result of _____________, while in the feline it is most commonly result of _______________, predominantly a ___________ (type) located in the pars _______________. For cats, females/males are predisposed. |
|
Definition
Acromegaly
Progesterone
Neoplasia
Macroadenoma
Pars distalis
Males |
|
|
Term
| The catabolic/anabolic effects of hypersomatotropism tend to win out in the long run. |
|
Definition
|
|
Term
| Describe some changes that may be appreciated in a case of suspected hypersomatotropism: |
|
Definition
Big head, big feet, big abdomen
Hypertrophy of soft tissue, especially around head and neck
Increased respiratory noises
Widened interdental spaces
Note: appreciate changes in individual animals from *their baseline* |
|
|
Term
| Hypersomatotropism should be suspected in a poorly controlled diabetic cat when insulin doses are greater than ___ IU/kg. |
|
Definition
|
|
Term
| What are some the clinicopathologic abnormalities seen in animals with hypersomatotropism? |
|
Definition
Hyperglycemia
Glucosuria
Elevated liver enzymes
Hypercholesterolemia
Similar findings to diabetes mellitus |
|
|
Term
| What are the diagnostic tests that can be done to diagnose hypersomatotropism? Of these tests, which is preferred? |
|
Definition
Basal GH levels (acromegaly >10ng/mL)
Basal IGF-1 levels (acromegaly >100nmol/L)
CT or MRI to demonstrate neoplasia
Basal IGF-1 levels are the preferred method to diagnose |
|
|
Term
| What is the therapy and prognosis for hypersomatotropism? |
|
Definition
Remove progesterone source if progesterone induced
Radiation/chemo for neoplasia
Control diabetes with insulin
The prognosis for progesterone-induced hypersomatotropism is good, but for neoplasia the disease carries a poor long-term prognosis |
|
|
Term
|
Definition
| Osmolality is the number of osmoles per kg of solvent. |
|
|
Term
| ________ is the most important osmole, but __________ and ____________ are also potent osmoles. |
|
Definition
|
|
Term
| ADH is also known as ____________ or _____(abbreviation) |
|
Definition
|
|
Term
| What is the action of ADH? |
|
Definition
|
|
Term
| _____________ is the most important stimulus for thirst. |
|
Definition
| Plasma osmolality. Normal in dog: 288-305 mOsml/kg Normal in cat: 280-305 mOsml/kg |
|
|
Term
| A ____% change in osmolality can cause ADH release, while ____% change in blood volume will cause ADH release. |
|
Definition
|
|
Term
| What are the two basic ways to decrease osmolality? |
|
Definition
Increase water intake
Decrease water excretion |
|
|
Term
| Osmoreceptors are located primarily in the ___________, while ___________ are located in the heart and vasculature. |
|
Definition
|
|
Term
| T/F: osmoreceptors are in contact with the CSF and therefore considered inside the BBB. |
|
Definition
| False: in contact with plasma and outside BBB. |
|
|
Term
| T/F: ADH has systemic effects on multiple organs. |
|
Definition
|
|
Term
| What is the effect of ADH on the kidney? |
|
Definition
| ADH increases the kidney's permeability to water to allow reabsorption of solute free water, decrease urine production, and increase urine osmolality. |
|
|
Term
| Polyuria is considered when urine production exceeds _____ ml/kg/day. |
|
Definition
|
|
Term
| Polydipsia is considered when water intake exceeds ____ ml/kg/day. |
|
Definition
|
|
Term
| T/F: polydipsia that cannot be explained as a compensatory mechanism for polyuria or excessive water loss is termed "primary polydipsia" and is determined by a diagnosis of absolute exclusion. |
|
Definition
|
|
Term
| Describe the process of osmotic diuresis: |
|
Definition
| Increase in urinary solutes-->pulls water into urine-->diuresis-->hypovolemia-->stimulates thirst-->compensatory polydipsia |
|
|
Term
| List four conditions that can cause osmotic diuresis: |
|
Definition
Diabetes mellitus
Fanconi syndrome (Basenjis)
Chronic renal failure
Post obstructive diuresis |
|
|
Term
| List the two forms of diabetes insipidus: |
|
Definition
Central--lack of ADH production--RARE
Nephrogenic--partial or complete lack of renal response to ADH |
|
|
Term
| What are the two forms of nephrogenic diabetes insipidus? |
|
Definition
Congenital--genetic renal problem with ADH receptors or mechanisms for normal ADH response--RARE
Acquired/secondary--ADH present but interference of normal interaction between ADH and renal tissue--MOST COMMON CAUSE OF NDI |
|
|
Term
| What are the common causes of NDI? |
|
Definition
Pyometra
Hypercalcemia
Hepatic Disease
Hyperadrenocorticism
Pyelonephritis
Hyperthyroidism
Hypoadrenocorticism
Polycythemia
Acromegaly
Hyperaldosteronism
Hypokalemia |
|
|
Term
| What is the mechanism behind NDI and Cushing's disease? |
|
Definition
| Cortisol inhibits ADH release |
|
|
Term
| What is the mechanism behind NDI and hepatic disease? |
|
Definition
| Low BUN leads to loss of renal medullary concentration gradient |
|
|
Term
| What is the mechanism behind NDI and pyometra? |
|
Definition
| Endotoxins (especially E. coli) compete with ADH for renal binding sites. |
|
|
Term
| Most cases of DI are __________ and ___________, with ___________ occurring first and resulting in a compensatory ____________ to prevent dehydration. In most cases, limiting water is good/bad. |
|
Definition
Acquired
Nephrogenic
Polyuria
Bad |
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