Exam 3: Clinical Pathology: Endocrinology
Dexamethasone suppression test: A diseased pituitary gland continues to producing excessive _________ in spite of dexamethasone administration. This test can be useful to differentiate between pituitary dependent and adrenal dependent HAC.
ACTH
Hyperadrenocorticism/CUSHINGS: Typical patient is polyuric, polydipsic, produces large amounts of urine with low specific gravity (<1.015), has a pot-bellied appearance, dermatologic changes, frequent urinary tract infections, increased _______ on bloodwork, etc. The pituitary dependent form is more common than the adrenal dependent form.
ALP
C-cells between thyroid follicles produce? Hint- it helps maintain blood calcium levels!
Calcitonin
This hormone is used to measure the level of estradiol in serum? Changes may occur with skin disease or neoplasia. Levels indicate the presence or absence of functional ovarian tissue.
Estrogen
What hormone test is used in horses, donkeys to indicate pregnancy?
Estrone Sulfate
Secreting a hormone externally via a duct is called?
Exocrine
_________ Calcium is not bound to protein, levels are most accurate, but required special machines such as the Abaxis iStat or specialized handling/shipping.
Ionized
What is the central timing event of the bitch's cycle?
LH surge
What is the name of the posture assumed by female cat during estrus cycle, ventral curvature of the spine?
Lordosis
A large surge of _________ ____________ is required for ovulation. It results in follicles luteinizing and transforming into _____________ secreting corpora lutea (CL).
Luteinizing Hormone (LH), progesterone
First estrus cycle occurs around ___-____ months of age, can be later for large breed dogs (up to 12 months).
6-9 (months)
What is a dog's gestation time?
61 days
What is the gestation period for a cat?
65 days
The _____________ pancreas produces digestive enzymes such as lipase, amylase and trypsin.
exocrine
Hypoadrenocorticism (Addison's Disease): Diagnosis is ACTH stim test and ____________ of the adrenals to produce any cortisone and characteristic physical and electrolyte abnormalities.ìTreatment consists of supplementation of corticosteroids and mineralocorticoids.
failure
Hypoadrenocorticism (Addison's Disease): Decreased production of ______________________(aldosterone) and sometimes corticosteroids by adrenal cortex.
mineralocorticoids
Negative feedback systems: When the level of a specific hormone drops below needed levels, the appropriate endocrine gland is stimulated to produce ______ hormone. Once the proper hormone level is present in the bloodstream, stimulation of that endocrine gland is reduced and production of that hormone is reduced.
more
Luteinizing Hormone (LH): -Completes the process of follicle development in ovary. -LH levels reach a peak when the follicle is fully mature. -Usually causes _______________.
ovulation
____________-Effects on uterus - causes contraction of the myometrium at the time of breeding and at parturition. -Induces uterine contractions that aid transport of spermatozoa to the oviducts. -Stimulates uterine contractions that aid in the delivery of the fetus and the placenta.
oxytocin
Chronic relapsing ______________ with progressive loss of both exocrine and endocrine cells and their replacement by fibrous connective tissue results in diabetes mellitus.
pancreatitis
PTH stand for?
parathyroid hormone
What gland is known as the 'master gland' or the 'hypophysis'?
pituitary gland
Counting the LH surge as day 0, peak fertile period is days 4,5 and 6. Determining the actual day of the LH surge requires daily blood testing. The time of the LH surge can be estimated by monitoring ___________ serum levels.
progesterone
What hormone is an indicator of luteal activity and can be used in many species to indicate likelihood of pregnancy? Also used in dogs to determine the proper time window for breeding?
progesterone
What are some reasons to run repro hormone tests: -To facilitate procreation of an animal. -To rule out underlying pathology causing reproductive failure (infertility). -To rule out underlying pathology causing behavioral issues. (example is unacceptable behavior in spayed female cat caused by ovarian remnant syndrome). -To help with diagnosis of hormone responsive dermatopathy. (example: estrogen responsive dermatosis, alopecia of hypothyroidism) -To diagnose pregnancy.
-
adrenocorticotropic hormone (ACTH): -Regulated by feedback from the hormones of the adrenal glands -ACTH can also be released quickly as a result of stimulation of the hypothalamus by other parts of the brain. -Hyperadrenocorticism can be a result of a pituitary tumor or adrenal disease. -Measurement of ACTH concentrations can help differentiate between pituitary-dependent and adrenal-dependent hyperadrenocorticism.
-
Causes for Hypoadrenocorticism/Addison's Dz are extensive: 1.autoimmune process. 2.destruction of the adrenal gland by granulomatous disease 3.metastatic tumor 4.hemorrhage 5.infarction 6.overdose of mitotane (o,p′-DDD) or trilostane (Vetoryl)
-
Diabetes mellitus is more commonly known simply as diabetes. It's when your pancreas doesn't produce enough insulin to control the amount of glucose, or sugar, in your blood. Diabetes insipidus is a rare condition that has nothing to do with the pancreas or blood sugar.
-
Disorders Associated with Endocrine Dysfunction: -Hyperadrenocorticism -Hypoadrenocorticism -Pheochromocytoma -Hypothyrodism -Hyperthyrodism -Hyperparathyroidism -Diabetes mellitus -Diabetes insipidus -Insulinoma -Acromegaly -And the list goes on...
-
Disorders of the thyroid gland can include overproduction of hormones (hyperthyroidism) or underproduction (hypothyroidism). Many cats with hyperthyroidism have a palpably enlarged thyroid gland.
-
Effects of Thyroid Hormones: 1.Influences development and maturation of CNS; growth and development of muscles and bones 2.Calorigenic effect - regulates the metabolic rate of all the body's cells 3.Allows animal to generate heat and maintain constant internal body temperature 4.Production increases with exposure to cold and then increases metabolic rate to generate more heat 5.Affects metabolism of proteins, carbohydrates, and lipids much like GH does 6.Helps regulate Calcium metabolism (parafollicular thyroid or C cells)
-
Hemolysis and lipemia can alter calcium results as high or low respectively.
-
Hyperadrenocorticism can occur due to: 1. brain or pituitary tumors secreting excessive CRF and causing secondary bilateral adrenal hyperplasia; 2. Idiopathic adrenal hyperplasia; 3. Adrenal neoplasia (one or both); 4. Over enthusiastic administration of exogenous (not made in the body) glucocorticoid therapy.
-
Intact female dogs/cats may have: pyometra, mammary neoplasia, ovarian cysts, uterine neoplasia, dermatology issues like demodicosis, and behavioral issues.
-
Intact male dogs (RARELY cats) have an increased risk of: -Neoplasia -prostatic infection, abscesses, hyperplasia -behavioral issues -Derm issues like Alopecia X
-
Known anterior pituitary hormones: 1. Growth hormone (GH) 2. Prolactin 3. Thyroid-stimulating hormone (TSH) 4. Adrenocorticotropic hormone (ACTH) 5. Follicle-stimulating hormone (FSH) 6. Luteinizing hormone (LH) 7. Melanocyte-stimulating hormone (MSH)
-
Many non-thyroidal illnesses (sick euthyroid syndrome) and administration of various drugs including glucocorticoids, sulfonamides, anticonvulsants (phenobarbital), NSAIDs, and radiocontrast agents may "falsely" lower serum T4 concentrations in dogs. Because of this, it can be hard to differentiate between actual hypothyroidism and falsely lowered levels of thyroid hormones. Various tests are available to diagnose and help differentiate between falsely lowered and actual hypothyroid patients. TSH response test, TRH, T3 levels, T4 levels, FT4 levels, anti-thyroid antibody levels, etc.
-
Treatment of feline hyperthyrodism: medications to block synthesis of thyroid hormone (methimazole, Felimazole brand, Tapazole, etc.), surgery to remove overactive gland, radioactive iodine to selectively irradiates and destroys overactive tissue, or diet change to limit iodine intake (Hill's feline Y/D food).
-
The renal threshold for glucose is ~_______ mg/dL in dogs and ~240 mg/dL in cats.
180 (mg/dL)
Relaxin can be measured in the bloodstream to confirm pregnancy ____ -_____ days after breeding.
25-32
An ________ stimulation test measures the adrenal's response to exogenous adrenocorticotropic hormone (ACTH). A baseline cortisol level is obtained, synthetic ACTH is given, and a second sample is drawn at set times post-administration. Animals with adrenal tumors have an exaggerated response while animals with hypoplastic adrenal glands have a diminished response.
ACTH
______________-Helps trigger and maintain lactation & secretion of milk by the mammary glands.
Prolactin
____________, a peptide hormone produced by the follicles, uterus and the placenta. Levels are consistently higher after implantation in the pregnant vs. non-pregnant bitch, so can be measured to confirm pregnancy.
Relaxin
__________ ______________ _____________ can be measured, often as part of a thyroid panel.
Thyroid stimulating hormone (TSH)
_________________ disease is characterized by recurrent episodes of gastroenteritis, a slowly progressive loss of body condition, and failure to respond appropriately to stress. Also called __________________.
addison's, hypoadrenocorticism
No test is 100% specific when it comes to _______function, so must be interpreted along with physical exam findings, concurrent test results, etc
adrenal
Which hormone stimulates growth and development of the adrenal cortex and release of some of its hormones?
adrenocorticotropic hormone (ACTH)
Rising _________ levels result in clinical signs of estrus.
estrogen
How often does the estrus cycle occur (after the first one)?
every 6 months
Hypothyroidism in the dog: -Overweight, less active than usual -"Tragic" expression in severe cases due to myxedema- thickening of the skin occurs secondary to accumulation of glycosaminoglycans (mostly hyaluronic acid) in the dermis. From Merck Veterinary Manual -Hair coat changes or failure of hair to grow back after shaving, grooming, etc. -Often have bilaterally symmetrical flank _____________.
alopecia
The adrenal cortex sex hormones are?
androgen, estrogen
Thyroid Hormone Testing, the hormones produced can be measured. T3 and T4 are produced when TSH from _____ _______reaches the thyroid gland.
anterior pituitary
The posterior Pituitary stores two hormones produced in the hypothalamus: 1.) ______-___________ ___________ 2.) _____________ -Transported from hypothalamus to posterior pituitary and stored in nerve endings. -Periodically released into the bloodstream in response to nerve impulses from hypothalamus.
anti-diuretic hormones oxytocin
The Hypothalamus secretes what? These hormones are transported to the posterior pituitary for STORAGE. And released into the bloodstream by nerve impulses from the hypothalamus.
antidiuretic hormone and oxytocin
When we give too many glucocorticoids over time, the adrenal glands ___________. This sudden withdrawal results in hypofunction unless you taper off the doses. Hypofunction of the adrenal glands is called _________.
atrophy, hypoadrenocorticism (Addisons Dz)
If a pet owner doesn't know their cat is in heat, they may misjudge 'lordosis' as what?
back injury
Which cells of the pancreas produce insulin? Which produces glucagon?
beta, alpha,
Calcitonin prevents hypercalcemia by encouraging excess calcium to be deposited in the _________. Calcium is involved in muscle contraction, blood clotting, milk letdown, and formation of the skeletal system.
bones
Calcium is bound to albumin in circulation, therefore, low albumin levels can result in falsely lowered __________ levels.
calcium
Parathyroid hormone is released in response to _________ levels. Produced by the parathyroid glands. Help maintain blood calcium levels by preventing hypocalcemia. PTH causes the kidney to retain Ca, withdraws Ca from bones and food.
calcium
After ovulation, LH stimulates cells in the empty follicle to multiply and develop into the ___________ ____________. -Corpus luteum produces progestin hormones necessary for the maintenance of pregnancy -In the male, LH stimulates interstitial cells to develop and produce testosterone.
corpus luteum
Hyperadrenocorticism, (Cushing's syndrome), results from excessive production and release of?
cortisol
The adrenal glands are located near the __________ ends of the kidneys.
cranial
The thyroid gland consists of two lobes on either side of the larynx. Thyroid hormone is produced in follicles. Simple ____________ glandular cells surrounding globule of thyroid hormone precursor.
cuboidal
____________ ___________ is a chronic disorder of carbohydrate metabolism due to insulin deficiency. Causes can be the destruction of pancreatic islet cells, secondary to either immune destruction or severe pancreatitis (dogs) or amyloidosis (cats).
diabetes mellitus
____________ _________________ (DKA) is a serious complication of diabetes mellitus and is considered a medical emergency. Treatment is by correcting fluid and electrolyte imbalances, insulin therapy and intensive/frequent blood glucose monitoring.
diabetic ketoacidosis
Hormone Secretion can be controlled by: 1) flight or fight 2) negative feedback 3) __________ stimulation from the nervous system.
direct
Antidiuretic Hormone (ADH) -Helps prevent ____________. -Receptors in hypothalamus detect changes in osmotic pressure of blood that result from dehydration/hemoconcentration, then stimulate release of ADH. -ADH travels to the kidney - causes kidneys to reabsorb more _________from the urine and return it to the bloodstream. -ADH deficiency causes diabetes insipidus (DI). -Pets affected with DI have chronic polyuria that does not respond to dehydration. Other causes of PU, such as renal disease, must be ruled out first. -Diabetes insipidus is diagnosed by the response to exogenous Desmopressin administration or a carefully monitored water deprivation test.
diuresis, water
The adrenal cortex mineralocorticoid aldosterone helps regulate the levels of __________ in the body.
electrolytes (mineral salts)
Diabetes Mellitus diagnosis is based on a persistent fasting ____________ of glucose accompanied by glycosuria.
elevation
Secreting a hormone internally/directly is called?
endocrine
Adrenal gland hormones include corticosteroids such as cortisol, and catecholamines such as ______________ and _______________. Also produce androgens and aldosterone.
epinephrine, norepinephrine
Typical protocol for initial T4 levels is to pull a ________ baseline for submission to the lab or in house testing. If monitoring levels after beginning supplementation with levothyroxine (Soloxine brand, others), the sample is pulled approximately 4-8 hours after the morning dose of medication to measure peak levels.
fasting
Secretion of some hormones is stimulated by sympathetic nerve impulses when an animal feels threatened, called the?
flight or fight response
Follicle-Stimulating Hormone (FSH): -In females, stimulates growth and development of ovarian ___________ - oogenesis. -Also stimulates cells lining the follicles to produce and secrete estrogens. -In the male, stimulates spermatogenesis.
follicles
The adrenal cortex produces numerous steroid hormones which can be broken down into three main groups: 1) _____________________ 2) Mineralocorticoids (aldosterone) 3) sex hormones (androgens/estrogens)
glucocorticoids
Glucagon is the opposite of insulin. Glucagon is stored in the pancreas and released in situations of very low blood ___________. It causes the liver to convert its stored glycogen into glucose, thereby raising the blood glucose level.
glucose
Insulin is responsible for _________ control and utilization.
glucose
Anterior pituitary - is also called the adenohypophysis; rostral portion. Regulates thyroid glands, adrenal glands, and produces ________ ____________. Stimulated by hypothalamus and direct feedback from target organs and tissues to produce its hormones
growth hormone
A chemical transmitter substance produced by cells of the body and transported by the bloodstream and other means to the cells and organs which carry specific receptors for the hormone and on which it has a specific regulatory effect?
hormone
UCCR, Urine Cortisol/Creatinine Ratio is only effective to rule out the diagnosis of _______________________. Easy, quick to perform. Collect first urine sample of the morning.
hyperadrenocorticism
The adrenal cortex glucocorticoid hormones cortisone, cortisol, and corticosterone have a ______________ effect. They also help maintain _______ ____________ and help the body resist the effects of stress.
hyperglycemic, blood pressure
A problem in cats of an overactive thyroid, typically caused by an adenoma, is called?
hyperthyroidism
Posterior pituitary - also called the neurohypophysis; caudal portion: Stores and releases hormones produced in the_____________ (ADH and oxytocin)
hypothalamus
The ____________ CONTROLS activities of the pituitary gland.
hypothalamus
Growth Hormone: -Produced in ________________. Released from anterior Pituitary. Also known as 'somatotropin' and 'somatotropic' hormone. -Promotes ________ ___________ in young animals. -Helps regulate the metabolism of proteins, carbohydrates, and lipids in all the body's cells. -Overproduction causes _______________. -Underproduction causes short stature or growth deficiency. -Diagnosis of acromegaly is by measuring serial GH levels. Affected animals have constant levels rather than the fluctuations seen in normal animals. -Can also be diagnosed by GH releasing hormone stimulation test.
hypothalamus, body growth, acromegaly (bones increase in size)
____________- hypofunction, usually occurs in dogs, horses, ruminants, and swine. Can be caused by dietary iodine deficiency, neoplasia, or autoimmune dz.
hypothyroidism
Pheochromocytoma is a RARE disease of the adrenal gland resulting in a tumor that causes _____________ secretion of catecholamines. Patients present tachycaridic, with edema. Diagnosis based on U/S of adrenal glands or exp. laparotmy.
increased,
Therefore, the _____ rise in progesterone correlates closely to the LH surge and can be used reliably to plan breeding during the bitch's peak fertile period.
initial
The endocrine pancreas produces hormones such as ____________., ____________, somatostatin, and others.
insulin, glucagon
______________ is a pancreatic tumor that secretes insulin. Diagnosis is based on fasting hypoglycemia (< 50) in spite of normal or elevated insulin levels.
insulinoma
Adrenals are near the proximal pole of _____________ (ad-renals).
kidneys
Hyperthyroidism in the cat is typically a middle-aged to older cat (older than 8 years of age) Weight _____ in spite of normal to increased appetite, intermittent vomiting, possibly increased thirst or urination, hyper-excitability, possible cardiac murmur, and possible palpable thyroid enlargement.
loss,
Should not use EDTA, oxalate or citrate anticoagulants to collect CALCIUM sample since they bind with calcium and result in _____ levels.
low
Some malignancies (lymphoma, anal sac carcinoma, etc.) produce PTHrP, parathyroid related protein which mimics the effect of PTH and results in hypercalcemia. In this way, hypercalcemia can be a marker for __________ cancer.
malignant
Feline reproduction: an egg is not released unless _________ has occurred. Making cats what?
mating, induced ovulators
The adrenal __________ produced epinephrine and norepinephrine. Secretion is controlled by the sympathetic portion of the autonomic nervous system. Fight or flight response. Increases HR and output, increases BP, dilates air passageways in the lungs, and decreases GI function.
medulla
Melanocyte-Stimulating Hormone (MSH): -Associated with control of color changes in the pigment cells (____________) of reptiles, fish, and amphibians. -Administration of artificially large amounts of MSH to higher mammals can cause darkening of the skin from melanocyte stimulation.
melanocytes
Function of the thyroid gland is to regulate the rate of ? It also affect the growth and rate of function of many other body systems. The principle hormones made are?
metabolism, T3 and T4
A false pregnancy occurs most frequently in dogs. Mammary development, nesting, aggression, etc. Will occur in following heat cycles too. These dogs should be spayed. What is the medical term for false pregnancy?
pseudocyesis
Hyperparathyroidism can be primary from parathyroid tumor or secondary as a consequence of _______ failure.
renal
Cats are ____________ polyestrous. This means that during times of prolonged sunlight, (approximately 12 hours per day), they will continue to cycle in and out of estrous until bred, or the season changes.
seasonally
AMH, the anti Mullerian hormone, tests for a protein produced by ovarian follilcles. Can be run during estrus and anestrus and helps determine if a female dog is _______________
spayed
Pancreas is adjacent to proximal duodenum and greater curvature of ___________ in dog.
stomach
The adrenal glands are responsible for releasing hormones in response to?
stress
A feline heat cycle lasts 2-3 weeks and they can mate with more than one male, having mutlipe fathers to their kittens. The term for this is?
super fecund
Ovarian Remnant Syndrome: signs of estrus in previous spayed animal. Caused by ____________ error, or ectopic ovarian tissue.
surgical
What hormone is tested for in stallions to help detect testicular tissue in potential cryptorchids?
testosterone
Thyroid Stimulating Hormone (TSH) -Stimulates growth and development of ___________ gland and causes it to produce its hormones. -Secretion is regulated by ______________- from the thyroid gland. -Thyroid imbalances are usually a result of thyroid gland disease, but can also be related to pituitary dysfunction or tumor.
thyroid, feedback
What is another name for TSH?
thyrotrophic hormone
Thyroid and parathyroid are located adjacent to the?
trachea
Endocrine disorders are the result of overproduction or underproduction of hormones. True or false?
true
Older ferrets commonly have an enlarged and overactive adrenal gland caused by an adrenal _______
tumor
The pituitary gland is made up of _____ separate glands with different structures, functions, and embryological origins.
two
What test can help pinpoint a dog's fertile days?
vaginal cytology
Pituitary gland (hypophysis) is located on the __________ aspect of the brain, adjacent to the caudal roof of the mouth in most species. Controlled by the hypothalamus in the brain.
ventral
Can a bitch be bred to more than one male resulting in different sires for different puppies?
yes