Exam 1 Flashcards
What are peptide hormones
Chains of AA that are hydrophilic and have receptors on the cell membrane examples are calcitonin, insulin, and melatonin
What are steroid hormones
Cholesterol based so they are hydrophobic and have receptors in the cytoplasm or nucleus examples are estrogen and cortisol
What are monoamine hormones
Made of AA that can be hydrophilic such as catecholamine hormones (epi and norepi) and hydophobic such as thyroid hormones
What are the endocrine glands
Hypothalamus, pineal gland, thryoid gland, parathyroid gland, adrenal gland (cortex and medulla), pituitary gland (anterior and posterior), pancreas, ovary, and testes
Where is the hypothalamus and what does it regulate
It is part of the diencephalon and it regulates the appetite, body, temperature, and wake-sleep cycles and serves as the link btw the nervous and endocrine systems by signaling the pituitary gland and receive signals from the body
What is another name for the pituitary
Hypophysis
What are the different receptors in the hypothalamus and what do they sense
Neurons sense blood glucose and hormones (leptin causes satiety), ghrelin stimulates appetite, thermoreceptors, and osmoreceptors stimulate ADH and thirst center in the hypothalamus
How do neurons in the hypothalamus respond to the cold
By causing peripheral vasoconstriction, pilerection, and shivering
What is piloerection
Goosebumps caused by muscle contraction in a hair follicle
How do neurons in the hypothalamus respond to heat
Peripheral vasodilation, sweating, and panting
What are the releasing hormones produced by the hypothalamus that affect the anterior pituitary
Thyrotropin releasing hormone, growth hormone releasing hormone, gonadotrophin releasing hormone, prolactin releasing hormone, and alpha melanocyte stimulation hormone
What are the inhibitory hormones produced by the hypothalamus that affect the anterior pituitary
Growth hormone inhibiting hormone (somatostatin), gonadotrophin inhibiting hormone, and dopamine
What hormones are produced by the anterior pituitary
Growth hormone (GH), prolactin, thyroid stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), follicle stimulating hormone, lutenizing hormone, and melanocyte stimulating hormone
What is the effect of ADH
Water resorption in kidney
What is the effect of oxytocin
Uterine contraction and milk release from mammary gland
How are hormones transfered from the hypothalamus to the posterior pituitary
The hormone are transported along nerve fibers and stored in nerve endings
How are hormones from the hypothalamus sent to the anterior pituitary
The portal vein system
What does ADH act on and function
Acts on the kidneys to reabsorb water it is released with increased osmotic pressure (dehydration) to increase the concentration of urine
How is urine specific gravity affected by dehydration
It should increase w/ dehydration if everything is working properly
What can inhibit the release of ADH
Caffeine and alcohol
What does ADH deficiency lead to
Central diabetes insipidus which causes the urine volume to increase and the USG to decrease
What does oxytocin cause in the body
Contraction of the myometrium of the uterus and contraction of the myoepithelial cells in the mammary glands
In what situations is injectable oxytocin good for
Dystocia, retained fetal membranes, post op C-cection, and if the dam has a poor milk supply
What does TSH do
It stimulates growth/development of the thyroid gland and production of its hormones so it has a potent negative feedback on TRH and TSH secretion by thyroid hormones
What does ACTH do
Stimulates the growth and development of the adrenal cortex and release of its hormone
What does GH (somatotropin) do
Promotes growth in young animals and regulates metabolism of proteins, carbs, and lipids throughout life
How does GH regulate the metabolism of proteins
Uses the anabolism of proteins for ongoing repair in the body
How does GH regulate the metabolism of lipids
It mobilizes lipids from fat with catabolism for energy production
How does GH regulate the metabolism of carbs
Discourages cells from using carbs in case of a hyperglycemic event
What does FSH do in females
Stimulates growth/development of follicles in ovaries (oogenesis) and stimulates estrogen production from the follicles
What does FSH do in males
Causes spermatogenesis
What does LH do in females
Completes follicle development that FSH started, increases w/ estrogen, and supports the corpus luteum that develops after ovulatio
What does LH do in males
Stimulates the interstitial cells in the testes to produce testosterone
What does prolactin do
Triggers and maintains milk production and in order for this hormone to continue to be produced nursing must be occuring
What does MSH do
It is responsible for the pigment/color change in melanocytes of reptiles, fish, and amphibians
What is the pineal gland
A pine cone shaped gland just rostral to the cerebellum
What is the function of the pineal gland
Informs the rest of the body about environmental light utilized for biological rhythms (circadian rhythm) and reproductive cycles
What can melatonin be used for
Pattern baldness and seasonal flank alopecia, canine cognitive dysfunction, and immune-mediated hemolytic anemia (IMHA) for cytokine production and immune-mediated thrombocytopenia (ITP) for an increased platelets
What is the parathyroid gland
It is closely associated w/ the thyroid gland that produces parathyroid hormone
What does PTH do in the body
It is involved in blood calcium homeostasis by preventing hypocalcemia and it causes kidneys to retain calcium that the intestines absorb from food, and withdraws it from bone
What might be connecting the thyroid glands
The isthmus
What comprises the thyroid gland on a microscopic level
Follicles and parafollicular cell (c cell)
What are the 2 parts of the follicles of the thyroid gland
The colloid and the follicular cell
What is the active form of thyroid hormone
T3 triiodothronine
What is the precursor of T3
T4 that is converted to T3 by the liver, kidney, and muscle
What are the affects thyroid hormone has on the body
Calorigenic effect, protein/carb/lipid metabolism, and growth/development of juveniles
What is the calorigenic effect of thyroid hormone
It maintains body temp by regulating metabolism
What can inhibit the thyroid hormones calorigenic effect
Emotional or physical stress
How does thyroid hormone affect protein, carb, and lipid metabolism
Anabolism of protein, hyperglycemic effect, and catabolism lipids
What growth/development is affected by the thyroid hormone
CNS, muscle, and bone
What produces calcitonin in the thyroid gland
C cells
What does calcitonin do in the body
It prevents hypercalcemia by inhibiting the breakdown of bone by osteoclasts and decreases reabsorption by kidney
What species is more likely to have hypothyroidism
Dogs
What are the 2 primary causes of hypothryoidism
Autoimmune or idiopathic atrophy of the thyroid gland
What are clinical signs of hypothryoidism
Lethargy, seeking warmth, weight gain w/o increasing consumption/appetite, alopecia around trunk or tail, tragic expression, discoloration of skin, and chronic ear/skin infections
What are common breeds that we see hypothryoidism
Golden retrievers, doberman pinschers, irish setters, dachshunds, cocker spaniels, and airedale terriers
What are the 2 tests that we use to primarily test for hypothyroidism
Free T4 and TSH
What species is a total T4 test good for
Cats
What are the different thyroid tests
Free T4, total T4, TSH, T3, TSH response test, and thyroid panel
What does a thryoid panel include
Total T4, fT4ed, T3, TSH, and antibodies
How is a TSH test done
Draw blood, inject TSH, then draw again 6 hrs later, and compare results
What is the treatment for hypothroidism
Levothyroxine
What is the most frequently diagnosed endocrine disease in cats
Hyperthryoidism
What causes thyrotoxicosis
A benign mass on one or both lobes of the thyroid gland
What age do we tend to start seeing hyperthyroidism in cats
8+ commonly ages 12-13
What are clinical signs of hyperthyroidism
Weight loss despite good appetite, behavior change, vomiting, diarrhea, PU/PD, unkempt haircoat, thyroid gland enlargement, tachycardia, heart murmur, and around 10% can get depressed and decreased appetite
What is a thyroid slip
When the thyroid gland gets larger allowing it to be felt along w/ a small lympth node behind it
What diagnositic tests are done for hyperthyroidism
CBC, chemistry, and total T4
How does a cats thyroid level naturally do as they age
They decrease so you could have a cat w/in “normal” levels but still be hyperthyroid
What are the treatment options for hyperthyroidism
Diet, long term medication, radioactive iodine therapy, and surgery
What medication is commonly used for hyperthyroidism and what does it do
Methimazole controls the production of the thyroid hormone
What are the follow up steps when giving medication for hyper or hypo thryoidism
After 2-4 weeks do a total T4 to see if medication dose needs adjusting when treating for hyperthyroidism monitor liver valuse
What are side effects to methimazole
Vomiting, anorexia, fever, anemia, lethargic, facial pruritus, and exoriations
What can long term use of methimazole possibly cause
Liver damage and bone marrow suppression
How long should cats stay isolated after recieving radioiodine therapy
About 4-5 days
How long after radioiodine treatment should a T4 be rechecked
1 and 3 months post treatment
What risk comes w/ surgically removing thyroid glands
Laryngeal paralysis
Where are the adreneal glands located
Near the cranial polls of the kidneys
What are the 2 parts of the adrenal gland
Adrenal cortex and adrenal medulla
What hormones are produced by the adrenal cortex
Glucocorticoids (cortisol), mineralocorticoids (aldosterone), and sex hormones
Where are mineralocorticoids produced in the adrenal cortex and what do they do
They are produced in the outer layer of the cortex and they regulate the electrolyte levels
Where are the glucocorticoids produced in the adrenal cortex and what do they do
They are produced in the middle layer and they cause general hyperglycemic effect, help maintain BP, and help the body resist effects of stress
What does the adrenal medulla resemble
Nervous tissue
What 2 hormones are produced in the medulla
Epinephrine and norepinephrine
What is cushing’s disease
Hyperadrenocorticism
What causes hyperadrenocorticism
Pituitary over production of ACTH or adrenal over production of corticosteroid
What are the clinical signs of hyperadrenocorticism
Bilateral symmetric alopecia, PU/PD/polyphagia, muscle weakness, panting, pendulous abdomen, recurrent UTI, lethargy, pyoderma, and skin fragility (cats)
What are the baseline labs that are ran when suspecting hyperadrenocorticism
CBC, chem panel, urinalysis
What are findings on the baseline labs if the patient has hyperadrenocorticism
elevated alkaline phosphatase, hyperglycemia, hypercholesterolemia, and thrombocytosis
What are other diagnostic tests that we use to confirm hyperadrenocorticism
Urine cortisol:creatinine ratio (UCCR), ACTH stimulation test, low dose dexamethasone suppression test (LDDST), and high dose dexamethasone suppression test (HDDST)
What are the 2 tests do we run most often when definitively diagnosting hyperadrenocorticism
ACTH stimulation test and LDDST
What is the UCCR
A screening test to see if there is more cortisol to creatinine in the urine this test is not considered diagnostic and is only ran if you really think its cushings and you need a small confirmation
What does the ACTH stimulation test show
Elevates degree of response to administration of exogenous ACTH that will show an exaggerated response if cushing’s is present
What is the only test we do for hypoadrenocorticism and what does it show
ACTH stimulation test which will show a diminished response
What is the procedure of an ACTH stimulation test
Collect baseline blood sample, administer ACTH, give synthetic ACTH IV or IM, collect blood sample 1-2 hrs after, send to lab, and get results
What is the procedure for an LDDST
Collect a fasted blood sample early in morning, administer low dose of dexamethasone IV, collect blood sample at 4 & 8 hrs after, send to lab for measuring of the cortisol levels if there is no change then it is diagnostic for hyperadrenocorticism
What is the procedure of HDDST
Collect blood sample, administer dexamethasone IV, collect blood at 4&8 hrs after, look at results to determine if the cushings is pituitary (levels fall at 4 hr mark) or adrenal based (no change at the 4 hr mark)
What medications are used for hyperadrenocorticism
Mitotane (lysodren) destroys glucocorticoid secreting cells and trilostane (vetoryl) inhibits enzyme needed for glucocorticoid and mineral corticoid production
What monitoring is done after treatment for hyperadrenocorticism is started
ACTH stimulation and trough cortisol level
What is addison’s disease
Hypoadrenocorticism which is a lack of cortisol or aldosterone
What are clinical signs of hypoadrenocorticism
Waxing (worse) and waning (getting better) of lethargy, anorexia, vomiting, diarrhea, weight loss, shaking, and PU/PD
What does the mineralocorticoid deficiency mean for addison’s patients
They have an inability to excrete potassium and retain sodium leading to hyperkalemia which can cause myocardial toxicity or hyponatreia which can cause dehydration, hypotension, weakness, and depression
What does glucocorticoid deficiency mean for addison’s patients
Leads to anorexia, vomiting, and lethargy
What is typical addison’s disease
Missing both glucocorticoids and mineralcorticoid
What is atypical addison’s disease
Only missing glucocorticoids
What are diagnostic tests for hypoadrenocorticism
CBC, chem, UA, and ACTH stimulation test
What is are the treatments for hypoadrenocorticism
Lifelong glucocorticoid and mineralcorticoid replacement therapy, increases glucorticoids are required for stressful times, extremely low dose of prednisone, DOCP (desoxycorticosterone pivalate) injection, and fludrocortisone acetate
What routine testing should be done for patiets w/ hypoadrenocorticism
BUN, creatinine, and electrolyte levels
What are clinical signs of an addisonian crisis
Sudden weakness, shock, collapse, vomiting, and diarrhea due to inability to compensate for stress this is a life threatening emergency
What ae diagnostics to due during an addisonian crisis
Bloodwork including electrolytes that could show hyperkalemia, hyponatremia, and hypoglycemia and BP that could be hypotensive
What are treatments for an addisonian crisis
IV fluids +/- dextrose, dexamethasone sodium phosphate, DOCP, and calcium gluconate
What is the exocrine pancreas function
Excretes enzymes to break down the proteins, lipids, CHOs, and nucleic acids in food
What is the endocrine pancreas function
Islets langerhans such as alpha cells, beta cells, and delta cells produce glucagon, insulin, and somatostatin respectively
What does glucagon do
Has a hyperglycemic effect by stimulating the breakdown of glycogen stored in liver and hepatic gluconeogenesis from fat/protein to increase blood sugar
What does insulin do
Facilitates glucose, AA, and FA entry into cells to lower blood glucose and stimulates the liver to store glucose as glycogen
What does somatostatin do
Inhibits secretion of other hormones such as GH, TSH, glucagon, and insulin it also is produced by the GI epithelium to reduce secretion of gastric acid, gastrin, secretin, and pepsin
What is type 1 diabetes mellitus
When the pancreas does not produce enough insulin (dogs)
What is type 2 diabetes mellitus
Does not respond to insulin present (cats)
What age range does diabetes mellitus occur
Middle age to older dogs and cats, more common in female dogs and male cats, and obese cats
Predisposing factors of endocrine diseases
Overweight or obese, inflammation of pancreas, long term corticosteroid use, and other metabolic disease such as hyperadrenocorticism and hyperthyroidism
What can untreated diabetes mellitus lead to
PU/PD because water follows sugar, sugar is deprived from the brain so their appetite increases and polyphagia, use stored energy sources and lose weight creating ketone bodies
What can untreated pets w/ diabetes mellitus get
Bladder, kidney, and skin infections, blindness, and nerve and muscle dysfunction
What type of diabetics should be hospitilized
Diabetics w/ ketoacidosis
What are the 2 main tests that are used to diagnosis diabetes
Blood test (hyperglycemia) and urinalysis (glucosuria and ketonuria)
What treatment methods are used w/ diabetic patients w/ ketoacidosis
IV fluids w/ rapid acting insulin
What are other treatments for diabetic cats
Glipizide (glucotrol), bexagliflozin (bexacat), velagliflozin (senvelgo), and special diet (low carb)
What are the types of insulin used
Short acting (regular), NPH/lente are intermediate acting, and ultralente/PZI are long acting (dogs)
What insulin can push cats into remission most often
Glargine
What are frequently preformed diagnostics that are used to monitor diabetics
Glucose curve, continuous glucose monitoring, urine dipstick, and fructosamine
What is a glucose curve
Insulin glucose response curve measures blood glucose every 1-2 hrs for 12-24 hrs to figure out which insulin to use, how much to give, how often to give, and best time to feed animals
What is the somogyi phenomenon
To much insulin is given glucagon is released to increase the blood sugar
What is continuous glucose monitoring
The freestyle libre measures interstital glucose concentration
What is a fructosamine test
Tests for glycated albumin or other proteins to show regulation for the past 2 weeks this is very helpful in cats
What are proper ways to handle insulin
Less effective if it gets too hot or cold, should be refrigerated, has an expiration date, and should be gently mixed
What are signs of hypoglycemia
Weakness, staggering, seizures, and lethargic
What are complicating factors that make managing diabetes mellicus difficult
Periodontal disease, UTIs, cushing’s disease, and intact females
What is diabetes insipidus
A central or nephrogenic issue with ADH secretion
What is central diabetes insipidus
Deficiency of ADH secretion this starts at a young age
What is nephrogenic diabetes insipidus
Kidneys insensitive to ADH this can occur at any age
What are signs of diabetes insipidus
PU and PD
What are ways to diagnosis diabetes insipidus
Water deprivation test and ADH therapeutic trial
What is treatment for diabetes insipidus
Daily desmopressin
What triggers the production of testosterone from leydig cells
LH
What does testosterone cause males to do
Develope male secondary characteristics, acessory sex gland development, and spermatogenesis
What is produced as a response of FSH in females
Estrogen which leads to physical and behavioral changes that prepare the female for breeding and pregnancy
What is produced in the reponse of LH in females
Progesterone which prepares the female to receive a fertilized ovum and maintain pregnancy
What does hypoxemia cause the kidneys to produce
Erythropoietin to increase RBC production
What does gastrin do in the stomach
Stimulates gastric acid secretion and muscular contraction of stomach wall
What does secretin do in the small intestine
Stimulates pancreas to secrete fluid rich in sodium bicarbonate into the duodenum to neutralize chyme
What does cholecystokinin do in the small intestine
Stimulates the release of digestive enzymes from the pancreas into the duodenum
What enzymes inhibit gastric acid secretion and gastric motility
Secretin and cholecystokinin
What does the thymus produce
Thymosin and thymypoietin stimulates T cell development
