basically science (1&2)
Can you describe autocrine cell signaling?
specialized cell secretes chemicals to signal nearby cells of the same type
Which cells of the endocrine pancreas secrete insulin? What kind of hormone is insulin?
B cells, protein hormone
What is the main stimulus for thyroid production? what inhibits it?
stimulus: cold/decreased body temperature
inhibition: stress and increased T3/T4
Growth hormone is released from the _____________ and acts directly on ___________ ____________ and indirectly on __________ and ____________ due to ________ _______ ________ __________. It also has _________ __________ effects, which force the use of lipids for energy instead in glucose-independent tissues.
anterior pituitary
directly on adipose tissues and indirectly on liver and muscle (insulin like growth factor)
anti-insulin
What is the role of aldosterone and name some target tissues?
reabsorption of water and sodium, excretion of potassium and hydrogen
distal tubules, collecting ducts, salivary glands, sweat glands, gastric mucose
what are characteristics of steroid hormones?
lipophilic, have intracellular receptors, are bound to proteins in circulation, quickly produced and released, longer half life
What is the MAIN stimulus for insulin secretion?
HYPERglycemia
Which hormones are released from hypothalamus, anterior pituitary, and from thyroid gland for this pathway?
hypothalamus: TSH releasing hormone/thyrotropin releasing hormone
AP: thyroid stimulating hormone
thyroid gland: T3/T4
What is acromegaly and what other disease can have similar clinical signs?
excess growth hormone
diabetes mellitus
What causes ventroflexion to be one of the most common clinical signs of hyperaldosteronism?
increased aldosterone increases K+ excretion, hypokalemia causes ventroflexion and flaccid paresis
What hormones are secreted from the posterior pituitary?
ADH (anti-diuretic hormone)
oxytocin
T/F: alpha cells of the pancreas are insulin insensitive. explain your answer.
false: alpha cells are insulin SENSITIVE. they need to sense when glucose is high/low which is indicated by the presence/absence of insulin.
glucagon is inhibited by insulin/hyperglycemia.
How does excess thyroid hormone affect the circulatory and respiratory system?
tachycardia, hypertension, tachypnea, increased inotropic (heart contraction) and chronotropic (heart rate) effects = beta-1-receptor excitability!!
What is the most common cause of cushings syndrome in animals? Name some clinical signs.
adenomas of the AP cause excess ACTH, excess cortisol = pituitary dependent hyperadrenocorticism
PU/PD, alopecia around chest or abdomen, polyphasia (anti-insulin, affects satiety), pendulus abdomen!!!!, hepatomegaly, hypertension
Name the three hormones and three organs primarily involved in Ca-P homeostasis.
Parathyroid hormone, vitamin D, calcitonin
GI, bone, kidney
CRH, TRH, GnRH, GHRH, PRL all come from the WHAT?
What are their full names?
hypothalamus
corticotropin releasing hormone
thyrotropin releasing hormone
gonadotropin releasing hormone
growth hormone releasing hormone
prolactin releasing hormone
Name some common clinical signs of diabetes mellitus and explain their basic mechanism.
persistent hyperglycemia, glucosuria, polyuria/polydipsia
glucose in plasma is not being used by tissues, becomes too much for kidney to filter and eventually glucose is excreted when it's not supposed to be. glucose is osmotically active, water will follow causing pu/pd. bacteria also love glucose, cause increased UTI frequency
What are the effects of thyroid hormone excess and hormone deficiencies in young vs adult animals?
young animals: excess thyroid hormone accelerates growth (anabolic), eventually stunted growth bc epiphysis close too early
deficiency causes cretinism (CNS and body growth retardation)
adult animals: excess causes weight loss (catabolic)
deficiency causes weight gain
name the effects of glucocorticoids on the liver and extra-hepatic tissues.
liver: INCREASE in gluconeogenesis, glycogenesis, protein synthesis, ketone bodies and VLDLs, glycogenolysis (bc glucagon stimulation, cortisol has anti-insulin effects)
extra-hepatic: decreased glucose uptake, increased proteolysis & lipolysis (fat is distributed to abdomen)
How does the body compensate for chronic hypocalcemia?
PTH is released due to low calcium levels, calcium is mobilized from bone. long term can cause softening/demineralization/osteomalacia = compensatory hyperparathyroidism
A) Describe the hypothalamic-pituitary portal system.
B) What is the pars intermedia and what does it secrete?
A) between the hypothalamus and the anterior pituitary (aka adenohypophysis), neuroendocrine cells from hypothalamus extend axons into first capillary bed (no BBB), hormones diffuse from first to second capillary bed, and reach endocrine cells of AP to inhibit or stimulate tropic hormones
B) middle of the pituitary gland, MSH (melanocyte secreting hormone)
A 6-year-old Persian cat named Praline comes into your clinic with polyuria, polydipsia, and what appears to be cataracts in her right eye. What is the most likely diagnosis? What would you expect to see on bloodwork if you could measure anything you wanted?
Type II diabetes (more common in middle aged cats)
hyperglycemia and hyperinsulinemia and fructosamines!! (what would you see in type 1?)
In what species/age is hyperthyroidism most common? Name common clinical signs.
do the same for hypothyroid :)
hyper: middle-aged/older cats caused mainly by adenomas of the thyroid (benign tumor) CS: weight loss, hyperactivity, heat intolerance, increased temp, tachycardia!!!, high BP, retinal detachment, rapid claw growth
hypo: middle aged/older dogs mostly caused by defects of thyroid CS: variable but commonly weight gain, heat seeking, skin changes!!! alopecia, seborrhea, pigmentation, myxedema (hyaluronic acid accumulation in face and tail)
A 4-year-old male boxer named Hector comes into the clinic panting with clear alopecia over several areas. There is a pendulous appearance to the abdomen, and owner says he has been eating like crazy over the past few months. You discover this pet has been given glucocorticoid therapy for severe allergies since January. How would you expect the plasma ACTH to look upon evaluation?
ACTH would be decreased because of the negative feedback loops. increased cortisol from the drugs would inhibit CRH which inhibits ACTH from being released
Describe the pathogenesis of milk fever vs eclampsia.
Milk fever: high producing dairy cows 3ish days post birth after 3/4 lactations, mild hypocalcemia = flaccid paresis at first (can't stand, lateral recumbency), later complete flaccid paresis, coma and death
eclampsia: small dogs at peak lactation 2-3 weeks post whelping, acute hypocalcemia, increases conductivity of Na+ channels, excitation, tremors, tetany, tachycardia