Book Questions for Quiz 1 Flashcards
Which one of the following is the least involved in regulating plasma Ca, Mg, and PO4 levels?
a. kidney
b. parathyroid gland
c. bone
d. hypothalmic-pituitary axis
e. GI tract
d. hypothalamic-pituitary axis
The free cytoplasmic Ca concentration is normally about how many times lower than the plasma concentration?
10,000
Appox. what percentage of plasma Ca is normally protein-bound?
40%
Which one of the following attributes is best associated with Ca?
a. activates PKA
b. intracellular 2nd messenger
c. urinary buffer
d. second most plentiful cytoplasmic cation
e. normally chelated cytoplasmic ATP
b. intracellular 2nd messenger
What percentage of Ca traversing the canine intestinal lumen is normally absorbed each day?
40%
Intestinal calcium absorption is reduced by:
glucocorticoids
Which one of the following normally has the lowest renal reabsorption efficiency?
a. tyrosine
b. PO4
c. glucose
d. Ca
e. Mg
b. PO4
Which one of the following typically has the highest absorption efficiency in the GI tract, and is not bound in the plasma to protein?
a. Ca
b. PTH
c. PO4
d. Mg
e. Insulin
c. PO4
Renal diseases affecting the proximal tubules could have profound influences on the plasma concentration of which of the following?
a. Ca
b. glucose
c. PO4
d. tyrosine
e. all of the above
e. all of the above
Phosphate is found in erythrocytes in association with:
membrane-bound phospholipids, 2,3-BPG, carbohydrate metabolism intermediates, ATP
PTH, either directly or indirectly, stimulates all of the following, except:
a. bone resorption
b. adenyl cyclase activity in its target cells
c. renal Ca absoprtion
d. renal PO4 reabsorption
e. renal vit D activation
d. renal PO4 reabsorption
Which of the following is/are true?
a. osteoblasts possess 1,25(OH)2D receptors
b. osteoclasts possess CT receptors
c. osteoblasts are capable of producing cytokines that activate osteoclasts
d. osteoblasts possess PTH receptors
e. all of the above
e. all of the above
Which one of the following exerts the greatest positive influence on PTH release?
a. stress
b. a low serum ionized PO4 concentration
c. a low serum ionized Ca concentration
d. a low serum ionized Mg concentration
e. estrogen
c. a low serum ionized Ca concentration
Select the true statements below regarding the kidneys and the Ca/PO4 homeostasis:
a. PTH promotes Ca reabsorption and urinary PO4 concentrations
b. loop diuretics promotes Ca retention
c. PTH promotes HCO3 retention and urinary Ca excretion
d. thiazide diuretics enhance urinary Ca excretion
e. all of the above
a. PTH promotes Ca reabsorption and urinary PO4 excretion
The circulating half life of PTH in mammals is about:
20 min
Pseudohyperparathyroidism is due to elevated serum levels of:
PTH
Which portions of the functional nephron have no PTH receptors?
CDs
Select the true statement below regarding CT:
a. it has a greater influence on overall Ca homeostasis than PTH
b. it inhibits intestinal Ca absorption
c. it’s release is inhibited by gastrin
d. it may protect the skeleton of the dam from excess Ca loss during pregnancy
e. it’s synthesized and secreted by the parathyroid glands
d. it may protect the skeleton of the dam from excess Ca loss during pregnancy
Select the true statement below regarding calcitriol:
a. formation from D3 requires normally functioning hepatocytes and kidneys
b. inhibits bone resorption
c. receptors for the seco-steroid are found in osteoclasts
d. inhibits the action of PTH in kidney
e. the dehydroxylated form of the compond is known as calcitonin
a. formation from D3 requires normally functioning hepatocytes and kidneys
Which hormone stimulates CT secretion, inhibits the action of PTH on bone, and helps to activate vitamin D in the kidney?
estrogen
Which vit D derivative is physiologically active without being hydroxylated by the kidneys?
DHT
The “anticipatory” hormone for CT release appears to be:
gastrin
A more potent hypocalcemic factor in mammals than endogenous CT appears to be:
salmon CT
Plasma ionized Ca levels are typically elevated in:
primary hyperparathyroidism
Pathophysiological effects associated with hypocalcemia includes all of the following, EXCEPT:
a. coagulopathies
b. prolonged Q-T intervals of the ECG
c. bronchospasm
d. hypercalcemia
e. nephrocalcinosis
e. nephrocalcinosis
Malabsorption secondary hyperparathyroidism is best associated with:
hypocalciuria
What is the second most reported cause of hypercalcemia in dogs?
pseudohyperparathyroidism
Renal secondary hyperparathyroidism is best associated with:
reduced renal 1alpha-hydroxylase activity
Pathophysiologic effects associated with hypercalcemia include all of the following, EXCEPT:
a. fatigue
b. bone dissolution
c. increased neuromuscular excitability
d. constipation
e. metabolic acidosis
c. increased neuromuscular excitability
The acute hypophosphatemia seen with milk fever in dairy cows is potentially associated with:
hemoglobinuria
Dairy cows fed a low rather than a high Ca prepartal diets:
are more capable of mobilizing Ca from bone at the time of parturition
Hormones affect diverse metabolic functions by:
increasing or decreasing the rates of specific reactions inside target cells
All of the following are considered to be endocrine organs, EXCEPT:
a. kidneys
b. pineal glands
c. lungs
d. GI tract
e. parathyroids
c. lungs
Thyroid hormone action is dependent upon:
concurrent effects of antagonistsic or synergistsic hormones, the rate of synthesis and/or secretion of T4 from the thyroid gland, the plasma concentration of liver-derived transport proteins, and conversion of T4 to a more active form within target cells
The CNS is a major component of the endocrine system and neurons can produce and secrete hormones into blood
True
Which chemical regulator below, would have difficulty passing through most cell membranes of the body?
a. eicosanoid
b. biogenic amine
c. steroid
d. thyroid hormone
e. none of the above (all exhibit high lipophilicity)
b. biogenic amine (ex: epinephrine)
Select the true statements below:
a. a given hormone might affect several different cell types
b. over 50 different hormones are known to exist in mammals
c. more than one hormone can affect a given cell type
d. hormones exist in bacteria, worms, insects, and plants
e. all of the above
e. all of the above
Which one of the following best exemplifies an autocrine secretion?
a. a pheromone secreted through an exocrine duct to the body surface
b. estrogen secreted from the ovary into the vascular system
c. a chemical messenger acting on neighboring target cells without entering the circulation
d. thromboxane secreted by a platelet to then act on that platelet to promote its aggregation to other platelets
e. a NT released into blood to affect target cells at distant locations
d. thromboxane secreted by a platelet to then act on that platelet to promote its aggregation to other platelets
Select the true statement below:
a. prostaglandins are polypeptide hormones secreted in an autocrine fashion
b. the pars nervosa is primarily controlled by release and release-inhibiting hormones from the hypothalamus
c. there is considerable structural conservation of chemical messengers across species lines
d. the anterior pituitary controls release of PTH from the parathyroids, and glucagon from the pancreas
e. the only known endocrine function for PRL is to stimulate milk production and secretion in mammals
c. there is considerable structural conservation of chemical messengers across species lines (from invertebrates to vertebrates)
Which adenohypophyseal hormone stimulates hepatic IGF-1 release?
GH
What is known to inhibit PRL, ACTH, TSH, and alpha-MSH release from adenohypophysis?
dopamine
What is the major adenohypophyseal endocrine-secreting cell type in mammals?
somatotroph
Which of the following statements regarding the anterior pituitary is true?
a. it secretes tropic hormones that promote insulin release
b. it comprises about 80% of total pituitary weight in most species
c. it secretes primary release and release-inhibiting hormones into the systemic circulation
d. it stores neuropeptides, like the posterior pituitary
e. all of the above are true
b. it comprises about 80% of total pituitary weight in most species
Select the false statement below:
a. oxytocin is stored in and secreted from the neurohypophysis
b. circumventricular organs appear to be independent of the blood-brain barrier evident in other sections of the CNS
c. ACTH is produced by the equine and canine pars intermedia
d. opioid peptides have no influence on anterior pituitary hormone secretion
e. the gonadotropins and TSH are glycoproteins
d. opioid peptides have no influence on anterior pituitary hormone secretion
