midterm 1 Flashcards
Which ion does have higher intracellular than extracellular concentration?
Sodium Chloride Calcium Potassium Bicarbonate
Potassium
The function of which of the following is increased by an elevated parathyroid hormone concentration?
Osteoclasts
Hepatic formation of 25-hydroxycholecalciferol
Phosphate reabsorptive pathways in the renal tubules
All of the above
Osteoclasts
What does cause nervous system excitement and tetany?
High concentration of calcium ions in the extracellular fluid
Low concentration of calcium ions in the extracellular fluid
High concentration of chloride ions in the extracellular fluid
High concentration of magnesium ions in the extracellular fluid
Low concentration of potassium ions in the extracellular fluid
Low concentration of calcium ions in the extracellular fluid
A 30-year-old woman is breast-feeding her infant. During suckling, which of the following hormonal responses is expected?
*
1-Increased secretion of antidiuretic hormone (ADH) from the supraoptic nuclei
2-Increased secretion of ADH from the paraventricular nuclei
3-Increased secretion of oxytocin from the paraventricular nuclei
4-Decreased secretion of neurophysin
5-Increased plasma levels of both oxytocin and ADH
3-Increased secretion of oxytocin from the paraventricular nuclei
From what steroid hormones are usually synthesized?
Tyrosine Glucose Cholesterol Phospholipids DNA
Cholesterol
Why is it important to feed newborn infants every few hours?
*
The hepatic capacity to store and synthesize glycogen and glucose is not adequate to maintain the plasma glucose concentration in a normal range for more than a few hours after feeding
If adequate fluid is not ingested frequently, the plasma protein concentration will rise to greater than normal levels within a few hours
The function of the gastrointestinal system is poorly developed and can be improved by keeping food in the stomach at all times
The hepatic capacity to form plasma proteins is minimal and requires the constant availability of amino acids from food to avoid hypoproteinemic edema
The hepatic capacity to store and synthesize glycogen and glucose is not adequate to maintain the plasma glucose concentration in a normal range for more than a few hours after feeding
Which of the following tends to decrease potassium secretion by the cortical collecting tubule?
*
Increased plasma potassium concentration
A diuretic that decreases proximal tubule sodium reabsorption
A diuretic that inhibits the action of aldosterone (e.g., spironolactone)
Acute alkalosis
High sodium intake
A diuretic that inhibits the action of aldosterone (e.g., spironolactone)
Which compound below is a second messenger that mediates hormone responses? * G-protein Adenylyl cyclase cAMP Phospholipase C Prostaglandins
cAMP
What kind of receptors do thyroid hormones activate in the target cells?
Ion channel–linked receptors on the cell surface
G Protein–linked receptors on the cell surface
Enzyme-linked receptors on the cell surface
Receptors in the cell cytoplasm
Receptors in the cell nucleus
Receptors in the cell nucleus
What effect does insulin have? * Promotes gluconeogenesis Inhibits conversion of excess glucose into fatty acids Promotes muscle and liver glucose uptake Suppress protein synthesis Inhibits growth
Promotes muscle and liver glucose uptake
What mineral is required for the formation of thyroxine? * Iodine Calcium Iron Sodium Magnesium
Iodine
Under conditions of normal renal function, which of the following is true of the concentration of urea in tubular fluid at the end of the proximal tubule?
*
a-It is higher than the concentration of urea in tubular fluid at the tip of the loop of Henle
b-It is higher than the concentration of urea in the plasma
c-It is higher than the concentration of urea in the final urine in antidiuresis
d-It is lower than plasma urea concentration because of active urea reabsorption along the proximal tubule
e-Other:
It is higher than the concentration of urea in the plasma
What is osmosis?
*
1-Water diffusion through a semipermeable membrane
2-Active transport of water through a semipermeable membrane
3-Diffusion of sodium and chloride ions through a semipermeable membrane
4-Amino acid diffusion through a semipermeable membrane
5-Glucose diffusion through a semipermeable membrane
Water diffusion through a semipermeable membrane
What is the composition of G-proteins that mediate hormone responses from the cell surface? * Consists of two subunits Consists of three subunits Consists of four subunits Consists of five subunits Consists of six subunits
Consists of three subunits
Which of the following stimulates the secretion of parathyroid hormone (PTH)?
*
Increase in extracellular calcium ion activity above the normal value
Increase in calcitonin concentration
Respiratory acidosis
Increased secretion of PTH-releasing hormone from the hypothalamus
None of the above
None of the above