Match the following mechanism of polyspermy (Column I) with events (Column II).

Column I	Column II
A. Fast block to polyspermy	i. chemicals from the fusing sperm cytoplasm alter the sodium ion (Na+) channels on the membrane
B. Slow block to polyspermy	ii. enzyme cortical granule serine protease, cleaves the protein posts that connect the vitelline envelope
	iii the concentration of free Ca2+ in the egg cytoplasm increases
	iv. an electric change in the egg cell membrane
	v. the concentration of free Na+ in the egg cytoplasm increases

Which of the following is correct?

#Question id: 11943

#Unit 7. System Physiology – Animal

Which of the following changes tends to increase GFR?

#Question id: 11944

#Unit 7. System Physiology – Animal

The maximum clearance rate possible for a substance that is totally cleared from the plasma is equal to which of the following?

#Question id: 11945

#Unit 7. System Physiology – Animal

A patient has the following laboratory values: arterial pH = 7.13, plasma HCO3− = 15 mEq/L, plasma chloride concentration = 118 mEq/L, arterial Pco2 = 28 mm Hg, and plasma Na+ concentration = 141 mEq/L. What is the most likely cause of his acidosis?

#Question id: 11946

#Unit 7. System Physiology – Animal

A 3-week-old infant is brought to the emergency room in a comatose condition. The history reveals that her parents have been feeding her concentrated, undiluted formula for 5 days. (Infant formula preparations are often sold in concentrated forms that must be properly diluted with water before feeding.) The infant’s plasma osmolality is 352 mOsm/L (normal is 280 to 300 mOsm/L), and the osmolality of the urine is 497 mOsm/L. What is the explanation for the hyperosmotic condition of the plasma?

#Question id: 11947

#Unit 7. System Physiology – Animal

Why is milk produced only after delivery, not before?

#Question id: 11948

#Unit 7. System Physiology – Animal

Which of the following increases the rate of excretion of calcium ions by the kidney?