Which vessel is guarded by a semilunar valve at its base?
A) superior vena cava B) pulmonary trunk C) pulmonary vein D) coronary sinus
Answer: B
You might also like to view...
________ are immature erythrocytes that are present in the circulation
A) Erythroblasts B) Normoblasts C) Myeloblasts D) Band cells E) Reticulocytes
Myopia generally occurs when the ________.
A. cornea is uneven B. eyeball is too long C. lens is uneven D. eyeball is too short
What attaches epithelial cells to the basement membrane?
A. gap junction B. hemidesmosomes C. adhesion belt D. tight junction E. desmosomes
Which of the following events is NOT a characteristic of an action potential?
A. In repolarization, K+ flow out of the cell. B. As Na+ enter, the inside of the plasma membrane becomes more negative. C. The plasma membrane becomes highly permeable to Na+ and depolarization results. D. At the peak of depolarization, Na+ channels begin to close and K+ channels open. E. Action potentials occur according to the all-or-none principle.