In a normal ECG, no separate wave is detected for atrial repolarization because
a. the amount of atrial tissue is too little for the current to be detected by the ECG electrodes.
b. the time period between atrial depolarization and repolarization occurs too rapidly.
c. atrial repolarization and ventricular depolarization are simultaneous, and the expected wave is masked by the QRS complex.
d. None of these.
C
You might also like to view...
Cytoplasm is located between the cell membrane and the nuclear envelope
Indicate whether the statement is true or false
Which enzymes are secreted in the small intestine?
a. carboxypeptidase b. pepsin c. sucrase d. maltase e. aminopeptidase
In a histology section of the digestive tract, you observe that the mucosa is made of simple columnar epithelium and the tissue has three layers of smooth muscles. This section represents ________
A) stomach B) esophagus C) duodenum D) large intestine
Pitch refers to the ________ of sound waves; pitch is determined by the tension produced by ________ laryngeal muscles.
A. loudness; intrinsic B. frequency; extrinsic C. loudness; extrinsic D. frequency; intrinsic