QRS complexes on the ECG tracings show that:
1. The atria are depolarizing.
2. The ventricles are depolarizing.
3. The ventricles are repolarizing.
4. The heart is at rest.
The aortic semilunar valve prevents blood from returning to the _____.
1. | left ventricle | 2. | aorta |
3. | right ventricle | 4. | left atrium |
Pulmonary veins return the oxygenated blood from the lungs to:
1. | right atrium | 2. | left atrium |
3. | right ventricle | 4. | left ventricle |
Erythrocytes in humans are destroyed mainly in:
1. | liver and spleen | 2. | heart and lungs |
3. | bone marrow | 4. | kidney |
The most common WBC under normal physiological conditions are:
1. Neutrophils | 2. Macrophages |
3. Monocytes | 4. Lymphocytes |
In a normal ECG, The T wave represents:
1. | ventricular depolarization | 2. | atrial repolarization |
3. | ventricular repolarization | 4. | atrial depolarization |
The chamber with the thickest musculature in the human heart would be:
1. the right atrium | 2. the left atrium |
3. the left ventricle | 4. the right ventricle |
The correct path of circulation of the blood in the human heart is represented by:
1. | left atrium, left ventricle, lungs, right atrium, right ventricle, body |
2. | right atrium, right ventricle, lungs, left atrium, left ventricle, body |
3. | left atrium, left ventricle, right atrium, right ventricle, lungs, body |
4. | right atrium, lungs, right ventricle, left atrium, body, left ventricle |
Sympathetic stimulation would lead to:
1. increased heart rate.
2. increased stroke volume.
3. vasoconstriction in visceral blood vessels.
4. all of the above.
The innermost layer of blood vessel walls made up of one layer of endothelium and in direct contact with the blood is:
1. tunica adventitia | 2. tunica intima |
3. tunica media | 4. tunica muscularis |