5. The P wave of an electrocardiogram (ECG) indicates: --Ventricular depolarizat

Question

5. The P wave of an electrocardiogram (ECG) indicates:

--Ventricular depolarization

-- Ventricular repolarization

-- Atrial depolarization

---Atrial repolarization

6. Which of the following is FALSE about Cardiac Output?

---it is genetically determined and does not change throughout the day

---Ach (acetylcholine) decreases CO

---when venous return of blood increases, CO increases

---it is determined by Heart Rate and Stroke Volume

--- sympathetic activation increases CO

7. The period when Na+ channels are closed, K+ channels are open, and Ca2+ channels are open, is referred to as the _________. During this phase, a cardiac cell is in an extended depolarized state.

--repolariztion

--ionic flux

--Threshold

--Plateau

8. Increased PCO2 within an alveolus would cause:

--- its bronchiole to dilate

--its bronchiole to constrict

---decreased breathing rate

---arterioles serving it to dilate

Explanation / Answer

5.(C) The P wave of an ECG indicates Atrial Depolarization. A change in membrane potential and the potential enters a positive state. This change in potential occurs due to the depolarization of Atria and is marked by the P wave in ECG.

6. The statement that is FALSE is Cardiac output is genetically determined and does not change throughout the day.

Cardiac Output = Heart Rate * Stroke Volume

Heart rate and stroke volume varies throughout the day due to several reasons hence the Cardiac output also varies through out the day.

7. (A)The Na+ channels are closed whereas the K+ and Ca2+ channels are opened represents the state of Repolarization. As Na+ channels close the K+ channels are open which decreases the membrane potential of the Cell and the action potential falls. This phase is repolarization phase.

8. (A) Increase in PCO2 within an alveolus would cause its bronchioles to dilate and also dilates the systemic arterioles.

Related Questions

Navigate

• Browse (All)
• Browse 5
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.