Physicology

1. The source of the electrical currents that you measured on the skin throughout a normal electrocardiogram is:   a. regional differences in depolarization state between parts of the myocardium       b. The SA node cells   c. the opening and closing of the tricuspid and bicuspid valves   d. depolarizations of the muscle and nerve cells close to the electrode site    e. The AV node cells  2. Release or discharge from which of the following is likely to produce a slowing in the rate at which the AV node transmits a depolarization?    a. Your coffee cup (caffeine)    b. the posterior lobe of the pituitary gland (Oxytocin)      c. the sympathetic nervous system    d. the parasympathetic nervous system (vagus nerve)    e. the medulla of the adrenal gland (epinephrine)  3.Which of the following is unlikely to affect the force of contraction of an individual ventricular myocyte (muscle cell)?   a. the amount of…

4. On the base of ECG analyses define what structure is the pacemaker of heart. Explain why you think so. سلسلية سليل بليد

7. Label the waves (P, QRS, T) and intervals (P-Q, S-T, Q-T) on the following ECG. 8. Match the portion of the ECG with the description. P wave A. This segment is elevated in acute myocardial infarction (heart attack). QRS complex B. Beginning of atrial excitation to beginning of ventricular excitation. T wave C. Ventricular depolarization P-Q interval D. Atrial depolarization S-T segment E. Ventricular repolarization F. Beginning of ventricular depolarization to end of ventricular repolarization. Q-T interval

In the given diagram, how many statement are correct. Give reason for your choice. A. It is the ECG of healthy person. B. It displays weak cardiac muscles. C. It displays complete blockage and no synchrony between ventricular and atrial activity. D. It is showing the partial blockage because of AV node damage.

3. Evaluate the following statements as true or false T/F T/F T/F T/F T/F Jet lesions are most common in the left ventricle The tricuspid is situated between the left atrium and left ventricle The endocardial layer is thickest in the atria Systole is when semilunar valves close to prevent blood backflow into the heart The sinoatrial and atrioventricular nodes are similar histologically

6. During which part of the EKG does each event occur? (Be as specific as possible.) Use this interactive activity to practice. Atrial depolarization AV nodal delay Ventricular depolarization Ventricles are contracting and emptying Ventricular repolarization Ventricles are relaxed and filling I Part of EKG During Which Event Occurs

All of the following are true of the conduction system of the heart except A. The SA node is known as the pacemaker of the heart B. The AV node has an intrinsic rate between 60 and 100 beats/min C. The AV bundle conduct signals to the bundle branches D. The purkinje fibers connect to the muscle and chordinea tendinea Choose the correct answer

9. Patients with diastolic heart failure have abnormalities in LV relaxation and distensibility that can be characterized in PV loops, and by echocardiography. Which phase in the PV loop represents the time of isovolumetric relaxation of the LV that can be affected during diastolic failure? 120 LV Pressure 80 (mm Hg) 40 в 20 60 100 140 180 220 LV Volume (ml) A. A B. C. D. D

According to the figure, one of the following sentences is correct: 30 cm/s 600 cm 600 20 400 10 200 5 cmis 3 cm 1 mm/s 18 cm? Aorta Capillaries Vena cava Position along the Systemic System O a. The cross-sectional area of the aorta is very large so the velocity of the blood is the largest. O b. The velocity of blood in vena cava is the largest. O. The velocity of blood in the Aorta is larger than the velocity in the capillaries. O d. The velocity of blood in the capillaries is the largest. Flow speed (cm/s) Total area (cm²)