CRITICAL THINKING QUESTIONS AND ANSWERS AND CYCLE 2 LAB EXAM TEMPLATE There are two main mechanisms that work in conjunction to return the blood THE CARDIAC PUMP 1) The forward pull(vis a fronte) This is the negative pressure gradient generated by the relaxation of a contracted right atrium(diastole) and the piston pump effect due to the downward movement of the A-V valve (tricuspid) during contraction(systole). 2) The forward push (vis a tergo) This is due to the positive pressure gradient created by the contraction of the left ventricle that pushes out the blood through the circulatory system. And also due to the windkessel effect( elastic recoil of the arteries that help push the blood back on track) THE RESPIRATORY PUMP This is the aid of inspiration in pulling up the blood to the heart. The normal intra thoracic pressure(inside chest cavity , outside lungs) at the end of expiration is -2 mmHg. This changes to -5 mmHg at the end of inspiration due to increased chest cavity volume. The rise in negative pressure helps in reducing the resistance to thoracic venous return. Also the diaphragm having moved to intra abdominal position now squeezes out the venous blood in the abdominal area due to the now increased intra abdominal pressure. Tracing Blood flow from heart to other parts of the body and vice versa Trace the flow of arterial blood from the heart to the brain Heart-Aorta-Aortic arch-Brachiocephalic-Right common carotid Trace the flow of venous blood from the brain to the heart Head-superior sagittal sinus-internal jugular-brachiocephalic Trace the flow of arterial blood from the heart to the right arm Heart-Aorta-Aortic Arch-Brachiocephalic trunk-Right subclavian artery-right axillary artery-right brachial artery-RIGHT radial artery-ulnar artery -palmer arteries Trace the flow of arterial blood from the heart to the left arm Heart-Aorta-Aortic Arch- Brachiocephalic trunk-left subclavian artery-left axillary artery-left brachial artery-LEFT radial artery-ulnar artery -palmer arteries Trace the flow of venous blood from the palm to the heart Palm-basilic-median cubital-cephalic-axillary-subclavian-brachiocephalic Trace the flow of arterial blood from the heart to the abdomen Heart-Aorta-Descending aorta-celiac trunk: •superior mesenteric •renal •inferior mesenteric •common iliac Trace the flow of venous blood from the kidneys and intestines to the heart Kidneys-renal-vena cava intestines-mesenteric-vena cava Trace the flow of arterial blood from the heart to the stomach, liver and spleen

Heart-Aorta-Descending aorta-Celiac Trunk: •gastric •spleenic •common hepatic Trace the flow of venous blood from the stomach, liver and spleen to the heart Stomach/liver/spleen-splenic/hepatic-venacava Trace the flow of arterial blood from the heart to the legs Heart-Aorta-Descending Aorta-Celiac Trunk-Common iliac-external/internal iliac-femoral-popliteal-tibial-fibular-plantar arch Trace the flow of venous blood from the foot to the heart Foot-tibials-saphenous-popliteal-saphenous-femoral-iliac-vena cava R-R interval: measurment Peak of an R deflection to peak of next R deflection R-R interval: representation Duration of one cardiac cycle P wave: measurement Begin and end on the baseline; normally upright in standard limb leads; start of P deflection to return to isoelectric line P wave: representation Depolarization of the atrial muscle as negativity spreads from the SA node toward the ventricles P-R interval (also called P-Q interval): measurement From start of P deflection to start of Q deflection P-R interval (also call P-Q interval): representation Time it takes for the impulse sent from the SA node to travel to the ventricles P-R segment: measurement From end of P wave to start of Q deflection P-R segment: representation Interval between atrial depolarization and ventricular depolarization QRS complex: measurement Begin and end on the isoelectric line (baseline) from start of Q deflection to end of S wave (return to isoelectric line) QRS complex: representation Spread of excitement through ventricular myocardium - results in depolarization of ventricular muscle. Atrial repolarization is also part of this segment, but the electrical signal for atrial repolarization is masked by the larger QRS complex. Q-T interval: measurement Start of Q deflection to end of T wave

Q-T interval: representation Electrical systole, when ventricular beat is generated S-T segment: measurement Interval between end of S deflection and start of T wave S-T segment: representation Period during which ventricles are more or less uniformly excited T wave: measurement Start of T deflection to return to isoelectric line T wave: representation Beginning of ventricular relaxation What part of an ECG corresponds with ventricular systole? Q-T interval What part of an ECG corresponds with ventricular diastole? End of T wave to next R wave Comparing the mean delta T and BPM from Segment 1 (lying down) and Segment 4 (after exercise), in which segment is delta T greatest? BPM greatest? Segment 1: delta T = greatest Segment 4: BPM = greatest What is the relationship between elapsed time between R waves (delta T) and heart rate? As delta T increases, BPM decreases (and vice versa) How did BPM change from Segment 1 (lying down) to Segment 2 (sitting quietly)? BPM increased How does body position cause a change in BPM? Explain using HR x SV = CO. When you are supine, blood can easily circulate through body tissues and back to heart - don't need a high SV or HR because blood flows easily on its own. When sitting, blood begins to pool in lower extremities, making it harder for venous return - need higher SV and HR to pump blood around and deliver adequate O2 to body. Differences between end of T wave to next R wave at rest and after exercise - At rest = HR slower, more time for heart to relax - greater ventricular diastole - After exercise = HR faster, heart contracts more frequently, not as much time for it to relax - narrower ventricular diastole Differences between Q-T intervals at rest, while sitting quietly, and after exercise As activity increases, length of of Q-T interval decreases. With each of these increasing activities, HR increases, heart contracts faster, so ventricles must contract more quickly

Normal rhythm (Read the EKG pattern) Delta T – 0.83 60-100 BPM Tachycardia (Read the EKG pattern) Delta T < 0.62 >100 BPM Bradycardia (Read the EKG pattern) Delta T >0.9 <60 BPM What is atrial fibrillation and what causes it? (Read the EKG pattern) - Rapid, uncoordinated heart contractions that don't pump blood - Prolonged tachycardia What is the normal pacemaker of the heart? SA (sinoatrial) node How fast does paper in ECG move through printer? 25 mm/sec If each small square on ECG strip is 1 mm in length, how much time does each square represent? 0.04 sec How much time does each large square (5 squares 1 mm in length) represent? 0.20 sec How can BPM be precisely calculated from ECG strip? BPM = (60 sec/min) / (0.04 sec x # squares from R wave to R wave) How much time is represented in between time markings? 3 sec How can you quickly estimate BPM from and ECG strip without a calculator? - Count # QRS complexes that occur in 6 sec (2 time markings) and multiply this by 10 (because there are 6 x 10 sec/min) - # QRS complexes x 10 = BPM, estimated Abnormally long P-Q interval could suggest... Heart block - reduced electrical conduction from the atria to the ventricles What is complete heart block? When ventricles depolarize independently of atria (because no electrical impulses pass from atria to the ventricles) When QRS complex is longer than 0.12 sec, it could indicate... Right or Left bundle branch block - when the 2 ventricles do not contract simultaneously What cause the Q-T interval to lengthen? Decrease in HR and myocardial ischemia/damage

What is considered "quiescent period" on ECG strip? End of T wave to next P wave

Lab Exam – Anatomy and Physiology 2 – Exam 2 Key template Answer any 25 questions (25*2= 50)

1. Compare the ECG deflections for your three bipolar lead set-ups, Lead I, Lead II, and Lead III.

Describe the differences you observe in these three recordings. What accounts for the differences you see in their deflections?

2. ECG…complete peak evaluation. 3. Using the ECG strip, differentiate heart pumping abnormalities such as Tachycardia,

Bradycardia, and atrial fibrillation. 4. Trace the flow of blood from heart to other parts of the body and vice versa. (prepare the chart

given above) 5. What are the two major blood vessels? How are they different from each other in terms of their

functions in circulatory system? 6. Compare the structural features and respective functions of fetal and adult circulatory patterns.

Explain the structural difference between the walls of arteries and veins. 7. What is the role of one-way valve in the return of blood to the heart? Do all veins have valves? 8. Draw and label the structure of an antibody? What types of cells produce antibodies? 9. Describe the role of lymphatic system in cancer metastasis. 10. List the differences between cell-mediated immunity and humoral immunity. 11. Histology of Spleen, lymph node, lymphatic vessels, blood vessels. 12. Compare the functions of the red pulp and white pulp in the spleen tissue. 13. Explain the process blood microcirculatory system and exchange with the lymphatic

circulations. 14. What is pulmonary embolism? What are the cause and consequences of pulmonary

embolism? 15. Name the three types of tonsils involved in immune defense, and describe their locations in

the cephalic region. 16. What are primary ad secondary lymphoid organs? Explain their roles in immune system. 17. Draw the pattern of flow of lymph in the lymphatic vasculature. 18. What are the two mechanisms by which the body defends itself against pathogens? Describe

their role in elicitation of host immune responses. 19. What is MALT? Describe their functions in immune defense. 20. Read the cases in MAKE CONNECTIONS SEGMENTS for all three chapters. 21. 22. 23. 24. 25. 26. 27.

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