ATI LPN
Timby's Introductory Medical-Surgical Nursing Thirteenth, North American Edition
Chapter 22 : Introduction to the Cardiovascular System Questions
Question 1 of 5
The nurse is assessing a client who has dyspnea and considering the process of gas exchange. Which structural characteristic of capillaries best enables gas exchange at the cellular level?
Correct Answer: A
Rationale: Capillaries are one cell-layer thick and in direct contact with the cells of all tissues. This allows ease of gas exchange. Capillaries do form a complex network; however, it is the one cell structure that facilitates gas exchange. Venules and veins transport blood back to the heart. Arteries are elastic.
Question 2 of 5
The nurse is reviewing lab work for a client whose blood CO2 level is elevated. The nurse is most correct to suspect an impairment of which?
Correct Answer: A
Rationale: Gas exchange occurs in the lung where oxygen in inspired air exchanges for CO2 in the venous blood. The CO2 is then transferred to the alveoli to be exhaled. No gas exchange occurs in the bronchi. The pulmonary artery carries deoxygenated blood to the lungs, and the pulmonary vein brings oxygenated blood back to the heart to be pumped to the tissues.
Question 3 of 5
The nurse provides care for a client who is diagnosed with an infarction of the posterior wall of the right atrium. Which clinical finding should the nurse anticipate relating to the infarction location?
Correct Answer: B
Rationale: The posterior wall of the right atrium is the location of the sinoatrial node (SA node), which is the pacemaker of the heart. Damage to this location may result in an irregular heart rate due to a disturbance of electrical pulse initiation. Jugular vein distension and peripheral edema are anticipated for the client who is experiencing heart failure, not myocardial infarction (MI). Although fever can increase the client's heart rate, this is not an expected finding with an MI.
Question 4 of 5
When caring for a client with dysfunction in the conduction system, at which period would the nurse note that cells are resistant to stimulation?
Correct Answer: D
Rationale: The refractory period is the time when cells are resistant to electrical stimulation. Repolarization is when the ions realign themselves to wait for an electrical signal. Depolarization occurs during muscle contraction when positive ions move inside the myocardial cell membrane and negative ions move outside. Before an impulse is generated, the cells are in a polarized state.
Question 5 of 5
The nurse is caring for a client with an elevated blood pressure and no previous history of hypertension. At 0900, the blood pressure was 158/90 mm Hg. At 0930, the blood pressure is 142/82 mm Hg. The nurse is most correct when relating the fall in blood pressure to which structure?
Correct Answer: C
Rationale: Baroreceptors sense pressure in nerve endings in the walls of the atria and major blood vessels. The baroreceptors respond accordingly to raise or lower the pressure. Chemoreceptors are sensitive to pH, CO2, and O2 in the blood. Sympathetic nerve fibers increase the heart rate. The vagus nerve slows the heart rate.