NURS 231 Pathophysiology Exam 4 Questions With Verified Answers

NURS 231 Pathophysiology Exam 4 Questions With Verified Answers function of blood - answerTransportation materials to and from cells Transports nutrients, carries O2, waste products, hormones to their target cells, regulates body temperature, protects against bacteria and viruses three stages of hemostasis - answerVascular constriction, platelet plug formation, blood coagulation What is vitamin K needed to synthesize? - answerFactors II, VII, IX, and X, prothrombin, and protein C Discuss the intrinsic and extrinsic pathways - answerboth form prothrombin activator. Both pathways converge to activate factor X, the conversion of prothrombin to thrombin. Thrombin then converts fibrinogen to fibrin, the material needed to stabilize a clot. Both methods are needed for successful hemostasis. intrinsic pathway - answerThe intrinsic pathway begins with activation of factor XII and can cause clotting in 1 to 6 minutes, considered the slower process. extrinsic pathway - answerThe extrinsic pathway can cause clotting in 15 seconds and begins with the release of tissue thromboplastin from the subendothelial cells. It is the quicker of the two pathways, forming a clot in approximately 15 seconds. Natural anticoagulants - answerAntithrombin III, protein C, protein S Drug therapy anticoagulants - answerwarfarin, heparin, Dabigatran, Rivaroxaban, Apixaban peripheral vascular resistance - answerThe collective resistance of all the vessels in the peripheral circulation Hemodynamics or blood flow is affected by what factors? - answerPressure, resistance, flow, radius, blood viscosity, compliance, wall tension cardiac output - answerThe efficiency of the heart's pump is measured by the cardiac output. The cardiac output (CO) is the amount of blood the heart pumps each minute. It is the product of the stroke volume (SV) and the heart rate (HR). CO = SV x HR. preload - answerPreload is the end-diastolic pressure when the ventricle has been filled and represents the volume work of the heart. afterload - answerpressure the heart must generate to move blood into the aorta. cardiac contractility - answerability of the heart to change its force of contraction without changing its resting (diastolic) length. inotrope - answerAn inotropic influence is one that increases the strength of the muscular contraction. mean arterial pressure - answeraverage pressure in the arterial system during ventricular contraction and relaxation. It is a good indicator of tissue perfusion. MAP = CO x PVR Understand the renin-angiotensin-aldosterone system in figure 4.9. - answerThe renin- angiotensin-aldosterone system plays a vital role in blood pressure regulation. If there are changes in extracellular fluid, extracellular sodium levels, a drop in blood pressure, or increased sympathetic activity, the kidney will release renin. Once in the bloodstream, renin converts angiotensinogen (a plasma protein) to angiotensin I. Angiotensin I is then converted to angiotensin II in the lungs by the angiotensin-converting enzyme (ACE). Angiotensin II is a potent vasoconstrictor, mainly of the arterioles, and to some extent, the veins. Arteriole constriction will increase the PVR, regulating blood pressure for a short period of time. Angiotensin II also stimulates the adrenal gland to secrete aldosterone. Aldosterone will increase salt and water retention by the kidney contributing to the long-term regulation of blood pressure. Figure 4.9 summarizes the control of blood pressure by the renin-angiotensin-aldosterone system. Be familiar with hypercoagulability states in table 4.2. - answerIncreased Platelet Function: Reactive disorders (iron deficiency anemia, splenectomy, chronic inflammation) Myeloproliferative disorders (polycythemia vera) Atherosclerosis Diabetes mellitus Smoking Elevated cholesterol levels Increased platelet levels Accelerated Activity of the Clotting System Inherited disorders (primary): Mutation of factor V Leiden