Chapter 20, Problem 1RE

A.

Summary Introduction

To determine: Thepresence of uncontrolled hypertension and coronary artery disease to the development of heart failure in the woman.

Introduction. The cardiovascular system is made of different components. The heart is composed of the primary organs of the system, and the arteries, veins and blood capillariesand the associated structures of the cardiovascular system.

Explanation of Solution

The presence of uncontrolled hypertension and coronary artery disease can result in the progression of the interference in the blood flow to the heart. The obstruction of major heart vessels that is the coronary artery in CAD (coronary artery disease) can cause persistent pressure on heart resulting in blockage of oxygen supply to heart causing heart failure. The presence of hypertension escalates the process by increasing the blood pressure and effort on heart muscles.

B.

Summary Introduction

To determine: The significance of left ventricular hypertrophy in terms of compensatory and pathological mechanisms.

Introduction: The preload is defined as the end-diastolic volume which results in stretching of the left and the right ventricle of the heart to the maximum dimensions under some physiological demand. Whereas, the afterload can be defined as the pressure against which the muscles of the heart work to eject the filled blood during systole.

Explanation of Solution

The hypertrophy of the left ventricle that can take place from the gradual increase in the pressure that occurs in the aorta where the left ventricle pumps the blood to transport to the entire body. This results in the subsequent stiffness of the cardiac muscle tissue. The increase in the aortic pressure occurs from continued increase in the stiffness of the aorta and other arteries.

The myocardial cells also accumulate more lipids, collagen fibers in the cardiac tissue which makes these muscles stiffer and less compliant. The increase in the volume of the left ventricle can also result in higher pressure in the left atria that can increase pulmonary capillary pressure. This is pathological hypertrophy. The myocardium is thicker at the ventricles in order to provide more strength and support as the ventriclepushes the blood with more force out of the heart as compared to the atria. Among ventricles, the left ventricle is thicker as compared to the right ventricle. This is compensatory hypertrophy

C.

Summary Introduction

To determine: The reason for shortness of breath and nonproductive cough.

Introduction: The human heart undergoes double circulation. The first circulation occurs when the deoxygenated blood from the body enters the right chambers and is transported to the lungs. The other organisms undergo single circulation where blood only passes one time through the heart.

Explanation of Solution

Persistent hypertension and coronary artery blockage result in heart attack which causes shortness of breath, dizziness, dyspnea, fatigue, nausea and so on. The shortness of breath occurs due to the lack of oxygen that is pumped from the heart to the body’s tissues due to artery blockage or death of heart tissue. The coughing mechanism is to compensate for the forced supply of oxygen from the surrounding air to the lungs for supplying oxygen to heart and other vital organs. The coughing is not accompanied by cough as it is not produced from pathogen infestation.