KINS 256 – Cardiovascular Homework
Outline the flow of blood through the heart.
The flow of blood through the heart is a complex and crucial process that is essential for maintaining the health of the cardiovascular system. The flow of blood through the heart is described as follows in KINS 256 – Cardiovascular Homework:
- Blood enters the right atrium of the heart from the superior and inferior venacava, which collect deoxygenated blood from the body.
- The right atrium contracts, forcing blood into the right ventricle.
- The right ventricle contracts, sending blood into the lungs through the pulmonary artery. In the lungs, the blood is oxygenated and returns to the heart through the pulmonary veins.
- Oxygenated blood enters the left atrium of the heart from the pulmonary veins.
- The left atrium contracts, sending blood into the left ventricle.
- The left ventricle contracts, sending blood into the aorta, which is the largest artery in the body. The aorta distributes oxygenated blood to the rest of the body.
- The blood circulates through the body, delivering oxygen and nutrients to the tissues. The blood returns to the heart through the superior and inferior venacava, completing the cycle
The phases of the Cardiac Cycle
The cardiac cycle refers to the sequence of events that occur in the heart during one complete heart beat. There are two main phases in the cardiac cycle, which are described in detail in KINS 256 –
Cardiovascular Homework:Systole: This is the contraction phase of the heart, during which the ventricles contract and pump blood out of the heart and into the circulatory system. The SA node, also known as the pacemaker, generates an electrical impulse that spreads through the atria, causing them to contract. The electrical impulse then reaches the AV node, which slows it down before it reaches the Purkinje fibers and spreads throughout the ventricles, causing them to contract.
Diastole: This is the relaxation phase of the heart, during which the ventricles fill with blood. The heart is relaxed and blood flows into the atria and then into the ventricles. The AV node and Purkinje fibers ensure that the ventricles fill with blood before the next contraction, ensuring that the heart beats in a coordinated and efficient manner.
Cardiac Output and Its Equation
Cardiac Output (CO) is a measure of the amount of blood that the heart pumps out per minute. In KINS 256 – Cardiovascular Homework, CO is an important parameter in the study of cardiovascular physiology and is often used to evaluate the effectiveness of the heart in pumping blood throughout the body.
The equation used to determine cardiac output is: CO = Stroke Volume (SV) x Heart Rate (HR)
Stroke Volume (SV) is the volume of blood that the heart pumps out with each beat. Heart Rate (HR) is the number of beats per minute. When multiplied, these two parameters give the total volume of blood pumped by the heart per minute, which is the cardiac output.
Knowing the cardiac output is important in assessing the cardiovascular function and the effectiveness of the circulatory system. Abnormal values of cardiac output can indicate cardiovascular disease, and changes in cardiac output can indicate changes in the functioning of the cardiovascular system. Understanding the concept of cardiac output and its importance in cardiovascular physiology is essential for understanding the functioning of the cardiovascular system and the health implications of cardiovascular disease, as discussed in KINS 256 – Cardiovascular Homework.
Explain what would happen to stroke volume if EDV increases and ESV remained constant or decreased.
Stroke volume (SV) is the volume of blood that is pumped out by the heart with each beat. It is calculated by subtracting the end-systolic volume (ESV) from the end-diastolic volume (EDV).
If EDV increases, the volume of blood that fills the ventricles of the heart also increases. This increased EDV will increase the stroke volume, provided the ESV remains constant or decreases. When the EDV increases and the ESV remains constant, the difference between the two (EDV – ESV) will increase, which will result in an increased stroke volume. The increased stroke volume means that the heart is pumping out a larger volume of blood with each beat, which can improve cardiac function.
However, if the ESV decreases, it may indicate a decreased ventricular contractility, which can result in a decrease in stroke volume. In this case, the heart may be unable to pump out a sufficient amount of blood with each beat, resulting in decreased cardiac function.
Therefore, it is important to consider both EDV and ESV when evaluating stroke volume and cardiac function. An increase in EDV can result in an increase in stroke volume, but this relationship may not hold if ESV decreases.
The SA node, AV node, and Purkinje fibers play a crucial role in the control of the cardiac cycle by generating and spreading the electrical impulses that regulate the contraction and relaxation of the heart. These electrical impulses are responsible for the coordinated and efficient functioning of the heart, and any changes or disruptions in the electrical system can lead to heart rhythm disorders. Understanding the phases of the cardiac cycle and the role of the electrical system is essential for understanding the functioning of the cardiovascular system and the health implications of cardiovascular disease.
- Pretend you have a client that asked you to explain to them why regular exercise can help lower their blood pressure.
- What changes would you expect to see in a person’s HR, SBP and DBP respectively, in response to exercise?
- Discuss what VO2 is, including the components of the equation used to calculate this. Discuss the expected difference in VO2 max for trained vs. untrained individuals including why you would expect to see that difference.
- Discuss the physiological adaptations to the Cardiovascular system during exercise (Don’t just list, discuss briefly how each responds).
- From a physiological perspective, what concerns might you have if an athlete’s labs indicated their hematocrit values were low. What could this mean, and why could this impact training?
- Explain the physiological processes that result in the redistribution of blood flow during exercise.