Exercise Physiology Chapter #9 Quiz

When there is a blockage in the coronary vessels, it means that the blood flow to the cardiac muscles is restricted. This can lead to a lack of oxygen and nutrients reaching the heart muscle, causing damage to the cardiac muscle tissue. Therefore, it is true that blockage in the coronary vessels can result in cardiac muscle damage.

Regular exercise has been shown to improve the heart's antioxidant capacity. Antioxidants help to neutralize harmful free radicals in the body, which can cause damage to cells and contribute to various diseases, including heart disease. Exercise stimulates the production of antioxidants in the body, which in turn helps to protect the heart from oxidative stress and damage. This ultimately improves the heart's overall health and function. Therefore, the statement that exercise improves the heart's antioxidant capacity is true.

Heart muscle cells, also known as cardiomyocytes, require calcium ions for contraction. Calcium plays a crucial role in the regulation of muscle contraction by binding to specific proteins, such as troponin, in the muscle fibers. This binding triggers a series of events that ultimately leads to the contraction of the heart muscle. Without sufficient calcium, the heart muscle would not be able to contract effectively, leading to impaired cardiac function. Therefore, it is true that the heart muscle needs calcium for contraction.

Myocardial infarction is commonly referred to as a heart attack because it involves the blockage of blood flow to the heart muscle, leading to the death of heart tissue. This condition occurs when a coronary artery, which supplies oxygen-rich blood to the heart, becomes blocked by a blood clot or a buildup of plaque. The lack of blood flow and oxygen to the heart muscle can cause severe chest pain, shortness of breath, and other symptoms. Therefore, it is accurate to say that myocardial infarction is commonly known as a heart attack.

Exercise improves the function of ATP-sensitive potassium channels. This means that when we engage in physical activity, it enhances the effectiveness of these channels in our body. ATP-sensitive potassium channels play a crucial role in regulating the electrical activity of cells, including muscle cells. By improving their function, exercise can promote better muscle function and overall cellular health.

The correct answer is "Contraction phase." Systole refers to the phase of the cardiac cycle when the heart muscle contracts, pumping blood out of the chambers and into the arteries. During systole, the ventricles contract, creating pressure that forces blood out of the heart. This is followed by the relaxation phase, known as diastole, where the heart muscles relax and the chambers fill with blood again.

Arteries and arterioles are blood vessels that carry oxygenated blood away from the heart to various parts of the body. They have thick and elastic walls that help maintain blood pressure and ensure efficient blood flow. As the heart pumps blood, it is pushed into the arteries and arterioles, which then distribute it to the capillaries where oxygen and nutrients are exchanged with tissues. Therefore, the correct answer is "Carry blood away from the heart."

During the cardiac cycle, the heart goes through two main phases: diastole and systole. Diastole is the relaxation phase when the heart chambers fill with blood, while systole is the contraction phase when the heart pumps blood out. At rest, the heart rate is typically slower, and therefore the diastole phase is longer than the systole phase. This allows for more time for the heart to fill with blood and ensures efficient blood circulation throughout the body. Hence, the given statement "At rest the diastole is longer than the systole" is true.

The first sound of the heartbeat occurs when the atrioventricular (AV) valves close. This is because the AV valves separate the atria from the ventricles, and when they close, it prevents blood from flowing back into the atria. The closure of the AV valves produces the first sound of the heartbeat, known as the "lub" sound. Therefore, the statement is true.

During systole, the ventricles of the heart contract, which leads to an increase in pressure. This increase in pressure allows the blood to be pumped out of the ventricles and into the arteries, supplying oxygen and nutrients to the body. Therefore, it is true that the pressure in the ventricles rises during systole.

The left side of the heart is responsible for pumping oxygenated blood to the body through the aorta, which is the largest artery in the body. This blood carries oxygen and nutrients to all the organs and tissues, ensuring their proper functioning. Therefore, the statement is true.

The right side of the heart is responsible for pumping deoxygenated blood from the body to the lungs for oxygenation. This circulation of blood between the heart and the lungs is known as the pulmonary circuit. The right atrium receives deoxygenated blood from the body and pumps it into the right ventricle. The right ventricle then contracts, sending the deoxygenated blood to the lungs through the pulmonary artery. In the lungs, the blood picks up oxygen and gets rid of carbon dioxide before returning to the left side of the heart. Therefore, the correct answer is the pulmonary circuit.

The left side of the heart pumps blood to the body. This is because the left side of the heart receives oxygenated blood from the lungs and then pumps it out to supply oxygen and nutrients to all the organs and tissues in the body. The left ventricle, which is the main pumping chamber on the left side of the heart, contracts and forces the oxygenated blood into the aorta, which is the largest artery in the body. From the aorta, the blood is distributed to the rest of the body through a network of smaller arteries and capillaries.

Veins and venules are blood vessels that carry blood towards the heart. They have valves that prevent the backflow of blood and rely on the contraction of surrounding muscles to help propel the blood forward. This is in contrast to arteries and arterioles, which carry blood away from the heart. Therefore, the correct answer is "Carry blood to the heart."

Skeletal muscle and cardiac muscle differ in terms of calcium storage. Skeletal muscle stores calcium in the sarcoplasmic reticulum, a specialized endoplasmic reticulum, while cardiac muscle stores calcium in the sarcoplasmic reticulum as well as in the mitochondria. This difference in calcium storage is important for the functioning of these muscles.

The left and right sides of the heart are divided by the septum. The septum is a muscular wall that separates the two sides of the heart, preventing the mixing of oxygenated and deoxygenated blood. This division is crucial for the proper functioning of the heart and ensures that oxygen-rich blood is pumped to the body while deoxygenated blood is sent to the lungs for oxygenation.

The given statement is incorrect. One cardiac cycle actually includes one systole phase and one diastole phase. During systole, the heart contracts and pumps blood, while during diastole, the heart relaxes and fills with blood. Therefore, there is only one diastole phase in a cardiac cycle, not two.

The endocardium is the correct answer because it is the protective inner lining of the chambers of the heart. It is composed of a thin layer of endothelial cells that help prevent blood clotting and provide a smooth surface for blood flow. The endocardium also helps to regulate the contraction and relaxation of the heart chambers.

During exercise, both systole and diastole change. Systole, the phase when the heart contracts and pumps blood, becomes longer and more forceful during exercise to meet the increased demand for oxygen and nutrients. Diastole, the phase when the heart relaxes and refills with blood, also changes during exercise. It becomes shorter as the heart rate increases, allowing less time for the heart to fill with blood before the next contraction. Therefore, the correct answer is False.

Cardiac muscle is similar to skeletal muscle because both types of muscle are striated and contractile. They both contain sarcomeres, which are the basic units responsible for muscle contraction. Additionally, both cardiac and skeletal muscles are under voluntary control, meaning they can be consciously controlled by the individual. However, there are also some differences between the two types of muscle. Cardiac muscle is found only in the heart and is responsible for pumping blood, while skeletal muscle is attached to bones and is responsible for movement.

Blood flows to the left atrium from the pulmonary vein. This is because the pulmonary vein carries oxygenated blood from the lungs back to the heart, specifically into the left atrium. From there, the blood is pumped into the left ventricle and then to the rest of the body. Therefore, it is correct to say that blood flows to the left atrium from the pulmonary vein.

The myocardium is the middle layer of the heart wall and is composed of cardiac muscle tissue. It is responsible for the contraction and relaxation of the heart, pumping blood throughout the body. The coronary vessels, including the coronary arteries and veins, are located within the myocardium. These vessels supply oxygenated blood to the heart muscle itself, ensuring its proper functioning. Therefore, the correct answer is the myocardium.

The average resting heart rate is 75bpm. Resting heart rate refers to the number of times the heart beats per minute when a person is at rest. A lower resting heart rate generally indicates better cardiovascular fitness. The average resting heart rate can vary depending on factors such as age, fitness level, and overall health. However, a resting heart rate of 75bpm is considered within the normal range for adults.

During isovolumetric ventricular contraction, the ventricles of the heart are contracting but all the heart valves are closed. This is because the contraction of the ventricles is occurring while the blood is still being ejected from the atria into the ventricles and the ventricles are not yet ready to pump blood out to the rest of the body. The closure of the heart valves during this phase prevents any backflow of blood and ensures that the blood is directed in the correct direction once the ventricles are ready to pump.

During heavy exercise, the cardiac cycle is approximately 0.33 seconds. This is because during intense physical activity, the body requires more oxygen and nutrients, and the heart needs to pump blood at a faster rate to meet these demands. As a result, the cardiac cycle, which includes both the systolic and diastolic phases, is shortened. This allows the heart to contract and relax more frequently, ensuring an adequate supply of oxygenated blood to the working muscles.

The correct answer is tricuspid valve. The tricuspid valve is located between the right atrium and the right ventricle in the heart. It prevents the backflow of blood from the right ventricle to the right atrium. When the right atrium contracts, the tricuspid valve opens, allowing blood to flow into the right ventricle. Once the ventricle is filled, the tricuspid valve closes to prevent blood from flowing back into the atrium. From the right ventricle, blood is then pumped to the lungs for oxygenation.

The arrangement of cardiac fibers via intercalated discs allows for coordinated contraction and electrical signaling throughout the heart. This interconnected network of cells forms a functional syncytium, meaning that the cells work together as a single unit to efficiently pump blood and maintain the heart's rhythm.

During diastole, the pressure in the ventricles is low because the ventricles are relaxed and not contracting. This allows the blood to flow passively from the atria into the ventricles. The semilunar valves are closed during diastole to prevent the backflow of blood from the arteries into the ventricles. When the pressure in the atria exceeds the pressure in the ventricles, the atrioventricular valves open and blood flows from the atria into the ventricles, filling them with blood.

CHR is not usually associated with low levels of free radicals. Chronic inflammation and oxidative stress, which are common in chronic health conditions, can lead to an increase in free radicals. These free radicals can cause damage to cells and tissues, contributing to the development and progression of various diseases. Therefore, the statement is false.

The given statement is incorrect. Cardiac muscle is not smooth, but rather it is striated or striped in appearance. Cardiac muscle is found only in the heart and is responsible for the contraction and pumping of blood throughout the body. Unlike smooth muscle, which is found in organs like the intestines and blood vessels, cardiac muscle has a unique structure that allows for coordinated and rhythmic contractions. Therefore, the correct answer is false.

Cardiac muscle is unable to repair itself via satellite cells. Unlike skeletal muscle, which has satellite cells that can regenerate damaged muscle fibers, cardiac muscle cells do not possess the ability to divide and repair themselves. Therefore, the statement that cardiac muscle can repair itself via satellite cells is false.

The correct answer is .8 sec because the average cardiac cycle refers to the time it takes for the heart to complete one full cycle of contraction and relaxation. This includes the systole phase (contraction) and the diastole phase (relaxation). The average duration of a cardiac cycle is around 0.8 seconds, which is the time taken for the heart to pump blood to the body and receive blood from the lungs.

Oxygenated blood returns to the left side of the heart via the pulmonary veins, not the pulmonary artery. The pulmonary artery carries deoxygenated blood from the right side of the heart to the lungs for oxygenation.

The heart muscle contracts via the sliding filament theory, which is the mechanism by which muscle fibers generate force. It contains actin and myosin in the myocardium, which are the proteins responsible for muscle contraction. The heart muscle is striated, meaning it has a striped appearance due to the arrangement of its contractile proteins. However, the heart muscle is not voluntary, as it is controlled by the autonomic nervous system and contracts involuntarily.

The endocardium is the innermost layer of the heart that lines the chambers and valves. It is not responsible for providing muscular contraction, but rather serves as a protective layer and helps facilitate smooth blood flow within the heart. The muscular contraction that ejects blood from the heart chambers is primarily carried out by the myocardium, the middle layer of the heart. Therefore, the given statement is false.

The heart muscle receives its blood supply from the coronary vessels. These vessels are responsible for delivering oxygenated blood to the heart muscle itself, ensuring that it receives the necessary nutrients and oxygen to function properly. The pulmonary artery carries deoxygenated blood from the heart to the lungs, while the pulmonary vein carries oxygenated blood from the lungs back to the heart. The superior vena cava brings deoxygenated blood from the upper body to the heart. Therefore, none of these vessels directly supply blood to the heart muscle.

Oxygenated blood returns to the left side of the heart via veins, not the right side. The right side of the heart receives deoxygenated blood from the body via the superior and inferior vena cava, and pumps it to the lungs for oxygenation. Once oxygenated, the blood returns to the left side of the heart via the pulmonary veins.

During diastole, the heart is in the relaxation phase and fills with blood. This is because diastole is the period of the cardiac cycle when the heart muscle relaxes and expands, allowing the chambers to fill with blood. This is followed by systole, where the heart contracts and ejects the blood. Therefore, both "fills with blood" and "is in the relaxation phase" are correct statements for the given question.

During ventricular contraction, the heart pumps blood out of the ventricles and into the arteries. The amount of blood ejected during each contraction is known as the stroke volume. The stroke volume is typically around 70% of the total volume of blood in the ventricles. This means that 70% of the blood in the ventricles is pumped out with each contraction, while the remaining 30% remains in the ventricles. This ensures a continuous flow of blood throughout the body and is an important factor in maintaining proper circulation.

The heart requires calcium for proper functioning. The sarcoplasmic reticulum is a specialized organelle in muscle cells, including heart cells, that stores and releases calcium ions during muscle contraction. Therefore, the sarcoplasmic reticulum is a source of calcium for the heart. Additionally, extracellular calcium, which is calcium present outside of the cells, can also enter the heart cells and contribute to the calcium levels necessary for proper heart function. Therefore, both the sarcoplasmic reticulum and extracellular calcium are sources of calcium for the heart.

The correct answer is 100% because the right atrium receives deoxygenated blood from the body and pumps it into the right ventricle. The right ventricle then pumps this blood to the lungs for oxygenation. Therefore, all the blood that enters the right atrium is eventually moved to the ventricle before being pumped to the lungs, making it 100%.

Extracellular calcium is a source of calcium for the heart. Calcium ions play a crucial role in the contraction and relaxation of cardiac muscles, allowing the heart to pump blood effectively. Extracellular calcium is present outside the cells and is necessary for the influx of calcium ions into the cardiac muscle cells during each heartbeat. This influx triggers the release of more calcium from the sarcoplasmic reticulum, leading to muscle contraction. Therefore, extracellular calcium is essential for the proper functioning of the heart.

The improved ATP-sensitive potassium channels can reduce calcium overload. Calcium overload refers to an excessive accumulation of calcium ions in the cells, which can lead to various harmful effects. By reducing calcium overload, the improved potassium channels help maintain the balance of calcium ions in the cells, preventing potential damage and maintaining cellular function. This is why the answer "Reduces calcium overload" is correct.

Cardiac muscle is different from skeletal muscle in several ways. Firstly, cardiac muscle fibers are shorter in length compared to skeletal muscle fibers. Secondly, cardiac muscle has more mitochondria than type I skeletal muscle. Lastly, cardiac muscle does not have different fiber types like skeletal muscle. These characteristics make all the statements true.