Lecture 1 And 2 Fill-in-the-blanks

1. Decreased red blood cell production, increased red blood cell destruction, and blood loss can all result in _____.

Anemia can occur due to various reasons, including decreased red blood cell production, increased red blood cell destruction, and blood loss. When the production of red blood cells decreases, the body may not have enough healthy red blood cells to carry oxygen to the tissues, leading to anemia. Similarly, if there is an increased destruction of red blood cells or excessive blood loss, it can also result in anemia as the body loses its ability to maintain an adequate number of red blood cells.

Explanation

Anemia can occur due to various reasons, including decreased red blood cell production, increased red blood cell destruction, and blood loss. When the production of red blood cells decreases, the body may not have enough healthy red blood cells to carry oxygen to the tissues, leading to anemia. Similarly, if there is an increased destruction of red blood cells or excessive blood loss, it can also result in anemia as the body loses its ability to maintain an adequate number of red blood cells.

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2. The _____, a brief spike in pressure seen on an aortic pressure graph, is caused by blood flowing back from the aortic arch striking the closed aortic semilunar valve.

The dicrotic notch is a brief spike in pressure seen on an aortic pressure graph. It is caused by blood flowing back from the aortic arch striking the closed aortic semilunar valve.

Explanation

The dicrotic notch is a brief spike in pressure seen on an aortic pressure graph. It is caused by blood flowing back from the aortic arch striking the closed aortic semilunar valve.

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3. A primary function of blood is gas exchange, since blood is responsible for carrying _____ to the tissues and carrying _____ away from the tissues. Gas exchange occurs at the level of the _____, which are lined by a single layer of simple squamous _____ cells.

Blood is responsible for carrying oxygen (O2) to the tissues and carrying carbon dioxide (CO2) away from the tissues. Gas exchange occurs at the level of the capillaries, which are lined by a single layer of simple squamous endothelial cells.

Explanation

Blood is responsible for carrying oxygen (O2) to the tissues and carrying carbon dioxide (CO2) away from the tissues. Gas exchange occurs at the level of the capillaries, which are lined by a single layer of simple squamous endothelial cells.

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4. _____ can be caused by coronary atherosclerosis, increased blood pressure in the aorta, myocardial infarctions, or dilated cardiomyopathy (DCM).

Congestive Heart Failure (CHF) can be caused by various factors such as coronary atherosclerosis, increased blood pressure in the aorta, myocardial infarctions, or dilated cardiomyopathy (DCM). These conditions can lead to the heart's inability to pump blood effectively, resulting in fluid accumulation and congestion in the body, particularly the lungs. This can cause symptoms such as shortness of breath, fatigue, and fluid retention. Therefore, CHF is the correct answer as it encompasses the various causes and symptoms mentioned in the question.

Explanation

Congestive Heart Failure (CHF) can be caused by various factors such as coronary atherosclerosis, increased blood pressure in the aorta, myocardial infarctions, or dilated cardiomyopathy (DCM). These conditions can lead to the heart's inability to pump blood effectively, resulting in fluid accumulation and congestion in the body, particularly the lungs. This can cause symptoms such as shortness of breath, fatigue, and fluid retention. Therefore, CHF is the correct answer as it encompasses the various causes and symptoms mentioned in the question.

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5. During the initial portion of systole (phase 2a), ventricular pressure _____, while volume is _____.

During the initial portion of systole (phase 2a), ventricular pressure increases as the heart contracts and pushes blood out of the ventricles. At the same time, the volume of blood in the ventricles remains constant, as the valves leading to the arteries are still closed. This phase is known as isovolumetric contraction, where the volume of blood in the ventricles does not change while the pressure increases.

Explanation

During the initial portion of systole (phase 2a), ventricular pressure increases as the heart contracts and pushes blood out of the ventricles. At the same time, the volume of blood in the ventricles remains constant, as the valves leading to the arteries are still closed. This phase is known as isovolumetric contraction, where the volume of blood in the ventricles does not change while the pressure increases.

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6. _____ is a condition marked by potassium levels in the blood that are higher than normal.

Hyperkalemia is a condition marked by higher than normal levels of potassium in the blood. This can occur due to various factors such as kidney problems, certain medications, or hormonal imbalances. Hyperkalemia can lead to symptoms like muscle weakness, irregular heart rhythms, and numbness or tingling sensations. Treatment for hyperkalemia typically involves addressing the underlying cause and may include dietary changes, medication adjustments, or medical interventions to lower potassium levels in the blood.

Explanation

Hyperkalemia is a condition marked by higher than normal levels of potassium in the blood. This can occur due to various factors such as kidney problems, certain medications, or hormonal imbalances. Hyperkalemia can lead to symptoms like muscle weakness, irregular heart rhythms, and numbness or tingling sensations. Treatment for hyperkalemia typically involves addressing the underlying cause and may include dietary changes, medication adjustments, or medical interventions to lower potassium levels in the blood.

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7. In the lower extremities, a _____ can increase venous return by propelling blood toward the heart during contraction.

The skeletal muscle pump refers to the mechanism by which the contraction of skeletal muscles helps to propel blood towards the heart in the lower extremities. When muscles contract, they squeeze the veins, which helps to push blood against gravity and towards the heart. This action increases venous return, ensuring that blood is efficiently circulated back to the heart for oxygenation and distribution to the rest of the body. Therefore, the skeletal muscle pump plays a crucial role in maintaining proper blood flow and preventing blood pooling in the lower extremities.

Explanation

The skeletal muscle pump refers to the mechanism by which the contraction of skeletal muscles helps to propel blood towards the heart in the lower extremities. When muscles contract, they squeeze the veins, which helps to push blood against gravity and towards the heart. This action increases venous return, ensuring that blood is efficiently circulated back to the heart for oxygenation and distribution to the rest of the body. Therefore, the skeletal muscle pump plays a crucial role in maintaining proper blood flow and preventing blood pooling in the lower extremities.

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8. In fetal circulation, the _____ is a shunt that allows blood to pass from the right atrium to the left atrium.

The foramen ovale is a shunt that allows blood to pass from the right atrium to the left atrium in fetal circulation. This opening is present in the fetal heart to bypass the non-functioning lungs, as the oxygen supply is provided by the mother through the placenta. It allows oxygenated blood to bypass the right ventricle and flow directly into the left atrium, from where it can be pumped out to the rest of the body. After birth, the foramen ovale usually closes as the lungs become functional and the need for the shunt diminishes.

Explanation

The foramen ovale is a shunt that allows blood to pass from the right atrium to the left atrium in fetal circulation. This opening is present in the fetal heart to bypass the non-functioning lungs, as the oxygen supply is provided by the mother through the placenta. It allows oxygenated blood to bypass the right ventricle and flow directly into the left atrium, from where it can be pumped out to the rest of the body. After birth, the foramen ovale usually closes as the lungs become functional and the need for the shunt diminishes.

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9. The _____ bypasses the underdeveloped fetal pulmonary circuit by shunting blood from the pulmonary artery to the aorta.

The ductus arteriosus is a blood vessel that connects the pulmonary artery to the aorta in a developing fetus. It allows blood to bypass the underdeveloped fetal pulmonary circuit, ensuring that oxygenated blood from the placenta can reach the rest of the body. After birth, the ductus arteriosus typically closes as the baby starts breathing on its own and the lungs become functional.

Explanation

The ductus arteriosus is a blood vessel that connects the pulmonary artery to the aorta in a developing fetus. It allows blood to bypass the underdeveloped fetal pulmonary circuit, ensuring that oxygenated blood from the placenta can reach the rest of the body. After birth, the ductus arteriosus typically closes as the baby starts breathing on its own and the lungs become functional.

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10. Vasodilation and vasoconstriction of _____ allows for variance in blood flow distribution to target organs.

Arterioles are small blood vessels that are responsible for regulating blood flow to different organs and tissues. Vasodilation refers to the widening of these arterioles, allowing for increased blood flow to specific areas, while vasoconstriction refers to the narrowing of arterioles, reducing blood flow to certain regions. This variability in arteriole size and function enables the redistribution of blood flow according to the specific needs of different organs, ensuring that they receive an adequate supply of oxygen and nutrients.

Explanation

Arterioles are small blood vessels that are responsible for regulating blood flow to different organs and tissues. Vasodilation refers to the widening of these arterioles, allowing for increased blood flow to specific areas, while vasoconstriction refers to the narrowing of arterioles, reducing blood flow to certain regions. This variability in arteriole size and function enables the redistribution of blood flow according to the specific needs of different organs, ensuring that they receive an adequate supply of oxygen and nutrients.

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11. A serious hemorrhage could result in _____ shock if too much blood is lost from the circulatory system.

A serious hemorrhage could result in hypovolemic shock if too much blood is lost from the circulatory system. Hypovolemic shock occurs when there is a significant decrease in blood volume, leading to inadequate perfusion of organs and tissues. In the case of a serious hemorrhage, the loss of blood volume can be substantial, causing a drop in blood pressure and depriving the body of oxygen and nutrients. This can result in organ dysfunction and potentially life-threatening complications.

Explanation

A serious hemorrhage could result in hypovolemic shock if too much blood is lost from the circulatory system. Hypovolemic shock occurs when there is a significant decrease in blood volume, leading to inadequate perfusion of organs and tissues. In the case of a serious hemorrhage, the loss of blood volume can be substantial, causing a drop in blood pressure and depriving the body of oxygen and nutrients. This can result in organ dysfunction and potentially life-threatening complications.

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12. The binding of epinephrine to the beta2-adrenergic receptors on arteriolar smooth muscle cells, instead of the alpha-adrenergic receptors, causes muscle cells to _____.

When epinephrine binds to the beta2-adrenergic receptors on arteriolar smooth muscle cells, it triggers a signaling cascade that leads to the relaxation of these muscle cells. This relaxation causes the arterioles to dilate, increasing blood flow to the surrounding tissues. By binding to the beta2-adrenergic receptors instead of the alpha-adrenergic receptors, epinephrine promotes vasodilation and ultimately causes the muscle cells to relax.

Explanation

When epinephrine binds to the beta2-adrenergic receptors on arteriolar smooth muscle cells, it triggers a signaling cascade that leads to the relaxation of these muscle cells. This relaxation causes the arterioles to dilate, increasing blood flow to the surrounding tissues. By binding to the beta2-adrenergic receptors instead of the alpha-adrenergic receptors, epinephrine promotes vasodilation and ultimately causes the muscle cells to relax.

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13. When a drop in arteriole blood pressure decreases the blood flow to an organ, the arterioles supplying that organ dilate to limit resistance and restore normal blood flow in the local control mechanism known as _____

When there is a decrease in arteriole blood pressure, the blood flow to an organ is reduced. In order to restore normal blood flow and prevent further decrease in blood supply, the arterioles supplying that organ dilate. This dilation helps to limit resistance in the blood vessels, allowing more blood to flow through and restore adequate blood flow to the organ. This local control mechanism is known as flow autoregulation, as it helps to regulate and maintain the flow of blood to an organ despite changes in arterial pressure.

Explanation

When there is a decrease in arteriole blood pressure, the blood flow to an organ is reduced. In order to restore normal blood flow and prevent further decrease in blood supply, the arterioles supplying that organ dilate. This dilation helps to limit resistance in the blood vessels, allowing more blood to flow through and restore adequate blood flow to the organ. This local control mechanism is known as flow autoregulation, as it helps to regulate and maintain the flow of blood to an organ despite changes in arterial pressure.

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14. _____ = diastolic pressure + 1/3(pulse pressure).

The given equation represents the calculation of mean arterial pressure (MAP). MAP is calculated by adding the diastolic pressure to one-third of the pulse pressure. This equation is commonly used in medical settings to determine the average pressure in the arteries during a cardiac cycle.

Explanation

The given equation represents the calculation of mean arterial pressure (MAP). MAP is calculated by adding the diastolic pressure to one-third of the pulse pressure. This equation is commonly used in medical settings to determine the average pressure in the arteries during a cardiac cycle.

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15. When using a blood pressure cuff to measure blood pressure, the first sound heard through the sphygmomanometer is when cuff pressure drops just below _____ pressure. The second sound is when cuff pressure drops just below _____ pressure.

When using a blood pressure cuff to measure blood pressure, the first sound heard through the sphygmomanometer is when cuff pressure drops just below systolic pressure. This is because the systolic pressure is the highest pressure in the arteries when the heart contracts and pushes blood out. The second sound is when cuff pressure drops just below diastolic pressure. Diastolic pressure is the lowest pressure in the arteries when the heart is at rest and filling with blood.

Explanation

When using a blood pressure cuff to measure blood pressure, the first sound heard through the sphygmomanometer is when cuff pressure drops just below systolic pressure. This is because the systolic pressure is the highest pressure in the arteries when the heart contracts and pushes blood out. The second sound is when cuff pressure drops just below diastolic pressure. Diastolic pressure is the lowest pressure in the arteries when the heart is at rest and filling with blood.

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16. There are _____ (numeric value) heart chambers that are comprised of _____ (numeric value) superior atria and _____ (numeric value) inferior _____

The human heart is composed of four chambers, two superior atria, and two inferior ventricles. The atria receive blood returning to the heart, while the ventricles pump blood out of the heart to the rest of the body.

Explanation

The human heart is composed of four chambers, two superior atria, and two inferior ventricles. The atria receive blood returning to the heart, while the ventricles pump blood out of the heart to the rest of the body.

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17. For each period labeled "A" in the cardiac graph cycle below, is the associated valve open or closed (hint: all valves labeled "A" are in the same state)?A) _____During each period labeled "B" in the cardiac graph cycle below, is the associated valve open or closed (hint: all valves labeled "B" are in the same state)?B) _____

For each period labeled "A", the associated valve is open. This is because during period A, the heart is in systole, which is the phase of the cardiac cycle when the ventricles contract and blood is pumped out of the heart. In order for blood to be pumped out, the valves (specifically the aortic and pulmonary valves) must be open to allow blood to flow out of the ventricles and into the respective arteries.

For each period labeled "B", the associated valve is closed. This is because during period B, the heart is in diastole, which is the phase of the cardiac cycle when the ventricles relax and fill with blood. In order for the ventricles to fill, the valves (specifically the aortic and pulmonary valves) must be closed to prevent blood from flowing back into the ventricles from the arteries.

Explanation

For each period labeled "A", the associated valve is open. This is because during period A, the heart is in systole, which is the phase of the cardiac cycle when the ventricles contract and blood is pumped out of the heart. In order for blood to be pumped out, the valves (specifically the aortic and pulmonary valves) must be open to allow blood to flow out of the ventricles and into the respective arteries.

For each period labeled "B", the associated valve is closed. This is because during period B, the heart is in diastole, which is the phase of the cardiac cycle when the ventricles relax and fill with blood. In order for the ventricles to fill, the valves (specifically the aortic and pulmonary valves) must be closed to prevent blood from flowing back into the ventricles from the arteries.

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18. A cut _____ has even blood flow, since blood pressure is relatively constant in these vessels, whereas blood flows from a cut _____ in spurts due to pressure pulsation.

Veins have even blood flow because blood pressure is relatively constant in these vessels. On the other hand, blood flows from an artery in spurts due to pressure pulsation.

Explanation

Veins have even blood flow because blood pressure is relatively constant in these vessels. On the other hand, blood flows from an artery in spurts due to pressure pulsation.

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19. _____ is the primary oxygen-carrying molecule in muscle, which has a greater oxygen-binding affinity than _____, the primary oxygen-carrying molecule in blood.

Myoglobin is the primary oxygen-carrying molecule in muscle, while hemoglobin is the primary oxygen-carrying molecule in blood. Myoglobin has a greater oxygen-binding affinity than hemoglobin, meaning it has a stronger attraction to oxygen molecules. This allows myoglobin to efficiently store and release oxygen in muscle tissues, ensuring an adequate oxygen supply for muscle function. Hemoglobin, on the other hand, is responsible for transporting oxygen from the lungs to the rest of the body.

Explanation

Myoglobin is the primary oxygen-carrying molecule in muscle, while hemoglobin is the primary oxygen-carrying molecule in blood. Myoglobin has a greater oxygen-binding affinity than hemoglobin, meaning it has a stronger attraction to oxygen molecules. This allows myoglobin to efficiently store and release oxygen in muscle tissues, ensuring an adequate oxygen supply for muscle function. Hemoglobin, on the other hand, is responsible for transporting oxygen from the lungs to the rest of the body.

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20. Carbon monoxide binds to the _____ group in hemoglobin more tightly than _____, which is what ultimately causes carbon monoxide poisoning.

Carbon monoxide binds to the heme group in hemoglobin more tightly than oxygen, which is what ultimately causes carbon monoxide poisoning.

Explanation

Carbon monoxide binds to the heme group in hemoglobin more tightly than oxygen, which is what ultimately causes carbon monoxide poisoning.

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21. The circle labeled _____ represents the point where there is a pause in signal at the AV node. The circle labeled _____ is the point at which the signal spreads through the ventricle walls, causing them to contract.

The circle labeled A represents the point where there is a pause in signal at the AV node. This is known as the atrioventricular (AV) delay, which allows time for the atria to fully contract and empty their blood into the ventricles before the ventricles contract. The circle labeled B represents the point at which the signal spreads through the ventricle walls, causing them to contract. This is known as ventricular depolarization, which leads to the contraction of the ventricles and the pumping of blood out of the heart.

Explanation

The circle labeled A represents the point where there is a pause in signal at the AV node. This is known as the atrioventricular (AV) delay, which allows time for the atria to fully contract and empty their blood into the ventricles before the ventricles contract. The circle labeled B represents the point at which the signal spreads through the ventricle walls, causing them to contract. This is known as ventricular depolarization, which leads to the contraction of the ventricles and the pumping of blood out of the heart.

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22. Line _____ (hint: letter) represents adult hemoglobin in the graph below, while line _____ (hint: letter) represents fetal hemoglobin. _____ hemoglobin has the higher oxygen-binding affinity.

In the given graph, line B represents adult hemoglobin and line A represents fetal hemoglobin. The question states that line [Blank] (B) represents adult hemoglobin, while line [Blank] (A) represents fetal hemoglobin. Therefore, fetal hemoglobin has the higher oxygen-binding affinity.

Explanation

In the given graph, line B represents adult hemoglobin and line A represents fetal hemoglobin. The question states that line [Blank] (B) represents adult hemoglobin, while line [Blank] (A) represents fetal hemoglobin. Therefore, fetal hemoglobin has the higher oxygen-binding affinity.

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23. Label the missing structures shared by both veins and arteries.A. _____B. _____C. _____

The missing structures shared by both veins and arteries are the tunica interna, tunica media, and tunica externa. These layers are found in the walls of both veins and arteries and contribute to their overall structure and function. The tunica interna, also known as the intima, is the innermost layer and is composed of endothelial cells. The tunica media is the middle layer and is made up of smooth muscle cells and elastic fibers. The tunica externa, also known as the adventitia, is the outermost layer and consists of connective tissue. These layers help to support and protect the blood vessels and regulate blood flow.

Explanation

The missing structures shared by both veins and arteries are the tunica interna, tunica media, and tunica externa. These layers are found in the walls of both veins and arteries and contribute to their overall structure and function. The tunica interna, also known as the intima, is the innermost layer and is composed of endothelial cells. The tunica media is the middle layer and is made up of smooth muscle cells and elastic fibers. The tunica externa, also known as the adventitia, is the outermost layer and consists of connective tissue. These layers help to support and protect the blood vessels and regulate blood flow.

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24. Red blood cells exhibit a _____ shape that leads to a(n) _____ in surface area, and allows for greater oxygen absorption.

Red blood cells have a bi-concave or biconcave shape, meaning they are concave on both sides. This shape increases their surface area, allowing for greater oxygen absorption.

Explanation

Red blood cells have a bi-concave or biconcave shape, meaning they are concave on both sides. This shape increases their surface area, allowing for greater oxygen absorption.

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25. The "lub" heart sound corresponds to the closing of the _____ valves, while "dub" corresponds to the closing of the _____ valves.

The "lub" heart sound corresponds to the closing of the AV (atrioventricular) valves, while "dub" corresponds to the closing of the semilunar valves.

Explanation

The "lub" heart sound corresponds to the closing of the AV (atrioventricular) valves, while "dub" corresponds to the closing of the semilunar valves.

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26. The sequence of electrical and mechanical events associated with each heartbeat is referred to as the _____. This mechanism is characterized by ventricular contraction, also known as _____, and ventricular relaxation, also known as _____.

The sequence of electrical and mechanical events associated with each heartbeat is referred to as the cardiac cycle. This mechanism is characterized by ventricular contraction, also known as systole, and ventricular relaxation, also known as diastole. During systole, the ventricles contract and pump blood out of the heart, while during diastole, the ventricles relax and fill with blood. The cardiac cycle is essential for maintaining the circulation of blood throughout the body.

Explanation

The sequence of electrical and mechanical events associated with each heartbeat is referred to as the cardiac cycle. This mechanism is characterized by ventricular contraction, also known as systole, and ventricular relaxation, also known as diastole. During systole, the ventricles contract and pump blood out of the heart, while during diastole, the ventricles relax and fill with blood. The cardiac cycle is essential for maintaining the circulation of blood throughout the body.

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27. The velocity of blood moving though the capillaries is _____ than in the aorta due to the _____ in cross-sectional area.

The velocity of blood moving through the capillaries is slower than in the aorta due to the lower cross-sectional area. As blood flows from the larger aorta into the smaller capillaries, the total cross-sectional area increases. This causes the blood to spread out and flow more slowly, allowing for efficient exchange of oxygen, nutrients, and waste products between the blood and surrounding tissues.

Explanation

The velocity of blood moving through the capillaries is slower than in the aorta due to the lower cross-sectional area. As blood flows from the larger aorta into the smaller capillaries, the total cross-sectional area increases. This causes the blood to spread out and flow more slowly, allowing for efficient exchange of oxygen, nutrients, and waste products between the blood and surrounding tissues.

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28. This is the major vessel that carries blood from the head, upper torso and arms. It is located as, _____ on the figure and is called the _____. This is the major vessel that carries blood to the heart from the lower torso and legs. It is located on the figure as _____ and is called the _____.

The major vessel that carries blood from the head, upper torso, and arms is called the superior vena cava. It is located as B on the figure. On the other hand, the major vessel that carries blood to the heart from the lower torso and legs is called the inferior vena cava. It is located on the figure as A.

Explanation

The major vessel that carries blood from the head, upper torso, and arms is called the superior vena cava. It is located as B on the figure. On the other hand, the major vessel that carries blood to the heart from the lower torso and legs is called the inferior vena cava. It is located on the figure as A.

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29. The _____ side of the heart flows oxygen-rich, CO2-poor blood to the _____ circuit, while the _____ side of the heart flows oxygen-poor, CO2-rich blood to the _____ circuit.

The left side of the heart flows oxygen-rich, CO2-poor blood to the systemic circuit, while the right side of the heart flows oxygen-poor, CO2-rich blood to the pulmonary circuit.

Explanation

The left side of the heart flows oxygen-rich, CO2-poor blood to the systemic circuit, while the right side of the heart flows oxygen-poor, CO2-rich blood to the pulmonary circuit.

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30. Contraction of the heart starts at point _____, called the _____ of the heart, and travels to point _____, called the base of the heart.

The contraction of the heart starts at the apex, which is the lowest point of the heart, and travels to the base, which is the top of the heart.

Explanation

The contraction of the heart starts at the apex, which is the lowest point of the heart, and travels to the base, which is the top of the heart.

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31. Reduced _____ levels trigger red blood cell production by stimulating the kidneys to release _____. This is an example of a _____ feedback loop.

Reduced oxygen levels trigger red blood cell production by stimulating the kidneys to release erythropoietin (EPO). This is an example of a negative feedback loop, where the response (increased red blood cell production) works to counteract the initial stimulus (reduced oxygen levels).

Explanation

Reduced oxygen levels trigger red blood cell production by stimulating the kidneys to release erythropoietin (EPO). This is an example of a negative feedback loop, where the response (increased red blood cell production) works to counteract the initial stimulus (reduced oxygen levels).

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32. When the adrenal medulla secretes epinephrine, the effects of the resulting increase in plasma epinephrine levels depend largely on the type of receptor that epinephrine binds. When binding to beta 2 receptors, arteriolar radius is _____, resulting in _____. When binding to alpha receptors, arteriolar radius is _____, resulting in _____.

When epinephrine binds to beta 2 receptors, it causes the arteriolar radius to increase, resulting in vasodilation. This means that the blood vessels widen, allowing for increased blood flow. On the other hand, when epinephrine binds to alpha receptors, it causes the arteriolar radius to decrease, resulting in vasoconstriction. This means that the blood vessels narrow, reducing blood flow.

Explanation

When epinephrine binds to beta 2 receptors, it causes the arteriolar radius to increase, resulting in vasodilation. This means that the blood vessels widen, allowing for increased blood flow. On the other hand, when epinephrine binds to alpha receptors, it causes the arteriolar radius to decrease, resulting in vasoconstriction. This means that the blood vessels narrow, reducing blood flow.

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33. An increase in extracellular norepinephrine levels, following release by postganglionic neurons of the _____ nervous system, causes _____ of arterioles. This _____ resistance to blood flow.

An increase in extracellular norepinephrine levels, following release by postganglionic neurons of the sympathetic nervous system, causes vasoconstriction of arterioles. This constriction increases resistance to blood flow.

Explanation

An increase in extracellular norepinephrine levels, following release by postganglionic neurons of the sympathetic nervous system, causes vasoconstriction of arterioles. This constriction increases resistance to blood flow.

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34. Letter _____ is the point at which the excitation starts. This is called the _____, otherwise known as the pacemaker.This is the second point of excitation where there is a 0.1 second pause to allow ventricular filling—this is at the _____ and this corresponds to letter _____.

The correct answer is B. The Sinoatrial Node (SA Node) is the point at which the excitation starts and is also known as the pacemaker. This is the second point of excitation where there is a 0.1 second pause to allow ventricular filling, and this corresponds to the Atrioventricular Node (AV Node).

Explanation

The correct answer is B. The Sinoatrial Node (SA Node) is the point at which the excitation starts and is also known as the pacemaker. This is the second point of excitation where there is a 0.1 second pause to allow ventricular filling, and this corresponds to the Atrioventricular Node (AV Node).

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35. Each hemoglobin subunit consists of a(n) _____ ring with a(n) _____ atom in its center. Each subunit is capable of binding _____ oxygen molecule(s), with a maximum binding of _____ oxygen molecule(s) per hemoglobin molecule.

Hemoglobin is composed of four subunits, each containing a porphyrin ring with an iron atom in its center. Each subunit can bind one oxygen molecule, allowing a maximum binding of four oxygen molecules per hemoglobin molecule.

Explanation

Hemoglobin is composed of four subunits, each containing a porphyrin ring with an iron atom in its center. Each subunit can bind one oxygen molecule, allowing a maximum binding of four oxygen molecules per hemoglobin molecule.

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36. According to _____'s law, an increase in venous return results in a(n) _____ in end diastolic volume, corresponding to an increase in _____

According to Starling's law, an increase in venous return results in an increase in end diastolic volume, corresponding to an increase in stroke volume. This means that when the amount of blood returning to the heart increases, the heart stretches more during diastole, leading to a stronger contraction during systole and a greater volume of blood being pumped out of the heart with each beat. This is known as the stroke volume and is often represented by the abbreviation SV.

Explanation

According to Starling's law, an increase in venous return results in an increase in end diastolic volume, corresponding to an increase in stroke volume. This means that when the amount of blood returning to the heart increases, the heart stretches more during diastole, leading to a stronger contraction during systole and a greater volume of blood being pumped out of the heart with each beat. This is known as the stroke volume and is often represented by the abbreviation SV.

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37. After blood is centrifuged to separate out its components, the top layer of the sample consists of _____, the middle layer of the sample consists of _____, and the bottom layer of the consists of _____.

After blood is centrifuged, the different components of the blood separate based on their density. The top layer of the sample is the plasma, which is the liquid component of the blood and contains various proteins, electrolytes, and nutrients. The middle layer is the buffy coat, which consists of white blood cells and platelets. The bottom layer is made up of erythrocytes, or red blood cells, which are responsible for carrying oxygen throughout the body.

Explanation

After blood is centrifuged, the different components of the blood separate based on their density. The top layer of the sample is the plasma, which is the liquid component of the blood and contains various proteins, electrolytes, and nutrients. The middle layer is the buffy coat, which consists of white blood cells and platelets. The bottom layer is made up of erythrocytes, or red blood cells, which are responsible for carrying oxygen throughout the body.

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38. The heart is able to contract in a coordinated fashion due to the presence of special intracellular connections called _____. If these close, ischemia leading to a(n) _____ will occur.

Gap junctions are special intracellular connections that allow for the coordinated contraction of the heart. These connections allow electrical signals to pass between cardiac muscle cells, ensuring that the heart beats in a synchronized manner. If these gap junctions close, it can disrupt the electrical conduction in the heart, leading to ischemia, which is a lack of blood flow to the heart muscle. Prolonged ischemia can result in myocardial infarction, commonly known as a heart attack, where a portion of the heart muscle dies due to lack of oxygen and nutrients.

Explanation

Gap junctions are special intracellular connections that allow for the coordinated contraction of the heart. These connections allow electrical signals to pass between cardiac muscle cells, ensuring that the heart beats in a synchronized manner. If these gap junctions close, it can disrupt the electrical conduction in the heart, leading to ischemia, which is a lack of blood flow to the heart muscle. Prolonged ischemia can result in myocardial infarction, commonly known as a heart attack, where a portion of the heart muscle dies due to lack of oxygen and nutrients.

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39. A) On the graph, _____ is the point at which potassium permeability decreases and is accompanied by slow _____ entry. B) On the graph, _____ is the point at which fast calcium channels open C) On the graph, _____ is the point at which there is slow depolarization. This is known as _____.

On the graph, point C represents the point at which there is slow depolarization. This slow depolarization is known as the pacemaker potential. Point C is associated with the entry of sodium ions (Na+). On the other hand, point A represents the point at which potassium permeability decreases, leading to slow entry of sodium ions (Na+). Point B represents the point at which fast calcium channels open. Therefore, the correct answer is C for point C, Sodium (Na+) for the blank, A for point A, B for point B, and Pacemaker Potential for the blank.

Explanation

On the graph, point C represents the point at which there is slow depolarization. This slow depolarization is known as the pacemaker potential. Point C is associated with the entry of sodium ions (Na+). On the other hand, point A represents the point at which potassium permeability decreases, leading to slow entry of sodium ions (Na+). Point B represents the point at which fast calcium channels open. Therefore, the correct answer is C for point C, Sodium (Na+) for the blank, A for point A, B for point B, and Pacemaker Potential for the blank.

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40. It is adaptive for hemoglobin to release oxygen at _____ levels when exercising, since tissues have a(n) _____ demand for oxygen. This causes a _____ shift on an oxygen-dissociation curve.

When exercising, tissues have a higher demand for oxygen. In order to meet this increased demand, it is adaptive for hemoglobin to release oxygen at increased levels. This causes a higher shift on an oxygen-dissociation curve, indicating that more oxygen is being released by hemoglobin to the tissues. The term "right" refers to the direction of the shift on the curve, indicating an increase in oxygen release.

Explanation

When exercising, tissues have a higher demand for oxygen. In order to meet this increased demand, it is adaptive for hemoglobin to release oxygen at increased levels. This causes a higher shift on an oxygen-dissociation curve, indicating that more oxygen is being released by hemoglobin to the tissues. The term "right" refers to the direction of the shift on the curve, indicating an increase in oxygen release.

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41. For the corresponding flow chart, label A, B and C for factors that influence heart rate.A. _____B. _____C. _____

The factors that influence heart rate are the sympathetic nervous system, the parasympathetic nervous system, and the SA Node (sinoatrial node). The sympathetic nervous system increases heart rate, while the parasympathetic nervous system decreases heart rate. The SA Node is responsible for initiating the electrical impulses that regulate the heart's rhythm.

Explanation

The factors that influence heart rate are the sympathetic nervous system, the parasympathetic nervous system, and the SA Node (sinoatrial node). The sympathetic nervous system increases heart rate, while the parasympathetic nervous system decreases heart rate. The SA Node is responsible for initiating the electrical impulses that regulate the heart's rhythm.

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42. Fill in the blanks relating the phase of a cardiac action potential to the points on an EKG.A) The _____ is the point at which the atria depolarize. B) The _____ represents ventricular repolarization. C) The QRS complex is that point at which there is _____.

The P wave is the point at which the atria depolarize. The T wave represents ventricular repolarization. The QRS complex is that point at which there is ventricular depolarization.

Explanation

The P wave is the point at which the atria depolarize. The T wave represents ventricular repolarization. The QRS complex is that point at which there is ventricular depolarization.

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43. For the figures of the compromised valves shown below, the valve labeled _____ will result in a murmur because it is leaky, causing _____. The valve labeled _____ will also result in a murmur because it is _____, causing turbulent flow.

The valve labeled B will result in a murmur because it is leaky, causing turbulent backflow. The valve labeled D will also result in a murmur because it is narrowed, causing turbulent flow.

Explanation

The valve labeled B will result in a murmur because it is leaky, causing turbulent backflow. The valve labeled D will also result in a murmur because it is narrowed, causing turbulent flow.

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44. Name the missing components of the Circulatory SystemA. _____B. _____C. _____D. _____

The missing components of the Circulatory System are the Pulmonary trunk, Aorta, Capillaries, and Venae cavae/Vena cava. The circulatory system is responsible for transporting oxygen, nutrients, hormones, and waste products throughout the body. The Pulmonary trunk carries deoxygenated blood from the right ventricle to the lungs, where it picks up oxygen. The Aorta is the largest artery in the body and carries oxygenated blood from the left ventricle to the rest of the body. Capillaries are tiny blood vessels that connect arteries and veins, allowing for the exchange of oxygen, nutrients, and waste products with the body's tissues. The Venae cavae/Vena cava are large veins that carry deoxygenated blood from the body back to the heart.

Explanation

The missing components of the Circulatory System are the Pulmonary trunk, Aorta, Capillaries, and Venae cavae/Vena cava. The circulatory system is responsible for transporting oxygen, nutrients, hormones, and waste products throughout the body. The Pulmonary trunk carries deoxygenated blood from the right ventricle to the lungs, where it picks up oxygen. The Aorta is the largest artery in the body and carries oxygenated blood from the left ventricle to the rest of the body. Capillaries are tiny blood vessels that connect arteries and veins, allowing for the exchange of oxygen, nutrients, and waste products with the body's tissues. The Venae cavae/Vena cava are large veins that carry deoxygenated blood from the body back to the heart.

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45. Blood cell formation, also called _____, occurs in the _____ bone marrow.

Blood cell formation, also known as hematopoiesis or haematopoiesis, takes place in the red bone marrow. This process involves the production of various types of blood cells, including red blood cells, white blood cells, and platelets. The red bone marrow contains stem cells that differentiate into these different types of blood cells, ensuring a constant supply of healthy blood cells in the body.

Explanation

Blood cell formation, also known as hematopoiesis or haematopoiesis, takes place in the red bone marrow. This process involves the production of various types of blood cells, including red blood cells, white blood cells, and platelets. The red bone marrow contains stem cells that differentiate into these different types of blood cells, ensuring a constant supply of healthy blood cells in the body.

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46. Environmental factors that could have caused the _____-shift in the oxygen dissociation curve below include increased _____, increased _____, or reduced _____.

The correct answer is "right, temperature, altitude, altitude, temperature, pH". Environmental factors such as temperature, altitude, and pH can cause a shift in the oxygen dissociation curve. An increase in temperature can shift the curve to the right, indicating a decrease in the affinity of hemoglobin for oxygen. Similarly, an increase in altitude can also shift the curve to the right due to lower oxygen availability. Changes in pH can affect the affinity of hemoglobin for oxygen, with a decrease in pH (acidic conditions) causing a right shift.

Explanation

The correct answer is "right, temperature, altitude, altitude, temperature, pH". Environmental factors such as temperature, altitude, and pH can cause a shift in the oxygen dissociation curve. An increase in temperature can shift the curve to the right, indicating a decrease in the affinity of hemoglobin for oxygen. Similarly, an increase in altitude can also shift the curve to the right due to lower oxygen availability. Changes in pH can affect the affinity of hemoglobin for oxygen, with a decrease in pH (acidic conditions) causing a right shift.

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47. For the associated flow chart, indicate which general category of control (A-C) is denoted and whether the specific controls within each category are best categorized as vasoconstrictors or vasodilators.A. _____B. _____C. _____D. _____E. _____

The correct answer indicates that the flow chart represents the general categories of control in the body, which are neural, hormonal, and local controls. Within each category, the specific controls can be categorized as either vasoconstrictors or vasodilators.

Explanation

The correct answer indicates that the flow chart represents the general categories of control in the body, which are neural, hormonal, and local controls. Within each category, the specific controls can be categorized as either vasoconstrictors or vasodilators.

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48. The _____ shaped curve appearing in oxygen-hemoglobin dissociation graphs (pictured below) occurs as a result of _____ binding. The increasing slope of this graph indicates increased _____.

The correct answer is "sigmoidal, S, cooperative, binding affinity". In oxygen-hemoglobin dissociation graphs, the sigmoidal or S-shaped curve is observed due to cooperative binding. Cooperative binding refers to the binding of oxygen molecules to hemoglobin, where the binding of one oxygen molecule facilitates the binding of subsequent molecules. This results in a steepening of the curve, indicating increased binding affinity between hemoglobin and oxygen.

Explanation

The correct answer is "sigmoidal, S, cooperative, binding affinity". In oxygen-hemoglobin dissociation graphs, the sigmoidal or S-shaped curve is observed due to cooperative binding. Cooperative binding refers to the binding of oxygen molecules to hemoglobin, where the binding of one oxygen molecule facilitates the binding of subsequent molecules. This results in a steepening of the curve, indicating increased binding affinity between hemoglobin and oxygen.

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49. P.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica; -webkit-text-stroke: #000000} span.s1 {font-kerning: none}The three sources of resistance that are most prominent in the blood vessels are _____, _____, and _____. Of these three sources, _____ is the only one that changes substantially.

The correct answer is blood vessel diameter, blood viscosity, blood vessel length. The resistance in blood vessels is determined by three factors: blood vessel diameter, blood viscosity, and blood vessel length. Of these three factors, blood vessel diameter is the most influential in determining resistance. Changes in blood vessel diameter can greatly affect the flow of blood and resistance in the vessels. Blood viscosity, which refers to the thickness or stickiness of the blood, also plays a role in resistance. Finally, blood vessel length can contribute to resistance, but it is the least influential factor among the three.

Explanation

The correct answer is blood vessel diameter, blood viscosity, blood vessel length. The resistance in blood vessels is determined by three factors: blood vessel diameter, blood viscosity, and blood vessel length. Of these three factors, blood vessel diameter is the most influential in determining resistance. Changes in blood vessel diameter can greatly affect the flow of blood and resistance in the vessels. Blood viscosity, which refers to the thickness or stickiness of the blood, also plays a role in resistance. Finally, blood vessel length can contribute to resistance, but it is the least influential factor among the three.

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50. Means of stimulation: Cardiac muscle cells are _____, while skeletal muscle cells require a(n) _____ input to reach depolarization.

Cardiac muscle cells are self-excitable, meaning they can generate electrical impulses on their own without any external stimulation. On the other hand, skeletal muscle cells require a nervous system input to reach depolarization, which means they need a signal from the nervous system to initiate contraction.

Explanation

Cardiac muscle cells are self-excitable, meaning they can generate electrical impulses on their own without any external stimulation. On the other hand, skeletal muscle cells require a nervous system input to reach depolarization, which means they need a signal from the nervous system to initiate contraction.

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51. All erythrocytes originate from _____ stem cells, which then transform into committed cells, also called _____. These cells produce high levels of _____ in Phase 1 (the early erythroblast phase) of the developmental pathway.

Erythrocytes, also known as red blood cells, are derived from hemocytoblast stem cells. These stem cells differentiate into committed cells called proerythroblasts. During Phase 1 of the developmental pathway, proerythroblasts produce high levels of ribosomes, which are responsible for protein synthesis.

Explanation

Erythrocytes, also known as red blood cells, are derived from hemocytoblast stem cells. These stem cells differentiate into committed cells called proerythroblasts. During Phase 1 of the developmental pathway, proerythroblasts produce high levels of ribosomes, which are responsible for protein synthesis.

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52. When all valves in the heart are closed the heart is in _____ ventricular contraction or relaxation. The constant volume of blood in the ventricles in this stage makes it analogous to _____ contraction, where muscle fibers develop tension but do not shorten.

When all valves in the heart are closed, the heart is in isovolumetric ventricular contraction or relaxation. In this stage, the volume of blood in the ventricles remains constant, meaning that no blood is being ejected or filled. This is similar to isometric skeletal muscle contraction, where the muscle fibers develop tension but do not shorten. In both cases, there is no change in length or volume, but tension is being generated.

Explanation

When all valves in the heart are closed, the heart is in isovolumetric ventricular contraction or relaxation. In this stage, the volume of blood in the ventricles remains constant, meaning that no blood is being ejected or filled. This is similar to isometric skeletal muscle contraction, where the muscle fibers develop tension but do not shorten. In both cases, there is no change in length or volume, but tension is being generated.

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53. An increase in ventricular pressure causes the _____ valve to open. During ventricular relaxation, this valve is as pictured in figure _____ below, to control back flow of blood into the ventricle.

An increase in ventricular pressure causes the semilunar valve to open. During ventricular relaxation, this valve is as pictured in figure B below, to control backflow of blood into the ventricle.

Explanation

An increase in ventricular pressure causes the semilunar valve to open. During ventricular relaxation, this valve is as pictured in figure B below, to control backflow of blood into the ventricle.

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54. Oxygen dissociates from _____, diffuses across the muscle cell membrane, and binds _____. Inside the muscle cell, oxygen is released from _____ and moves into the mitochondria as a result of the _____ gradient.

Oxygen dissociates from hemoglobin, which is a protein found in red blood cells, and diffuses across the muscle cell membrane. Inside the muscle cell, oxygen binds to myoglobin, another protein that is present in muscle cells. Oxygen is then released from myoglobin and moves into the mitochondria, the powerhouse of the cell, as a result of the partial pressure gradient.

Explanation

Oxygen dissociates from hemoglobin, which is a protein found in red blood cells, and diffuses across the muscle cell membrane. Inside the muscle cell, oxygen binds to myoglobin, another protein that is present in muscle cells. Oxygen is then released from myoglobin and moves into the mitochondria, the powerhouse of the cell, as a result of the partial pressure gradient.

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55. Label the ventricular stages in the corresponding graph of the cardiac cycle.A. _____B. _____C. _____

The correct answer is Ventricular filling, diastole, Ventricular Systole, systole, Early Diastole, ventricular relaxation. In the cardiac cycle, the ventricular filling occurs during diastole when the ventricles are relaxed and blood is flowing into them. Ventricular systole refers to the contraction of the ventricles, which occurs during systole. Early diastole is the phase when the ventricles are relaxing and refilling with blood after contraction. Therefore, the labeling of the ventricular stages in the corresponding graph of the cardiac cycle is correctly represented by Ventricular filling, diastole, Ventricular Systole, systole, Early Diastole, ventricular relaxation.

Explanation

The correct answer is Ventricular filling, diastole, Ventricular Systole, systole, Early Diastole, ventricular relaxation. In the cardiac cycle, the ventricular filling occurs during diastole when the ventricles are relaxed and blood is flowing into them. Ventricular systole refers to the contraction of the ventricles, which occurs during systole. Early diastole is the phase when the ventricles are relaxing and refilling with blood after contraction. Therefore, the labeling of the ventricular stages in the corresponding graph of the cardiac cycle is correctly represented by Ventricular filling, diastole, Ventricular Systole, systole, Early Diastole, ventricular relaxation.

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56. On the figure below, A is known as the _____. In cardiac muscle, this is longer than in skeletal muscle in order to prevent summation of nervous signals called _____.

In cardiac muscle, the A is known as the refractory period. This is longer than in skeletal muscle in order to prevent summation of nervous signals called tetanus, tetanic contraction, or tetanic contractions. The refractory period is a period of time after a muscle has contracted where it cannot be stimulated again. This prevents the muscle from contracting too frequently and allows for proper relaxation and filling of the chambers of the heart. Tetanus, on the other hand, refers to a sustained contraction of a muscle due to rapid and continuous stimulation.

Explanation

In cardiac muscle, the A is known as the refractory period. This is longer than in skeletal muscle in order to prevent summation of nervous signals called tetanus, tetanic contraction, or tetanic contractions. The refractory period is a period of time after a muscle has contracted where it cannot be stimulated again. This prevents the muscle from contracting too frequently and allows for proper relaxation and filling of the chambers of the heart. Tetanus, on the other hand, refers to a sustained contraction of a muscle due to rapid and continuous stimulation.

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57. The two layers of the pericardium are the _____ and serous layers. The myocardium, is otherwise known as the cardiac muscle and is located on the figure as letter _____. This is the very slippery layer closest to the heart chamber that is known for reducing friction in the heart. It is called the _____ and is located on the figure as letter _____.

The two layers of the pericardium are the fibrous and serous layers. The myocardium, which is the cardiac muscle, is located on the figure as letter B. The layer closest to the heart chamber that reduces friction in the heart is called the endocardium, which is located on the figure as letter D.

Explanation

The two layers of the pericardium are the fibrous and serous layers. The myocardium, which is the cardiac muscle, is located on the figure as letter B. The layer closest to the heart chamber that reduces friction in the heart is called the endocardium, which is located on the figure as letter D.

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58. The image below depicts a _____ cell ejecting its nucleus to become a(n) _____. The color of the cell has become yellowish-orange due to the accumulation of _____ protein.

A normoblast is a type of cell that is ejecting its nucleus to become a reticulocyte. The color of the cell has become yellowish-orange due to the accumulation of hemoglobin protein.

Explanation

A normoblast is a type of cell that is ejecting its nucleus to become a reticulocyte. The color of the cell has become yellowish-orange due to the accumulation of hemoglobin protein.

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59. The release of _____ initiates a cascade of events in the heart, leading to increased calcium entry into cardiac myocytes, activation of thin filaments, and increased cross bridge cycling. Collectively, these events serve to _____ the velocity and force of ventricular contraction.

The release of cAMP, also known as cyclic AMP or cyclicAMP, triggers a series of events in the heart. It causes an influx of calcium into cardiac myocytes, which leads to the activation of thin filaments and an increase in cross bridge cycling. These events collectively work to enhance the velocity and force of ventricular contraction.

Explanation

The release of cAMP, also known as cyclic AMP or cyclicAMP, triggers a series of events in the heart. It causes an influx of calcium into cardiac myocytes, which leads to the activation of thin filaments and an increase in cross bridge cycling. These events collectively work to enhance the velocity and force of ventricular contraction.

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60. The red X in the figure below represents the disruption of an electrical signal which results in an issue called a _______________

The red X in the figure represents the disruption of an electrical signal in the heart, which can lead to a condition called heart block. Heart block refers to a delay or complete blockage of the electrical impulses that regulate the heartbeat, causing an abnormal heart rhythm. The term "defective SA node" is not directly mentioned in the question or figure, so it is not a suitable explanation for the red X.

Explanation

The red X in the figure represents the disruption of an electrical signal in the heart, which can lead to a condition called heart block. Heart block refers to a delay or complete blockage of the electrical impulses that regulate the heartbeat, causing an abnormal heart rhythm. The term "defective SA node" is not directly mentioned in the question or figure, so it is not a suitable explanation for the red X.

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