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Questions and Answers
What are the three main components of the circulatory system?
What are the three main components of the circulatory system?
The three main components of the circulatory system are the heart, blood vessels, and blood.
As cells get larger, their surface area to volume ratio increases.
As cells get larger, their surface area to volume ratio increases.
False (B)
What is the evolutionary need for a circulatory system?
What is the evolutionary need for a circulatory system?
Cells need a circulatory system to deliver nutrients and oxygen to their interiors and remove waste products.
What are the two main types of circulatory systems?
What are the two main types of circulatory systems?
What is hemolymph?
What is hemolymph?
What is the difference between open and closed circulatory systems?
What is the difference between open and closed circulatory systems?
What is the function of the endothelium?
What is the function of the endothelium?
Blood is pumped around the body in vessels, which it never leaves, by a heart.
Blood is pumped around the body in vessels, which it never leaves, by a heart.
What does the human circulatory system need?
What does the human circulatory system need?
What are the four chambers of the heart?
What are the four chambers of the heart?
Which chamber of the heart receives deoxygenated blood from the body?
Which chamber of the heart receives deoxygenated blood from the body?
What is the function of the AV valves?
What is the function of the AV valves?
What is the function of the semilunar valves?
What is the function of the semilunar valves?
Which of the following accurately describes the human circulatory system?
Which of the following accurately describes the human circulatory system?
What is the difference between the pulmonary and systemic circulations?
What is the difference between the pulmonary and systemic circulations?
The pulmonary circulation has a lower pressure and higher flow compared to the systemic circulation.
The pulmonary circulation has a lower pressure and higher flow compared to the systemic circulation.
What is the primary function of the vascular system?
What is the primary function of the vascular system?
What are the four main types of blood vessels?
What are the four main types of blood vessels?
Which type of blood vessel carries blood away from the heart?
Which type of blood vessel carries blood away from the heart?
Which type of blood vessel carries blood back to the heart?
Which type of blood vessel carries blood back to the heart?
Match the following blood vessels with their respective functions:
Match the following blood vessels with their respective functions:
What is the function of the vascular smooth muscle cells?
What is the function of the vascular smooth muscle cells?
What is the primary cause of pulmonary hypertension?
What is the primary cause of pulmonary hypertension?
Pulmonary hypertension is a common and treatable condition.
Pulmonary hypertension is a common and treatable condition.
What are the major risk factors for pulmonary hypertension?
What are the major risk factors for pulmonary hypertension?
What is the goal of pulmonary hypertension therapy?
What is the goal of pulmonary hypertension therapy?
What is the primary function of the heart's sinoatrial (SA) node?
What is the primary function of the heart's sinoatrial (SA) node?
The atrioventricular (AV) node slows down the electrical impulse from the SA node, allowing the atria to contract before the ventricles.
The atrioventricular (AV) node slows down the electrical impulse from the SA node, allowing the atria to contract before the ventricles.
What is the function of the Bundle of His?
What is the function of the Bundle of His?
What is the role of the Purkinje fibers?
What is the role of the Purkinje fibers?
What is excitation-contraction (EC) coupling?
What is excitation-contraction (EC) coupling?
The action potential in a cardiomyocyte is similar to the action potential in a skeletal muscle cell.
The action potential in a cardiomyocyte is similar to the action potential in a skeletal muscle cell.
Why is a ventricular action potential different from a skeletal muscle action potential?
Why is a ventricular action potential different from a skeletal muscle action potential?
Which of the following structures are found at the sarcolemma of cardiomyocytes?
Which of the following structures are found at the sarcolemma of cardiomyocytes?
What is the function of gap junctions in cardiomyocytes?
What is the function of gap junctions in cardiomyocytes?
The depolarization phase of the cardiac action potential is primarily due to the influx of sodium ions, while the repolarization phase is primarily due to the efflux of potassium ions.
The depolarization phase of the cardiac action potential is primarily due to the influx of sodium ions, while the repolarization phase is primarily due to the efflux of potassium ions.
Describe the events that occur during the plateau phase of the ventricular action potential.
Describe the events that occur during the plateau phase of the ventricular action potential.
What is the main difference between the cardiac action potentials of the sinoatrial node and a ventricular cardiomyocyte?
What is the main difference between the cardiac action potentials of the sinoatrial node and a ventricular cardiomyocyte?
Flashcards
Cell survival requires nutrient, waste and gas exchange
Cell survival requires nutrient, waste and gas exchange
The process by which cells obtain necessary nutrients, remove waste products, and exchange gases.
Surface area to volume ratio decreases as cells get larger
Surface area to volume ratio decreases as cells get larger
As a cell's size increases, its surface area to volume ratio decreases, meaning it becomes less efficient at exchanging materials with its surroundings.
Diffusion
Diffusion
The process by which cells move substances across their membrane without the need for energy expenditure.
Multicellularity allows for increased surface area to volume ratio
Multicellularity allows for increased surface area to volume ratio
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Circulatory system
Circulatory system
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Open circulatory system
Open circulatory system
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Closed circulatory system
Closed circulatory system
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Heart
Heart
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Dynamic responsiveness of the heart
Dynamic responsiveness of the heart
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Contractile cells of the heart
Contractile cells of the heart
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Nervous and hormonal responsiveness of the heart
Nervous and hormonal responsiveness of the heart
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Cardiac output
Cardiac output
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Blood pressure
Blood pressure
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Hemodynamics
Hemodynamics
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Pumping deoxygenated blood to the lungs
Pumping deoxygenated blood to the lungs
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Circuit to deliver oxygenated blood to the body
Circuit to deliver oxygenated blood to the body
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Vascular system
Vascular system
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Arteries
Arteries
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Arterioles
Arterioles
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Veins
Veins
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Venules
Venules
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Capillaries
Capillaries
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Lymphatic system
Lymphatic system
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Endothelial cells
Endothelial cells
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Pulmonary hypertension
Pulmonary hypertension
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Vascular remodelling
Vascular remodelling
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Right heart failure
Right heart failure
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Cardiomyocytes
Cardiomyocytes
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Fascia adherens, desmosomes, and gap junctions
Fascia adherens, desmosomes, and gap junctions
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Electrical Conduction System of the Heart
Electrical Conduction System of the Heart
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Cardiac excitation
Cardiac excitation
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Study Notes
Human Physiology: The Circulatory System and Heart (Part 1)
- The human circulatory system is essential for cell survival as it facilitates nutrient, waste, and gas exchange.
- As cells grow larger, their surface area to volume ratio decreases. This reduces the efficiency of diffusion-based nutrient and waste exchange.
- Multicellular organisms evolved closed circulatory systems with pumps to overcome the limitations of diffusion alone.
- Open circulatory systems, such as those in insects and some mollusks, pump hemolymph, which is not confined to vessels. It bathes tissues directly. This system is less efficient than a closed circulatory system for larger, more complex organisms.
- Closed circulatory systems, seen in vertebrates, utilize vessels to keep blood confined. Blood is pumped by a heart, never leaving the vessels. Exchange occurs across the vessel endothelium. Blood volume can be controlled via vessel contraction or relaxation for better regulation of flow.
- Mammals have a closed circulatory system comprised of two circuits: pulmonary and systemic.
- The pulmonary circuit circulates blood to the lungs to pick up oxygen and release carbon dioxide.
- The systemic circuit circulates oxygenated blood to the body’s tissues and returns deoxygenated blood to the heart.
- The human heart is a complex organ with several chambers and valves that regulate blood flow.
- The heart's four chambers are the two atria and two ventricles. Atria receive blood, and ventricles pump blood out.
- The heart has valves to ensure one-way blood flow, preventing backflow.
- The electrical conduction system of the heart is a specialized network of cells that coordinates the heart's contractions. This system ensures that the heart contracts in a coordinated way.
- The sinoatrial node (SA node) acts as the pacemaker of the heart.
- The atrioventricular (AV) node delays the impulse, allowing the atria to contract completely before the ventricles contract.
- The bundle of His and Purkinje fibers transmit the impulse throughout the ventricles, causing them to contract.
- The heart relies on electrical signals to coordinate the contractions of the atria and ventricles. This ensures the heart functions as a pump.
- Cardiac action potentials are electrical impulses that cause the heart muscle cells to contract. These potentials are triggered by changes in the permeability of the cell membrane to certain ions.
- The series of events that link the action potential to contraction is termed excitation-contraction coupling.
- Cardiomyocytes, specialized heart muscle cells, are interconnected via intercalated discs to facilitate rapid impulse conduction and synchronized contraction. These intercalated discs contain fascia adherens, desmosomes, and gap junctions.
- The different phases of a cardiac action potential illustrate the ionic mechanisms involved in the cell’s electrical activity. Ions play a crucial role in conducting impulses.
Anatomy of the Human Heart
- Main components and structures are shown.
- The heart has multiple components, each with particular roles and functions in blood flow.
Pulmonary and Systemic Circulations
- Two separate circuits enable blood flow throughout the body.
- The pulmonary circuit transports deoxygenated blood to the lungs for oxygen uptake.
- The systemic circuit delivers oxygenated blood and nutrients to body tissues, takes away waste products and returns deoxygenated blood to the heart.
Vascular System
- The circulatory system comprises arteries, arterioles, capillaries, venules, and veins.
- Arteries have thicker walls, supporting higher blood pressure, for quick transport.
- Veins have thinner walls and valves, which help to move blood back to the heart against gravity.
- Capillaries have thin walls to facilitate exchange between blood and tissues.
Cardiac Action Potentials
- Electrical signals, called action potentials, are the driving force for cardiac muscle contraction.
- Sinoatrial node (SA node) action potentials differ from ventricular action potentials in shape because of the differences in the ion channels involved in different cell types.
Excitation-Contraction Coupling
- Describes the events connecting action potentials to muscle contraction in heart cells.
- Release of calcium initiates the contraction process in the cardiomyocites.
Pulmonary Hypertension
- A rare, life-threatening disorder characterized by abnormally elevated pulmonary pressures and right heart failure.
- Vascular remodeling, causing distal vessel obliteration, often features in the disease.
- Different factors can be associated with the onset and development of pulmonary hypertension.
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Description
Explore the vital functions of the human circulatory system in this quiz. Learn about the differences between open and closed circulatory systems, the role of the heart, and how nutrient and waste exchange occurs. Test your knowledge on how these systems support multicellular life.
