A&p II Exam 3 Review
We all get pre-exam jitters, when studying for that human anatomy and physiology final exam one needs all the help they can get so as to nail down a pass grade. This means enrolling in study groups and taking quizzes to polish up your knowledge. Give the test review below a try. All the best
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- 2.
Erythrocytes lack a nucleus.
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True
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False
Correct Answer
A. TrueExplanation
Erythrocytes, also known as red blood cells, lack a nucleus. This is because during their development, the nucleus is expelled to create more space for hemoglobin, the molecule responsible for carrying oxygen. Without a nucleus, erythrocytes have a biconcave shape that allows them to efficiently transport oxygen throughout the body.Rate this question:
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- 3.
Hemorrhagic anemias result from blood loss.
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True
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False
Correct Answer
A. TrueExplanation
Hemorrhagic anemias occur when there is excessive blood loss, leading to a decrease in the number of red blood cells and a decrease in hemoglobin levels. This can happen due to various reasons such as trauma, gastrointestinal bleeding, or excessive menstrual bleeding. Therefore, the statement "Hemorrhagic anemias result from blood loss" is true.Rate this question:
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- 4.
What is the average normal pH range of blood?
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4.65-4.75
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8.35-8.45
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7.35-7.45
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7.75-7.85
Correct Answer
A. 7.35-7.45Explanation
The average normal pH range of blood is 7.35-7.45. This range is slightly alkaline, indicating that blood is slightly basic. Maintaining this pH range is crucial for the proper functioning of various physiological processes in the body, including enzyme activity, oxygen transport, and acid-base balance. Any significant deviation from this range can lead to health issues and disrupt normal bodily functions.Rate this question:
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- 5.
Which blood type is generally called the universal donor?
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A
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O
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AB
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B
Correct Answer
A. OExplanation
Blood type O is generally called the universal donor because it lacks both A and B antigens on the red blood cells. This means that it can be transfused to individuals with any blood type without causing an adverse immune reaction. In contrast, individuals with blood types A, B, or AB have antigens on their red blood cells that can potentially react with antibodies in the recipient's blood, leading to complications. Therefore, blood type O is considered the safest and most compatible for transfusions in emergency situations or when the recipient's blood type is unknown.Rate this question:
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- 6.
The normal RBC "graveyard" is the liver.
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True
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False
Correct Answer
A. FalseExplanation
The normal RBC "graveyard" is not the liver. RBCs are broken down and destroyed by macrophages in the spleen. The spleen acts as a filter for the blood, removing old and damaged RBCs from circulation. The liver also plays a role in the breakdown of RBCs, but it is not the primary site for their destruction. Therefore, the correct answer is False.Rate this question:
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- 7.
A person who lacks agglutinogens A and B would have blood type ____________.
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O
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AB
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B
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A
Correct Answer
A. OExplanation
A person who lacks agglutinogens A and B would have blood type O. Agglutinogens are the antigens found on the surface of red blood cells. Blood type O individuals do not have either A or B antigens, making them universal donors as their blood does not contain any antigens that could potentially react with the recipient's antibodies.Rate this question:
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- 8.
Which of the following is true of the structure of an erythrocyte?
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Erythrocytes are a fixed shape and cannot change shape
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Erythrocytes are shaped like biconcave discs
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Erythrocytes are cell fragments
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Erythrocytes are nucleated cells
Correct Answer
A. Erythrocytes are shaped like biconcave discsExplanation
Erythrocytes, also known as red blood cells, are shaped like biconcave discs. This means that they have a concave shape on both sides, resembling a disc with a thinner middle region. This unique shape allows erythrocytes to have a larger surface area for the exchange of gases, such as oxygen and carbon dioxide, in the bloodstream. The biconcave shape also enables erythrocytes to be flexible and squeeze through narrow capillaries, ensuring efficient oxygen delivery to tissues throughout the body.Rate this question:
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- 9.
The __________ valve is located between the right atrium and the right ventricle.
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Tricuspid
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Aortic semilumar
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Mitral
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Pulmonary semilunar
Correct Answer
A. TricuspidExplanation
The tricuspid valve is located between the right atrium and the right ventricle. It consists of three leaflets or cusps, which open to allow blood to flow from the right atrium to the right ventricle, and close to prevent backflow of blood. This valve plays a crucial role in ensuring that blood flows in the correct direction within the heart, specifically from the atrium to the ventricle.Rate this question:
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- 10.
One of the changes that occur in the pacemaker potential (unstable resting membrane potential) in the SA node (an autorhythmic cell) is a decreased efflux of what ion?
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Calcium
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Sodium
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Potassium
Correct Answer
A. PotassiumExplanation
In the pacemaker potential of the SA node, the resting membrane potential becomes more unstable. This change is characterized by a decreased efflux of potassium ions. Potassium ions play a crucial role in repolarizing the cell after an action potential, so a decrease in their efflux would result in a slower repolarization process. This slower repolarization allows the cell to reach the threshold for firing an action potential more gradually, contributing to the rhythmicity of the SA node as it generates electrical impulses for the heart's contraction.Rate this question:
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- 11.
Which of the following is a part of the second line of defense against microorganisms?
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Macrophage
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Gastric juice
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Keratin
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Cilia
Correct Answer
A. MacrophageExplanation
Macrophages are a type of white blood cell that play a crucial role in the body's immune response. They are part of the second line of defense against microorganisms, as they engulf and destroy foreign particles, including bacteria and viruses. Macrophages are particularly effective in phagocytosis, the process of engulfing and digesting pathogens. They also release chemicals that help activate other immune cells and initiate an inflammatory response. Overall, macrophages are an important component of the body's immune system and contribute to the second line of defense against microorganisms.Rate this question:
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- 12.
What organ in the body regulates erythrocyte production?
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Kidney
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Pancreas
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Brain
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Liver
Correct Answer
A. KidneyExplanation
The kidney is responsible for regulating erythrocyte production in the body. It produces a hormone called erythropoietin (EPO) which stimulates the bone marrow to produce red blood cells (erythrocytes). When the oxygen levels in the body are low, the kidney detects this and releases EPO, which then signals the bone marrow to increase the production of red blood cells. This process helps to maintain the balance of red blood cells in the body and ensure adequate oxygen delivery to tissues and organs.Rate this question:
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- 13.
Action potentials generated by the autorhythmic cells spread to the contractile cells through what structures in the membrane?
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Tight junctions
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Desmosomes
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Gap junctions
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Intercalated discs
Correct Answer
A. Gap junctionsExplanation
Gap junctions are specialized protein channels that allow for direct electrical communication between cells. In the context of the question, they are responsible for transmitting action potentials from the autorhythmic cells (which generate the electrical signals) to the contractile cells in the heart. These gap junctions create a pathway for the rapid spread of electrical impulses, ensuring coordinated contraction of the cardiac muscle. Tight junctions and desmosomes are involved in cell adhesion and do not play a role in electrical signal transmission. Intercalated discs, on the other hand, are specialized regions of the cell membrane that contain both gap junctions and desmosomes, facilitating both electrical and mechanical coupling between cardiac cells.Rate this question:
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- 14.
Which of the following factors does not influence heart rate?
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Age
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Skin color
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Body temperature
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Gender
Correct Answer
A. Skin colorExplanation
Heart rate is primarily influenced by factors such as age, body temperature, and gender. Skin color, on the other hand, does not directly affect heart rate. Skin color is determined by the amount of melanin in the skin, which is a pigment that protects against harmful UV radiation. While skin color can vary among individuals, it does not have a direct impact on heart rate regulation.Rate this question:
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- 15.
Which of the following would increase heart rate?
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Epinephrine and norepinephrine
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Aceytlcholine
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Decreased activity of the sympathetic nervous system
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Increased activity of the parasympathetic nervous system
Correct Answer
A. Epinephrine and norepinephrineExplanation
Epinephrine and norepinephrine are both hormones that are released during times of stress or excitement. These hormones bind to specific receptors in the heart, causing it to beat faster and stronger. This increase in heart rate is part of the body's response to prepare for physical activity or a perceived threat.Rate this question:
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- 16.
Blood within the pulmonary veins returns to the ___________.
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Left atrium
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Left ventricle
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Right atrium
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Right ventricle
Correct Answer
A. Left atriumExplanation
Blood within the pulmonary veins returns to the left atrium. The pulmonary veins are responsible for carrying oxygenated blood from the lungs back to the heart. Once the blood reaches the left atrium, it is then pumped into the left ventricle, which will eventually pump it out to the rest of the body. Therefore, the correct answer is the left atrium.Rate this question:
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- 17.
Hemoglobin is made up of the protein heme and red pigment globin.
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True
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False
Correct Answer
A. FalseExplanation
Hemoglobin is actually made up of the protein globin and the red pigment heme. The statement in the question is incorrect, as it states that hemoglobin is made up of heme and globin. Therefore, the correct answer is False.Rate this question:
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- 18.
If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells, ______________.
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Contractions would last as long as the refractory period
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It would be less than 1-2m
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Tetanic contractions might occur, which would stop the heart's pumping action
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It would be much longer before cardiac cells could respond to a second stimulation
Correct Answer
A. Tetanic contractions might occur, which would stop the heart's pumping actionExplanation
If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells, tetanic contractions might occur, which would stop the heart's pumping action. This is because tetanic contractions are sustained contractions that occur when a muscle is stimulated rapidly and does not have enough time to relax between contractions. In skeletal muscle cells, the refractory period is short, allowing for rapid contractions. However, in cardiac muscle cells, the refractory period is longer to ensure that the heart has enough time to relax and refill with blood before the next contraction. If the refractory period in cardiac cells was as short as in skeletal cells, the heart would not have enough time to relax, leading to sustained contractions and a cessation of pumping action.Rate this question:
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- 19.
Choose the compatible transfusion
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Donate type O blood to a recipient with type AB blood
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Donate type B blood to a recipient with type O blood
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Donate AB blood to a recipient with type B blood
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Donate type A blood to a recipient with type B blood
Correct Answer
A. Donate type O blood to a recipient with type AB bloodExplanation
Type AB blood is considered the universal recipient, as it can receive blood from any blood type. Type O blood is considered the universal donor, as it can be donated to any blood type. Therefore, donating type O blood to a recipient with type AB blood is compatible, as the recipient can safely receive the type O blood.Rate this question:
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- 20.
Which of the following terms is correctly matched to its description?
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Systole: relaxed period
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Stoke volume: amount of blood pumped out by each ventricle in one minute
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Quiescent period: total heart relaxation between heartbeats
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Diastole: contraction period
Correct Answer
A. Stoke volume: amount of blood pumped out by each ventricle in one minuteExplanation
Stoke volume refers to the amount of blood that is pumped out by each ventricle in one minute. This is the correct match because stoke volume specifically measures the volume of blood ejected by the ventricles during each heartbeat. It is an important parameter in assessing cardiac function and can be used to diagnose and monitor various cardiovascular conditions.Rate this question:
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- 21.
Which of the following is NOT a formed element of the blood?
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Erythrocytes
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Leukocytes
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Platelets
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Antibodies
Correct Answer
A. AntibodiesExplanation
Antibodies are not considered a formed element of the blood. Formed elements refer to the cellular components of blood, such as erythrocytes (red blood cells), leukocytes (white blood cells), and platelets. Antibodies, on the other hand, are proteins produced by certain white blood cells called B lymphocytes in response to the presence of foreign substances (antigens) in the body. They play a crucial role in the immune response by recognizing and neutralizing antigens.Rate this question:
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- 22.
Which portion of the electrocardiogram represents the time during which the atria repolarize?
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P wave
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QRS complex
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T wave
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Q-T interval
Correct Answer
A. QRS complexExplanation
The QRS complex represents the time during which the ventricles depolarize and contract. Since the question asks for the time during which the atria repolarize, the correct answer is not available.Rate this question:
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- 23.
The P wave of a normal electrocardiogram indicates _____________.
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Atrial depolarization
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Ventricular repolarization
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Atrial repolarization
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Ventricular depolarization
Correct Answer
A. Atrial depolarizationExplanation
The P wave of a normal electrocardiogram indicates atrial depolarization. This means that the atria are contracting and sending an electrical signal to initiate the contraction of the ventricles. The P wave represents the depolarization of the atria, which is the process of the cardiac muscle cells becoming electrically charged and ready to contract. This is an important step in the cardiac cycle and helps to maintain proper heart function and blood flow throughout the body.Rate this question:
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- 24.
If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells _________.
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Contractions would last as long as the refractory period
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It would be less than 1-2 ms
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Tetanic contractions might occur, which would stop the heart's pumping action
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It would be much longer before cardiac cells would respond to a second stimulation
Correct Answer
A. Tetanic contractions might occur, which would stop the heart's pumping actionExplanation
If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells, tetanic contractions might occur, which would stop the heart's pumping action. The absolute refractory period is the period during which a muscle cell cannot be stimulated to contract again, and in skeletal muscle cells, it is very short (1-2 ms). If the refractory period in cardiac muscle cells was the same, it would be much longer before the cells could respond to a second stimulation. This delay could lead to tetanic contractions, which are sustained contractions without relaxation, and this could interrupt the heart's normal pumping action.Rate this question:
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- 25.
Which of the following cells combines bother cell-mediated and antibody-mediated immunity?
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Cytotoxic T cells
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APC
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B cell
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Helper T cell
Correct Answer
A. Helper T cellExplanation
Helper T cells combine both cell-mediated and antibody-mediated immunity. They play a crucial role in coordinating the immune response by activating other immune cells such as B cells and cytotoxic T cells. Helper T cells recognize antigens presented by antigen-presenting cells (APCs) and release chemical signals called cytokines, which stimulate the production of antibodies by B cells and activate cytotoxic T cells to destroy infected cells. Therefore, helper T cells are essential for the effective functioning of both the cellular and humoral immune responses.Rate this question:
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- 26.
Examples of physical barriers against pathogens include
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Mucus
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Sebaceous glands
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Epidermal layers
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Epithelia
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All of the answers are correct
Correct Answer
A. All of the answers are correctExplanation
All of the options listed (mucus, sebaceous glands, epidermal layers, and epithelia) are examples of physical barriers that can protect against pathogens. Mucus acts as a sticky trap for pathogens, preventing them from entering the body. Sebaceous glands produce an oily substance that can create a protective barrier on the skin, preventing pathogens from penetrating. Epidermal layers provide a tough outer layer of skin that acts as a physical barrier against pathogens. Epithelia, which are found in various tissues and organs, form a protective layer that can prevent the entry of pathogens. Therefore, all of the options listed are correct examples of physical barriers against pathogens.Rate this question:
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- 27.
Platelets _______________.
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Are the precursors of leukocytes
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Have a life span of about 120 days
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Stick to the damaged area of a blood vessel and help seal the break
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Have multiple nuclei
Correct Answer
A. Stick to the damaged area of a blood vessel and help seal the breakExplanation
Platelets are small cell fragments that play a crucial role in the process of blood clotting. When a blood vessel is damaged, platelets adhere to the site of injury and form a plug, which helps to seal the break and prevent excessive bleeding. This process is essential for the body to initiate the healing process and prevent further damage. Therefore, the statement "Stick to the damaged area of a blood vessel and help seal the break" accurately describes the function of platelets.Rate this question:
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- 28.
The heart's pacemaker is the __________.
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Atrioventricular bundle
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Atrioventricular node
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Purkinje fibers
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Sinoatrial node
Correct Answer
A. Sinoatrial nodeExplanation
The sinoatrial node is known as the heart's pacemaker because it is responsible for initiating the electrical impulses that regulate the heart's rhythm. Located in the right atrium, the sinoatrial node generates electrical signals that cause the atria to contract, initiating the heartbeat. These signals then travel to the atrioventricular node, which acts as a relay station, sending the impulses to the ventricles to complete the contraction and pump blood throughout the body. The sinoatrial node is crucial in maintaining a regular and coordinated heartbeat.Rate this question:
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- 29.
Inflammation produces localized
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Heat
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Pain
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Swelling
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Redness
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All of the answers are correct
Correct Answer
A. All of the answers are correctExplanation
Inflammation is a natural response of the body to injury or infection. It is characterized by various symptoms such as heat, pain, swelling, and redness in the affected area. These symptoms occur due to increased blood flow and accumulation of immune cells at the site of inflammation. Therefore, all of the given answers - heat, pain, swelling, and redness - are correct as they are common manifestations of localized inflammation.Rate this question:
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- 30.
T cells and B cells can be activated only by
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Interleukins, interferons, and colony-stimulating factors
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Exposure to a specific antigen at a specific site in a plasma membrane
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Pathogens
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Cells infected with viruses, bacteria, or cancer cells
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Disease-causing agents
Correct Answer
A. Exposure to a specific antigen at a specific site in a plasma membraneExplanation
T cells and B cells are specialized types of white blood cells that play a crucial role in the immune response. They can be activated by exposure to a specific antigen at a specific site in a plasma membrane. Antigens are molecules that are recognized by the immune system as foreign, such as those found on pathogens or infected cells. When T or B cells encounter an antigen that matches their specific receptors, they become activated and initiate an immune response to eliminate the threat. This activation process is essential for the body to mount an effective immune response against pathogens, viruses, bacteria, or cancer cells.Rate this question:
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- 31.
Which of the following might trigger erythropoiesis?
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An increased number of RBCs
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Hypoxia of EPO-producing cells
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Moving to a lower altitude
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Decreased tissue demand for oxygen
Correct Answer
A. Hypoxia of EPO-producing cellsExplanation
Hypoxia is a condition in which there is a deficiency of oxygen in the body's tissues. EPO (erythropoietin) is a hormone produced by the kidneys in response to low oxygen levels in the blood. When EPO-producing cells detect hypoxia, they release erythropoietin, which stimulates the production of red blood cells (RBCs) in the bone marrow. Therefore, hypoxia of EPO-producing cells can trigger erythropoiesis, the process of RBC production, in order to increase oxygen-carrying capacity and alleviate the oxygen deficiency in the body.Rate this question:
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- 32.
The fact that the left ventricle of the heart is thicker than the right ventricle reveals that it _____________.
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Expands the thoracic cage
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Sends blood through a smaller valve
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Pumps blood against a greater resistance
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Pumps a greater volume of blood
Correct Answer
A. Pumps blood against a greater resistanceExplanation
The left ventricle of the heart is thicker than the right ventricle because it needs to pump blood against a greater resistance. The left ventricle is responsible for pumping oxygenated blood to the rest of the body, while the right ventricle pumps deoxygenated blood to the lungs. Since the body's systemic circulation has a higher resistance compared to the pulmonary circulation, the left ventricle needs to generate more force to overcome this resistance. This is why it has a thicker muscular wall, allowing it to pump blood effectively against the greater resistance.Rate this question:
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- 33.
Which of the following is NOT a function of blood?
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Regulation
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Hormone production
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Protection
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Disteibution
Correct Answer
A. Hormone productionExplanation
Blood performs several important functions in the body, including regulation, protection, and distribution. However, hormone production is not a function of blood. Hormones are produced by various endocrine glands in the body, such as the pituitary gland, thyroid gland, and adrenal glands. These glands release hormones directly into the bloodstream, but the blood itself does not produce hormones. Instead, it serves as a transport system, carrying hormones to their target organs and tissues.Rate this question:
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- 34.
The left ventricular wall of the heart is thicker than the right wall in order to ___________.
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Expand the thoracic cage during diastole
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Pump blood with greater pressure
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Accommodate a greater volume of blood
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Pump blood through a smaller valve
Correct Answer
A. Pump blood with greater pressureExplanation
The left ventricular wall of the heart is thicker than the right wall in order to pump blood with greater pressure. The left ventricle is responsible for pumping oxygenated blood to the rest of the body, while the right ventricle pumps deoxygenated blood to the lungs. Since the left ventricle has to pump blood to the entire body, it needs to generate higher pressure to overcome the resistance of the systemic circulation. Therefore, the left ventricular wall is thicker to provide the necessary strength and force to pump blood with greater pressure.Rate this question:
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- 35.
The layers of the heart wall from superficial to deep are:
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Myocardium, endocardium, and epicardium
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Epicardium, endocardium, and myocardium
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Epicardium, myocardium, and endocardium
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Endocardium, myocardium, and epicardium
Correct Answer
A. Epicardium, myocardium, and endocardiumExplanation
The correct answer is "Epicardium, myocardium, and endocardium". The epicardium is the outermost layer of the heart wall, followed by the myocardium which is the middle layer responsible for the contraction of the heart. The endocardium is the innermost layer that lines the chambers of the heart and covers the heart valves.Rate this question:
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- 36.
During the period of ventricular filling __________.
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The atria remain in diastole
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It is represented by the P wave on the ECG
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Blood flow mostly passively through the atria and the open AV valves into the ventricles
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Pressure in the heart is at its peak
Correct Answer
A. Blood flow mostly passively through the atria and the open AV valves into the ventriclesExplanation
During the period of ventricular filling, blood flow mostly passively through the atria and the open AV valves into the ventricles. This is because the atria are relaxed (in diastole) and the AV valves are open, allowing blood to flow into the ventricles due to the pressure difference. The P wave on the ECG represents atrial depolarization, which occurs just before ventricular filling. The statement about pressure in the heart being at its peak is incorrect, as pressure in the heart is actually low during ventricular filling.Rate this question:
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- 37.
Cytotoxic T cells
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Require the double recognition signal of I MHC plus II MHC on the target cell in order to function
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Self-destruct once the antigen has been neutralized
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Function mainly to stimulate the proliferation of other T cell populations
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Are the only T cells that can directly attack and kill other cells
Correct Answer
A. Are the only T cells that can directly attack and kill other cellsExplanation
Cytotoxic T cells are the only T cells that can directly attack and kill other cells. They do not require the double recognition signal of I MHC plus II MHC on the target cell in order to function. They do not self-destruct once the antigen has been neutralized. They do not function mainly to stimulate the proliferation of other T cell populations. The given answer correctly identifies the unique ability of cytotoxic T cells to directly attack and kill other cells.Rate this question:
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- 38.
Select the correct statement about the function of antibodies.
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Neutralization is the process by which antibodies cause invading cells to clump together
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Antibodies may directly destroy "invaders"
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Complement activation is the main mechanism by which antibodies provide protection
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The most potent agglutinating agent is IgG
Correct Answer
A. Complement activation is the main mechanism by which antibodies provide protectionExplanation
Complement activation is the main mechanism by which antibodies provide protection. When antibodies bind to antigens on the surface of invading cells, they can activate the complement system. This triggers a cascade of reactions that lead to the formation of membrane attack complexes, which can puncture and destroy the cell membrane of the invader. This mechanism helps in neutralizing and eliminating the invading cells, providing protection against infections.Rate this question:
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- 39.
If preload increases, what effect will that have on Stroke Volume?
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Not enough information known
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It will increase
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It will decrease
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There is no relationship
Correct Answer
A. It will increaseExplanation
An increase in preload refers to an increase in the volume of blood that fills the ventricles of the heart during diastole (relaxation phase). This increased volume stretches the myocardial fibers, leading to a more forceful contraction during systole (contraction phase). As a result, the stroke volume, which is the amount of blood pumped out of the heart with each beat, will increase.Rate this question:
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- 40.
How many oxygen molecules can be transported by one hemoglobin molecule?
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Four
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Two
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Eight
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Six
Correct Answer
A. FourExplanation
One hemoglobin molecule can transport four oxygen molecules. Hemoglobin is a protein found in red blood cells that carries oxygen from the lungs to the body's tissues. Each hemoglobin molecule consists of four subunits, each of which can bind to one oxygen molecule. Therefore, when fully saturated, one hemoglobin molecule can transport four oxygen molecules.Rate this question:
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- 41.
Choose the statement that is true concerning hemoglobin.
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When hemoglobin is not bound to oxygen, it appears blue
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It is composed of four protein chains and four heme groups
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It is found in the plasma portion of blood
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It can bind a maximum of three oxygen molecules
Correct Answer
A. It is composed of four protein chains and four heme groupsExplanation
Hemoglobin is a protein found in red blood cells that is responsible for carrying oxygen throughout the body. It is composed of four protein chains and four heme groups. Each heme group contains an iron atom that can bind to one molecule of oxygen. When oxygen binds to hemoglobin, it changes its color from blue to red. Therefore, the statement that is true concerning hemoglobin is that it is composed of four protein chains and four heme groups.Rate this question:
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- 42.
Which layer of the heart wall contracts and is composed primarily of cardiac muscle tissue?
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Epicardium
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Visceral layer of the serous pericardium
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Endocardium
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Myocardium
Correct Answer
A. MyocardiumExplanation
The correct answer is myocardium because it is the layer of the heart wall that contracts and is primarily composed of cardiac muscle tissue. The myocardium is responsible for the pumping action of the heart, as it contracts and relaxes to pump blood throughout the body. It is the thickest layer of the heart wall and provides the strength and force needed for the heart to function properly.Rate this question:
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- 43.
Which of the events below does not occur when the semilunar valves are open?
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Ventricles are in diastole
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Ventricles are in systole
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Blood enters pulmonary arteries and the aorta
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AV valve are closed
Correct Answer
A. Ventricles are in diastoleExplanation
When the semilunar valves are open, blood enters the pulmonary arteries and the aorta. This happens during systole, which is the phase of the cardiac cycle when the ventricles contract and pump blood out of the heart. Diastole, on the other hand, is the phase when the ventricles relax and fill with blood. Therefore, when the semilunar valves are open, the ventricles are not in diastole.Rate this question:
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- 44.
In a health individual which of the following would be low?
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Contractility
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Afterload
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Stroke volume
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Perload
Correct Answer
A. AfterloadExplanation
Afterload refers to the amount of resistance the heart must overcome to pump blood out of the left ventricle and into the systemic circulation. In a healthy individual, the afterload is typically low because the blood vessels are relaxed and not constricted. This allows for easier blood flow and reduces the workload on the heart. Therefore, in a healthy individual, afterload would be low.Rate this question:
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- 45.
Which portion of the electrocardiogram represents the depolarization wave received by the atria from the sinoatrial (SA) node?
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S-T segment
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QRS complex
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T wave
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P wave
Correct Answer
A. P waveExplanation
The P wave represents the depolarization wave received by the atria from the sinoatrial (SA) node. During this phase, the SA node sends an electrical signal to the atria, causing them to contract and pump blood into the ventricles. The P wave is the first deflection seen on the ECG and represents the atrial depolarization. This wave is followed by the QRS complex, which represents ventricular depolarization, and the T wave, which represents ventricular repolarization. The S-T segment is the isoelectric period between the QRS complex and the T wave.Rate this question:
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- 46.
What is happening during the "pause" when the heart is resting (relaxing)?
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Ventricles are filling
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Ventricles are contracting
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Atria are contracting
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Valves are closing
Correct Answer
A. Ventricles are fillingExplanation
During the "pause" when the heart is resting (relaxing), the ventricles are filling. This is the phase known as diastole, where the heart muscles relax and the ventricles expand to allow blood to flow into them. The atria have already contracted to push blood into the ventricles, and the valves are closed to prevent backflow of blood. This filling phase prepares the ventricles for the next contraction (systole) to pump the blood out of the heart.Rate this question:
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- 47.
Which of the following is not an age-related change affecting the heart?
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Atherosclerosis
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Fibrosis of cardiac muscle
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Thinning of the valve flaps
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Decline in cardiac reserve
Correct Answer
A. Thinning of the valve flapsExplanation
Thinning of the valve flaps is not an age-related change affecting the heart. As people age, they commonly experience atherosclerosis, which is the buildup of plaque in the arteries, leading to narrowing and hardening of the blood vessels. Fibrosis of the cardiac muscle refers to the replacement of healthy heart muscle tissue with scar tissue, which can occur with age. Additionally, there is a decline in cardiac reserve, which is the ability of the heart to respond to increased demands, as people get older. However, thinning of the valve flaps is not a typical age-related change in the heart.Rate this question:
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- 48.
What is occurring in the left atrium at the circle labeled "2" on the graph?
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Left atrium is receiving pressure from the left ventricle
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Left atrial pressure is decreasing
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Left atrium is in diastole
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Left atrium is pressurizing the left ventricle
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Left atrium is in systole
Correct Answer
A. Left atrium is in systoleExplanation
The left atrium is in systole. This means that the left atrium is contracting to push blood into the left ventricle. During systole, the atria contract to push blood into the ventricles, while the ventricles relax. This allows for the efficient filling of the ventricles before they contract during ventricular systole.Rate this question:
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- 49.
If preload increases because venous return increases, what effect will that have on Cardiac Output?
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It will increase
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Not enough information known
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It will decrease
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There is no relationship
Correct Answer
A. It will increaseExplanation
If preload increases because venous return increases, it means that more blood is being returned to the heart, leading to an increase in the volume of blood in the ventricles before contraction. This increased preload results in a stronger contraction of the heart muscle, leading to an increase in stroke volume. Since cardiac output is the product of stroke volume and heart rate, an increase in stroke volume will ultimately lead to an increase in cardiac output. Therefore, the correct answer is that it will increase.Rate this question:
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Mar 22, 2023Quiz Edited by
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Apr 02, 2016Quiz Created by
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