1.
Which is NOT a major function of the blood?
Correct Answer
C. Production of oxygen
Explanation
Blood does not produce oxygen; instead, it carries oxygen from the lungs to the body's tissues. The major functions of blood include transporting nutrients, regulating blood pH, and carrying oxygen and carbon dioxide.
2.
The normal average temperature of blood is around
Correct Answer
C. 100.4OF
Explanation
The normal average temperature of blood is around 100.4OF. This is the correct answer because it is the only option that falls within the typical range for human body temperature. The average normal body temperature is commonly accepted to be 98.6OF, so the blood temperature would be expected to be in a similar range. The other options, 90.8OF and 100.4OF, are outside of this typical range and would be considered abnormal temperatures for blood.
3.
The normal pH range for blood
Correct Answer
A. 7.35-7.45
Explanation
The normal pH range for blood is 7.35-7.45. This range is important for maintaining the balance of acids and bases in the body. If the pH of blood falls below 7.35, it can indicate acidosis, which can be caused by conditions such as diabetes or kidney disease. On the other hand, if the pH rises above 7.45, it can indicate alkalosis, which can be caused by conditions such as hyperventilation or liver disease. Therefore, a pH range of 7.35-7.45 is considered normal for blood.
4.
Which of the following is not a component of blood?
Correct Answer
C. Carbon dioxide
Explanation
Carbon dioxide is not a component of blood. It is a waste product produced by cells during cellular respiration and is transported to the lungs for elimination. Blood plasma is the liquid component of blood that carries nutrients, hormones, and waste products. Platelets are cell fragments that help in blood clotting.
5.
The hematocrit is composed of
Correct Answer
C. RBC
Explanation
The hematocrit is a measure of the volume percentage of red blood cells in the total blood volume. It represents the proportion of blood that is made up of red blood cells. Therefore, the correct answer is RBC, as the hematocrit is composed of red blood cells and not white blood cells or platelets.
6.
How much of blood plasma is water (approximately)?
Correct Answer
B. 91%
Explanation
Blood plasma is the liquid component of blood that carries various substances throughout the body. It is primarily composed of water, along with proteins, electrolytes, hormones, and waste products. The correct answer is 91% because approximately 91% of blood plasma is water. This high percentage of water in blood plasma is essential for maintaining proper hydration and facilitating the transport of nutrients and waste products within the body.
7.
Which of the following plasma proteins plays a role in disease resistance
Correct Answer
B. Globulins
Explanation
Globulins are a group of plasma proteins that play a crucial role in disease resistance. They are involved in the immune response and help to defend the body against pathogens such as bacteria and viruses. Globulins include antibodies, which are proteins that specifically target and neutralize foreign invaders. By producing antibodies, globulins aid in the recognition and elimination of pathogens, thereby contributing to disease resistance.
8.
Which of the following plasma proteins plays a role in blood clotting?
Correct Answer
B. Fibrinogens
Explanation
Fibrinogens are plasma proteins that play a crucial role in blood clotting. When there is an injury or damage to blood vessels, fibrinogens are converted into fibrin, which forms a mesh-like structure to trap blood cells and platelets, forming a clot. This clot helps to stop bleeding and initiate the healing process. Therefore, fibrinogens are essential in the coagulation cascade and blood clot formation.
9.
A hemocrit measures
Correct Answer
A. Percentage of RBC in packed blood
Explanation
A hemocrit measures the percentage of red blood cells (RBC) in packed blood. It is a test that determines the volume of RBCs in relation to the total blood volume. This measurement is important in diagnosing and monitoring conditions such as anemia and polycythemia, as well as evaluating the overall health of the blood. The hemocrit value is expressed as a percentage, indicating the proportion of RBCs in the blood sample.
10.
The process by which formed elements of the blood develop is called:
Correct Answer
B. Hemopoiesis
Explanation
Hemopoiesis is the correct answer because it refers to the process by which formed elements of the blood, such as red blood cells, white blood cells, and platelets, are produced. Immunology, on the other hand, is the study of the immune system and its response to pathogens and foreign substances. Therefore, immunology is not the correct answer. "None of the above" is also not the correct answer as Hemopoiesis is the accurate term for the development of formed elements of the blood.
11.
A megakaryoblast will develop into
Correct Answer
B. Platelet
Explanation
A megakaryoblast is a precursor cell that gives rise to platelets. Platelets are small, irregularly shaped cell fragments that play a crucial role in blood clotting. They are derived from the fragmentation of megakaryocytes, which are large cells found in the bone marrow. Platelets are released into the bloodstream and help in the formation of blood clots to prevent excessive bleeding. Therefore, the correct answer is Platelet.
12.
During hemopoiesis, some of the myeloid stem cells differentiate into
Correct Answer
A. Progenitor cells
Explanation
During hemopoiesis, myeloid stem cells differentiate into progenitor cells. Progenitor cells are the intermediate stage between stem cells and fully differentiated cells. They have a limited ability to self-renew and can differentiate into multiple cell types within a specific lineage. In the case of hemopoiesis, myeloid progenitor cells can further differentiate into various types of blood cells, including red blood cells, platelets, and certain types of white blood cells. This process is essential for the production and maintenance of a healthy blood cell population in the body.
13.
This hormone stimulates proliferation of red blood cells in red bone marrow
Correct Answer
A. EPO
Explanation
EPO, or erythropoietin, is a hormone that stimulates the production of red blood cells in the red bone marrow. It is released by the kidneys in response to low oxygen levels in the blood. EPO binds to receptors on the surface of stem cells in the bone marrow, promoting their differentiation into red blood cells. This increased production of red blood cells helps to enhance oxygen-carrying capacity and improve oxygen delivery to tissues throughout the body. TPO, or thrombopoietin, is a hormone that stimulates the production of platelets, not red blood cells. Human growth hormone does not have a direct effect on red blood cell production.
14.
How many hemoglobin molecules are in each RBC?
Correct Answer
C. 280 million
Explanation
Each red blood cell (RBC) contains approximately 280 million hemoglobin molecules. Hemoglobin is a protein found in red blood cells that carries oxygen from the lungs to the body's tissues. The large number of hemoglobin molecules in each RBC allows for efficient oxygen transport throughout the body.
15.
Ferritin is used to
Correct Answer
B. Store iron
Explanation
Ferritin is a protein that plays a crucial role in iron storage within cells. It forms a complex with iron molecules, allowing them to be stored in a non-toxic and soluble form. This helps to regulate the levels of iron in the body, as excess iron can be harmful. Therefore, the correct answer is "Store iron."
16.
A red blood cell’s function is
Correct Answer
C. Gas transport
Explanation
The correct answer is gas transport. Red blood cells, also known as erythrocytes, are responsible for carrying oxygen from the lungs to the body tissues and carbon dioxide from the tissues back to the lungs for elimination. This is facilitated by the presence of hemoglobin, a protein in red blood cells that binds to oxygen and carbon dioxide. Through this process, red blood cells ensure the efficient delivery of oxygen to cells and the removal of waste carbon dioxide, thereby playing a vital role in gas transport within the body.
17.
A red blood cell without a nucleus is called a
Correct Answer
C. Reticulocyte
Explanation
A red blood cell without a nucleus is called a reticulocyte. Reticulocytes are immature red blood cells that still contain some remnants of their nucleus. As they mature, these remnants are removed and the reticulocytes become fully functional red blood cells. The absence of a nucleus allows red blood cells to have more space to carry oxygen and increases their flexibility to pass through narrow blood vessels.
18.
Which of the following is a phagocyte?
Correct Answer
A. Monocytes
Explanation
Monocytes are a type of white blood cell that plays a crucial role in the immune system. They are considered phagocytes because they have the ability to engulf and destroy foreign particles, such as bacteria and dead cells, through a process called phagocytosis. This allows them to help eliminate pathogens and debris from the body and contribute to the defense against infections. Lymphocytes, on the other hand, are responsible for specific immune responses and do not possess phagocytic abilities. Platelets are involved in blood clotting and have no phagocytic functions.
19.
Which of the following reduces blood loss?
Correct Answer
B. Platelet
Explanation
Platelets are responsible for blood clotting and play a crucial role in reducing blood loss. When a blood vessel is damaged, platelets aggregate at the site to form a plug, preventing further bleeding. They also release chemicals that help in the formation of a fibrin mesh, which reinforces the platelet plug and forms a stable blood clot. This clotting process helps to reduce blood loss and initiate the healing process. Erythrocytes (red blood cells) carry oxygen and nutrients, while lymphocytes are a type of white blood cell involved in the immune response and not directly related to reducing blood loss.
20.
Which of the following promotes inflammation?
Correct Answer
B. BasopHil
Explanation
Basophils are a type of white blood cell that promotes inflammation. They release histamine, a chemical that causes blood vessels to dilate and become more permeable, leading to increased blood flow and the recruitment of other immune cells to the site of inflammation. This response is part of the body's defense mechanism against infections and injuries. Monocytes and lymphocytes, on the other hand, are involved in different aspects of the immune response but do not directly promote inflammation.
21.
Which of the following destroys antigen-antibody complexes?
Correct Answer
A. EosinopHil
Explanation
Eosinophils are a type of white blood cell that are involved in the immune response against parasites and allergic reactions. They release enzymes and toxic proteins that can destroy antigen-antibody complexes. This makes eosinophils an important component of the immune system in clearing these complexes and maintaining immune homeostasis. Monocytes and lymphocytes, on the other hand, have different roles in the immune response and are not specifically involved in the destruction of antigen-antibody complexes.
22.
Which of the following destroys provides immune responses?
Correct Answer
A. EosinopHil
Explanation
Eosinophils are a type of white blood cell that plays a role in immune responses, particularly in fighting off parasitic infections and allergic reactions. They release toxic substances to destroy pathogens and modulate the immune response. Macrophages and lymphocytes also contribute to immune responses, but eosinophils are specifically known for their ability to destroy and provide immune responses against parasites.
23.
Which of the following is not an agranular leukocyte?
Correct Answer
C. BasopHil
Explanation
Agranular leukocytes are a type of white blood cell that lack granules in their cytoplasm. Macrophages and lymphocytes are examples of agranular leukocytes. However, basophils are granular leukocytes, meaning they contain granules in their cytoplasm. Therefore, basophil is not an agranular leukocyte.
24.
The process of a white blood cell squeezing between cells to exit the blood vessel is called
Correct Answer
A. Emigration
Explanation
Emigration refers to the process of a white blood cell squeezing between cells to exit the blood vessel. This term accurately describes the movement of white blood cells from the bloodstream into the surrounding tissues. Wandering and adhesion are not appropriate terms to describe this specific process.
25.
Which of the following do mast cells not release?
Correct Answer
B. Nitric oxide
Explanation
Mast cells are known for releasing various substances during an immune response, such as heparin, histamine, and other inflammatory mediators. However, mast cells do not release nitric oxide. Nitric oxide is primarily produced by endothelial cells and certain neurons. It functions as a signaling molecule and plays a role in vasodilation and neurotransmission. While mast cells can contribute to inflammation and allergic reactions through the release of heparin and histamine, they do not release nitric oxide.
26.
This hormone causes the development of megakaryoblasts.
Correct Answer
B. Thrombopoietin
Explanation
Thrombopoietin is the correct answer because it is a hormone that stimulates the development and maturation of megakaryoblasts, which are the precursor cells of platelets. Erythropoietin is a hormone that stimulates the production of red blood cells, and nitric oxide is a signaling molecule involved in various physiological processes.
27.
Which methods provide hemostasis
Correct Answer
A. Platelet plug formation, vascular spasm, clotting
Explanation
The correct answer is platelet plug formation, vascular spasm, clotting. Hemostasis refers to the process of stopping bleeding, and these three methods are key components of this process. Platelet plug formation involves platelets clumping together to form a plug at the site of injury. Vascular spasm is the constriction of blood vessels to reduce blood flow to the injured area. Clotting, also known as coagulation, involves the formation of a blood clot to seal the wound and prevent further bleeding. Together, these methods work to achieve hemostasis and stop bleeding.
28.
Once this is formed, the intrinsic and extrinsic pathways are identical.
Correct Answer
C. Prothrombinase
Explanation
Prothrombinase is the correct answer because it is the enzyme responsible for converting prothrombin into thrombin, which is a crucial step in the blood clotting process. Once prothrombinase is formed, both the intrinsic and extrinsic pathways converge and become identical, leading to the activation of prothrombin and the formation of a blood clot. Thromboplastin and fibrinogen are also involved in the clotting process, but they do not play the same central role as prothrombinase.
29.
Which of the following clotting factors has the most to do with strengthening and stabilizing a blood clot?
Correct Answer
B. Factor XIII
Explanation
Factor XIII is responsible for cross-linking fibrin strands in a blood clot, thereby strengthening and stabilizing it. This factor plays a crucial role in preventing the breakdown of the clot and ensuring its durability. Factors XI and XIV are involved in the clotting cascade but do not directly contribute to the stability of the clot.
30.
Considering Rh blood types, which of the below situations would result in maternal antibodies attacking the fetus?
Correct Answer
A. Mom is Rh negative and fetus is Rh positive
Explanation
When the mother is Rh negative and the fetus is Rh positive, there is a risk of maternal antibodies attacking the fetus. This is because if the mother is exposed to the Rh positive blood from the fetus during pregnancy or childbirth, her immune system may produce antibodies against the Rh factor. These antibodies can then cross the placenta and attack the red blood cells of the Rh positive fetus, leading to a condition called Rh incompatibility or hemolytic disease of the newborn. This can result in severe complications for the fetus, including anemia, jaundice, and organ damage.
31.
Which of the following opposes the action of thromboxane A2
Correct Answer
C. Prostacyclin
Explanation
Prostacyclin is the correct answer because it opposes the action of thromboxane A2. Thromboxane A2 is a molecule that promotes platelet aggregation and vasoconstriction, which can lead to the formation of blood clots. Prostacyclin, on the other hand, inhibits platelet aggregation and promotes vasodilation, thus counteracting the effects of thromboxane A2 and helping to prevent the formation of blood clots. Plasmin and antithrombin are not directly involved in opposing the action of thromboxane A2.
32.
Which of the following is an anticoagulant?
Correct Answer
A. Heparin
Explanation
Heparin is an anticoagulant because it prevents blood clotting by inhibiting the formation of fibrin, which is necessary for clotting. It does this by enhancing the activity of antithrombin, a natural protein that inhibits clotting factors. Fibrinogen, on the other hand, is a clotting factor that is converted to fibrin during the clotting process. Protease is an enzyme that breaks down proteins and is not directly involved in blood clotting. Therefore, the correct answer is Heparin.
33.
This is the mass of tissue from the sternum to the vertebral column between the lungs.
Correct Answer
B. Mediastinum
Explanation
The correct answer is "Mediastinum". The mediastinum is a mass of tissue located between the sternum and the vertebral column, and it is situated between the lungs. It contains various structures such as the heart, esophagus, trachea, and major blood vessels. The mediastinum plays a crucial role in supporting and protecting these vital organs.
34.
This is the layer that protects the heart.
Correct Answer
A. Epicardium
Explanation
The epicardium is the outermost layer of the heart and acts as a protective covering. It is a thin layer of connective tissue that surrounds the heart and provides a barrier against infection and injury. The epicardium also contains blood vessels and nerves that supply the heart muscle.
35.
To which side of the body is the apex pointed?
Correct Answer
B. To the left
Explanation
The apex of the body is pointed towards the left side.
36.
Which of the following consists of inelastic dense irregular connective tissue?
Correct Answer
C. Fibrous pericardium
Explanation
The fibrous pericardium consists of inelastic dense irregular connective tissue. This tissue provides strength and support to the pericardium, which is the protective sac surrounding the heart. The fibrous pericardium helps to maintain the shape and position of the heart within the chest cavity, and it also prevents overstretching of the heart during contraction.
37.
This is used to reduce the friction between membranes of the heart.
Correct Answer
B. Pericardial (serous) fluid
Explanation
Pericardial (serous) fluid is the correct answer because it acts as a lubricant between the membranes of the heart, specifically the visceral and parietal layers of the pericardium. This fluid helps to reduce friction and allows the heart to beat smoothly within the pericardial sac.
38.
This consists of mesothelium and connective tissue.
Correct Answer
A. Epicardium
Explanation
The correct answer is Epicardium. The epicardium is the outermost layer of the heart wall and consists of mesothelium and connective tissue. It acts as a protective layer for the heart and helps reduce friction during heart contractions. The myocardium is the middle layer of the heart wall and is responsible for the contraction of the heart. The endocardium is the innermost layer of the heart wall and lines the chambers of the heart.
39.
Which layer consists of cardiac muscle tissue?
Correct Answer
C. Myocardium
Explanation
The myocardium is the correct answer because it is the layer of the heart that consists of cardiac muscle tissue. The myocardium is responsible for the contraction of the heart, pumping blood throughout the body. It is the thickest layer of the heart and is located between the epicardium (outer layer) and the endocardium (inner layer). The myocardium plays a crucial role in maintaining the heart's function and is essential for proper cardiac function.
40.
This is used to increase the capacity of the atrium.
Correct Answer
C. Auricle
Explanation
The auricle is a part of the heart that is used to increase the capacity of the atrium. It is a small, muscular pouch-like structure that is attached to the atrium. When the atrium contracts, the auricle expands, allowing it to hold more blood. This increased capacity helps to improve the efficiency of the heart's pumping action.
41.
This marks the boundary between the ventricles.
Correct Answer
C. Anterior and posterior intercentricular sulcus
Explanation
The correct answer is "Anterior and posterior interventricular sulcus". The anterior and posterior interventricular sulcus are grooves on the surface of the heart that mark the boundary between the ventricles. These sulci contain blood vessels and are important for the circulation of blood within the heart. The other options mentioned, the posterior interventricular sulcus and the coronary sulcus, are incorrect as they do not accurately describe the boundary between the ventricles.
42.
These extend into the auricle.
Correct Answer
A. Pectinate muscles
Explanation
The pectinate muscles are found in the atria of the heart and extend into the auricle. These muscles are responsible for increasing the surface area of the atria, allowing for more efficient contraction and blood flow. They also help to prevent the atria from overstretching during filling. The other options mentioned, such as the interatrial septum and coronary sulcus, do not extend into the auricle.
43.
Through which structure does blood pass from the right atrium to the right ventricle?
Correct Answer
C. Tricuspid valve
Explanation
Blood passes from the right atrium to the right ventricle through the tricuspid valve. The tricuspid valve is located between the right atrium and the right ventricle and consists of three cusps or flaps. When the atrium contracts, the tricuspid valve opens, allowing blood to flow into the ventricle. When the ventricle contracts, the tricuspid valve closes to prevent the backflow of blood into the atrium. This ensures that blood flows in one direction, from the atrium to the ventricle, enabling efficient circulation throughout the body.
44.
What types of tissue comprise the valves of the heart?
Correct Answer
B. Dense irregular connective tissue
Explanation
The valves of the heart are composed of dense irregular connective tissue. This type of tissue provides strength and flexibility to the valves, allowing them to open and close properly to regulate blood flow. Dense irregular connective tissue is made up of collagen fibers arranged in a random pattern, which gives it its strength and ability to withstand tension from different directions. This arrangement is ideal for the valves, as they need to withstand the pressure and force exerted by the blood as it flows through the heart.
45.
From the left ventricle, where does blood pass?
Correct Answer
B. Aortic semilunar valve
Explanation
Blood passes from the left ventricle through the aortic semilunar valve. This valve prevents the backflow of blood from the aorta into the ventricle when the ventricle relaxes.
46.
In a fetus, this structure temporarily shunts blood from the pulmonary trunk into the aorta.
Correct Answer
C. Ductus arteriosus
Explanation
The structure that temporarily shunts blood from the pulmonary trunk into the aorta in a fetus is the ductus arteriosus. This is a small blood vessel that connects the pulmonary artery to the descending aorta. It allows oxygenated blood from the placenta to bypass the lungs and flow directly to the body. After birth, the ductus arteriosus usually closes, redirecting blood flow to the lungs for oxygenation.
47.
As each ventricle contracts, where does blood move?
Correct Answer
A. Into an artery
Explanation
When each ventricle contracts, blood is pumped out of the heart and into the arteries. The arteries carry oxygenated blood from the left ventricle to the rest of the body, while the pulmonary artery carries deoxygenated blood from the right ventricle to the lungs. Therefore, the correct answer is "Into an artery."
48.
As each atrium contracts where does blood move?
Correct Answer
A. Through an atrioventricular valve
Explanation
When each atrium contracts, blood moves through an atrioventricular valve. The atrioventricular valve is located between the atrium and ventricle, and it opens to allow blood to flow from the atrium to the ventricle when the atrium contracts. This valve prevents the backflow of blood from the ventricle to the atrium, ensuring that blood moves in the correct direction through the heart.
49.
Which of the below valves prevents blood from flowing back from the lungs?
Correct Answer
C. Pulmonary valve
Explanation
The pulmonary valve prevents blood from flowing back from the lungs. It is located between the right ventricle and the pulmonary artery. When the right ventricle contracts, the pulmonary valve opens, allowing blood to flow into the pulmonary artery and to the lungs for oxygenation. After oxygenation, the pulmonary valve closes, preventing blood from flowing back into the right ventricle. This ensures that oxygenated blood is sent to the rest of the body and not mixed with deoxygenated blood.
50.
In this disorder the aortic valve is narrowed.
Correct Answer
B. Aortic stenosis
Explanation
Aortic stenosis is a disorder where the aortic valve, which controls blood flow from the heart to the rest of the body, becomes narrowed. This narrowing can restrict blood flow and cause symptoms such as chest pain, shortness of breath, and fainting. Mitral valve prolapse refers to the improper closing of the mitral valve, while mitral insufficiency is the inability of the mitral valve to properly close, leading to blood leakage. Therefore, the correct answer is aortic stenosis, as it specifically describes the narrowing of the aortic valve.