Cardiovascular System MCQ Exam Quiz!

Sustained elevated arterial blood pressure above 140/90 mm Hg is a condition known as hypertension, also commonly referred to as high blood pressure. This condition occurs when the force of blood against the walls of the arteries is consistently too high, leading to potential damage to the blood vessels and organs. Hypertension is a significant risk factor for various cardiovascular diseases, such as heart attack and stroke, and it is often managed through lifestyle changes and medication.

The bicuspid valve is also referred to as the mitral valve. This is because the valve is located between the left atrium and the left ventricle of the heart and has two cusps, resembling a bishop's mitre or hat. It prevents the backflow of blood from the left ventricle to the left atrium during ventricular contraction. The term "mitral" is derived from the Latin word "mitra," meaning a bishop's headdress.

The average heart beats about 75 times per minute. This is considered a normal resting heart rate for adults. It indicates that the heart is pumping blood efficiently throughout the body. Higher heart rates may indicate physical exertion or stress, while lower heart rates may suggest good cardiovascular fitness.

The tiny white cords that anchor the cusps or flaps of the endocardium to the walls of the ventricles are called chordae tendineae. These cords play a crucial role in preventing the cusps from inverting into the atria during ventricular contraction, ensuring the proper flow of blood through the heart. The myocardium refers to the muscular tissue of the heart, while the ductus venosus and ligamentum arteriosum are structures found in fetal circulation that close off after birth.

The first heart sound, "lub," is caused by the closure of the atrioventricular (AV) valves. These valves, also known as the mitral and tricuspid valves, separate the atria from the ventricles. When the ventricles contract, the AV valves close to prevent the backflow of blood into the atria. This closure produces the "lub" sound, which is the first sound heard during a heartbeat.

The heart is situated within the medial section of the thoracic cavity known as the mediastinum. The mediastinum is the central compartment of the thoracic cavity, located between the two pleural cavities. It contains various structures such as the heart, great vessels, thymus, esophagus, and trachea. The heart is specifically positioned within the mediastinum, allowing it to be protected and surrounded by other vital structures.

The left ventricle is the correct answer because it acts as the more powerful systemic pump of the heart. It is responsible for pumping oxygenated blood to the rest of the body, so its walls need to be thicker and stronger compared to the other chambers of the heart. The left ventricle contracts forcefully to push blood out of the heart and into the arteries, which is why it requires more muscle mass and a thicker wall to generate enough pressure for efficient circulation.

During ventricular contraction, the bicuspid (mitral) valve prevents blood from flowing from the left ventricle to the left atrium. This valve is located between the left ventricle and the left atrium, and its purpose is to ensure that blood flows in the correct direction, preventing any backflow into the atrium.

Hemostasis refers to the process of stopping bleeding. It involves a series of events such as blood vessel constriction, platelet aggregation, and blood clot formation to prevent further blood loss. Erythropoiesis is the production of red blood cells, hematopoiesis is the formation of blood cells, and homeostasis is the maintenance of a stable internal environment.

The correct answer is chordae tendineae. Chordae tendineae are fibrous cords that anchor the flaps (or cusps) of the atrioventricular valves (specifically the mitral and tricuspid valves) to the walls of the ventricles. They prevent the valves from inverting or prolapsing during ventricular contraction, ensuring that blood flows in the correct direction through the heart.

The liver is responsible for the synthesis of clotting factors. It produces several proteins that are essential for the clotting process, including fibrinogen, prothrombin, and factors II, V, VII, IX, X, XI, and XII. These clotting factors help in the formation of a stable blood clot to prevent excessive bleeding. The liver also plays a role in regulating the balance of clotting factors in the blood. In addition to clotting factors, the liver performs many other vital functions in the body, including detoxification, metabolism, and the production of bile.

Platelets are small, disc-shaped cell fragments that play a crucial role in blood clotting. They are derived from a large, multinucleate cell called a megakaryocyte. Megakaryocytes reside in the bone marrow and undergo a process called fragmentation, releasing numerous platelets into the bloodstream. These platelets help to form blood clots at the site of injury, preventing excessive bleeding. Therefore, the correct answer is megakaryocyte.

The foramen ovale is a fetal shunt that allows blood to bypass the lungs by directly connecting the right atrium and the left atrium. This shunt is important during fetal development to ensure that oxygenated blood from the placenta is able to reach the systemic circulation without having to pass through the non-functional fetal lungs. After birth, the foramen ovale typically closes as the pressure in the left atrium increases, forcing the flaps of the foramen ovale to close and redirecting blood flow through the lungs.

Hemostasis refers to the series of reactions that occur in order to stop blood flow following a cut or injury. It involves various processes such as vasoconstriction, platelet activation and aggregation, and the formation of a blood clot to seal the wound. This mechanism is crucial in preventing excessive bleeding and maintaining the balance of blood flow in the body.

Agglutination is the process in which antibodies bind to antigens on the surface of red blood cells (RBCs), causing them to clump together. This reaction occurs when there is a mismatch between the blood types of the donor and recipient, leading to the formation of clumps or aggregates of RBCs. Agglutination can be used in blood typing and cross-matching tests to determine blood compatibility for transfusions. It is an important immune response mechanism that helps to neutralize and remove pathogens from the body.