Circulatory System — Set 1
Biology · परिसंचरण तंत्र · Questions 1–10 of 50
Which of the following blood vessels carries deoxygenated blood from the heart to the lungs?
Correct Answer: D. Pulmonary artery
The pulmonary artery is unique because it carries oxygen-poor blood away from the heart. It specifically transports this blood to the lungs for gas exchange. Most other arteries in the body carry oxygenated blood.
What is the normal blood pressure range for a healthy adult human?
Correct Answer: A. 120/80 mmHg
A reading of 120/80 mmHg is generally considered the standard for healthy blood pressure. The top number represents systolic pressure, while the bottom number represents diastolic pressure. Maintaining this range reduces the risk of cardiovascular diseases.
Which part of the human heart is known as the natural pacemaker?
Correct Answer: A. SA node
The Sinoatrial (SA) node initiates the electrical impulses that set the heart's rhythm. It is located in the upper wall of the right atrium. If this node fails, artificial pacemakers are often surgically implanted.
In which part of the blood are nutrients, hormones, and waste products primarily transported?
Correct Answer: A. Plasma
Plasma is the liquid component of blood that makes up about 55% of its total volume. It serves as a medium for transporting essential substances and metabolic heat. Most of the water in our circulatory system is found within the plasma.
Which of the following chambers of the human heart has the thickest muscular walls?
Correct Answer: B. Left ventricle
The left ventricle has thick walls because it must pump blood to the entire body. It generates high pressure to overcome the resistance of the systemic circulation. In contrast, the right ventricle only pumps blood to the nearby lungs.
The double-layered sac that surrounds and protects the human heart is called the?
Correct Answer: D. Pericardium
The pericardium anchors the heart in place and prevents it from overfilling with blood. It contains a small amount of fluid that reduces friction during heartbeats. This protection is vital for maintaining the heart's mechanical efficiency.
Which blood group is known as the 'Universal Donor'?
Correct Answer: B. O negative
O negative blood lacks A, B, and Rh antigens on the surface of red blood cells. This characteristic prevents an immune reaction in recipients of any other blood type. It is the most critical blood type during emergency transfusions.
The instrument used by doctors to listen to the sounds of the heart is the?
Correct Answer: B. Stethoscope
A stethoscope allows healthcare professionals to hear the 'lub-dub' sounds of heart valves closing. It was invented in France by René Laennec in the early 19th century. These sounds help in diagnosing various internal heart conditions.
Which valve is located between the left atrium and the left ventricle?
Correct Answer: C. Mitral valve
The mitral valve, also called the bicuspid valve, prevents blood from flowing backward into the atrium. It consists of two flaps or cusps that open and close during the cardiac cycle. This ensures that blood moves in one direction through the heart's left side.
What is the primary function of white blood cells (leukocytes)?
Correct Answer: A. Immune defense
Leukocytes are the key components of the body's immune system that fight infections. They can migrate through vessel walls to reach the site of an injury or infection. An abnormal count of these cells often indicates a hidden health issue.