Human Circulatory System

The kidneys are the primary organs responsible for filtering blood, removing waste products and excess fluids. The heart pumps blood, lungs exchange gases, and the spleen filters blood cells and fights infection, but only kidneys perform blood filtration.

Smoking stimulates the bone marrow to produce more red blood cells (polycythemia) as a response to carbon monoxide in cigarette smoke, which reduces oxygen-carrying capacity. This increased red blood cell count makes the blood more viscous (thicker). The thickened blood flows more slowly and is more prone to clotting. Combined with smoking-induced damage to blood vessel walls, this significantly increases the risk of clots that can block narrowed arteries, causing heart attacks or strokes. Therefore, True is correct.

The statement claims nicotine causes arteries to dilate (expand), increasing heart blood supply. This is incorrect - nicotine actually causes ARTERIAL CONSTRICTION (narrowing), not dilation. Nicotine stimulates the sympathetic nervous system, causing blood vessels to constrict, which increases blood pressure and REDUCES blood flow to the heart. This constriction forces the heart to work harder and increases cardiovascular risk. Therefore, False is the correct answer.

A biopsy is a medical procedure where tissue is extracted from a LIVING patient for microscopic examination. Post-mortem tissue examination is called an autopsy. Blood draws (phlebotomy) from veins or arteries are separate diagnostic procedures, not biopsies.

A red blood cell actually takes about 20-60 seconds to complete one full circulation through the body, not one minute. The heart pumps approximately 5 liters of blood per minute, and each red blood cell makes thousands of trips through the circulatory system in its 120-day lifespan. The one-minute estimate is close but not precise enough.

AFMC stands for Armed Forces Medical College, a prestigious medical institution in Pune. The other options are fictional expansions. This college trains medical professionals for the Indian Armed Forces.

The pulmonary artery is unique because it carries deoxygenated blood from the right ventricle to the lungs for oxygenation. All other arteries carry oxygenated blood away from the heart to body tissues. The coronary artery supplies the heart muscle itself.

Veins are the blood vessels that return blood to the heart from throughout the body. They carry deoxygenated blood (except pulmonary veins) back to the heart's right atrium. Arteries carry blood away from the heart, capillaries facilitate exchange, and lymph nodes are part of the immune system.

Kidneys are the primary blood filtration organs, removing waste products and excess substances through approximately 1 million nephrons per kidney. Blood enters through renal arteries and is filtered as it passes through glomeruli. While the liver detoxifies blood, the kidneys perform systematic filtration to produce urine.

False - nicotine causes vasoconstriction, not vasodilation. It narrows arteries, reducing blood supply to the heart and increasing cardiac workload. This is why nicotine contributes to cardiovascular disease - it increases oxygen demand while restricting supply through narrowed arteries.

Angiology is the medical specialty that studies the anatomy and diseases of blood vessels and lymphatic system. Hematology focuses on blood and blood-forming organs, Lymphology studies lymph vessels and nodes, while Serology studies blood serum and immune reactions.

Red blood cells (erythrocytes) are produced in the bone marrow through a process called erythropoiesis. In adults, the primary sites are the vertebrae, ribs, sternum, and pelvis. The liver, kidneys, and heart are not involved in RBC production, though the kidneys produce erythropoietin which stimulates RBC production.

Red blood corpuscles (RBCs) are formed in the bone marrow through a process called erythropoiesis. In adults, this primarily occurs in flat bones like the sternum, pelvis, and ribs. The liver produces RBCs during fetal development, while kidneys produce the hormone erythropoiesis-stimulating erythropoietin but not the actual cells.

Stroke (cerebrovascular accident) affects blood supply to the brain, caused by blockage (ischemic stroke) or rupture (hemorrhagic stroke) of blood vessels in the brain. This disrupts oxygen and nutrient delivery to brain tissue. The heart, liver, and lungs are not directly affected by stroke in the same way.

The pulmonary artery carries deoxygenated blood from the heart to the lungs. This is the only artery in the body that carries deoxygenated blood (all other arteries carry oxygenated blood away from the heart). In the lungs, blood picks up oxygen and returns to the heart via pulmonary veins. The kidney, liver, and spleen are not connected to the pulmonary circulation.