Human Circulatory System

About 1 liter of blood flows through the brain per minute (around 750 ml/min, but 1 liter is the closest option). The brain receives about 15-20% of the heart's output despite being only 2% of body weight. Option A (per second) would be 60 liters/minute - impossibly high. Option D (per millisecond) is absurdly impossible.

The kidneys are the primary organs responsible for filtering blood, removing waste products, and producing urine. Each kidney contains approximately one million nephrons that perform this essential filtration function.

Blood is classified as a fluid connective tissue because it consists of cells (red blood cells, white blood cells, platelets) suspended in a fluid matrix (plasma). Its liquid state does not disqualify it from being a tissue. Connective tissues are defined by having cells in an extracellular matrix, which blood satisfies.

The heart is the muscular organ that acts as a pump, circulating blood throughout the body via the circulatory system. The brain controls the nervous system, kidneys filter blood, and lungs facilitate gas exchange - none pump blood.

Blood transfusion is the medical procedure of transferring blood or blood components from one person (donor) into another person's (recipient's bloodstream. This is done to replace lost blood during surgery, treat certain diseases, or restore blood cell counts. Clotting is a different process where blood forms solid clots to stop bleeding.

Red blood cells (erythrocytes) are produced in the bone marrow through a process called erythropoiesis. In adults, this primarily occurs in the vertebrae, sternum, ribs, and pelvic bones. The liver produces blood cells only during fetal development, while kidneys and heart have no role in RBC production.

Red blood cells are produced in the bone marrow through erythropoiesis, primarily in flat bones like the sternum, ribs, and pelvis. The liver, kidneys, and heart have other essential functions but do not produce RBCs.

Red blood cells (erythrocytes) are produced in the bone marrow through a process called erythropoiesis. In adults, this primarily occurs in the vertebrae, sternum, ribs, and pelvic bones. The liver produces RBCs only during fetal development, while kidneys and heart have no role in RBC production.

Biopsy involves removing and examining tissue from a living body to diagnose disease. It is performed on living patients to detect cancer, infections, or other conditions. Post-mortem tissue examination is called an autopsy, not biopsy, and blood samples are not biopsies.

The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs for oxygenation. Unlike most arteries, pulmonary vessels carry oxygen-poor blood away from the heart. Pulmonary veins return oxygenated blood to the left atrium.

The lung is part of the respiratory system, exchanging oxygen and carbon dioxide. The circulatory system comprises the heart, blood vessels (arteries, veins, capillaries), and blood - which transport materials throughout the body. Lungs and heart work together but belong to different systems.