Science MCQs

During inhalation, the intercostal muscles contract, pulling the ribs upward and outward to expand the chest cavity.

Bronchioles are part of the respiratory system, not the circulatory system.

The aorta is the main and largest artery, carrying oxygenated blood from the left ventricle to the body.

When the diaphragm contracts, it flattens and moves downward, increasing the volume of the chest cavity and causing inhalation.

Fibrinogen is a plasma protein that is converted into fibrin to form a blood clot.

A myocardial infarction is the medical term for a heart attack, which is the death of heart muscle due to blocked blood flow.

Red Blood Cells (erythrocytes) are the most abundant cell type in human blood.

The circulatory system transports blood, which carries oxygen, nutrients, wastes, and other materials.

Muscles need more energy during exercise, requiring more oxygen for aerobic respiration, so breathing rate increases.

The pulmonary vein is unique as it carries oxygenated blood from the lungs back to the left atrium of the heart.