فسيولوجيا الدم والقلب والأوعية الدموية

Composition of Blood

• Blood is composed of red blood cells, white blood cells, platelets, and plasma.
• Red blood cells transport oxygen.
• White blood cells fight infections.
• Plasma transports chemicals, maintaining body temperature.
• Platelets clump to form blood clots.

Composition of the Heart

• The heart is roughly the size of a clenched fist.
• It's located on the left side of the chest.
• It's made of cardiac muscle.
• It contracts to pump blood throughout the body.
• The heart has four chambers: two atria and two ventricles.
• The right side pumps blood to the lungs.
• The left side pumps blood to the rest of the body.

Blood Vessels

• Arteries: Carry blood away from the heart at high pressure.
• Artery walls are thick and strong.
• Arteries do not have valves.
• Veins: Carry blood to the heart at low pressure.
• Vein walls are thinner and weaker than artery walls.
• Veins have valves to prevent backflow.
• Capillaries: Tiny blood vessels connecting arteries and veins.
• Capillary walls are thin, allowing material exchange.

Taking a Pulse

• Place your hand on your wrist or neck to feel a pulse.

Benefits of Exercise

• Exercise reduces the risk of heart disease, diabetes, and some cancers.
• Exercise aids in weight management.