Functions of the Circulatory System

Functions of the Circulatory System

• The circulatory system transports oxygen, glucose, and carbon dioxide throughout the body.
• It maintains homeostasis by regulating pH, temperature, and osmotic pressure.

Blood

• Blood comprises plasma and cellular components.
• Plasma, the liquid portion, contains water, proteins, salts, and lipids.
• Cellular components include red blood cells, white blood cells, and platelets.
• Red blood cells carry gases, containing hemoglobin for oxygen binding, giving blood its red hue.
• White blood cells fight infections.
• Platelets are cell fragments aiding blood clotting.

Heart Anatomy

• The heart has two sections: a deoxygenated (low-oxygen) and an oxygenated (high-oxygen) side.
• It consists of four chambers: right atrium, right ventricle, left atrium, and left ventricle.
• Atria, located at the top, have thinner walls than ventricles.
• Ventricles, at the bottom, have thicker walls for powerful pumping.
• Heart valves are one-way structures preventing backflow.

Blood Flow Through the Heart

• Deoxygenated blood from the body enters through the inferior vena cava.
• Blood flows to the right atrium, through the tricuspid valve to the right ventricle.
• The right ventricle pumps blood through the pulmonary valve into the pulmonary artery.
• The pulmonary artery carries deoxygenated blood to the lungs for oxygen uptake and carbon dioxide release.
• Oxygenated blood returns to the heart through the pulmonary vein to the left atrium.
• Blood passes through the mitral valve (bicuspid) into the left ventricle.
• The left ventricle pumps blood through the aortic valve into the aorta.
• The aorta distributes oxygenated blood throughout the body.
• Coronary arteries, branching from the aorta, supply the heart muscle with blood.

The Cardiac Cycle

• The cardiac cycle is the rhythmic contraction and relaxation of the heart.
• The human heart beats over 100,000 times daily, requiring coordinated contractions.

Atrial Septal Defect

• An atrial septal defect (ASD) is a congenital heart condition.
• It involves an opening in the atrial septum, separating the right and left atria.
• This allows oxygen-rich and oxygen-poor blood to mix, potentially causing abnormal heartbeats, stroke, or heart failure.

Key Terms

• Arteries: Generally carry oxygenated blood away from the heart.
• Veins: Generally carry deoxygenated blood toward the heart.
• Capillaries: Tiny blood vessels enabling gas exchange between blood and tissues.
• Hemoglobin: An iron-containing protein in red blood cells binding oxygen.
• Pulmonary: Related to the lungs.
• Aorta: The main artery carrying oxygenated blood from the heart.
• Vena Cava: The large vein carrying deoxygenated blood to the heart.

Explore the essential functions of the circulatory system, including the transport of oxygen, glucose, and carbon dioxide. Learn about the blood components and their roles, as well as the anatomy of the heart and its chambers. This quiz covers the critical aspects of how our circulatory system operates.