The circulatory system

• The circulatory system is an organ system that enables blood circulation, transporting nutrients (amino acids, electrolytes, lymph), oxygen, carbon dioxide, hormones, and blood cells to and from body cells.
• This facilitates nutrition, aids in disease resistance, stabilizes temperature and pH, and maintains homeostasis.

Key Components

• The circulatory system consists of the heart, blood vessels, and blood.
• The lymphatic system is considered part of the circulatory system because it collects excess fluid and returns it to the bloodstream.

Heart

• The heart is a muscular organ that pumps blood through blood vessels via rhythmic contractions.
• It is located in the mediastinum, between the lungs.
• The human heart has four chambers: two atria (upper) and two ventricles (lower).
• Atria receive blood, and ventricles pump blood out.
• Heart valves ensure unidirectional blood flow.
• The heart is enclosed in a protective sac called the pericardium.

Blood Vessels

• Blood vessels form a network of tubes that transport blood throughout the body.
• The three main types of blood vessels include arteries, veins, and capillaries.
• Arteries carry blood away from the heart to the tissues.
• Veins carry blood back to the heart.
• Capillaries are small blood vessels facilitating oxygen, nutrient, and waste exchange between blood and cells.

Blood

• Blood is a liquid connective tissue consisting of plasma, blood cells, and platelets.
• Plasma, the liquid portion of blood, contains water, proteins, electrolytes, nutrients, and waste products.
• The three primary types of blood cells are red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes).
• Red blood cells transport oxygen.
• White blood cells help fight infections.
• Platelets aid in blood clotting.

Blood Circulation

• Blood circulation refers to the movement of blood through the circulatory system.
• Two main circuits exist: pulmonary and systemic circulation.
• Pulmonary circulation carries blood from the heart to the lungs for oxygen acquisition and carbon dioxide release.
• Systemic circulation carries oxygenated blood from the heart to the rest of the body, supplying tissues with oxygen and nutrients.

Function

• The circulatory system's functions include:
• Transporting oxygen, nutrients, hormones, and waste products
• Protecting against pathogens and diseases
• Regulating body temperature and pH balance
• Facilitating blood clotting to prevent excessive blood loss

Common Disorders

• Atherosclerosis: Plaque buildup in artery walls reduces blood flow.
• Hypertension: High blood pressure can damage the heart and blood vessels.
• Coronary artery disease: Reduced blood flow to the heart muscle, leading to chest pain or heart attack.
• Heart failure: The heart's inability to pump enough blood to meet the body's needs.
• Stroke: Interruption of blood flow to the brain, causing cell damage or death.
• Arrhythmias: Irregular heart rhythms can cause dizziness or fainting.
• Deep vein thrombosis (DVT): Blood clot formation in a deep vein, usually in the legs.
• Pulmonary embolism (PE): Blockage of a pulmonary artery by a blood clot, which can be life-threatening.

Maintaining a Healthy Circulatory System

• Maintain a healthy lifestyle through a balanced diet and regular exercise.
• Refrain from smoking.
• Manage blood pressure and cholesterol levels.
• Control stress.
• Undergo regular check-ups and screenings for potential cardiovascular issues.

The circulatory system is an organ system that allows blood to circulate. It transports nutrients, oxygen, carbon dioxide, hormones to and from the cells in the body. The main components are the heart, the blood vessels, and the blood.