Cardiovascular System Basics

Definition and Function

• The cardiovascular system, also known as the circulatory system, is a network of organs and vessels that transport blood throughout the body.
• Its primary function is to deliver oxygen and nutrients to cells and remove waste products.

Components

• Heart: a muscular organ that pumps blood throughout the body
• Arteries: blood vessels that carry oxygenated blood away from the heart
• Veins: blood vessels that carry deoxygenated blood back to the heart
• Capillaries: tiny blood vessels where oxygen and nutrients are exchanged with cells
• Blood: a liquid tissue that transports oxygen, nutrients, and waste products

Blood Flow

• Pulmonary circulation: blood flows from the heart to the lungs to pick up oxygen
• Systemic circulation: blood flows from the heart to the rest of the body to deliver oxygen and nutrients

Blood Pressure

• Systolic pressure: the pressure in the arteries when the heart beats
• Diastolic pressure: the pressure in the arteries between beats
• Hypertension: high blood pressure, a major risk factor for cardiovascular disease

Blood Vessels

• Elastic arteries: arteries that stretch to accommodate blood pressure
• Muscular arteries: arteries that constrict or dilate to regulate blood pressure
• Veins: have one-way valves to prevent backflow of blood

Regulation of Blood Flow

• Autonomic nervous system: regulates heart rate and blood vessel diameter
• Baroreceptors: sensors that detect changes in blood pressure
• Chemoreceptors: sensors that detect changes in oxygen and carbon dioxide levels