Human Circulatory System: Arteries and Veins

Arteries And Veins

• Arteries:
  • Carry oxygenated blood away from the heart to the rest of the body
  • Thicker walls to withstand higher blood pressure
  • Divided into:
    • Elastic arteries (e.g., aorta) - stretch to accommodate blood pressure
    • Muscular arteries (e.g., arterioles) - regulate blood flow
• Veins:
  • Carry deoxygenated blood back to the heart
  • Thinner walls due to lower blood pressure
  • Contain one-way valves to prevent backflow
  • Divided into:
    • Superficial veins (close to the skin) - visible through the skin
    • Deep veins (farther from the skin) - paired with arteries

Blood Circulation

• Systemic Circulation:
  • Oxygenated blood pumped from the heart to the body
  • Deoxygenated blood returns to the heart
• Pulmonary Circulation:
  • Deoxygenated blood pumped from the heart to the lungs
  • Oxygenated blood returns to the heart
• Blood Flow:
  • Cardiac output (CO) = heart rate (HR) x stroke volume (SV)
  • Blood pressure (BP) = CO x peripheral resistance (PR)

Heart Anatomy

• Chambers:
  • Right atrium (RA) - receives deoxygenated blood
  • Right ventricle (RV) - pumps blood to the lungs
  • Left atrium (LA) - receives oxygenated blood
  • Left ventricle (LV) - pumps blood to the body
• Septum:
  • Divides the heart into right and left sides
• Valves:
  • Prevent backflow between chambers
  • Atrioventricular valves (AV) - between atria and ventricles
  • Semilunar valves - between ventricles and arteries

Blood Pressure

• Systolic Pressure:
  • Highest pressure during heart contraction (systole)
  • Averages 120 mmHg in a healthy adult
• Diastolic Pressure:
  • Lowest pressure during heart relaxation (diastole)
  • Averages 80 mmHg in a healthy adult
• Blood Pressure Regulation:
  • Short-term: autonomic nervous system (sympathetic and parasympathetic)
  • Long-term: kidney function and fluid balance

Arteries and Veins

• Arteries carry oxygenated blood away from the heart to the rest of the body
• They have thicker walls to withstand higher blood pressure
• There are two types of arteries: elastic arteries (e.g., aorta) that stretch to accommodate blood pressure, and muscular arteries (e.g., arterioles) that regulate blood flow
• Veins carry deoxygenated blood back to the heart
• They have thinner walls due to lower blood pressure
• Veins contain one-way valves to prevent backflow
• There are two types of veins: superficial veins (close to the skin) that are visible through the skin, and deep veins (farther from the skin) that are paired with arteries

Blood Circulation

• Systemic circulation involves oxygenated blood being pumped from the heart to the body, and deoxygenated blood returning to the heart
• Pulmonary circulation involves deoxygenated blood being pumped from the heart to the lungs, and oxygenated blood returning to the heart
• Blood flow is calculated by the formula: cardiac output (CO) = heart rate (HR) x stroke volume (SV)
• Blood pressure (BP) is calculated by the formula: BP = CO x peripheral resistance (PR)

Heart Anatomy

• The heart has four chambers: right atrium (RA), right ventricle (RV), left atrium (LA), and left ventricle (LV)
• The right atrium receives deoxygenated blood, and the right ventricle pumps blood to the lungs
• The left atrium receives oxygenated blood, and the left ventricle pumps blood to the body
• The septum divides the heart into right and left sides
• The heart has two types of valves: atrioventricular valves (AV) between atria and ventricles, and semilunar valves between ventricles and arteries

Blood Pressure

• Systolic pressure is the highest pressure during heart contraction (systole), and averages 120 mmHg in a healthy adult
• Diastolic pressure is the lowest pressure during heart relaxation (diastole), and averages 80 mmHg in a healthy adult
• Blood pressure is regulated in the short-term by the autonomic nervous system (sympathetic and parasympathetic), and in the long-term by kidney function and fluid balance

Learn about the differences between arteries and veins, including their functions, structure, and types. Understand how they work together to circulate blood throughout the body.