CIRCULATORY SYSTEM

• Circulatory system consists of the:

  • Heart
  • Blood vessels
  • Blood
• 3 Types of Blood Vessels:

  • Arteries
  • Veins
  • Capilllaries
• Structure of blood vessels (superficial to deep):

  • Tunica adventitia - connective tissue
  • Tunica media - smooth muscle & elastic tissue
  • Tunica intima - endothelial cells
• Lumen - space within a blood vessel through which the blood flow
• Arteries - large, thick-walled blood vessels that propels oxygenated blood to the capillaries
• Veins - thin-walled blood vessels that carry deoxygenated blood back to the heart
• Venipuncture - the procedure for removing blood from a vein for analysis
• Veins of choice during venipuncture:

  • First choice - Median cubital veins
  • Second choice - Cephalic vein
  • Last choice - Basilic vein
• Capillaries - smallest blood vessels that connect arteries and veins; site of gas exchange in the blood
• Electrocardiogram (ECG) - measures the cardiac cycle by placing electrodes connected to a recorder on the patient's arms, legs, and chest
• The heart contracts approximately 60 to 80 times per minute, which represents the pulse rate
• Arrythmia - irregular pulse rate
• Bradycardia - pulse rate less than 60 bpm
• Tachycardia - pulse rate greater than 100 bpm
• Average BP for an adult is 120/80 mmHg.
• An average adult has a blood volume of 5 to 6 L