Circulatory System

• An adult heart is about the size of 2 hands clasped together
• A child's heart is about the size of a fist
• Oxygenated (arterial) blood


  Bright red
• Deoxygenated (venous) blood


  Dark reddish-purple
• Stress cardiomyopathy


  • Sudden, temporary weakening of the muscle of the heart (the myocardium)
  • Results in symptoms akin to those of a heart attack, including chest pain, shortness of breath and arm aches
  • Also commonly known as "broken heart syndrome" because it can be caused by an emotionally stressful event, such as the death of a loved one or a divorce, breakup or physical separation from a loved one
• Circulatory system function


  Transports nutrients, hormones, removes waste products, facilitates gaseous exchange
• Circulatory system


  • Includes the heart, blood vessels and blood
  • Vital for fighting diseases and maintaining homeostasis (proper temperature and pH balance)
  • Main function is to transport blood, nutrients, gases and hormones to and from the cells throughout the body
• Blood


  Transport medium of nearly everything within the body, including hormones, nutrients, oxygen, antibodies, and other important things needed to keep the body healthy
• Human blood contains metal atoms including iron, chromium, manganese, zinc, lead, and copper, and small amounts of gold
• Four main components of blood

  • Plasma
  • Red blood cells
  • White blood cells
  • Platelets

  
• Plasma


  • Fluid portion, the largest part of the blood, about 55 percent of the blood
  • Light yellow liquid
  • Main role is to take nutrients, hormones, and proteins to the parts of the body that need it, and to take waste products from cells

  
• Red blood cells


  • Also called erythrocytes, make up about 40 to 45 percent of the blood's volume
  • Have no nucleus, can easily change shape as they move through the body's arteries and veins
  • Transport O2 and CO2
  • Contain hemoglobin which carries oxygen from the lungs to the rest of the body and returns carbon dioxide to the lungs, where it's exhaled

  
• Five major types of white blood cells

  • Neutrophils
  • B lymphocytes
  • T lymphocytes
  • Basophils
  • Eosinophils
  • Monocytes
• Platelets


  • Also called thrombocytes, are colorless cell fragments
  • Essential for blood clotting, stick to an injured blood vessel lining to provide the basis for a clot which stops bleeding and promotes healing

  
• Three main types of arteries


  • Elastic arteries
  • Muscular arteries
  • Arterioles
• Elastic arteries


  • The aorta and pulmonary arteries, nearest the heart
  • Receive blood directly from the heart and need to be elastic to accommodate the surge and contraction as blood pushes through with each heartbeat
  • The aorta is the body's most important artery, carries oxygenated blood
  • Pulmonary arteries take deoxygenated blood from the right ventricle to the lungs

  
• Muscular arteries


  • Move blood from the elastic arteries through the body
  • Made of smooth muscle, can expand and contract as blood flows
  • Examples include the femoral and coronary arteries

  
• Arterioles


  • The smallest arteries, move blood from the muscular arteries to the capillaries
  • Carry blood away from the heart to tissues and organs

  
• Capillaries


  • Smallest blood vessels, connect the arteries and veins
  • Where the exchange of nutrients and gases occurs
  • Number depends on the amount of material exchange needed in a body system

  
• Veins


  • Carry blood (deoxygenated) back to the heart
  • Have one-way valves to prevent backward flow
  • Walls are thinner than arteries, can hold more blood

  
• Valves in veins


  Small pieces of tissue that keep blood flowing in the right direction, prevent backward flow

  
• Four valves in the heart


  • Tricuspid valve
  • Mitral valve (or bicuspid valve)
  • Pulmonic valve (or pulmonary valve)
  • Aortic valve
• Heart


  • Cone-shaped organ about the size of a fist
  • Base is the broad superior end, apex is the inferior, pointed end that rests on the diaphragm
  • Apex points to the anatomical left
• Auricles


  Ear-shaped extensions of the atria
• Valves in the heart


  • Tricuspid valve
  • Mitral valve
  • Pulmonic valve
  • Aortic valve
• Tricuspid valve


  Separates the right atrium from the right ventricle
• Mitral valve


  Separates the left atrium from the left ventricle
• Pulmonic valve


  Separates the pulmonary artery from the right ventricle
• Aortic valve


  Separates the aorta and the left ventricle
• The heart rests near the center of the chest
• Heart


  • Cone-shaped organ about the size of a fist
  • Base is the broad superior end
  • Apex is the inferior, pointed end
  • Apex points to the anatomical left
• The auricles wrap around to the anterior side of the heart
• A quick and easy way to determine the anterior side of the heart is to look for the directional wrap of the auricles
• Coronary arteries


  Supply the heart muscle with oxygenated blood
• Coronary veins


  Blood returns from the heart wall

  
• Arteries


  Transport blood AWAY from the heart

  
• Veins


  Transport blood back IN/TO the heart

  
• Aortic arch


  • Curved portion of the aorta
  • Small arteries come off the aortic arch, which supply blood to the upper chest, neck, arms, and head
• Brachiocephalic trunk (innominate artery)


  Major branch coming off the right portion of the aortic arch
• Left common carotid


  Supplies the neck and head with blood