Circulatory System 1 - Heart

• Veins and arteries connect to the chambers of the heart.
• One loop carries deoxygenated blood from the heart to the lungs to gain oxygen, then back to the heart.
• The heart consists of four chambers (two atria and two ventricles) with thick muscular walls.
• The circulatory system is an organ system that transports oxygen and nutrients to the body's tissues.
• The circulatory system relies on three main components: blood, blood vessels, and the heart.
• The circulatory system can be thought of as a double circulatory system with two distinct loops.
• The other loop carries oxygenated blood to the rest of the body, where it gives up oxygen to the tissues and becomes deoxygenated, then flows back to the heart.
• Valves between the chambers and vessels prevent blood from flowing backwards.
• Blood flows into the heart via the vena cava and pulmonary vein.
• The right atrium receives deoxygenated blood, while the left atrium receives oxygenated blood.
• The atria contract, pushing blood into the ventricles.
• The ventricles contract, pushing blood out into the pulmonary artery (to the lungs) and the aorta (to the rest of the body).
• The cycle repeats around 70 times a minute.
• The heart has pacemaker cells in the right atrium that produce electrical impulses to regulate its contractions.
• In some cases, an artificial pacemaker may be implanted to regulate the heart's rhythm.
• Arteries carry blood away from the heart, while veins carry blood to the heart.
• Arteries and veins can carry either oxygenated or deoxygenated blood, depending on their location.
• The heart has its own supply of oxygenated blood through coronary arteries.
• Capillaries have thin walls, are permeable, and allow for exchange of substances with cells
• Veins have large lumens, thin walls, and valves to prevent backflow of blood
• Arteries have thick walls with muscle and elastic tissue to handle high pressures
• Veins carry blood back to the heart
• Arteries carry blood away from the heart
• Capillaries exchange nutrients and oxygen with tissues
• White blood cells: Essential part of the immune system, defend against infection
• Artificial blood: Blood substitute that adds volume to the circulatory system but does not contain red blood cells
• Platelets: Fragments of cells that help with clotting to stop bleeding
• Plasma: Pale, watery liquid that carries nutrients, waste products, hormones, proteins, and antibodies
• Red blood cells: Carry oxygen from the lungs to the body's tissues
• The heart is an organ that pumps blood around the body in a double circulatory system. The right ventricle pumps blood to the lungs where gas exchange takes place. The left ventricle pumps blood around the rest of the body.
• heart is made up of

  • aorta,
  • vena cava,
  • pulmonary artery,
  • pulmonary vein
  • coronary arteries.
• The natural resting heart rate is controlled by a group of cells located in the right atrium that act as a pacemaker. Artificial pacemakers are electrical devices used to correct irregularities in the heart rate.
• body contains three different types of blood vessel:

  • arteries

  • veins

  • capillaries.
• Blood is a tissue consisting of plasma, in which the red blood cells, white blood cells and platelets are suspended