The heart

• Circulatory system


  An example of an organ system whose role is to transport oxygen and nutrients to the body's tissues
• Circulatory system


  • Relies on 3 main things: blood, blood vessels, heart
• Blood


  Carries oxygen and nutrients
• Blood vessels


  Hold the blood
• Heart


  Pumps the blood to keep it moving through the vessels
• The circulatory system can be thought of as a double circulatory system
• Path of blood through the heart

  1. Flows into right atrium and left atrium

  2. Flows from atria into ventricles

  3. Flows out of ventricles into pulmonary artery and aorta

  4. Cycle repeats around 70 times per minute
• Atria


  Top chambers of the heart
• Ventricles


  Bottom chambers of the heart
• Valves


  Prevent blood from flowing backwards, ensure blood flows in the right direction
• Pacemaker cells


  Produce electrical impulses to make the heart contract regularly
• Artificial pacemaker


  Small device implanted to regulate the heart's contractions
• Artery


  Any vessel that carries blood away from the heart
• Vein


  Any vessel that carries blood to the heart
• Coronary arteries


  Small arteries that branch off the aorta to supply the heart muscle with oxygenated blood
• Arteries


  Transport oxygen-rich blood away from the heart to the body's tissues. Have thick, muscular walls to withstand high pressure.
• Capillaries


  Smallest and most numerous type of blood vessel. Facilitate the exchange of oxygen, nutrients, and waste products between the blood and the body's tissues. Regulate fluid balance.
• Blood vessels


  Tubular structures that transport blood throughout the body. Includes arteries, veins, and capillaries.
• Blood cells


  Formed elements found within the blood. Includes red blood cells, white blood cells, and platelets.
• Red blood cells (RBCs)

  Transport oxygen from the lungs to the body's tissues. Contain the protein hemoglobin, which binds to oxygen.
• White blood cells (WBCs)

  Part of the body's immune system. Help fight infections and remove foreign particles from the blood.
• Platelets


  Cell fragments that play a crucial role in blood clotting. Help prevent excessive bleeding in case of injury.
• Artery


  A blood vessel that carries blood away from the heart. Arteries have thick, muscular walls and branch off into smaller vessels called arterioles, which further divide into a network of tiny capillaries. Oxygen-rich blood is carried through the arteries to supply tissues and organs with the oxygen and nutrients they need to function properly.
• Function of arteries


  The main function of arteries is to carry blood away from the heart and distribute it to the rest of the body. They have thick, muscular walls that help to pump blood throughout the body, even when the heart is at rest. Arteries branch off into smaller vessels called arterioles, which further divide into a network of tiny capillaries. These capillaries allow oxygen and nutrients in the blood to reach the body's tissues and organs.
• Blood


  The transport medium that carries nutrients, oxygen, and waste products throughout the body.
• Blood vessels


  The channels through which blood flows. They include arteries, veins, and capillaries.
• Arteries


  The blood vessels that carry blood away from the heart.
• Veins


  The blood vessels that carry blood back to the heart.
• Heart


  The pump that drives the circulation of blood. It contracts and relaxes in a regular rhythm, causing blood to be pumped through the blood vessels.
• Capillaries


  The blood vessels that connect arteries and veins and facilitate the exchange of nutrients and waste products between the blood and the body's tissues.
• Systemic circulation


  The part of the circulatory system that delivers oxygenated blood to the body's tissues and organs.
• Pulmonary circulation


  The part of the circulatory system that carries deoxygenated blood from the body to the lungs, where it picks up oxygen and releases carbon dioxide.