The heart and its diseases

• Heart


  • Central pump of the circulatory system
  • Supplies oxygenated blood to tissues and organs
  • Returns deoxygenated blood to the lungs
  • Walls made of muscle tissue that contract to pump blood
  • Contains valves to prevent backflow
• How the heart pumps blood

  1. Blood enters atria from vena cava and pulmonary vein

  2. Atria contract, pushing blood into ventricles

  3. Ventricles contract to send blood out via pulmonary artery and aorta
• Left side of the heart


  • Has thicker walls than the right side to pump blood to the rest of the body at higher pressure
• Double circulatory system


  Two separate circuits that work together, with the heart at the centre
• Double circulatory system


  • Right ventricle pumps blood to the lungs
  • Left ventricle pumps blood to the rest of the body
• Heart's oxygen supply


  • Received through its own network of coronary arteries
• Natural pacemaker


  Group of cells in the right atrium that regulate the heartbeat by generating electrical impulses
• Artificial pacemaker


  • Small device placed under the skin with a wire connecting it to the heart
  • Produces an electrical current to keep the heart beating
• The Heart's Oxygen Supply


  1. The heart receives oxygenated blood through its own network of CORONARY ARTERIES

  2. This ensures it has the oxygen it needs to function effectively

  3. This causes the heart muscles to contract
• The Heart's Natural Pacemaker

  • A group of cells in the RIGHT ATRIUM act as a natural PACEMAKER
  • It regulates the HEARTBEAT by generating ELECTRICAL IMPULSES that cause the heart muscles to contract
• The lungs are an important part of the circulatory system, which are involved in the OXYGENATING of the blood
• Structure of the Lungs


  1. Air enters the lungs through the TRACHEA

  2. The TRACHEA divides into two BRONCHI, one for each lung

  3. The BRONCHI branch into smaller tubes called BRONCHIOLES

  4. The BRONCHIOLES end in tiny air sacs known as ALVEOLI where gas exchange occurs
• Gas Exchange Process


  1. ALVEOLI are the sites of gas exchange, and are surrounded by a CAPILLARY NETWORK

  2. Oxygen diffuses from the alveoli into the blood

  3. Carbon dioxide moves from the blood into the alveoli to be exhaled

  4. This exchange ensures oxygenation of blood and removal of carbon dioxide, a by-product of respiration
• Cardiovascular Disease


  Diseases which are related to the CIRCULATORY SYSTEM
• Advantages of Statins


  • Statins are proven to decrease the chances of STROKE and HEART DISEASE
  • They contribute to increasing 'good' cholesterol, which helps remove bad cholesterol from the body
• Disadvantages of Statins

  • Regular, long-term medication is required, which means they must be taken as prescribed without interruption
  • Potential SIDE EFFECTS may impact patients' well-being and can range from mild to severe
  • The positive effects of statins on cholesterol levels are gradual and require time to become significant
• Artificial Hearts

  may be utilised when a patient's heart has failed and a heart transplant isn't immediately available or suitable

  • These devices are typically a temporary solution but can sometimes be permanent
  • The key benefit is REDUCED RISK OF REJECTION by the body's immune system because they are made from MAN-MADE materials, unlike donor hearts
  • However, there are risks of BLEEDING and INFECTION
  • Mechanical parts of the artificial heart can wear out, and the electrical motor could fail
• Valve Replacement Therapies


  • Damaged or faulty heart valves can be replaced with BIOLOGICAL or MECHANICAL valves
  • Biological valves are derived from other mammals, like cows or pigs
  • Mechanical valves are man-made and durable
  • Valve replacement is significant surgery but less so than heart transplantation
• Artificial hearts


  A pump that's placed in the chest to replace damaged heart ventricles and valves.
• Cholesterol


  A waxy substance found in your blood
• Transplant


  A surgical procedure in which tissue or an organ is transferred from one area of a person's body to another area, or from one person (the donor) to another person (the recipient).
• Parts of the heart

  A) Right side

  B) left side

  C) pulmonary artery

  D) aorta

  E) vena cava

  F) Pulmonary vein

  G) right atrium

  H) left atrium

  I) valves

  J) valves

  K) Right ventricle

  L) left ventricle

  
• The double Circulatory system

  A) Lungs

  B) Aorta

  C) Pulmonary artery

  D) vena cava

  E) pulmonary vein

  F) rest of the body

  
• Structure of Lungs

  A) trachea

  B) bronchioles

  C) alveoli

  D) bronchi

  E) capillary network

  F) alveoli

  
• Statins

  • A class of DRUGS used to lower cholesterol levels in the blood, particularly the 'bad' LDL cholesterol that contributes to fatty deposit build-up
  • By reducing LDL levels, statins help to slow the progression of CHD and can also stabilise existing fatty deposits, making it less likely to cause a heart attack

  
• Stents

  • A STENT is a device used to keep coronary arteries OPEN, ensuring adequate blood flow to the heart.
  • They are typically made of metal mesh and are inserted into clogged arteries
  • Stents can reduce the symptoms of CHD, like chest pain, and help minimise the risk of a heart attack by preventing the artery from re-narrowing

  A) fatty deposit

  B) stent

  
• Coronary heart disease (CHD)


  A significant health condition where the CORONARY ARTERIES (the blood vessels supplying oxygen-rich blood to the heart muscle) become narrowed by a gradual build-up of FATTY MATERIAL. This condition can lead to chest pain, shortness of breath, and in severe cases, HEART ATTACKS

  A) coronary artery

  B) fatty deposit

  C) normal artery

  D) blocked artery

  
• Types of blood vessels - each designed for specified functions within the circulatory system.

  A) artery

  B) capillaries

  C) vein

  
• Arteries - Organ - has a pulse

  • Transport blood AWAY from the heart under HIGH PRESSURE
  • Their walls are THICK and muscular, with elastic fibers to withstand and maintain this pressure
  • The LUMEN (the interior passage of a blood vessel) is SMALL in comparison to its walls

  A) small lumen

  B) thick walls

  
• Capillaries- Tissue

  • Where the actual EXCHANGE of gases and nutrients occurs
  • They are extremely small, with walls only ONE CELL THICK, facilitating the diffusion of substances
  • Oxygen and nutrients pass from capillaries to body cells, while carbon dioxide and other wastes are collected for removal

  A) one cell think wall

  
• Veins- Organ - Doesn't have a pulse

  • Carry deoxygenated blood back TOWARDS the heart
  • They have a LARGER LUMEN than arteries with THINNER WALLS
  • They carry blood at a LOWER PRESSURE, meaning that there's a risk of backflow - veins have valves to keep blood flowing in the right direction.

  A) valves

  B) large lumen

  C) thin walls

  
• Adaptations of the lungs

  • large surface area
  • efficient blood supply
  • Ventilated and moist
  • Membrane is thin for a short diffusion path
• Why is the heart described as an organ?

  It's made up of different tissues that perform specific functions.
• Explain the effects on a person if a valve developed a leak.

  Some blood would flow back into the heart so less oxygenated blood would be pumped to the body, cells require oxygen for respiration.