Heart

• what are cells

  cells are smallest unit that can exist in our bodies, they are the building blocks that can make up our body
• what is a tissue?

  A tissue is similar cells that work together to perform a certain function
• what is an organ?

  Organ is a group of different tissues that work together to perform a specific function
• what is an organ system

  An organ system is a group of different organs that work together to perform a certain function
• what are the five levels of organisation

  Cells, tissues, organs, organ systems, organisms
• name six different organ systems

  Digestive system, reproductive system, respiratory system immune system, muscular skeletal system, circulatory system
• what is blood?

  It’s a tissue that transport substances such as oxygen, small soluble food molecules, carbon dioxide hormones, and urea
• what is the function of plasma?

  Its function is to carry small soluble food molecules, carbon dioxide and waste products
• what is the function of red blood cells?

  also known as erythrocytes. Its function is to carry oxygen to the body cells. There are specialised cells to do this.
• what are the three adaptations of red blood cells and why are they useful?

  -No nucleus or other internal structures: create more room inside the cell oxygen

  -biconcave disc: creates a large surface area so more oxygen can be carried, easily against the walls of blood vessels

  -Haemoglobin: binds with oxygen
• what is the function of white blood cell

  engulfing pathogens, and producing antibodies
• what are the two types of white blood cells?

  phagocytes and lymphocytes.
• what do Phagocytes do?

  They engulf and destroy unwanted microorganisms that enter the blood by phagocytosis. They are a part of the bodies immune system.
• what do lymphocytes do?

  They are also part of the bodies immune system. They produce proteins called antibodies when a pathogen comes into the body. They release antibodies which attaches to the antigens on the pathogen and they release antitoxins which neutralise the toxins.
• what is a pathogen?

  A microorganism that causes a disease
• what is a platelet?

  They are involved in blood clotting
• describe the structure of an artery

  -Thick wall: to withstand high pressure

  -Elastic walls: so the artery can stretch and return to its original shape

  -Thick muscle: to maintain force on blood
• what is the function of an artery?

  To carry blood AWAY from the heart
• what are the three blood vessels?

  -Artery

  -Vein

  -capillary
• what is the function of a vein?

  To carry blood TOWARDS the heart
• describe the structure of a vein.

  -has valves: to prevent backflow of blood

  -Thin walls: compared to arteries because blood is at a lower pressure
• what type of blood do arteries carry?

  Oxygenated blood
• what type of blood does veins carry?

  de oxygenated blood
• what is the function of a capillary?

  To carry blood through tissues of the body
• describe the structure of a capillary

  -Thin walls: one Cell thick for a short diffusion pathway
• how do you calculate blood flow?

  Cardiac output (cm3/min) = heart rate (bpm) * stroke volume(cm3)
• what is a coronary artery?

  Coronary arteries supply blood containing oxygen to the heart muscles as the muscles need oxygen to respire
• what causes coronary heart disease?

  1. Fatty deposit build up on the walls of the coronary artery
  2. Blood flow is restricted
  3. So less oxygen reaches the heart muscles
  4. So the heart muscle can’t respire
  5. This results in a heart attack
• what do stents do?

  They hold open blocked arteries
• give three pros for stents

  -Allows blood flow to the heart

  -Stays in place for a long time

  -Rapid recovery
• Give three cons for stents

  -Risk of infection

  -Risk of surgery

  -Risk of blood clotting
• what are statins?

  They are a drug that reduces cholesterol. This reduces the buildup of fatty deposits and the coronary artery therefore prevents heart attacks.
• give three pros to statins

  -Reduces cholesterol

  -Slows down buildup of fatty deposits

  -increases blood flow to the heart
• give three cons of statins

  -People forget to take the drug

  -Needs to be taken long-term

  -Side effects
• what are leaky valves?

  Heart valves can leak, become stiff or not open fully making the heart less efficient. This can cause breathlessness when exercising.
• give two ways of fixing leaky valves

  Mechanical valves and biological valves
• what are mechanical valves?

  Valves that are Often made of titanium they last a long time, but you have to take meds for the rest of your life to prevent blood clotting
• what are biological valves?

  Their valves transported from animals. These work extremely well and the patient doesn’t need med, but they only last 12 to 15 years.