PE

• atria

  the two chambers at the top of the heart
• ventricle

  two chambers at the bottom of the heart
• vena cava

  large vein that carries deoxygenated blood from the body to the right atrium
• pulmonary artery

  the artery carrying blood from the right ventricle of the heart to the lungs for oxygenation
• pulmonary veins

  are large blood vessels that receive oxygenated blood the lungs and drain into the left atrium of the heart
• aorta

  the main artery of the body, supplying oxygenated blood to the body
• tricuspid valve

  forms the boundary between the right ventricle and the right atrium
• bicuspid valve

  situated between the left atrium and left ventricle
• Semi-lunar valve

  structures attached at the point at which the pulmonary artery and the aorta leave the ventricles
• cardiac conduction system

  a group specialised cardiac muscle cell in the walls of the heart that sends signals to the heart muscle causing it to contract
• sinoatrial node

  heart's natural pacemaker
• atrioventricular node

  The electrical relay station between the upper and lower chambers of the heart
• Bundle of His

  transmits impulses from AV node to ventricles
• systole

  when the heart contacts and pumps blood
• Purkinje fibers

  send nerve impulses to the cells in the ventricles of the heart and cause them to contract and pump blood either to the lungs or the rest of the body
• sympathetic system

  part of the nervous system that serves the slow the heart rate
• medulla oblongata

  a portion of the brain that controls autonomic functions such as breathing, digestion and heart rate
• Chemoreceptors

  detect the levels of carbon dioxide in the blood by monitoring acidity in the blood
• Baroreceptors

  sensors in the vascular system that respond to changes in blood pressure by increasing or decreasing heart rate
• adrenaline

  a substance that is released and that causes the heart to beat faster
• stroke volume

  the amount of blood ejected by the left ventricle of the heart in k e contraction
• Diastole phase

  part of the cardiac cycle when the heart refills with blood
• ejection fraction

  the fraction of blood ejected from the left ventricle of the heart with each heart beat
• starlings law

  states that the heart will eject a greater stroke volume if it is filled to a greater volume
• cardiac output

  the amount of blood the heart pumps in 1 minutes
• cardiac hypertrophy

  a thickening of the heart muscle
• bradycardia


  a heart rate of under 60bpm
• atherosclerosis

  a potentially serious condition where arteries become clogged with fatty substances
• atheroma

  small fatty lumps that develop within the inside lining of arteries
• angina

  chest pain that occurs when the blood supply to the muscles of the heart is restricted
• stroke

  occurs when the blood supply to the brain is cut off
• steady state

  where the oxygen demand meets the oxygen supply
• blood pressure

  the pressure of circulating blood on the walls of blood vessels
• systolic

  pressure in your arteries during contraction of your heart muscle
• Diastolic

  the pressure in the arteries when the heart rests between beats
• venous return

  the rate of blood flow back to the heart
• plasma

  liquid component of blood that normally holds the blood cells in whole blood in suspension
• Haemoglobin

  the protein molecule in red blood cells that carries oxygen from the lungs to the body's tissue and returns carbon dioxins from the tissue back to the lungs
• myoglobin

  an oxygen-storage unit, providing oxygen to the working muscles
• Mitrochondria

  Powerhouse of the cell where aerobic respiration takes place