PE GCSE - Cardiovascular system

• Components of the cardiovascular/circulatory system:

  • The heart
  • The blood vessels
  • The blood
• The heart functions as a pump
• Blood vessels serve as a transport network
• Blood is a substance in which oxygen, nutrients, and waste can be transported
• Functions of the cardiovascular system:

  • Maintains pressure
  • Transports O2, CO2
  • Transports waste, nutrients, and hormones
  • Enables healing and prevents infection
  • Temperature regulation
  • Helps fight infection
• Structure of the cardiac muscle (heart):

  • The septum is important for separating the left and right sides of the heart
  • Exercise impacts the walls of the cardiac muscle by making them thicker
• Blood vessels in the cardiac muscle:

  • Vena Cava: vein that takes de-oxygenated blood from the body back to the heart
  • Aorta: artery that takes oxygenated blood from the heart to the body
  • Pulmonary Artery: takes de-oxygenated blood from the heart to the lungs
  • Pulmonary Vein: takes oxygenated blood from the lungs back to the heart
• How the heart works:

  • When the heart is relaxed, it takes in blood
  • When the heart contracts, it pumps out blood
  • Blood enters the heart through the atria and leaves through the ventricles
  • Valves prevent blood flowing back in the wrong direction and maintain blood pressure
• Pathway of blood through the heart:

  • Double circulatory system with two circuits: systemic circuit and pulmonary circuit
  • Oxygen-loaded blood goes into the left side of the heart, while oxygen-poor blood goes into the right side
  • The heart is a pump in the double circulatory system
  • Valves prevent the backflow of blood
• Blood vessels in the vascular system:

  • Arteries carry blood away from the heart under high pressure, with elastic, thick walls and no valves
  • Veins carry blood to the heart (except pulmonary vein) with lower pressure, thin walls, and valves to prevent backflow
  • Capillaries are thin vessels that link arteries with veins, allowing for nutrient and gas exchange
• How blood is pumped around the body:

  • The heart pumps blood at high pressure into the arteries
  • Arteries stretch and contract to move blood along
  • Capillaries allow for nutrient and gas exchange
  • Veins carry deoxygenated blood back to the heart
• Vascular shunting:

  • Process of redistributing blood to active areas and away from inactive areas
  • Achieved through vasodilation (widening) and vasoconstriction (narrowing) of blood vessels
• Heart rate, stroke volume, and cardiac output:

  • Resting heart rate is the number of heartbeats per minute
  • Maximum heart rate can be estimated using the formula: 220 - age
  • Cardiac output is calculated by multiplying stroke volume by heart rate
• Cardiac output is the amount of blood pumped out of the left ventricle of the heart per minute
• Stroke volume is the amount of blood pumped out of the left ventricle per beat
• Cardiac output can be calculated by multiplying the stroke volume by the heart rate
• During exercise, the heart beats faster and with greater force to supply the body with oxygen and nutrients
• Regular exercise causes changes to the heart:

  • The heart gets larger
  • The muscular wall becomes thicker and stronger
  • Stroke volume at rest increases, leading to a lower resting heart rate
• Blood pressure depends on the speed of the blood coming into a vessel and the width of the vessel itself
• Factors affecting blood pressure include age, gender, stress, diet, and exercise
• Blood is made up of several major components: White Blood Cells, Red Blood Cells, Platelets, and Plasma
• Red blood cells carry oxygen, which is vital to muscle action, especially in endurance events
• Blood doping illegally boosts an athlete's red blood cell count, improving performance but leading to dangerous blood clots and heart problems
• What is blood pressure?

  The force of blood against the walls of the arteries.
• why is blood pressure important?

  because blood supplies oxygen to working muscles so maintaining a steady pressure ensures adequate oxygen to the muscles.
• What is blood shunting?

  The process of diverting blood from inactive areas to working muscles. This is done by vasoconstriction and vasodilation of the blood vessels to redirect the blood.
• Heart rate definition?

  Beats per minute
• Stroke volume definition?

  The amount of blood pumped out of the heart (left ventricle) in one beat
• Cardiac output definition?

  the amount of blood pumped out of the heart (left ventricle) per minute.