Single & double circulation

• Describe the structure of a fish heart in a single circulation system.?

  -it has 2 chambers

  -ATRIUM: receives deoxygenated blood from veins

  -VENTRICLE: pumps blood to gill capillaries via afferent arteries

  The blood then gains oxygen and flows through efferent arteries to the organs
• What type of circulation do fish have?

  Single closed circulation
• How does a single closed circulation system work?

  Blood contains haemoglobin which has a high affinity for oxygen, and transports it from the gills to the tissues
• What is a disadvantage of single closed circulation?

  Blood loses pressure around the circuit, resulting in slower circulation
• How does double circulation work?

  -blood passes through the heart twice in one circulation

  -the right side of the heart pumps blood to the lungs for gas exchange (PULMONARY circulation)

  -the blood returns to the heart and is pumped out to the tissues from the left side of the heart (SYSTEMIC circulation)
• Label this diagram of double circulation

  A) Lungs

  B) pulmonary circuit

  C) systemic circuit

  D) body

  E) oxygenated blood

  F) heart

  G) deoxygenated blood

  
• What is the advantage of double circulation?

  Blood is repressurised when it leaves the gas exchange surface, making circulation to tissues faster and more efficient.
• What is systemic circulation?

  where oxygenated blood is brought to the body tissues and deoxygenated blood is brought back to the heart
• What is pulmonary circulation?

  Where deoxygenated blood is taken from the heart to the lungs and oxygenated blood is brought back to the heart