Biology OCR Unit 1
Transport in Animals
, Circulatory Systems
OPEN AND CLOSED
All vertebrates have CLOSED systems .i.e.
Blood is always enclosed in vessels
• Insects have OPEN ones. Blood contains
nutrients etc, flows freely through the
body cavity. Blood doesn’t transport O2.
• O2 and CO2 exchanged by a system of
tubes called the tracheal system.
, Circulatory Systems
DOUBLE CIRCULATORY SYSTEM
• Human is double
• One part serves the lungs + is
called the pulmonary
circulation
• Other part serves the rest of
the body + is called the
systemic circulation
Transport in Animals
, Circulatory Systems
OPEN AND CLOSED
All vertebrates have CLOSED systems .i.e.
Blood is always enclosed in vessels
• Insects have OPEN ones. Blood contains
nutrients etc, flows freely through the
body cavity. Blood doesn’t transport O2.
• O2 and CO2 exchanged by a system of
tubes called the tracheal system.
, Circulatory Systems
DOUBLE CIRCULATORY SYSTEM
• Human is double
• One part serves the lungs + is
called the pulmonary
circulation
• Other part serves the rest of
the body + is called the
systemic circulation
