The Heart

What is the function of the circulatory system

To transport oxygen nutrients and waste products around the body

Why do multicellular organisms need transport systems

They are large have high metabolic rates and diffusion alone is too slow

Why is diffusion insufficient in multicellular organisms

Diffusion distances are too large to meet cellular demand quickly

What is a single circulatory system

Blood passes through the heart once per complete circuit

Which organisms have a single circulatory system

Fish

What is the pathway of blood in a fish circulatory system

Heart to gills to body tissues and back to heart

What is a double circulatory system

Blood passes through the heart twice per complete circuit

Which organisms have a double circulatory system

Mammals

What is the advantage of double circulation

It allows higher pressure and faster delivery of oxygenated blood to body tissues

What is an open circulatory system

Blood is not fully contained in vessels and flows freely through body cavities

Which organisms have open circulatory systems

Invertebrates such as insects

What is a closed circulatory system

Blood remains within vessels throughout circulation

Which organisms have closed circulatory systems

Vertebrates

What is the systemic circulation

The part of circulation that delivers oxygenated blood from the heart to body tissues and returns deoxygenated blood

What is the pulmonary circulation

The part of circulation that carries blood between the heart and lungs

What does the aorta do

Carries oxygenated blood from the heart to the body

What does the vena cava do

Returns deoxygenated blood from the body to the heart

What does the pulmonary artery do

Carries deoxygenated blood from the heart to the lungs

What does the pulmonary vein do

Returns oxygenated blood from the lungs to the heart