The Circulatory
System:
The Heart
The Blood
The Blood Vessels
Functions of the Circulatory System:
• Transport of gases,
nutrients, regulatory
molecules,and waste
• Maintenance of pH and
osmotic balance
• Maintenance of
temperature
• Generating and
maintaining blood pressure
Where is the heart?
The heart is in
the center of
the chest with
the apex
pointing to the
left.
Anatomy of the heart: Exterior
The Interior of the heart:
The Path Of Blood Flow:
Oxygen rich blood and
Oxygen poor blood never
mix. The right side of the
heart deals with O2 poor
blood (Pulmonary
Circulation) while the left
side deals with O2 rich
blood (Systemic
Circulation)
What are the Steps of Circulation?
• 1. Blood returns to the right atrium through the inferior and
superior vena cavae.
• 2. Blood passes through the tricuspid valve into the right ventricle
• 3. Blood passes through the pulmonary semi-lunar valve into the
pulmonary arteries
• 4. Blood releases CO2 and picks up O2 as it passes through the lungs
• 5. Blood returns to the heart through the pulmonary veins and
collects in the left atrium
• 6. Blood flows through the mitral (bicuspid) valve into the left
ventricle
• 7. Blood passes through the aortic semi-lunar valve and enters the
aorta.
• 8. Blood travels to all the cells of the body through the capillaries,
dropping off O2 and nutrients and picking up CO2 and waste.
• 9. Blood is collected by the veins to be returned to the heart.
Oxygenated and Deoxygenated Blood:
Arterial Blood
Venous Blood
Why is blood red?
• Blood is red due to the presence of hemoglobin
• When oxygen is attached to hemoglobin, it turns the
molecule a bright red color.
• When less oxygen is present, the molecule is a
burgundy color
Transport chemicals make blood different
colors:
Iron on hemoglobin
Copper for transport
Hemocyanin for
transport
Hemocyanin with
copper