The Circulatory System:

The HeartThe BloodThe 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)

http://fc.dekalb.k12.ga.us/~margaret_w_bowen/11CFB0B8-00870B29.0/heart_showing_blood_flow.gif

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