2. What is Circulation?
• All living things must capture materials from
their environment that enables them to carry on
life processes.
• Single celled organisms “capture” materials
from their environment through diffusion.
• In larger organisms, these “materials” not only
have to be captured, but also circulated to all
cells in the organism.
3. Human Circulatory Functions
• Transport oxygen gas
(hemoglobin).
• Transport carbon
dioxide gas.
• Transport food
molecules (lipids,
carbos, amino acids).
• Transport hormones.
• Maintain body
temperature.
• Works with immune
system to help fight
disease.
4. Blood
• In 1628, William Harvey
demonstrated that blood
travels in one direction and in
a “closed circuit.”
• Blood is pumped out of the
heart to all parts of the body to
“drop off” materials and “pick
up” waste products.
• Blood is a “liquid tissue” that
consists of different parts.
14. Blood Pressure
• When ventricles contract,
blood is forced into the
arteries.
• Pressure.
• When ventricles relax,
pressure decreases.
• How is blood pressure
measured?
15. Blood Pressure
• 120/80 mmHg What does this mean?
• Numerator gives pressure in artery when heart
is squeezed (systolic).
• Denominator gives pressure in artery when
heart is relaxed (diastolic).
• With age, arteries become less elastic (less
flexible) and pressure builds up.
16. Blood Chemistry
• With a blood sample, many things can be
studied about the blood.
• A “CBC” or complete blood count can
count the red and white blood cells,
platelets, and amount of plasma to look for
irregularities.
17. Cholesterol
• Cholesterol is needed by the body for
making cells and hormones.
• Two types: HDL and LDL
• LDL “bad cholesterol” cannot be removed
from the body. Builds up on artery walls.
• HDL “good cholesterol” can be carried to
the liver and removed from the body.
• A “cardiac risk profile” measures the
amount of cholesterol in the blood.
18. Diseases of the Heart
• “Cardiovascular disease.” Diseases of the
heart and blood vessels.
• Leading cause of death in the U.S.
• Plaque.
• Atherosclerosis (blocked arteries).
• Results in hypertension (high blood
pressure), strokes, or heart attacks.
