Cardiovascular System
Aka: The Circulatory System
What does it do?
• Moves the blood• Protects the body• Transports nutrients• Removes metabolic
waste• Regulates body
temperature
Structure
• Heart
• Blood Vessels
• Blood
Blood
Blood is made of…
• Erythrocytes (RBC)
• Leukocytes (WBC)
• Platelets
• Plasma
Differentiated Blood Cells
Erythrocytes
• Red Blood Cells (RBC)• Transport Oxygen and
Carbon Dioxide• Flattened Doughnuts
with depressed center for increased surface
• Flexible to get through vessels
• No nucleus – last 120 days broken down in spleen
Leukocytes
• White Blood Cells (WBC)
• Protects body from foreign microbes and toxins
• Found in blood stream and some tissue
• Last 18-36 days• Three types
Types of Leukocytes• Lymphocytes: Immune function• Granulocytes: Destroy bacteria, viruses, parasites• Macrophages: Break down old blood cells and foreign
matter like dust and asbestos
Platelets
• Aka: Thrombocytes• Clot blood• Release coagulating
chemicals• No nucleus• Fragments of
Megakaryocytes• Stimulate Immune
System and Fight Infections
Plasma
• Clear liquid protein and salt part of the blood
• 55% of our blood volume
• 95% of plasma is H2O
• Contains: nutrients, clotting factor, hormones, antibodies, vitamins, lipids, sugars, other proteins, metabolic waste
Blood Formation - Hematopoiesis
• Bone Marrow produces red blood cells, most white blood cells and platelets
• All blood cells originate from stem cells
• Production is based on body need such as infection or bleeding
The Heart - Structure
• Four cavities that fill with blood
• Two are Atria (Upper “Round” Half)
• Two are Ventricles (Lower “pointed” Half)
• Points to left side of chest at the bottom
• Size of fist• Pumps 4300
gallons / day
Four Steps of Circulation
• Step 1: From right side of heart to lungs to collect O2 turning blood bright red and CO2 leaves the capillaries through diffusion.
• Step 2: Oxygenated blood returns to the left side of the heart. (Pulmonary Circulation)
• Step 3: Blood is pumped to all parts of the body distributing O2 and nutrients
• Step 4: Blood returns to the right side of the heart a reddish-blue color to be oxygenated again (Systemic Circulation)
How blood circulates….
• Closed system of blood vessels
• Four chambers of the heart
• Review the steps from the previous slide
Heart - Function
• Connects to Aorta at the top. Main artery carrying blood away
• Pulmonary Artery connects heart to lungs
• Two largest veins = Carry blood into heart are superior vena cava and inferior vena cava.
Heart - Function
• Cardiac Muscle• Contracts 70-80 times
per minute• Nerves connected to
the heart regulate speed of muscle contraction
Blood Vessels - Structure• Three Types:
1. Arteries - thick and flexible due to forceful bloodflow
2. Veins- appear blue, thinner walls than arteries, less forceful flow
3. Capillaries – tiniest vessels, connect arteries and veins. Very thin walls
Blood Vessel - Function
• Arteries: Carry oxygenated blood from heart to tissues. Large to small: Arteries to Arterioles to capillaries
• Veins: Carry deoxygenated blood to heart. Small to large: Capillaries to Venuoles to Veins
• Capillaries: gas exchange and absorb metabolic waste
Pulse
• Rhythmic contractions of arteries can be felt through the skin.
• Keeps pace with heart beat.
• A way to measure vital health statistics
Blood Pressure
• The force of blood pushing against artery walls
• Strongest when heart contracts (systolic or the higher number)
• Weakest when heart relaxes (diastolic or the low number)
• 120/80 is considered normal BP
http://www.youtube.com/watch?v=E5huVSebZpM
• http://depts.washington.edu/learncpr/videodemo/two-step-cpr.html