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