Explain the function of each of the four components (organs) of the circulatory system Arteries: Veins: Heart: Capillaries:

4 parts to circulatory system 1. Heart: pump 2. Arteries: blood away from heart 3. Veins: blood toward heart 4. Capillaries: exchange: gasses, nutrients, waste, etc)

Fish Not good at delivering more blood at times of exertion Amphibian Strong ventricle able to pump a lot of blood to body when needed Prob: O2 and CO2 rich blood get mixed in common ventricle

No mixing between the two circuits Most efficient Reptile Partially divided ventricle sends most deoxygenated (CO2) blood to the lungs and most oxygenated blood goes to the body Less Mixing To body To lungs Bird / Mammal No mixing between the two circuits Most efficient Delivers the highest O2 concentration to tissues Most active creatures

Blood vessels have 3 layers Epithelial lining (smooth) Smooth muscle (regulates diameter) Connective tissue (elastic fibers)

Explain the role of interstitial fluid (where does it come from Explain the role of interstitial fluid (where does it come from? What does it do?)

Blood pressure forces water out of blood Some of the water returns to blood directly, but some stays out in the tissues = Interstitial fluid

The lymphatic system is responsible for returning interstitial fluid back to the circulatory system The immune system also resides inside the lymphatic system (lymph nodes)

Draw the “box heart” labeled diagram which shows a RBC going (“toe to toe”) through the human heart, lungs, and body

Pulmonary vs. systemic circuits

What is happening at each point of ECG?

Regulation of heart beat The heart’s pacemaker is in the R atrium. It depolarizes at a rate of ~70 times/ sec The pacemaker is wired to the atria first causing them to dump their blood into the ventricles Then the electrical impulse hits the ventricles causing them to pump blood to the lungs and to the body

AV Node SA Node

Explain what a blood pressure of 120/80 means

Systolic: Press wave from contraction of L. Ventricle Blood Pressure Systolic: Press wave from contraction of L. Ventricle Diastolic: Press that resides in system due to elasticity of arteries

Why is having high blood pressure for a prolonged period of time dangerous? What is a heart attack?

Cardiac diseases Plaques form inside arteries (cholesterol, calcium, + fat deposit on endothelium)

Plaques lead to cardiovascular disease A. Atherosclerosis (narrowing from plaque) B. Arteriosclerosis (atheroscl. + plaque hardens due to calcification) C. Stroke (narrowing blocks blood flow) Hypertension (high blood pressure) damages blood vessels and allows plaques to form

Awesome Asian blood vessel graphics

What does each do in blood? -RBC -WBC -Platelet

Blood has two components:

Carry oxygen to all of the body’s cells Red Blood Cells Circulatory, Respiratory, and Excretory Systems Carry oxygen to all of the body’s cells Consist of an iron-containing protein called hemoglobin Hemoglobin chemically binds with oxygen molecules and carries oxygen to the body’s cells.

Collect and stick to the vessel at the site of the wound Platelets Circulatory, Respiratory, and Excretory Systems Collect and stick to the vessel at the site of the wound Release chemicals that produce clots at sites of vessel injury

Recognize disease-causing organisms White Blood Cells Circulatory, Respiratory, and Excretory Systems Recognize disease-causing organisms Produce chemicals to fight the invaders Surround and kill the invaders