In this exercise we will be concerned strictly with the blood circulatory apparatus. The cardiovascular system can be anatomically subdivided into the heart and the blood vessels , and the latter category is further subdivided into different vessel types. These two major categories are broken down further, and there are subcategories of arteries and veins based on size, construction of the vessel wall, etc. However, the direction of blood flow is the criterion which separates arteries from veins, and which defines a vessel as being in one or the other major class. THIS IS NOT TRUE .
Some arteries carry deoxygenated, and some veins carry oxygenated blood.
The direction of flow is the only criterion for classification. We'll look at blood vessels later in another exercise , but for now, let's concentrate on the heart. The Heart Begin with slide 616, and start by holding it up to the light. After orienting yourself, place it on the microscope under low power. The atria and ventricles are separated from each other.