6 - 4 Cardiovascular System Flashcards
Circulatory System
The Heart is responsible for pumping blood throughout the body using the Veins, Arteries, and Capillaries as pathways for the blood.
Respiratory System
The Lungs provide the surface area for gas exchange. (O2 and CO2)
Arteries
They carry blood AWAY from the heart and they are round with thick walls of smooth muscle. Arteries are under HIGH pressure and mostly carry oxygen-rich blood. An exception is the Pulmonary Artery (to the lungs) which carries oxygen-poor blood.
Veins
They carry blood TOWARDS the heart and they are oval shaped with thin muscular walls. Veins are under LOW pressure and mostly carry oxygen-poor blood. An exception is the Pulmonary Vein (from the lungs) which carries oxygen-rich blood. Veins also have valves to prevent backward flow of the blood.
Capillaries
Capillaries are the smallest and most numerous of the blood vessels. They form the connection between Arteries and Veins. Their main job is to exchange materials (gases, nutrients, and wastes) between the blood and tissue cells.
Blood
Blood has 4 major components, the Plasma, Red Blood Cells (RBC), White Blood Cells (WBC) and Platelets.
Plasma
Yellow colored fluid and makes up the majority of blood. Its composed of water, glucose, vitamins, minerals, and provides a watery medium for blood cells to move in.
Red Blood Cells (RBC)
Small, disc shaped cells with no nucleus. They carry oxygen in the bloodstream using hemoglobin and need to be replaced every 14 days.
White Blood Cells (WBC)
Small, amoeba-like shaped cells that have a nucleus. They can move to fight infection and disease in the body and filter dead RBCs from the blood.
Platelets
Tiny, colorless, cells without nucleus. They look like torn pieces of RBCs and they help repair injured blood vessels (clotting).
Pulmonary Circulation
Pulmonary Circulation is when blood is pumped to the lungs to exchange deoxygenated blood (Lacking Oxygen) for oxygenated blood (Oxygen Rich).
Systemic Circulation
Systemic Circulation is when blood is moved between the heart and parts of the body delivering oxygen, nutrients, and removing waste.
Gas Exchange (Lungs)
In the lungs, capillaries from the circulatory system join with small air sacs known as alveoli from the respiratory system. The structure of the alveoli look like a bunch of grapes. This structure makes it easier for gases (O2 and CO2) to diffuse (be exchanged) across the semi-permeable membranes of the capillaries and the alveoli.
