Introduction

By: Dr.Norzaher

The cardiovascular/circulatory system transports food, hormones, metabolic wastes, and gases (Oxygen, carbon dioxide) to and from cells all over the body.

Components of the circulatory system include:
blood: consisting of liquid plasma and cells
blood vessels (vascular system): the "channels" (arteries, veins, capillaries) which carry blood to/from all tissues. (Arteries carry blood away from the heart. Veins return blood to the heart. Capillaries are thin-walled blood vessels in which gas/ nutrient/ waste exchange occurs.)
heart: a muscular pump to move the blood

There are two circulatory "circuits":
Pulmonary circulation, involving the "right heart," delivers blood to and from the lungs. The pulmonary artery carries oxygen-poor blood from the "right heart" to the lungs, where oxygenation and carbon-dioxide removal occur. Pulmonary veins carry oxygen-rich blood from tbe lungs back to the "left heart."
Systemic circulation, driven by the "left heart," carries blood to the rest of the body. Food products enter the sytem from the digestive organs into the portal vein. Waste products are removed by the liver and kidneys. All systems ultimately return to the "right heart" via the inferior and superior vena cavae.

A specialized component of the circulatory system is the lymphatic system, consisting of a moving fluid (lymph/interstitial fluid); vessels (lymphatics); lymph nodes, and organs (bone marrow, liver, spleen, thymus). Through the flow of blood in and out of arteries, and into the veins, and through the lymph nodes and into the lymph, the body is able to eliminate the products of cellular breakdown and bacterial invasion.