CIRCuLAToRy  SYsTEM
  
              CHARACTERISTICS:
              It is a system that interacts with the blood and the inmune system,in a addition to presenting an important organ like the heart,highly specialized to guide the pumping functions to the whole body.
                
                 This are the parts of the circulatory system:
THE BLOOD:
It is the transporting liguid of red coloration conformed by three types of cells,platelets,white blood cells and red blood cells.

CAPILLARY VESSELS:
Small tubes that irrigate many parts of the body an organs ,and are responsible for bringing oxigen and nutriens to each part that requines it,or tissues that need it.

THE ARTERIES:
Are tubes that carry purified blood for organs of the body of greater magnitude,from the heart to each of the other organs.

THE HEART:
It is a muscular organ covered by external membranes and outside also covered by coronary arteries.The heart is responsible for reciving and pumping blood to all tissues of the body through the arteries and capillaries.

VEINS: 
Are conduits that carry blood to the heart,from the organs of the body.Two of them reach the heart,veins dig,are a pair,and four of them called pulmonary.  

FUNCTIONS:
The function is to transport oxygen carried by the blood and pumped by the heart,to each of the tissues and organs of additions to taking unused waste to the bodies responsible for filtering or eliminating toxins.

RELATION BETWEEN CIRCULATORY SYSTEM AND RESPIRATORY SYSTEM:
 When we inspire we are introducing different gases into our lungs including oxygen ,when the inspired air reaches the pulmonary alucoli,the oxigen passes to the blood and through the hemoglobin it is transported by the arteries to the cells of the muscles.

7 FUN FACTS:
The circulatory system is extremely long

Red blood cells must squeze through blood vessels

Big bodies have slower heart rates 

The heart needs not a body

The people have studied the circulatory system for thousand of years  

Phisicians followed an incorect model of the circulatory system for 1500 years 

Red blood cells are special