Fitness/Diet and Nutrition
The Cardiovascular System
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The cardiovascular system includes the heart and blood vessels that carry the blood. This system leads on from the respiratory system and is almost like the next stage in ‘feeding energy’ to our bodies.
Your heart is basically a ‘hollow’ muscle that is approximately the size of your fist. It pumps blood around your body and the average human heart beats about 70 times per minute. With each beat the heart pushes 5 ounces of blood or about 4,000 gallons per day, around our bodies.
Need to know: Your heart rests for half the time and works for half the time. In a 70 year lifetime the heart will have worked for around 30 years and rested for 40 years!
Having 4 chambers, the heart is broken down into two ‘atria’ two ‘ventricles’, whose primary function is to receive blood and pump blood.
The right half of the heart receives blood from your veins that requires Oxygen and sends it to your lungs for a new supply of Oxygen. The left hand side of the heart then receives the new ‘Oxygenated’ blood from the lungs and pumps it back into your body through your arteries.
Need to know: A deep cut that is open and ‘squirting’ blood out of it could be a sign that an artery has been severed AND MUST BE STOPPED by covering and applying pressure (see our first aid section). Less serious cuts will bleed but won’t squirt blood.
The transferring around your body of energy, oxygen and carbon dioxide is of course done by your blood and blood can be broken down into 3 main components:
- Red Blood Cells – they carry oxygen and carbon dioxide around
- White Blood Cells – They fight infection and bacteria
- Platelets – they make your blood clot and heal when you have a cut or broken skin
- Plasma – the yellow part of blood that contains substances that aid digestion
To be continued ………..The Muscular System…….coming soon