Circulatory System
The circulatory system consists of the heart, the blood and the blood vessels. It’s purpose is to:
Transport nutrients and oxygen to cells
Carry waste products from cells such as CO2 to the lungs
Circulate white blood cells around the body
Moderate body temperature
Heart:
The heart is responsible for pumping blood all around the body.
Deoxygenated blood enters the right atrium through the superior and inferior vena cava, eventually entering the right ventricle.
Then, the CO2 filled blood gets pumped out into the lung capillaries through the pulmonary arteries.
In said capillaries, gas exchange occurs where CO2 from the red blood cells diffuses into the lungs while O2 from the lung diffuses into the red blood cells.
The now oxygenated red blood cells return to the heart and enter the left atrium through the pulmonary veins.
The oxygenated blood enters the left ventricle and gets pumped out through the aorta so it can supply the body’s cells with oxygen while simultaneously taking their waste products.
The oxygenated blood goes through multiple capillaries all around the body, giving cells oxygen and taking away their CO2.
The now deoxygenated blood returns to the right atrium through the superior and inferior vena cava, ready to repeat the cycle.
Blood vessels:
Artery:
These blood vessels take blood away from the heart. They have thick walls as they must withstand greater pressure from the pumping of the heart.
Vein:
These blood vessels bring blood back to the heart. They do not have walls as thick as arteries because they are under less pressure from the pumping of the heart.
Capillary:
The blood vessel where arteries and veins meet. Capillaries are very small and have thin walls so that gas exchange could occur. Oxygenated blood from an artery enters a capillary, giving away its O2 while simultaneously taking in CO2. The now deoxygenated blood returns to the heart through a vein.
Blood:
Red blood cell:
Carries O2, CO2, nutrients and/or waste around the body. These substances are carried by the iron-rich hemoglobin on the red blood cells. These cells do not have a nucleus and are very smooth.
White blood cell:
Attacks infections, viruses, diseases and unwanted visitors of the bloodstream. These cells have a nucleus and kill viruses by engulfing them using their flexible cell membrane or by injecting harmful chemicals into them.
Platelets:
These cells create blood clots to minimize bleeding of wounds and to prevent unwanted visitors from getting into the bloodstream. These cells are the smallest of the blood cells and do not have a nucleus.
Plasma:
A protein-rich liquid in which the blood cells are suspended in.
Circulatory System
The circulatory system consists of the heart, the blood and the blood vessels. It’s purpose is to:
Transport nutrients and oxygen to cells
Carry waste products from cells such as CO2 to the lungs
Circulate white blood cells around the body
Moderate body temperature
Heart:
The heart is responsible for pumping blood all around the body.
Deoxygenated blood enters the right atrium through the superior and inferior vena cava, eventually entering the right ventricle.
Then, the CO2 filled blood gets pumped out into the lung capillaries through the pulmonary arteries.
In said capillaries, gas exchange occurs where CO2 from the red blood cells diffuses into the lungs while O2 from the lung diffuses into the red blood cells.
The now oxygenated red blood cells return to the heart and enter the left atrium through the pulmonary veins.
The oxygenated blood enters the left ventricle and gets pumped out through the aorta so it can supply the body’s cells with oxygen while simultaneously taking their waste products.
The oxygenated blood goes through multiple capillaries all around the body, giving cells oxygen and taking away their CO2.
The now deoxygenated blood returns to the right atrium through the superior and inferior vena cava, ready to repeat the cycle.
Blood vessels:
Artery:
These blood vessels take blood away from the heart. They have thick walls as they must withstand greater pressure from the pumping of the heart.
Vein:
These blood vessels bring blood back to the heart. They do not have walls as thick as arteries because they are under less pressure from the pumping of the heart.
Capillary:
The blood vessel where arteries and veins meet. Capillaries are very small and have thin walls so that gas exchange could occur. Oxygenated blood from an artery enters a capillary, giving away its O2 while simultaneously taking in CO2. The now deoxygenated blood returns to the heart through a vein.
Blood:
Red blood cell:
Carries O2, CO2, nutrients and/or waste around the body. These substances are carried by the iron-rich hemoglobin on the red blood cells. These cells do not have a nucleus and are very smooth.
White blood cell:
Attacks infections, viruses, diseases and unwanted visitors of the bloodstream. These cells have a nucleus and kill viruses by engulfing them using their flexible cell membrane or by injecting harmful chemicals into them.
Platelets:
These cells create blood clots to minimize bleeding of wounds and to prevent unwanted visitors from getting into the bloodstream. These cells are the smallest of the blood cells and do not have a nucleus.
Plasma:
A protein-rich liquid in which the blood cells are suspended in.
