B2.2.3 - Heart and blood Flashcards
What is our heart made of?
It is made of cardiac muscle
How many times does a typical heart beat in a minute?
About 70 times
How many chambers does our heart have?
It has 4 chambers
What are the 2 small chambers at the top called?
Atria
What are the 2 larger chambers at the bottom called?
Ventricles
What do the valves in our heart do?
They separate the chambers and stop the blood from flowing backwards
What happens in the heart?
Deoxygenated blood enters the right atrium, it is then pumped unit the right ventricle when the heart beats. From here it is pumped to the lungs (through the pulmonary artery) to collect oxygen. The blood returns to the heart (via the pulmonary vein) into the left atrium
It is then pumped into the right ventricle. The muscle in the left ventricle has to be very thick, pump blood at a high pressure (through the aorta). This makes the blood travel all the way around your body
What is in blood?
Red blood cells, white blood cells, plasma and platelets
What are red blood cells?
They are small biconcave cells that have no nucleus and contain haemoglobin
What are white blood cells?
Large cells that contain a nucleus. They fight diseases by making anti-bodies, or by changing shape to engulf microorganisms
What is plasma?
It is straw coloured liquid that blood cells float in. Over 90% of plasma is water. Many materials are transport by being dissolved in plasma
What are platelets?
They are tiny structures that help the blood to clot
