The Role Of The Components In Performing The Functions Of The Cardiovascular System B2.5 Flashcards
(19 cards)
What are the components of the cardiovascular system?
The heart and blood vessels
How does the blood flow through the heart?
The blood enters via the right atrium and passes into the right ventricle. This then gets passed to the lungs and back into the left atrium. Then the blood goes to the left ventricle and is pumped around the rest of the body
What does the cardiovascular system transport?
- nutrients eg glucose and amino acids
- oxygen from the lungs to the tissues
- carbon dioxide from the tissues to the lungs
- hormones around the body
Why does the left ventricle have a thicker, stronger muscle wall?
To pump blood around the whole body
Why does the atria have relatively thin walls?
As they only need to pump blood into the adjacent ventricle
What do the bicuspid and tricuspid valves do?
They prevent blood flowing backwards from the ventricle into the atrium. When the pressure is higher in the atrium than the ventricle, the valves are pushed open. The tendons prevent the valves from being pushed too far so that they make a good seal
What do semi-lunar valves do?
They prevent back flow of blood from the blood vessels (pulmonary artery, aorta) into the ventricles
What are arteries?
They carry blood away from the heart
What is the largest artery?
Aorta
What are the smallest arteries called?
Arterioles
What is the structure of arteries?
- they have an outer layer of connective tissue that provides strength and support
- they have a thick layer of muscle and elastic tissue allowing constriction or dialation of the arteries to regulate blood flow.
What are capillaries?
The smallest vessels in the cardiovascular system and have a wall just one cell thick
What are veins?
Capillaries coming together to form venules that merge into larger veins. The blood is at much lower pressure because it has to force its way through the narrow capillaries
What is the structure of veins?
The lumen is much larger, and have thinner walls as they don’t need to absorb the pressure of the pumping of the heart
What is blood made up of?
- plasma
- platelets
- red blood cells
- white blood cells
What is plasma?
Straw coloured fluid that is left if all cells are removed. It contains proteins, hormones and all the small molecules and ions transported in blood
What are platelets?
Small disk shaped cell fragments without nuclei also called thrombocytes. They are present in large numbers of the blood and play a big role in blood clotting
What are red blood cells?
Erythrocytes are differentiated cells without a nucleus or majority of their organelles. They are filled with haemoglobin, the protein that transports the oxygen from the lungs to the tissues
What are white blood cells?
Leukocytes are cells that are mostly involved in protection against infection, including the immune response
