The Heart And Blood Vessels Flashcards
What are the parts of the heart
Vena carva Right atrium Right ventricle Pulmonary artery Pulmonary vein Left atrium Left ventricle Aorta Valves - 2 pairs on each side
What does the vena carva do?
Deoxygenated blood enters right atrium Through vena carva
What do the left and right atrium do
Atria contract to force blood into both ventricles
What does the pulmonary artery do
Delivers deoxygenated blood to the lungs
What does the pulmonary vein do
Delivers oxygenated blood to the heart from the lungs
What does the ventricles do
Right - pumps blood to lungs where gas exchange takes place
Left- pumps blood around rest of body
What do the valves do
Stop blood flowing backwards
What does the aorta do
Delivers oxygenated blood to the rest of the body
What are the 3 types of blood vessels
Arteries
Veins
Capillaries
Explain arteries
Thick outer layer because blood is at high pressure
Narrow lumen
No valves
Blood flows from heart through arteries to organs
If the arteries become narrow and restrict blood flow stents are used to keep them open
Explain veins
Thin outer layer because blood is travelling more slowly
Wide lumen
Valves to stop blood going backwards
Blood returns from veins to heart eg vena carva
Explain capillaries
Very thin outer layer because only one cell thick
Very narrow lumen
No valves
Blood flows through these through organs so substances can pass in and out of capillary walls
What is blood
Blood is a tissue consists of plasma in which red and white blood cells and platelets are suspended.
Blood plasma transports carbon dioxide from organs to lungs
Soluble products of digestion from small intestine to other organs
Urea from liver to kidneys
What does the heart do
Organ that pumps blood around body in double circulatory system
Much of heart wall made of muscle tissue
Natural resting Heart rate controlled by group of cells in right atrium acting a pace maker
Artificial pacemakers correct irregularities in the heart beat
What are the 2 separate circulation systems
One for the lungs
One for the rest of the organs of the body
