2.4 The Circulatory System Flashcards
what does the heart act as?
a powerful pump
what are the four chambers of the heart called?
right atrium
left atrium
right ventricle
left ventricle
describe the flow of blood from when it enters the heart to when if goes to the lungs…
enters in the vena cava, goes through right atrium, through tricuspid valve, through the right ventricle, through semilunar valve, pulmonary artery to lungs
Describe the flow of blood from the lungs to the heart and into the body…
lungs to pulmonary vein, through left atrium, through bicuspid valve, through left ventricle, through semilunar valve to aorta and then body tissues
How and why are the ventricle walls different?
the left is thicker and more muscular as it has to pump blood all around the body whereas the right is smaller as it only has to pump to the lungs
how does the heart obtain a blood supply?
through the coronary artery so it has necessary nutrients for muscular contraction
why are valves needed in the heart?
to prevent the back flow of blood into the heart from the arteries so bold only flows in one direction.
What are the three types of blood vessel called?
arteries, veins,capillaries
Which vessel takes blood away from heart and which takes blood towards the heart?
arteries away
veins to
describe an artery in terms of wall thickness, blood pressure, central channel size, valves and function…
thick muscular walls thin central channel high pressure no valves oxygenated blood away from heart apart from pulmonary artery
describe a vein in terms of wall thickness, blood pressure, central channel size, valves and function…
thin wall wide central channel low pressure valves to prevent back flow of blood deoxygenated blood to heart except for pulmonary vein
describe a capillary in terms of wall thickness, blood pressure, central channel size and function…
thin central channel thin walls only one cell thick high to low pressure no valves for gas exchange
give examples of substances transported in the blood..
O2 glucose co2 hormones minerals-ions bacteria
how are red blood cells specialised to carry oxygen?(4)
biconcave structure -larger surface area for absorption
no nucleus- more room for oxygen
have haemoglobin- carries oxygen
small -fit through capillaries
What is the function of haemoglobin in the transport of oxygen?
Haemoglobin associates with oxygen and carries it around the body and dissociates with oxygen when there is a low oxygen concentration so it can diffuse into body cells.
