The circulatory system Flashcards
What does the circularity system do ?
It carries nutrients and oxygen to the cells in the body
What type of circularity system do humans have ?
A double circularity system - two circuits joint together
What are the 4 chambers of the heart ?
Left ventricle, right ventricle, left atrium, right atrium
Which side of the heart has oxygenated blood in it ?
Left side
Describe the pathway of blood, starting with the vena cava ( mention when blood is oxygenated or not ) .
First deoxygenated blood passes through the vena cava into the the right atrium. the blood then flows into the right ventricle where it is pumped into the the pulmonary artery. The pulmonary artery carries deoxygenated blood to the lungs where is collects oxygen from the alveoli. The oxygenated blood then passes through the pulmonary vein back the left atrium. Blood then flows from the left atrium to the left ventricle where it is pumped out the aorta to the cells around your body.
What are the 3 types of blood vessels ?
Arteries, veins, capillaries
why does the heart have valves ?
It has valves to prevent blood from flowing backwards
What is the name of the arteries that supply blood to the heart ?
Coronary arteries
What causes the atrium to contract at the right time ?
The hearts pacemaker
What are the features of arteries ?
The walls are strong and elastic. The lumen ( hollow part of arteries ) is narrow compared to the walls. The walls contain thick layers of muscle and elastic fibres.
What are the features of capillaries ?
They are 1 cell thick which increase diffusion by decreasing the distance it occurs over, they have permeable walls for diffusion
What are the features of veins ?
The have thin walls because the pressure is lower then in arteries, they have a bigger lumen to allow blood to flow despite the lower pressure, they have valves to stop blood from flowing in the wrong direction
How do you calculate the rate of blood flow ?
rate of blood flow = volume of blood / number of minutes
What is the job of red blood cells ?
to carry oxygen to the cells and co2 away from the cells
what are the features of red blood cells ?
They have a biconcave shape, no nucleus, contain haemoglobin
