Circulatory System - The Heart, Blood vessels and Blood, Flashcards
Organisation
1
Q
what is a Circulatory system made up of?
A
the heart, blood vessels and blood and a double circulatory system is two circuits joined together
2
Q
what happens in the first circuit of a double circulatory system?
A
the heart pumps blood without oxygen to the lungs, blood with oxygen then returns to the heart
3
Q
what happens in the second circuit of a double circulatory system?
A
- the heart pumps oxygenated blood around all the other organs of the body, this delivers oxygen to the body cells
- deoxygenated blood returns to the heart heart to be pumped out to the lungs again
4
Q
what is the heart?
A
- an organ with four chambers, the walls of the chambers are mostly made of muscle tissue
- this muscle tissue is used to pump blood around the body
5
Q
how does the muscle tissue pump blood around the body?
A
- blood flows into the two atria from the vena cava and the pulmonary vein
- the atria pumps blood into the ventricles
- the ventricles pump the blood out of the heart
- the blood then flows to the organs through arteries and returns through veins
- the atria fills again and the cycle starts over
6
Q
how do the ventricles pump the blood out of the heart?
A
- blood from the right ventricle goes through the pulmonary artery to the lungs
- blood from the left ventricle goes through the aorta to the rest of the body
7
Q
what else happens in the heart?
A
- the valves in the heart stop the blood flowing backwards
- the heart also needs its own supply of oxygenated blood
- it gets oxygenated blood from arteries called coronary arteries, these branch off the aorta and surround the heart
8
Q
what is a pacemaker in the heart?
A
- your resting rate is controlled by a group of cells in the right atrium wall
- these cells act as a pacemaker, they tell the heart when to pump blood
- a pacemaker that doesn’t work properly causes an irregular heartbeat
