The Heart And Blood Vessels Flashcards
The capillaries join to small arteries called …… And small veins called ….
Arterioles and venules
The heart consists of which 8 things
- Aorta (to body)
- Pulmonary artery (to lungs)
- pulmonary veins (from lungs)
- 4 chambers
- AV valves
- Semi lunar valves (separates ventricles from aorta)
- Inferior vena cava (from lower body)
- Superior vena cava (from head to arms)
Is the lumen wider in the arteries or the veins?
veins
which blood vessel has the most smooth elastic muscle tissue?
arteries
Veins prevent ..
backflow
when does recoil occur?
during diastole the elasticity of the walls cause them to recoil allowing the blood to be pushed forward
how do valves work?
Skeletal muscles contract, this causes blood to be pushed forward through the open valves, once the blood has passed through the muscles relax causing the valves to shut behind.
what happens in atrial systole?
Blood under low pressure flows into the left and right atria from the pulmonary veins and vena cava
This builds up pressure so the AV valves open, the atria walls then contract forcing more blood into the ventricles
What happens in ventricular systole?
ventricles contract from the base upwards, pushing blood up and out of the arteries the pressure of blood against the AV valves closes them and prevents backflow.
what happens during diastole?
atria and ventricles both relax, the elastic recoil lowers pressure in the atria and the ventricles, blood under higher pressure in the arteries is drawn back towards the ventricles closing them semi lunar valves, the coronary arteries fill during diastole, low pressure in the atria helps draw blood into the heart from the veins,
what causes the lub dub sound?
The closing of the AV valves and them the semi lunar valves.
What is the pulmonary circuit?
Pumps blood to the lungs
