Heart And Blood Vessels Flashcards
What is blood pressure?
Blood pressure is the force the blood exerts against the wall of a blood vessel
What are valves?
Valves control the direction of blood flow
What is a portal system?
Blood pathway that begins and ends in capillaries
What is diastole?
When heart chambers relax
What is systole?
When the heart chambers contract
What is a pulse?
The alternate expansion and contraction of the arteries
What is an open circulatory system?
Heart pumps blood into open vessels
What is a closed circulatory system?
Blood remains in the blood vessels
Advantages of a closed circulatory system?
1) Increase bloodflow to particular organs if needed
2) Pump blood around body faster
What is the function of inelastic fibres?
Prevent walls over expanding
What is the function of muscle and elastic fibres?
To alter the size of the vessel
What is the function of the endothellium?
Separate lumen from muscular wall
What is the function of the coronary arteries?
Supply oxygen to the heart
Where do the coronary arteries originate?
Aorta
What is the function of the coronary veins?
Carry deoxygenated blood back to the heart via right atrium
Differences between arteries and veins?
Arteries have thick walls, small lumens, valves absent, etc
Veins have thin walls, large lumens, valves, etc
Where are the tricuspid valves located?
Right side of heart
Where is the bicuspid valve located?
Left side of heart
Where are the semilunar valves?
2 main arteries
What controls your heart beat?
Pacemaker (SA node)
Where is the pacemaker (SA node) located?
Wall at the top of right atrium
Describe how the pacemaker controls heartbeat?
1) SA node causes atria to contract
2) Electrical impulses from SA stimulate AV node.
3) The AV node sends electrical impulses down septum to the apex of heart.
4) Ventricles contract
Where is the AV nod located?
Right ventricle near the septum
What valves are open/closed and what chambers are relaxed in atrial diastole?
All valves closed
All chambers relaxed
What valves are open/closed and what chambers are relaxed in atrial systole?
Tri and bicuspid valves open- semilunars closed
Ventricles relax
What valves are open/closed and what chambers are relaxed in ventricular systole?
Semilunars open- tri and bicuspid valves closed
Atria relax
What does AV stand for?
Atrio-ventricular
What does SA stand for?
Sino-atrial
What is normal blood pressure?
80
What are the three stages of heartbeat?
Atrial diastole
Atrial systole
Ventricular systole
What is the pulmonary circuit?
Blood flows from heart to lungs and back
What is the systemic circuit?
Blood flows from heart to body and back
What is double circulation?
Blood flows around pulmonary and systemic circuit at the same time
