Heart: Walls Heart Chambers and Valves Flashcards
4 chambers of heart
two on the left and two on the right
Atria
Ventricles
Atria
are the two upper chambers.
Function is to receive blood returning to the heart.
walls are thin.
Ventricles
the two lower chambers.
Function is to receive blood from the atria and contract forcing the blood out of the heart into the arteries.
Septum
solid, wall-like structure which separates the atria and the ventricle on the left from those on the right
-keeps the blood within those chambers from mixing.
Interventricular septum
Interatrial septum
Valves
Atrioventricular
Semilunar
Atrioventricular valves
Tricuspid valve (RIght) Bicuspid (mitral) valve (Left)
Semilunar valves
Pulmonary valve
Aortic valve
TWO MAJOR CARDIOVASCULAR CIRCUITS
- Pulmonary circuit
2. Systemic circuit
two-sided simultaneous pump
the right side of the heart pumps blood to the lungs to become oxygenated and the left side of the heart pumps that oxygenated blood out to the body.
Pulmonary circuit
Transports blood from the heart to the lungs and back to the heart again.
Upon entering the circuit, the blood is low in oxygen concentration and high in carbon dioxide concentration.
Systemic circuit
Transports blood from the heart to the body cells and back to the heart again.
Upon entering the circuit, the blood is high in oxygen concentration and low in carbon dioxide concentration.
PATHS OF Blood vessels CIRCULATION
two major pathways:
Pulmonary circuit
Systemic circuit
Pulmonary circuit
consists of vessels that carry blood from the heart to the lungs and back to the heart.
Systemic circuit
consists of vessels that carry blood from the heart to all other parts of the body and back again.
Heart Chambers and Valves
ensures that one way blood flow
Pulmonary Circuit Process
- Blood enters the pulmonary circuit as it leaves the right ventricle through the pulmonary trunk.
- The pulmonary trunk divides into the right and left pulmonary arteries, which penetrate the right and left lungs, respectively.
- After repeated divisions, the pulmonary arteries give rise to arterioles that continue into the capillary networks associated with the walls of the alveoli, where gas is exchanged between the blood and the air.
- From the pulmonary capillaries, blood enters the venules, which merge to form small veins, and they, in turn, converge to form still larger veins.
- Four pulmonary veins, two from each lung, return blood to the left atrium. This completes the vascular loop of the pulmonary circuit.
Systemic Circuit Process
- Freshly oxygenated blood moves from the left atrium into the left ventricle.
- Contraction of the left ventricle forces this blood into the systemic circuit.
- This circuit includes the aorta and its branches that lead to all the body tissues, as well as the companion system of veins that returns blood to the right atrium.
