- CHAMBERS OF HEART;
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| Chambers of Heart |
*Heart is divided into four chambers.
Two right Atria and Two left atria.
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| Heart Chambers |
*RIGHT ATRIA;
Right Atria consist of two chambers i.e., Right Atrium and Right Ventricle.
1)Right Atrium;
*Right Atrium is a thin walled and low pressure chamber.
*Right Atrium is made up of main cavity and auricle.
*It contain sinoatrial node which produce cardiac impulse.
*Right Atrium receives venous blood by two large veins.
i)Superior Vena Cava
ii)Inferior Vena Cava
Openings In Right Atrium;
i)Superior Vena Cava opens in upper part right artrium and receives deoxygenated blood from head, neck and upper limbs.
ii)Inferior Vena Cava opens in lower part of right artrium and receives deoxygenated blood from lower half of body.
Inferior vena cava is larger than superior vena cava..
iii)Right Artrioventricular Orifice which is guarded by Tricuspid valve.
iv)Coronary Sinus are small veins that drain blood from heart wall.
2)RIGHT VENTRICLE;
*Right Atrium is thick walled.
*Blood enters from right atrium to right ventricle through atrioventricular orifice.
*Blood moves from right ventricle to pulmonary trunk through pulmonary orifice.
*There is many small projecting ridge which are called trabeculae carneae.
*Trabeculae carneae are rounded or irregular muscular columns which projects from inner surface of ventricles of heart.
*There are three types of trabeculae carneae;
i)First type forms prominent ridge.
ii)Second type is attached at the end to the ventriclular wall and is free in the middle.
iii)Third type(musculi papillares) are continous by their bases with the wall of the ventricle while their apexes gives origin to the chordae tendineae which pass to attach to the cusps of tricuspid valve.
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| heart chamber |
3)LEFT ATRIUM;
*It is situated behind right atrium.
*It is similar to right atrium i.e., it also consist of main cavity and auricle.
*It is also thin walled and low pressure chamber.
*Right and left atria are separated from one another by fibrous septum called interatrial septum.
*It forms greater part of posterior surface of heart.
Openings of Left Artrium;
*There are four pulmonary veins, two from each lung open in this chamber.
*These openings are not guarded by any valve.
*Left Artrium receives oxygenated blood through pulmonary veins.(keep in mind this is the only vein which carry deoxygenated blood).
*Blood enter from left artrium to left ventricle through artrioventricular orifice which are guarded by mitral valve(bicuspid valve).
*This valve contains two cusps.
4)LEFT VENTRICLE;
*The walls of left ventricle is three times thicker than the wall of right ventricle.*Right and left atria are separated from one another by interventricular septum.
*The upper part of this septum is membranous while the lower part of this septum is muscular in nature.
*Well developed trabeculae carneae are present.
Opening in Left Ventricles;
*Artrioventricular orifice where oxygenated blood enter from left atrium to left ventricle.
*Aortic orifice through which oxygenated blood moves to different parts of body.Aortic Orifice is guarded by aortic valve.