Anatomy for heart in ( cardiac system )

 NOTES NURSING & MEDICAL STUDENTS Notes for medical student and nursing student

HEART :- 

Introduction :- 

-the heart is a hollow muscular organ that is pyramidal in shape.

-it lies within the pericardium in the middle mediastinum .

- it is connected at its base to the the great blood vessels.

-the heart located in  thorax betwwen 2 lungs .

structure of heart  :- 

-the heart is divided into the left and right side by partitions called septa (singular septum).

-the interatrial septum separates the two upper chambers ,called atria .

- the interventricular septum separates the two lower chambers ,called venticle.

                                                

Relations of heart :-

-superioly :- the aorta ,superior vena cava ,p artery and pulmonary vein.

-inferioly - the diaphragm.

-anterioly -the ribs and intercostal muscles .

- posterioly - the esophagus ,trachea ,left and right brochus, descending aorta ,inferior vena cava and thoracic vertrbrae 

-laterioly :- the lungs .
cardiac heart chambers :-

-the heart is divided by a septum two halves , and the halves are in tum divided into four chambers .

-the upper chambers are called the left and right artia ,and the lower chamber are called the

left right ventricle .

-the left ventricle is the largest and strongest chamber in heart .

-the left ventricles chamber walls are only about a half inch thick , but they enough force to push blood through the aortic valve and into your body .

cardiac heart valves  :- 

-the heart valves are flap -like structure that allow blood to flow in one direction .

-four type of valves regulates blood flow through your heart .

-the tricspid valve regulate blood flow between the right atrium and the right ventricles .

-the pulmonary valve controls blood flow flow the right ventricle into the pulmonary arteries ,which carry blood to the lungs to pick up oxygen .

- the mitral valve lets oxygen -inch blood from your lungs pass from the left atrium into the left ventricle .

-the aortic valve opens the way for oxygen -rich blood to pass from the left ventricle into the

aorta ,your body largest artery .

surfaces :- 

-the sternocostal or anterior surfaces is deep to the sternum and ribs .

-the diaphragmatic or inferior surface is the part of the heart between the apex and right border.

-the pulmonary or left surfaces is occupies the cardiac notch of the left lung .

Borders:-

-the right border is formed by right atrium and it faces the right lungs and extends from the inferior surfaces to the base .

-the inferior border is formed by right ventricle and partly left ventricle . 

-the left border also called the pulmonary border ,is formed by left ventricle and the left auricle and it faces the left lung and extends from the base to apex.

layers  of the wall :- 

Pericardium -visceral pericardium 

Myocardium- cardiac muscle layer forming the bulk of the heart.

Endocardium -endothelial layer of the inner myocardial surfece.

blood supply to the heart :-

arterial supply :-

- heart is supplied by right and left copronary arteries.

- these surround the heart like an inverted crow .

-modifild muscular arteries with poorly developed internal elastic lamina.

-the blood vessels of the heart ,normally embedded in fat , located just deep to the epicardium.

Right coronary artery :-

-arises from anterior aortic sinus of the ascending aorta.

-it descends in the right areioventricular groove, 

- near inferior border continuous posteriorly along the artriventricular groove.

-anastomose with left coronary artery in the posterior interventricular groove.

Nerve supply of heart :- 

1) sympathetic fibers- 

-the terminate on SA & AV nodes ,cardiac muscles fibers & coranary artyeries .

2) parasympathetic fibers:-

- the terminate on SA node AV nodes and on coronary arteriesarteries.