You should be familiar with the following terms before comin

You should be familiar with the following terms before coming to lab. Layers of the Heart Wall Pericardium _____ Pericardial cavity _____ Myocardium _____ Endocardium _____ Atria (right and left)_____ Ventricles (right and left) _____ Tricuspid valve _____ Mitral (bicuspid) valve _____ Pulmonary valve_____ Aortic valve _____

Solution

Pericardium: The heart is enclosed in double-walled membranous called pericardium or pericardial sac.The outer layer of the sac is a tough fibrous membrane that is attatched to the mediastinum, the midline connective - tissue partition that separates the lungs.This attatchment anchors the heart so that it remains properly positioned within the chest.pericardium plays important role in preventing sudden overdistension of the chambers of the heart.

Pericardial cavity: It is the space formed between the two layers of serous membrane of pericardium around the heart.It contains a fluid which provide lubrication to prevent friction between the pericardial layers a these surfaces glide over each other with every beat of the heart.

Myocardium: It is the middle and thickest layer of heart composed of cardiac muscles.

Endocardium:It is the innermost layer of the tissue that lines the chambers of the heart.It provides protection to the valves and heart chambers.

Atria:The heart is composed of two upper small and thin walled chamber is the auricle or atrium and recieves blood from various parts of the body that is why also known as recieving chamber.It is divided into right and left atria by means of inter-auricular septum.

Ventricles:The heart is composed of two lower thich walled musclarised chambers called ventricles tht supply blood to the various body organs thus is also called the distributing chambers.since their function is pumping than recieving the ventricle has a thicker wall than the atrium.

Tricuspid valve:It is generally on the right dorsal side of the heart between the right atrium and right ventricle.They prevent the back flow of blood to the right atrium.They have three leaflet and three papillary muscles,they are under the control of chorda tendeneae.

Mitral valve(bicuspid valve): It lies between the left atrium and left ventricle.It has two leaflet which gaurd the opening.

Pulmonary valve:It lies between the right vetricle and pulmonary artery.It is also called semilunar valve.It also posses three cusps and opens in ventricular systole.

Aortic valve:It lies between the left ventricle and arota.It also has three cusps -left, right and posterior.It allows the blood to exit the left ventricle and to enter into the arota.