Question

Trace the path of a single erythrocyte through the heart from Superior Vena Cava to Aorta. Describe the characteristics of each chamber as the erythrocyte passes through. For each feature mentioned, include its location and a brief comment describing its function. Use terms like endocardium, myocardium, the names of great vessels, auricle, papillary muscle, pectinate muscle, types/names of valves, fossa ovalis, chordae tendineae, interventricular septum. (Note: Include the pulmonary circuit in your path, but do not detail the pulmonary circuit characteristics or vessels other than those directly attached to the heart.)

Answer 1

RBC starts the entry to the heart from the superior vena cava to the right atrium., where it follows the following path:

Superior vena cava - Right atrium - Tricuspid valve cross - Right ventricle - Pulmonary semilunar valve cross - Pulmonary artery - Lung (alveoli) - Recieves oxygen - Pulmonary vein - Left atrium - Bicuspid valve cross - Left ventricle - Aortic semilunar valve - Aorta - to body tissues

Right side

Inferior vena cacva and superior vena cava are the main veins that bring the blood into the right atrium of the heart from the tissues.There is another opening that opening into the right atrium called coronary sinus.There is a hole found between the right atrium & the left atrium(during birth). This foramen ovale will be turned into the scar tissue during the development called fossa ovalis. SA node is found (a bunch of neural cells) found near the right atrium which help in the cardiac rhythm.

Left side

The left pulmonary veins bringing oxygenated blood from the left lung, and the right pulmonary veins drain the oxygenated blood from the right lung to the left atrium.

Valves:

Tricuspid valve are found in between the right atrium and ventricle. The bicuspid (mitral )valve is found in between the left atrium and ventricle.There are collagen structures that connects the valves to the inner wall of the ventricle called chorda tendinae. The papillary muscles are found on the inner wall of the ventricle upon which the chorda tendinae is attached.On contraction and relaxation of these muscles, These chorda tendinae will help the respective valves to open and close whenever needed.

The right ventricle have to pump out the high volume of the blood into the pulmonary artery, where there is a valve present in the opening of the pulmonary artery, called pulmonary semilunar valve. Another one that separating the left ventricle and the aorta called aortic semilunar valve. Both function to prevent the back flow of the blood from these vessels.

The septum that separating the two ventricles is called the intervetricular septum.The septum present between the atriums is called interatrial septum.

Layers of the heart:

Inner wall is lined with the endothelium and beneath a little bit areolar connective tissue.The innermost layer is called the endocardium.The middle layer consist of smooth muscle fibres called myocardium, which helps in contraction of the heart.The left ventricular myocardium is thicker than that of the right since it has to pump out a large volume of the blood into the various parts of the body, with a high pressure.The next layer is the epicardium/visceral layer of the serous pericardium.The area next is filled with the fluid called pericardial cavity with pericardial fluid (Prevents the friction between the layers).The next is the parietal layers of the serous pericardium.The outermost layer is called the fibrous pericardium made up of dense irregular conective tissue.