Name: Interstitial Fluid: Insights
Uploaded: 2019-07-19
Duration: 4 min 54 s
Description: Here is an interesting video explaining the importance and location of interstitial fluid. Interstitial fluid has the major function of moving materials into and out of the cell.

Question

Describe the internal structure of human heart.

Accepted Answer

The diagram given below shows the internal structure of human heart:

The internal structure of the heart can be better studied by dissecting it from the ventral side.
(i) Atria:

The two thin walled atria are separated from each other by the interatrial septum. The right atrium receives the openings of superior vena cava, inferior vena cava and coronary sinus.

The opening of inferior vena cava is guarded by Eustachian valve. The Opening of the coronary sinus has coronary or the basian valve.

In the right atrium adjoining the interatrial septum, an oval depression, the fossa ovalis is present.

It marks the position of an opening, the foramen ovale, between the two atria in the foetus, but in the adult it persists only as a depression.

The left atrium receives four openings of pulmonary veins.

(ii) Bicuspid and Tricuspid Valves:

The atrioventricular opening between the left atrium and the left ventricle is guarded by the bicuspid valve, also called mitral valve(having two flaps).

The right atrioventricular opening is guarded by the tricuspid valve, as it has three flaps.

(iii) Ventricles:

Attached to the flaps of the bicuspid and tricuspid valves are special fibrous cords, the chordae tendineae, which are joined to the other ends with the special muscles of the ventricular wall, the papillary muscles.

The chordne tendineae prevent the bicuspid and tricuspid valves from collapsing back into the atria during powerful ventricular contractions.

The chordae tendineae can be seen extending from the valves to the columnae carneae, which are the muscular projections on the walls of the ventricles.

The columnae carneae divide the cavity of the ventricles into smaller spices, known as fissures. The walls of the ventricles are thicker than the atria.

The thickest part of the human heart u the wall of the left ventricle

(iv) Semilunar valves:

As stated in the external structure, the pulmonary trunk and aorta arise from the right and left ventricles respectively. At the base of the pulmonary trunk and aorta are located three half - moon shaped pockets known as pulmonary semilunar valves and aortic semilunar valves respectively.

These valves allow the free and forward flow of blood, but prevent any backward flow.

Describe the internal structure of human heart.

Important Questions on Body Fluids and Their Circulations

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