Left ventricle

Synonym: Ventriculus sinister, left ventricle

definition

The left ventricle is part of the "great" or body circulation, the left atrium (Atrium sinistrum) downstream and pumps the oxygen-rich blood freshly coming from the lungs into the aorta and thus into the body's circulation, where it supplies all important structures with oxygen.

Left ventricle anatomy

The heart lies rotated around its longitudinal axis in the left chest so that the right half of the heart more the anterior chest wall (ventral) is applied while the left half of the heart rather after back (dorsal) shows.
The left ventricle (left ventricle) is divided into an inflow and an outflow path. It is separated from the atrium by the bicuspid valve or mitral valve. This is through Tendon threads (Chordae tendineae) with the Papillary muscles connected that arise on the ventricular wall and ensure, that the Shut up at their end before and during the tension phase (Systole) the left ventricle does not strike back too hard into the left atrium.
The blood reaches the outflow path during systole after passing through the Aortic valve in the body circulation.
The ventricles (Ventricle) differ from each other due to their function:

  • The Wall of the left ventricle is with one Thickness of 10-12 mm much thicker than that of the right ventricle.
    While the left heart, when ejecting blood into the aorta, has to pump against the much higher pressure of the circulatory system, which is usually around 120 mmHg,
  • must right heart against one essential lower pressure, namely the one in the lung predominant pulmonary pressure with below 30 mmHg pump up.

The left and right ventricles are Chamber septum (Interventricular septum) separated from each other, the septum has a thickness of 5-10 mm.

Illustration of the left ventricle

Left ventricle illustration
  1. Left ventricle -
    Ventriculus sinister
  2. Left atrium -
    Atrium sinistrum
  3. Mitral valve -
    Valva mitralis
  4. Papillary muscle -
    Papillary muscle
  5. Left pulmonary veins -
    Vv. Pulmonary sinastrae
  6. Right pulmonary veins -
    Vv. Pulmonary dextrae
  7. Aortic valve -
    Valva aortae
  8. Ascending aorta -
    Pars ascendensaortae
  9. Aortic arch - Arcus aortae
  10. Right ventricle -
    Ventriculus dexter

    Great Cardiovascular System - (red)

You can find an overview of all Dr-Gumpert images at: medical illustrations

function

The heart will functionally divided into a left and a right heart. The right heart is part of the "great" circulation (body circulation), over four Pulmonary veins (Pulmonary veins) the blood reaches the left atrium and from there via the bicuspid valve (also: Mitral valve) into the left ventricle. After contraction of the left ventricle and opening of the aortic valve, the blood enters the Main artery (aorta), through which the blood flows through the body via various vessels and supplies it with oxygen (and other nutrients).

The heart action is roughly in two sections subdivided that diastole and the Systole. in the left heart this cycle takes place as follows:

  • During the diastole is the Musculature the ventricle relaxed. The AV valve (i.e. the valve between the atrium and ventricle, in the left heart the bicuspid valve) open and the chamber gets with blood filled.
  • The Systole is the phase of Tension. The AV valve is closedso that with the tension that now follows (contraction) no blood flows from the ventricle back into the atrium. In the tension phase of the systole, the aortic valve is also closed, so the blood remains in the chamber for the time being. Once the Pressure in the chamber, caused by the contraction of the Musculature arises, is big enough, the aortic valve opens and the Blood flows out of the chamber in the body circulation.

This Heart action consisting of systole and diastole runs synchronously with it and on the same principle in the right ventricle from which the blood first enters the Pulmonary circulation is pumped. After having it there oxygen Once saturated, it enters the left atrium and the cycle of diastole and systole repeats again.

Read more on the topic: Task of the heart

Histology - wall layering

The Wall layers are The same in all four interior heart rooms built up:

  • The innermost layer forms that Endocardium, consisting of a single-layer epithelium, which is lined by the connective tissue lamina propria.
  • This is followed by the muscle layer (Myocardium) on.
  • The outermost layer forms that Epicardium.

Blood supply

The heart gets over that Coronary arteries (Coronary vessels, vasa coronaria) supplied with blood. These are through the two main vessels, the left and right Coronary artery (Left and right coronary arteries) and their numerous branches.
This arise from the aorta, right after it leaves the heart. The left ventricle is mainly supplied by branches of the left coronary artery, but the right coronary artery also provides a small part of the supply.

Clinical Aspects

A Insufficiency of the heart means one Muscle weakness, due to the Pumping power of the heart Not more sufficient, to provide the body with sufficient oxygen.
Thereby jams more and more Blood in front of the affected part of the heart.

At a Left heart failure this backwater mainly takes the form of a Pulmonary edema, i.e. a noticeable accumulation of water in the lungs. Typically this causes pulmonary edema Difficulty breathing (Dyspnea). Another symptom of heart failure is - among others - a Decline in physical performance. causes can be for example:

  • congenital valve defects,
  • but also a past heart attack.

Ventricular septal defects are relatively common congenital malformationsthat have an opening in the ventricular septum. So there is one Short circuit (Shunt) between the left and right ventricle. This means that already oxygen-saturated blood from the left ventricle is not only ejected into the aorta, but also pumped back into the right ventricle (Left-right shunt). This leads to a increased stress on the left ventriclebecause it now has to do more work to pump the required volume into the body's circulation. This results in a Cardiac hypertrophy (Increase in thickness of the heart wall). To prevent this from happening, larger ventricular septal defects are made surgically corrected.