Endocardium

Source: Wikipedia, the free encyclopedia.
Endocardium
Interior of right side of heart
Details
Identifiers
Latinendocardium
MeSHD004699
TA98A12.1.05.001
TA23962
FMA7280
Anatomical terminology
Illustration depicting the layers of the heart wall including the innermost endocardium

The endocardium (pl.: endocardia) is the innermost layer of tissue that lines the chambers of the heart. Its cells are embryologically and biologically similar to the endothelial cells that line blood vessels. The endocardium also provides protection to the valves and heart chambers.[1]

The endocardium underlies the much more voluminous

epicardium and the heart is surrounded by a small amount of fluid enclosed by a fibrous sac called the pericardium.[2]

Function

Histology of the endocardium and subendocardium.

The endocardium, which is primarily made up of endothelial cells, controls myocardial function. This modulating role is separate from the homeometric and heterometric regulatory mechanisms that control myocardial contractility.[3] Moreover, the endothelium of the myocardial (heart muscle) capillaries, which is also closely appositioned to the cardiomyocytes (heart muscle cells), is involved in this modulatory role.[4] Thus, the cardiac endothelium (both the endocardial endothelium and the endothelium of the myocardial capillaries) controls the development of the heart in the embryo as well as in the adult, for example during hypertrophy. Additionally, the contractility and electrophysiological environment of the cardiomyocyte are regulated by the cardiac endothelium.[5]

The endocardial endothelium may also act as a kind of blood–heart barrier (analogous to the

cardiomyocytes bathe.[6]

Clinical significance

In

myocytes. This damaged region will conduct impulses more slowly, resulting in irregular rhythms.[8] The damaged region may enlarge or extend and become more life-threatening.[9] In the chronic setting, transmural infarctions are more dangerous due to the greater amount of muscular damage and the development of scar tissue leading to impaired systolic contractility, impaired diastolic relaxation, and increased risk for rupture and thrombus formation.[10][11]

During depolarization the impulse is carried from endocardium to epicardium, and during repolarization the impulse moves from epicardium to endocardium. In

bacteria.[12]

References

  1. PMID 1415782
    .
  2. PMID 31424779
    , retrieved 2023-02-23
  3. PMID 21989917
    .
  4. ^ "Endothelial Dysfunction". stanfordhealthcare.org. Retrieved 2023-02-23.
  5. PMID 8970576
    .
  6. PMID 30137840
    , retrieved 2023-02-23
  7. PMID 21169398
    .
  8. doi:10.1161/01.res.30.6.621
    – via ahajournals.org.
  9. doi:10.1016/B978-0-12-803997-7.00014-4 – via ScienceDirect
    .
  10. PMID 29262146
    , retrieved 2023-02-23
  11. PMID 30335314
    , retrieved 2023-02-23
  12. PMID 30725879
    , retrieved 2023-02-23

External links

  • Histology image: 64_06 at the University of Oklahoma Health Sciences Center - "Heart and AV valve" (atrial endocardium)
  • Histology image: 64_07 at the University of Oklahoma Health Sciences Center - "Heart and AV valve" (ventricular endocardium)
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