Cardiac muscle

Cardiac muscle
Cardiac muscle
Cardiac muscle tissue is only found in the heart
Details
Part of	Myocardium of the heart
Identifiers
Latin	Textus muscularis striatus cardiacus
MeSH	D009206
TA	A12.1.06.001
FMA	9462
Anatomical terminology [edit on Wikidata]

A cardiac muscle (heart muscle) is one of the three main types of muscle in vertebrates. It is involuntary: a person cannot control it consciously. Also, it is a striped muscle in the walls of the heart. It makes up the tissue called the myocardium.

The other types of muscle are the skeletal and smooth muscle. The cells that make up cardiac muscle have one (74%) or two (24.5%) nuclei.^[1][2] The myocardium forms a thick middle layer between the outer epicardium layer and the inner endocardium layer.

Coordinated contractions of cardiac muscle cells in the heart force blood out of the atria and ventricles to the blood vessels of the left/body/systemic and right/lungs/pulmonary circulatory systems. This mechanism illustrates systole (contraction) of the heart.

Cardiac muscle cells, unlike most other tissues in the body, rely on the coronary arteries to deliver oxygen and nutrients and remove waste products directly. There is no time for them to diffuse.

1. ↑ Olivetti G; Cigola E & Maestri R.; et al. (July 1996). "Aging, cardiac hypertrophy and ischemic cardiomyopathy do not affect the proportion of mononucleated and multinucleated myocytes in the human heart". Journal of Molecular and Cellular Cardiology. 28 (7): 1463–77. doi:10.1006/jmcc.1996.0137. PMID 8841934.{{cite journal}}: CS1 maint: multiple names: authors list (link)
2. ↑ Pollard, Thomas D. and Earnshaw, William. C. 2007. Cell biology. Philadelphia: Saunders.