Blog2 اااااااااااااااااااااااااا: Dangerous information about the heart muscle in a person

Dangerous information about the heart muscle in a person

The myocardium is one of three types of vertebrate muscles, with two others being the skeletal muscle and the smooth muscle. It is a involuntary striped muscle that forms the main tissue of the walls of the heart. The heart muscle forms a thick middle layer between the outer wall of the heart (pericardium) and the inner layer (endocardium), while providing blood through the coronary circulation. It consists of individual muscle heart cells (myocardial cells) linked together by means of rounded discs, coated with collagen fibers and other substances that make up the extracellular interstitial tissue.

The heart muscle contracts in a manner similar to the skeletal muscle, despite some important differences. Electrical stimulation in the form of a cardiac action potential causes calcium to be released from the cell's internal calcium repository, which is a muscular sarcoma network. The rise in calcium slips the muscle strands of the cell through each other in a process called conjunctival excitation.

Heart muscle diseases are of great importance. These include conditions that restrict blood to the muscles including angina, heart attack, and other heart muscle diseases known as cardiomyopathy.

The heart muscle is the largest part of the heart. The wall of the heart is a three-layered structure with a thick layer of heart muscle located between the endocardium and the outer pericardium (also known as visceral pericardium). The endocardium lines the heart's chambers, covers the heart valves, and joins the membranous lining that lines the vessels that connect to the heart. On the outer side of the heart muscle is the pericardial membrane that forms part of the pericardium, the sac that surrounds, protects, and greases the heart. Within the myocardium there are many plates of myocardial cells or myocardial cells. Muscle plates wrapping around the left ventricle closest to the endocardium are oriented perpendicular to the proximal membrane. When these plates shrink in a coordinated manner, they allow the ventricle to compress in several directions at once - longitudinally (it becomes shorter from top to base), diagonally (it becomes narrower from side to side), with torsional movement (similar to the movement of squeezing a wet cloth) to compress The maximum amount of blood outside the heart with each heartbeat.

Contraction of the heart muscle uses a lot of energy, and therefore requires a continuous flow of blood to provide oxygen and nutrients. Blood is brought to the heart muscle by coronary arteries. These originate from the aortic root and are located on the outer or epicardial surface of the heart. The blood is then drained through the coronary veins into the right atrium.

Histology

When viewed from a microscope, the heart muscle can be likened to the home wall. Most of the wall is built with bricks, which in the heart muscle are individual cardiac muscle cells or cardiac muscle cells. The mortar surrounding the brick is known as the extracellular interstitial tissue, produced by supportive cells known as fibrous cells. In the same way that the walls of the house contain electrical wires and plumbing, the heart muscle also contains specialized cells to quickly conduct electrical signals (the cardiac conduction system), and blood vessels to bring nutrients into muscle cells and dispose of waste (coronary arteries, veins, and capillary network).

Heart muscle cells

Myocardial or myocardial cells are contracting cells that allow the heart to pump. Each heart muscle cell needs to contract in coordination with adjacent cells - known as functional cell runway cells - to efficiently pump blood from the heart, and if this coordination is disrupted - despite the contraction of individual cells - the heart may not pump at all, such as what might It occurs during irregular heart rhythms such as ventricular fibrillation.

Due to the microscope, the cells of the heart muscle are almost rectangular, with sizes ranging from 100 to 150 microns in 30-40 microns. Individual cardiomyocytes are joined together at their ends by means of telephoto discs to form long fibers. Each cell contains fibrous muscle fibers, which are specialized protein fibers that pass through each other. These are organized into sarcomeres, the basic units of muscle cell contraction. The normal regulation of muscle fibers in the sarcomer gives the heart muscle cells a striped pattern when viewed through a microscope, similar to the skeleton and muscles. These disturbances are caused by the lighter I gangs mainly consisting of a protein called actin, and the darker A rings mainly consist of myosin.

The heart muscles contain transverse tubes, sacs of membrane that extend from the surface to the inside of the cell, which helps to improve shrinkage efficiency. Most of these cells contain only one nucleus (although they may contain up to four), unlike skeletal muscle cells that usually contain many nuclei. Myocardial cells contain many mitochondria that provide the energy needed for the cell in the form of adenosine triphosphate (ATP), making it very resistant to fatigue

Transverse tubes are microscopic tubes that extend from the cell surface to the depth of the cell. It is continuous with the cell membrane, and it is composed of the same phosphorous bilayer, and is open on the surface of the cell in front of the extracellular fluid surrounding the cell. The tubes in the cross section of the heart muscle are larger and wider than those in the skeletal muscles, but are fewer in number. In the center of the cell they join together, extending inside and along the cell as an axial transverse network. Within the cell is located near the cell's internal calcium store, the sarco-muscle network. Here, one tubular pair with a portion of the endoplasmic reticulum is called a terminal tank in a composition known as the duo.

The functions of T tubes include the rapidly transmitted electrical impulses known as the potential for movement from the surface of the cell to the cell core, and help to regulate the concentration of calcium within the cell