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Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscle tissues, the others being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall of the heart .
Serous membrane lines the pericardial cavity and reflects back to cover the heart—much the same way that an underinflated balloon would form two layers surrounding a fist. [ 1 ] The serous membrane (or serosa ) is a smooth tissue membrane of mesothelium lining the contents and inner walls of body cavities , which secrete serous fluid to allow ...
Heart tissue, like all cells in the body, needs to be supplied with oxygen, nutrients and a way of removing metabolic wastes. This is achieved by the coronary circulation, which includes arteries, veins, and lymphatic vessels. Blood flow through the coronary vessels occurs in peaks and troughs relating to the heart muscle's relaxation or ...
The heart is a muscular organ situated in the mediastinum.It consists of four chambers, four valves, two main arteries (the coronary arteries), and the conduction system. The left and right sides of the heart have different functions: the right side receives de-oxygenated blood through the superior and inferior venae cavae and pumps blood to the lungs through the pulmonary artery, and the left ...
In cardiac muscle the T-tubules are only found at the Z-lines. [1] When an action potential causes cells to contract, calcium is released from the sarcoplasmic reticulum of the cells as well as the T tubules. The calcium release triggers sliding of the actin and myosin fibrils leading to contraction. [3]
Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial (mesothelial) tissues line the outer surfaces of many internal organs, the corresponding inner surfaces of body cavities, and the inner surfaces of blood vessels.
Some types of chronic lung diseases are classified as restrictive lung disease, because of a restriction in the amount of lung tissue involved in respiration. These include pulmonary fibrosis which can occur when the lung is inflamed for a long period of time. Fibrosis in the lung replaces functioning lung tissue with fibrous connective tissue.
Smooth muscle cells are spindle-shaped with wide middles, and tapering ends. They have a single nucleus and range from 30 to 200 micrometers in length. This is thousands of times shorter than skeletal muscle fibers. The diameter of their cells is also much smaller which removes the need for T-tubules found in striated muscle cells. Although ...