Know the Cardiac muscles

The cardiac muscle (photo)is a type of involuntary striated muscle found in the walls of the heart. As it contracts, it propels blood into the heart and through the blood vessels of the circulatory system.

Cardiac Muscle Cardiac muscle, found only in the heart, drives blood through the circulatory system. Cardiac muscle cells connect to each other by specialized junctions called intercalated disks. Without a constant supply of oxygen, cardiac muscle will die, and heart attacks occur from the damage caused by insufficient blood supply to cardiac muscle.

This muscle tissue composes most of the vertebrate heart. The cells, which show both longitudinal and imperfect cross striations, differ from skeletal muscle primarily in having centrally placed nuclei and in the branching and interconnecting of fibers.

Cardiac muscle is not under voluntary control. It is supplied with nerves from the autonomic nervous system, but autonomic impulses merely speed or slow its action and are not responsible for the continuous rhythmic contraction characteristic of living cardiac muscle. The mechanism of cardiac contraction is not yet understood.
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Know the Skeletal, or Striated, Muscle tissue

Striated muscle is a form of fibres that are separated into parallel fibres

Skeletal muscle (photo) enables the voluntary movement of bones. Skeletal muscle consists of densely packed groups of elongated cells known as muscle fibers. Within these fibers, the alternation of thick and thin myofilaments gives skeletal muscles a striated, or striped, appearance.

This type of muscle is composed of long fibers surrounded by a membranous sheath, the sarcolemma. The fibers are elongated, sausage-shaped cells containing many nuclei and clearly display longitudinal and cross striations. Skeletal muscle is supplied with nerves from the central nervous system, and because it is partly under conscious control, it is also called voluntary muscle. Most skeletal muscle is attached to portions of the skeleton by connective-tissue attachments called tendons. Contractions of skeletal muscle serve to move the various bones and cartilages of the skeleton. Skeletal muscle forms most of the underlying flesh of vertebrates.

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Know the Smooth muscles

Smooth muscle (photo) is a type of non-striated muscle, found within the tunica media layer of arteries and veins, the bladder, uterus, male and female reproductive tracts, gastrointestinal tract, respiratory tract, the ciliary muscle, and iris of the eye.

The glomeruli of the kidneys contain a smooth muscle-like cell called the mesangial cell. Smooth muscle is fundamentally different from skeletal muscle and cardiac muscle in terms of structure, function, excitation-contraction coupling, and mechanism of contraction.

Smooth Muscle Human smooth muscle is composed of slender, spindle-shaped cells, each with a single nucleus. Smooth muscle cells contract in rhythmic waves to propel food through the digestive tract and provide tension in the urinary bladder, blood vessels, uterus, and other internal organs.

Muscle is composed of spindle-shaped cells, each having a central nucleus. The cells have no cross striations, although they do exhibit faint longitudinal striations. Stimuli for the contractions of smooth muscles are mediated by the autonomic nervous system. Smooth muscle is found in the skin, internal organs, reproductive system, major blood vessels, and excretory system.
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