MUSCLE TISSUE!
Muscle tissue is made of "excitable" cells that are capable of contraction. Of all of the tissues that this series discusses, muscle tissue is the most abundant tissue in most animals.
Heart Muscle Cell
Muscle Tissue Types
Muscle tissue has numerous microfilaments composed of actin and myosin which are contractile proteins. There are three major types of muscle tissue:
Cardiac Muscle
Cardiac muscle is so named because it is found in the heart. Cells are joined to one another by intercalated discs which allow the "synchronization" of the heart beat. Cardiac muscle is branched, striated muscle.
Skeletal Muscle
Skeletal muscle, which is attached to bones by tendons, is associated with the body's voluntary movements. Skeletal muscle is striated muscle. Unlike cardiac muscle, the cells are not branched.
Visceral (Smooth) Muscle
Visceral muscle is found in various parts of the body such as the arteries, the bladder, the digestive tract as well as in many other organs. Visceral muscle is smooth muscle as it doesn't have cross striations. Visceral muscle contracts slower than skeletal muscle but the contraction can be sustained over a longer period of time.
Interesting Tidbits
Interestingly, adults have a certain number of muscle cells. Through exercise, such as weight lifting, the cells present enlarge but the overall number of cells present does not increase.
Skeletal muscles are "voluntary" muscles because animals have control over their contraction. Visceral muscles are "involuntary" since, for the most part, they are not consciously controlled.
2006-07-26 13:52:12
·
answer #2
·
answered by Anonymous
·
0⤊
0⤋