Tissue is a contractile tissue present only in the heart. Cell junctions fuse the plasma membranes of cardiac muscle cells and make them stick together. Communication junctions (intercalated discs) at some fusion points allow the cells to contract as a unit, i.e., when one cell receives a signal to contract, its neighbours are also stimulated to contract. 6WULDWLRQV 1XFOHXV 1XFOHXV 6PRRWK PXVFOH ILEHUV 6WULDWLRQV 1XFOHXV -XQFWLRQ EHWZHHQ DGMDFHQWFHOOV LQWHUFDODWHGGLVF E 6PRRWKPXVFOHWLVVXH F &DUGLDFPXVFOHWLVVXH D 6NHOHWDOPXVFOHWLVVXH Figure .
Muscle Tissues Palmaris Muscle: This long narrow muscle runs from the elbow to the wrist and is important for hanging and climbing in primates, is missing in % of humans today.