Contraction cardiac muscle, physiology

The Ca2+-binding subunit TN-C is homologous to calmodulin with four EF-hands. In contrast to calmodulin, which is ubiquitously expressed in multicellular eukaryotic organisms and interacts with many targets, troponin specifically regulates muscle contraction. There are some structural differences between Troponin C in skeletal and cardiac muscles reflecting their physiological differences. 

The calcium ion liquid-membrane electrode is a valuable tool for physiological investigations because this ion plays important roles in such processes as nerve conduction, bone formation, muscle contraction, cardiac expansion and contraction, renal tubular function, and perhaps hypertension. Most of these processes are influenced more by the activity than the concentration of the calcium ion activity, of course, is the parameter measured by the membrane electrode. Thus, the calcium ion electrode (and the potassium ion electrode and others) is an important tool in studying physiological processes. 

The calcium membrane electrode is a vaittable Uh>I for physiological studies because calcium play s important roles in nerve conduction, bone furmati on, muscle contraction, cardiac conduction and contraction, and renal tubular function. At least some of these processes are influenced more by calcium ion activity than by calcium ion concentration activity, of course, is measured by the electrode. 

Autonomic nervous system The functional division of the nervous system that innervates most glands, the heart, and smooth muscle tissue in order to maintain the internal environment of the body. Cardiac muscle Involuntary muscle possessing much of the anatomic attributes of skeletal voluntary muscle and some of the physiologic attributes of involuntary smooth muscle tissue SA node-induced contraction of its interconnected network of fibers allows the heart to expel blood during systole. 

However, in some mammalian skeletal muscles, e.g., m. cambaloideus, an LDH isozyme distribution identical with that found in cardiac muscle was obtained. This could be explained by the fact that these muscles contain mainly red filaments. The primary physiological role of these muscles is to fix the body in a static position and, therefore, they are able to maintain contraction for long periods of time (Wilkinson, 1965). 

Pharmacology Potassium participates in a number of essential physiological processes, such as maintenance of intracellular tonicity and a proper relationship with sodium across cell membranes, cellular metabolism, transmission of nerve impulses, contraction of cardiac, skeletal, and smooth muscle, acid-base balance, and maintenance of normal renal function. Normal potassium serum levels range from 3.5 to 5 mEq/L. 

---