Muscle movement Essay Example | Topics and Well Written Essays - 750 words

Muscle movement - Essay Example ment to the muscles and many sets of muscles in the body work together in conjunction with each other in the form of various types of levers to bring about movement as a whole process. The typical skeletal muscle consists of three parts: It’s origin from a bone where it is attached to a large area, its main body of muscular tissue and the insertion at the other end which is in the form of a glistening white tendon. The body of the muscle is made up of hundreds of cylindrical fibers which usually run all the way from the origin to the insertion. These cylindrical fibers are composed of an array of myofibrils which are a specialized category of animal cells. Each muscle fiber develops from the fusion of many cells called myoblasts. Muscles contract by the action of Acetyl choline, a neurotransmitter secreted through the nerves which brings about a change in the action potential at the neuromuscular synapse leading to binding of actin and myosin molecules and bringing about contraction. Antagonistic Muscles: For every group of muscles that move a specific portion of the body, there is an opposite group of muscles which brings about the opposite movement. Such pairs of muscles are called antagonistic muscles. The main pairs of antagonistic muscles and their respective movements are explained below: 1. Biceps-Triceps: The upper end of the biceps or its origin is at the scapula and its other end or insertion is on the radius bone of the forearm. Contraction of biceps brings about flexion or rising of the forearm and is called a flexor muscle. The antagonistic triceps relaxes at this time. The triceps is located behind the upper arm and its origin is at the scapula as well as the Humerus bone in the upper arm and the point of insertion is at the Olecranon process of the ulna. Its contraction brings about straightening of the arm and hence it is known as an extensor muscle. 2. Anterior tibialis and gastrocnemius muscles: This pair is located in the lower leg. When a

The Pleistocene Age Bonneville Flood Event Research Paper

The Pleistocene Age Bonneville Flood Event - Research Paper Example Stunning erosion occurring as neglected channels, run offs, waterfalls, and scabland signifies the path followed by the flood between American Falls and Twin Falls (Malde, 1). This paper will discuss the conditions before this catastrophic flood, the flood events and the aftermath of the flood. Conditions before the Bonneville Flood Lake Bonneville had an enormous volume, which is almost the same with that of Lake Michigan. In addition, before the flood occurred, the lake occupied a vast area of approximately 20,000 square miles in western Utah, eastern Nevada and southern Idaho. Moreover, the surface of Lake Bonneville was roughly one third of the total area of Utah. This means that before the catastrophic flood occurred, the lake covered a very large area and had a huge volume (Austin, 2). Also before the flood event, Lake Bonneville covered seven inter-montane sub-basins of Utah, Nevada and Idaho. Among these sub-basins, three of them were substantially large while the remaining f our were not large enough, they were quite small. As the volume of the water continued to increase, the volume of the lake remained constant causing water to spill over into the Snake River drainage in Southern Idaho (Grayson, 100). Before the occurrence of the great flood, the lake was approximately the level of today’s Great Salt Lake (4,200 feet) at around 28, 000 years ago. As time progressed, the lake started to swell and rise to reach an elevation of roughly 4, 400 feet by approximately 26, 500 years ago. It became more and more hazardous as the lake continued to swell but it did not increase in its size. In addition, the lake continued to swell and rise such that it reached an elevation of 4,500 feet by around 22, 000 years ago. At this point the lake covered an area of approximately 9,300 square miles. This reveals that Lake Bonneville continued to rise through the years, a situation which increased the hazard of the occurrence of a great flood. For the following 1,30 0 years or so, the lake remained constant at approximately this level. However, during this interval, the lake also recorded some falls of approximately 150 meters and then rising occasionally. This phenomenon generated the complex of features referred to the stansbury shoreline (Grayson, 101). The flood event As a result of the constant rising of the water in the lake, the water in the southern side reached the level of 5, 100 feet of the dam. This led to the overflow and marked the beginning of the catastrophic flood. On the south side of the dam, there was extensive potential energy within the lake. This massive potential energy caused erosion, which eventually created a notch on the top of the dam. It then followed that there was a massive discharge of volumes of water as the notch in the dam got deeper, so did the. In addition, as the notch enlarged to form the overflow path, erosion enhanced. The spill was widened as the collapse of the dam commenced reaching to almost one mil e wide. At this point, this became the catastrophic flood with water discharge occurring at roughly 35 million cubic feet per second (Austin, 6). The outflow of the flood crashed down the Portneuf River to the current Pocatello and then followed route as it poured along the Snake River Drainage. The water filled up the whole Snake River Canyon in the current Twin Falls and Shoshone falls and still run