Anatomy Lab: Questions & Answers Baljinder Singh Ms. Tran TPJ 3M0 08/10/10 1. The skeletal muscles in the human body all differ in size and shape much like the bones in the body. Skeletal Muscles are what help us move our body and perform everyday actions. They are pretty much muscle fibres that attach to the body’s skeleton and help make smoother body contour. These muscles are usually single, very long, cylindrical, striated & multinucleate. The skeletal muscles are voluntary, so they only move when told to and they are controlled by the nervous system. These types of muscle, as well as other types have four main functions which are movement, maintaining posture, stabilizing joints, and generating heat. Ligaments are found all over the body, and there main job is two connect two bones together when they are flexed to limit the extension. They are made up of short bands of fibrous tissues, therefore they are found between two bones. The cells in ligaments are known as fibroblasts and are made up of about 80% collagen. 2. Hypertrophy – This is when the volume of an organ or tissue is increased due to the enlargement of its component cells. This can occur in many different parts of the body, such as in the breasts, in the heart, in muscles and etc. One of the most common forms is in the muscles and this can be done two ways. Either by itself or through exercise. Weight training is the most common thing that results in hypertrophy. Atrophy – This is when a part of or the entire part of a body is being wasted. This can be caused by some things like mutation, poor nourishment, poor circulation, loss of hormonal support and much more. Examples of atrophy in muscles include loss of power, strength and mass. This could happen in any part of the body and in any organ. Something like this could happen for example if a weight trainer takes a break from exercising. Hypertrophy Atrophy 3. Isotonic Exercises – This form of exercise includes a form of contraction & also the extension of muscles. In this type of exercise, it is necessary for tension to be present throughout the workout. The type of exercise can usually be done at home and can help develop and tone muscles and joints. A good example of an isotonic exercise is weightlifting, and also push-ups and pull-ups. This exercise helps tone muscles through gentle elongation and contraction of muscles. Isometric Exercises – This form of exercise is done when one works on specific training principles to help tone muscles. There is very little motion in this type of exercise and position of limbs rarely change. A person doing this exercise stays in one stance for a long period of time. The length of the muscle does not change in this exercise. Some examples of this form of exercise include wall sits, yoga, stretching and pilates. 4. A worker should lift a heavy load in front of him without causing injury to the back muscle by doing it cautiously. If the worker lifts it up quickly, there is a chance that the worker could pull a muscle and be in some severe pain. Also the worker should not only bend his hip to get the heavy load, he should squat down and pick up the load with both hands and then stand back up slowly while keeping the back straight. When standing back up, the worker should not use only his/her arms to lift the load up. Instead the worker should stand up using his legs since the leg muscles are stronger than the muscles in the arm. This way there will be a less chance of injury of injury to the muscle. While lifting deep breathing is recommended and it is advised that the worker keep the load close and at abdominal height. 5. A professional baseball pitcher must have one arm which is more muscular than the other because one arm must be able to bear the harsh pitching schedule of a professional league. A pitcher pitches with the same arm every day and probably throws more than 50 baseballs a game. In order for this to happen, the pitching arm needs to be strong with a lot of muscle so that it can pitch consistently. During pitching, there are many muscle motions. At first the pitcher flexes his arm (flexion) to bring the ball up (biceps & brachiordialos move closer), and then he must extend (extension) his arm to throw the ball (biceps & brachiordialos move apart). There is also dorsiflexion involved when the pitcher steps forward (all leg muscles involved). A pitcher can also involve rotation in the wrist if he wants to curve the ball. If the second arm is not muscular, it is alright because the pitcher is only going to need the one muscular arm to pitch with.