Structure of the Muscular System
The Muscular System has three kinds of muscle tissue, Cardiac, Smooth and Skeletal. They are all similar in ways but different in others. Cardiac and Skeletal muscle cells are both striated which means the actin and myosin filaments which facilitate muscle contractions are laid out in the same striped pattern yet cardiac muscle is involuntary muscle like smooth muscle while skeletal is voluntary muscle.
Smooth muscle creates the movement required for the blood vessels to constrict and dilate, the pupil of the eye to dilate and it is found in the walls of all the hollow organs allowing them to move whatever substance needs to move to function properly ...view middle of the document...
The nerve impulses are generated in the sinoatrial node, spread to the atrioventricular node where the impulses are redistributed to the other areas of the heart by purkinje fibres which make the ventricles contract simultaneously which is a heartbeat.
Ligaments are strong connective tissue which is made of long stringy white collagen fibres that are closely interlocked or packed together. The cells in ligaments are called fibroblasts. They make strong cords which are flexible due to their high elastin content but do not stretch. They attach bone to bone and define the range of movement a joint has. Muscles and tendons facilitate the movement while ligaments stop the range of movement from going too far causing the dislocation of the joint. Ligaments also work as shock absorbers allowing a joint to react to stress for example the spinal ligaments keep the vertebrae in alignment when picking up a heavy box. Groups of ligaments work together in different ways depending on what kind of joint they are at. There are four ligaments in the knee which limit all the possible axis of movement. The Medial Collateral Ligament and Lateral Collateral Ligament prevent the knee from moving too far side to side while the Anterior Cruciate Ligament and Posterior Cruciate Ligament prevent the knee from going too far back and forward. The ligaments are specifically shaped and grouped at each joint to allow a specific and safe range of movement for each joint. If a joint is pushed too far out of its allowed range of movement the damage to the ligament is likely to be very painful and slow to heal due to the limited blood supply found in this kind of connective tissue. (Martini 2003)
Joints are where two or more bones meet. There are three main types of joints in the body, fibrous joints, cartilaginous joints and synovial joints.
Fibrous joints are where the joints are immovable as they are held together with fibrous tissue like ligaments. In the lower leg the tibia and fibula are held together in an immovable joint as they are there to support muscle tissue rather than flex and move. The bones of the skull are also fibrous joints.
Cartilaginous joints are slightly moving joints as there is a small cushion of cartilage in between the bones. The vertebrae of the spine are examples of this as well as the pubic symphysis which is a small joint at front of the pelvic bones.
Synovial joints are the free moving joints which have a synovial capsule which is collagenous structure which surrounds the whole joint. Inside the synovial capsule each bony end is coated in articular cartilage and the space between these cartilage ends is filled with synovial fluid...