The Skeletal& Muscular Systems

By: Cynthia Segura


What is it?

The Skeletal System is what sets the frame for our body, provides protection,and allows for movement. This system allows us to move and complete our daily lives. In addition to this system made o f206 bones, the skeletal system also produces blood cells in the bone marrow, releases hormones,and stores special minerals/nutrients. Consisting of bones,ligaments,nerves,tendons, and muscles, the moving system allows us to keep moving.

roles in human movement.

  • Bones-allow us to move, protects organs, and make blood cells in bone marrow
  • Ligaments- prevent movement that can hurt a joint & flexibility
  • Muscles- pull our muscles
  • Tendons- connect muscle to bones
  • Nerves- send messages to move body


Like all other systems, disorders can be 100% possible. 2 major disorders include Osteoporosis and Leukemia. Osteoporosis is when the bones become very delicate and fragile, resulting is a greater chance of fracture. Some symptoms include bone fracture, weight loss, and back pain. This disease can be treated medically with medication and a specialist. Osteoporosis is very common, with 3 million cases in the country. Leukemia, also known as blood cancer, is a more rare disorder with more than 20-200 thousand cases a year in the united states. Leukemia is when a blood-forming tissue cancer takes over the body. It dramatically decreases the body's ability to fight back. Some of the symptoms include bone/back pain, rashes, blood in stool when using the restroom, weakness, and shortness of breath. Leukemia can be treated, yet not cured, with medication.



The muscular system is another body system found within us. This system is in charge of of movement to support our daily routines , help our posture, and contribute to blood circulation. These 650 muscles usually work with the legs and arms.In addition, this body system allows us to have facial expressions,eye movement, and physical personality. These muscles come in 3 different categories and shapes, they are all unique. Without the muscular system, we could not move our bodies and have a pumping heart.

Major Disorders (describe,signs,teating, statistics)

2 very common disorders in the muscular system include fibromyalgia and a torn muscle. Fibromyalgia is the inflammation of muscle tissue and fibrous connective tissue.Some symptoms include stiffness,muscle pain, and weakness in muscle sites.It can be treated with heat,massage,and medication. Fibromyalgia happens more that 3 million times in the United States every year.A torn muscle also is estimated to happen 3 million times a year in our country. A muscle strain is when a muscle is exposed to trauma (excessive use). Symptoms include pain,swelling,weakness,and limping. A strained muscle can be self treated if manageable.

The (3) types of Muscle Tissue

Muscle tissue can be broken down into 3 categories: cardiac, skeletal, and smooth. Cardiac muscle is found in the heart and in charge of pumping blood. These involuntary muscles contract to create a pacemaker and stimulate themselves to contract. Skeletal muscle are the only voluntary muscles we have and are in charge of every move we do. These muscles work with the skeletal system and are connected to 2 bones across a joint to be able to access movement.Lastly, smooth muscle is found inside organs and blood vessels.Being the weakest of all the 3 types of muscle, it has no banded appearance. They contract to flush and carry things throughout an organ.It is involuntary and cannot be controlled by the brain.

formation of cross-bridges, sliding of actin & myosin filaments & use of ATP.

The skeletal muscle contracts to allow us to move. They are arranged in opposite direction. When one contracts, one relaxes because it is nearly impossible to stimulate both at the same time so both could move.Calcium ions are released from the sarcoplasmic reticulum. A signal passing down the motor nerve of a muscle calls for a depolarization of the sarcolemma. This calls for the release of the ions to bond with myosin heads, resulting in contraction.Cross bridge is is the sticking of myosin with actin inside the cell.The myosin head bends while it pulls on the actin filament and slides toward the M line. ADP is released and out. Next, a new ATP sticks to the myosin head, the link between myosin and actin weakness, and the cross bridge detaches.When the ATP splits into ADP and inorganic phosphate, myosin is energized. The cycle rotates.