Lecture 3 The Musles/student copy

Have you ever tried to be perfectly still for just 1 minute? You can't do it no matter how you try. Somewhere in your body muscles are always working. Your heart, a muscle, keeps beating pushing blood through the various blood vessels. The muscles in your intestines keeps pushing food your intestines. Muscles are helping you breathe. Muscles hold you upright in a chair. If all your muscles rested at the same time, you would collapse. Your muscles are made up of ______ tissue and ____________ tissue. Muscles that attach to bones and the connective 'tis that attaches them make up the __________________.

Types of Muscle
There are three types of muscle tissue that make up the muscles in your body. _______________ is found in the digestive tract and the blood vessels. Its job is to move blood through the blood vessels and food through the digestive system. _________________ is a special type of muscle found only in your heart. Cardiac muscle causes the heart to beat. ___________________ are attached to your bones for movement, and they help protect your internal organs.

Making Your Move

Skeletal muscles produce hundreds of different voluntary movements. Whether you are making a funny face, running, chewing your food or lifting your hand, you are telling your muscles to move. To make this movement, you cause electrical signals to travel from the brain to the skeletal muscle cells. The muscle cells receiving the signal respond by contracting or getting shorter.

Muscles to Bones
Strands of tough connective tissue called ________ connect your skeletal muscles to your bones. When a muscle gets shorter, a pulling action occurs, bringing the bones closer together.

Working in Pairs
Your skeletal muscles work in pairs to cause smooth, controlled movements. Many basic movements are the result of muscle pairs that cause bending and straightening. If a muscle bends part of your body, then that muscle is called a _______. If the muscle straightens part of your body, than it is called an __________. The flexor muscle in your arm is the biceps. The extensor muscle of the arm is the triceps. In the image below the bicep is contracted and the tricep is relaxed.

Use It or Lose It
When someone breaks an arm and has to wear a cast, the muscles surrounding the injured bone change. That's because these muscles are not exercised, and they become smaller and weaker. On the other hand, exercised muscles are stronger and larger. Certain exercises can give muscles more endurance. This means they're able to work longer without getting tired. Strong muscles benefit other systems in your body too. When a muscle contracts, blood vessels in that muscle get squeezed. . This helps push blood along, increasing blood flow without demanding more work from your heart.

Resistance Exercises

____________________ are the most effective form of exercise, to develop the size and strength of your skeletal muscles. Resistance exercises require muscles to overcome the resistance (weight) of another object.

Aerobic Exercise

Steady, moderate-intensity activity, such as jogging, cycling, skating, swimming laps, or walking, is called aerobic exercise. ____________________ increases the size and strength of your skeletal muscles somewhat, but mostly it strengthens the heart while increasing the endurance of your skeletal muscles.