JH-KEADLE The Muscular System

Procedure Flex your right arm and wrap your left hand around your bicep and triceps muscles.

Procedure Bend and straighten your arm several times and feel the two main muscles working under your skin.

Procedure Working in pairs, help each other to measure your bicep length while it is relaxed (straightened). Use centimeters.

Procedure Working in pairs, help each other to measure your bicep length while it is contracted (flexed). Use centimeters.

Procedure Working in pairs, help each other to measure your triceps length while it is relaxed (bent). Use centimeters.

Procedure Working in pairs, help each other to measure your triceps length while it is contracted (straight). Use centimeters.

Procedure Now measure the circumference of your upper arm while bent and straight. Use centimeters.

How did the biceps and triceps change as you bent and straightened your arm? When the arm was extended, the biceps would relax (lengthen) and the triceps would contract (shorten). The reverse happen when the arm is bent.

Muscles are the motors that move body parts Bones and joints cannot move on their own There are approximately 600 muscles in your body 35 – 40% of body mass is muscle

Functions of the Muscular System pumps blood through your body. moves food through your digestive system allows you to breathe. allows you to move.

muscle vocabulary word! muscle – the tissue that contracts and relaxes, making movement possible.

voluntary muscles voluntary muscles - muscles under conscious control vocabulary word! voluntary muscles - muscles under conscious control smiling, walking, running, typing etc…

involuntary muscles vocabulary word! involuntary muscles - muscles not under conscious control You don’t have to think about them breathing, digesting, sneezing, heart beating

organs of the muscular system smooth muscle cardiac muscle skeletal muscle tendons

smooth muscle smooth muscle – involuntary muscle found in internal organs and blood vessels and helps move things around the body. blood vessels digestive system

smooth muscle

cardiac muscle cardiac muscle – involuntary muscle that makes up the heart. Cardiac muscle cells have a lot of mitochondria and do not tire.

cardiac muscle

skeletal muscle skeletal muscle – voluntary muscle that is attached to bones and helps you move. Skeletal muscle can become tired. They work in pairs.

skeletal muscle

tendon vocabulary word! tendon – tough strand of tissues that connects a muscle to a bone.

muscles at work Skeletal muscle movements are results of pairs of muscles working together. One muscle contracts while the other muscle relaxes. Muscles always pull; they never push. http://commons.wikimedia.org/wiki/File:Bicep_tricep.gif

muscles at work http://commons.wikimedia.org/wiki/File:Bicep_tricep.gif

muscles at work Results of Muscle Action Muscles contract This produces thermal energy, and it uses chemical energy. Thermal energy produces heat that helps keep body temperature constant. Chemical energy is from glucose. (When glucose is used up, muscles are tired and need to rest.)