The Muscular System Skeletal Muscular Systems 14 min

The Muscular System Skeletal & Muscular Systems (14 min)

Your Muscular Body • Your skeletal system provides shape, support, protection and allows movement but CANNOT actually move without the muscular system. – Your muscles are responsible for every move you make. • Blinking, breathing, running and lifting. • Muscle make up about 40% of your body mass. • More than 600 muscles make up the muscular system.

Muscle Categories & Types • Two Categories of Muscles: 1. Involuntary muscles • Not under our conscious control – breathing, heart beating, digestion 2. Voluntary muscles • Under our conscious control – smiling, bending or standing • Muscle is made up of muscle tissue. – Three kinds: 1. 2. 3. Skeletal Smooth Cardiac

Muscle Types 1. Skeletal Muscle (Striated) A. Attached to the bones of your skeleton by tendons used for movement. i. Pulls on bones to make the body move. ii. Voluntary – you control them. – Biceps, triceps, and quadriceps.

Skeletal Muscle Fibers Nucleus Striations

Muscle Types 2. Smooth Muscle A. Located in the internal organs of the body: i. Stomach, intestines, kidney, and liver. a. b. Movement of food through the digestive system Movement of blood through blood vessels ii. Involuntary – you don’t control them.

Smooth Muscle Fiber Nucleus

Muscle Types 3. Cardiac Muscle A. Found ONLY in the heart! B. Has characteristics in common with both smooth and skeletal muscle: i. Like smooth, it’s involuntary – no control ii. Like skeletal, it’s striated

Cardiac Muscle Nucleus Cardiac Muscle Fibers Striations

Muscles and Movement • Skeletal muscles are held to bone by tendons. – Tendons allow the muscles to pull on the bones and move the body - contraction. • This causes the muscle to get thicker and shorter. • Because muscles can ONLY contract they must work in pairs to complete an opposite movement, relax. Simulation – bicep/tricep

Biceps/Triceps Muscles Hinge Joint