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Muscular System. Notes 13-3. Muscular System has many functions:. Movement Body temperature Posture Food source. Work with skeletal system to move body contract = shorten/tighten Muscles PULL bones, never push muscle cells are called muscle fibers
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Muscular System Notes 13-3
Muscular System has many functions: • Movement • Body temperature • Posture • Food source
Work with skeletal system to move body contract = shorten/tighten Muscles PULL bones, never push muscle cells are called muscle fibers Often work in pairs/groups for one movement Function: Movement
Function: Body Temperature • HOMEOSTASIS: Muscle contraction releases heat to keep your body the right temperature • Shivers: fast muscle contractions to raise body temperature
Most muscles always hold a little bit of contraction/tension Tension = “muscle tone” Keep you standing up straight (posture) Function: Maintain Posture
Function: Food Source • Meat that you eat is muscle!
Skeletal Muscle Smooth Muscle Cardiac Muscle Skeletal = you control it (called VOLUNTARY) Smooth/Cardiac = you don’t control it (called INVOLUNTARY) Types of Muscle Tissue
Attached to your skeleton by tendons (CT) Voluntary Structure = bundles of fibers striated Examples: quadriceps, biceps, triceps, abs, etc. React quickly, tire quickly Skeletal Muscle
Skeletal muscles cross joints And work in pairs by contracting and relaxing.
Muscles at Work • Because muscle cells can only contract, not extend, skeletal muscles must work in pairs. While one muscle contracts, the other muscle in the pair relaxes to its original length.
FUN Facts! There are more than 630 muscles in the body. On average, the body weight is 40% muscle. Out of the 630 muscles, 30 of them are facial muscles, which help to create all those different faces of happiness, surprise, joy, sorrow, sadness, fright, etc. The biggest muscle in the bodyis the gluteus maximus (buttock)
Smooth Muscle • Inside organs • Involuntary (automatic movements) • Shorter fibers than skeletal muscle • React slowly, tire slowly • Example: pushes food through stomach and intestines
Cardiac Muscle • Fibers have branched shape (like tree branches) that form webs and layers • Make up the heart <3 • Striated • Involuntary • Never tire
Tendons • Attach muscles to bones • White skinny part of muscle • “Gristle”
Muscles and Exercise • Soreness DURING exercise: chemicals build-up as you use up energy (lactic acid) • Soreness AFTER exercise: tears and damage to muscle fibers • Healing and replacement of damaged cells = muscle growth • The muscle gets thicker and therefore stronger
Can Muscles get hurt? It is possible to hurt a muscle because they can become pulled, hence "pulled muscle." Can actually tear a muscle the same way that a ligament or tendon gets torn or a bone gets broke. And they can heal themselves with rest and time. Muscles can also cramp, which is when a muscle stays contracted
Skeletal muscles “mature” and strengthen as you grow up Increase coordination Babies can’t lift head (neck muscles still weak) Skeletal Muscle Development
Muscular System Video http://youtu.be/RsWNyqnHQ2I