Muscular System. Functions of the Muscular System Allows movement Maintains posture Stabilizes joints Gives the body shape Generates heat.

Muscular System

Muscular System

Functions of the Muscular SystemAllows movementMaintains postureStabilizes jointsGives the body shapeGenerates heat

2 Categories of MusclesVoluntary MusclesInvoluntary MusclesMuscles you can controlExamples: muscles in your arms and legsMuscles you cannot controlExamples: heart, stomach, diaphragm

3 Types of Muscle: SkeletalSkeletal: muscles that move bonesStriated (striped)VoluntaryTires easilyFound in bundles

3 Types of Muscle: SmoothSmooth: muscles that control internal organsNo striationsInvoluntaryMakes up internal organs (stomach, intestines)Does not tire

3 Types of Muscle: CardiacCardiac: muscle that makes up the heartStriated (striped)InvoluntaryDoes not tire

RememberWhat are ligaments?Strong bands of tissue that connect bones to each other at a joint

TendonsStrong bands of tissue that attach a muscle to a bone

Muscular InjuriesSprain: ligaments stretched or tornStrain: muscles stretched or tornCramp: a muscle involuntarily contracted that will not relax

Fun Fact!Sartorius: longest muscle in the human body

How skeletal muscles workMuscles only contractThey pull, they dont pushSkeletal muscles work in pairsExample in the arm:When the biceps contracts, the triceps relaxesWhen the triceps contracts, the biceps relaxes

EnergyMuscles use energy to moveWhen muscles run out of energy = muscle fatigueWhen true fatigue hits, a muscle cannot be contracted even when stimulatedhttps://youtu.be/LKhkvSRQZYo

2 Types of ExerciseAerobic Exercise (air exercise)Jogging, biking, swimmingMakes muscles stronger, more flexible, and more resistant to fatigueIncreases metabolismEnlarges heartLungs become more efficientDOES NOT increase muscle mass much

2 Types of ExerciseAnaerobic Exercise (no air exercise)WeightliftingIncreases muscle massDoes not increase endurance

Muscle BasicsMyofibril: a muscle cellSarcomere: a tiny contractile unit of a muscleA myofibril is made of many, many sarcomeres

Muscle BasicsOne sarcomere is made of interlocking actin and myosin