Muscular & Skeletal Muscular & Skeletal SystemsSystems

Muscular SystemMuscular System

Muscles are the Muscles are the organsorgans that that movemove body body parts.parts.

Bones and joints Bones and joints have have nono power to power to movemove on their own. on their own.

More than More than 600600 muscles in the bodymuscles in the body

35–4035–40% of body mass% of body mass isis musclemuscle

Muscular SystemMuscular System

MuscleMuscle—organ that —organ that contractscontracts and and becomes becomes shorter shorter oror expandsexpands andand becomesbecomes longerlonger

Result = Body parts Result = Body parts movemove, , energyenergy is is used, and used, and workwork is done. is done.

MuscularMuscular System System

Two Two Groups of MusclesGroups of Muscles

1.1. VoluntaryVoluntary—You —You cancan control control these.these.Arms, legs, hands, faceArms, legs, hands, face

2. Involuntary2. Involuntary—You —You cancan’’tt control control these; you donthese; you don’’t have to decide to t have to decide to make these muscles work.make these muscles work.Muscles around the Muscles around the heartheart

MuscularMuscular System System

Three Three Types of MuscleTypes of Muscle TissueTissue

1. Skeletal 1. Skeletal MuscleMuscleMost Most numerousnumerous in body in bodyLooks Looks stripedstriped ( (striatedstriated))Attached to the Attached to the bonesbones by by tendonstendons– Tendons—thick bands that Tendons—thick bands that pullpull on on

the bone as the muscle the bone as the muscle contractscontracts

VoluntaryVoluntaryContract Contract quicklyquickly, tire , tire easilyeasily

Muscular Muscular SystemSystem

Three Three Types of MuscleTypes of Muscle Tissue Tissue (cont.)(cont.)

2. Smooth 2. Smooth MuscleMuscleInvoluntaryInvoluntary

Found in: walls of Found in: walls of stomachstomach, ,

intestineintestine, , uterusuterus, etc., etc.

Contracts and relaxes Contracts and relaxes slowlyslowly

NoNo striations striations

Muscular SystemMuscular System

Three Three Types of MuscleTypes of Muscle Tissue Tissue (cont.)(cont.)

3. Cardiac 3. Cardiac MuscleMuscleOnly found in Only found in heartheart

InvoluntaryInvoluntary

Has Has striationsstriations

Contracts Contracts 7070 times per minute times per minute ((heartbeatheartbeat))

MusclesMuscles at Work at Work

SkeletalSkeletal muscle movements are muscle movements are

results of results of pairspairs of muscles of muscles

working working togethertogether..

– One muscleOne muscle contractscontracts while while

the other musclethe other muscle relaxesrelaxes..

– Muscles alwaysMuscles always pullpull; ;

theythey never pushnever push..

Muscles at WorkMuscles at Work

Results Results of Muscle Actionof Muscle Action

– Muscles contractMuscles contract

This producesThis produces thermalthermal energy, and it uses energy, and it uses chemicalchemical energy. energy.

Thermal energy produces Thermal energy produces heatheat that helps that helps keep keep body temperaturebody temperature constant. constant.

Chemical energy is from Chemical energy is from glucoseglucose.. (When (When glucose is glucose is used upused up, muscles are , muscles are tiredtired and and need to need to restrest..))

Muscles at WorkMuscles at Work

ResultsResults of Muscle action (cont.)of Muscle action (cont.)

– Over time, muscles become Over time, muscles become largerlarger or or smallersmaller, depending on how much , depending on how much workwork they do.they do.

Skeletal SystemSkeletal System

Made up of all of the Made up of all of the bonesbones in your body, in your body, it is the it is the framework framework of the body.of the body.

– Each bone in your body Each bone in your body is a livingis a living organorgan, made , made of differentof different tissuestissues..

Cells Cells in bones take in in bones take in foodfood and use and use energyenergy..

Skeletal SystemSkeletal System

Made up of all of the bones in your Made up of all of the bones in your body, it is the framework of the body.body, it is the framework of the body.

- Five Functions of Skeletal System- Five Functions of Skeletal System1. Framework gives 1. Framework gives shapeshape & &

supportsupport to the body. to the body.

Skeletal SystemSkeletal System

Made up of all of the bones in your Made up of all of the bones in your body, it is the framework of the body.body, it is the framework of the body.

– Five Functions of Skeletal SystemFive Functions of Skeletal System1. Framework gives shape 1. Framework gives shape

and support to the body.and support to the body.

2. Bones 2. Bones protectprotect the the

internalinternal organs. organs.

SkeletalSkeletal System System

Made up of all of the bones in your Made up of all of the bones in your body, it is the framework of the body.body, it is the framework of the body.

– Five Functions of Skeletal SystemFive Functions of Skeletal System1. Framework gives shape & support to the body.1. Framework gives shape & support to the body.

2. Bones protect the internal organs.2. Bones protect the internal organs.

3. Major 3. Major musclesmuscles of the body of the body

are are attachedattached to the to the

bones.bones.

Skeletal Skeletal SystemSystem

Made up of all of the bones in your Made up of all of the bones in your body, it is the framework of the body.body, it is the framework of the body.

– Five Functions of Skeletal SystemFive Functions of Skeletal System1. Framework gives shape & support to the body.1. Framework gives shape & support to the body.2. Bones protect the internal organs.2. Bones protect the internal organs.3. Major muscles of the body are 3. Major muscles of the body are

attached to the bones.attached to the bones.

4. 4. BloodBlood cells are formed cells are formed in in red marrowred marrow of some of some bones.bones.

Skeletal SystemSkeletal System

Made up of all of the bones in your body, Made up of all of the bones in your body, it is the framework of the body.it is the framework of the body.

– Five Five Functions of Skeletal SystemFunctions of Skeletal System1. Framework gives shape & support to the body.1. Framework gives shape & support to the body.2. Bones protect the internal organs.2. Bones protect the internal organs.3. Major muscles of the body are 3. Major muscles of the body are

attached to the bones.attached to the bones.4. Blood cells are formed in red 4. Blood cells are formed in red

marrow of some bones.marrow of some bones.

5. Skeleton is a place where 5. Skeleton is a place where major quantities of major quantities of calciumcalcium and and phosphorusphosphorus compounds compounds are are storedstored..

BonesBones

TheThe adultadult skeleton has skeleton has 206206 bones bones ((babybaby has has 270270).).

JointsJoints

Any place where Any place where twotwo or more bones or more bones meetmeet

LigamentsLigaments: tough : tough

bands of bands of tissuetissue that that

hold hold bones togetherbones together

at the jointsat the joints