Muscular systemMuscular system

ObjectivesObjectives

To identify the types of musclesTo identify the types of muscles Understand terms related to musclesUnderstand terms related to muscles To know how are the muscles namedTo know how are the muscles named

Types of the muscleTypes of the muscle

Skeletal:striated, and voluntary.Skeletal:striated, and voluntary. Smooth:nonstiated, and involuntary.Smooth:nonstiated, and involuntary. Cardiac:striated, and involuntary.Cardiac:striated, and involuntary.

Are effectors which enable movement Are effectors which enable movement to be carried outto be carried out

MusclesMuscles

Types of connective tissues Types of connective tissues wrappings of skeletal musclewrappings of skeletal muscle

EndomysiumEndomysium : a delicate connective tissue : a delicate connective tissue sheath surrounds muscle fibre.sheath surrounds muscle fibre.

PerimysiumPerimysium : a coarser fibrous membrane : a coarser fibrous membrane surrounds several sheathed muscle fibers to surrounds several sheathed muscle fibers to form bundle of fibers called a fascicle.form bundle of fibers called a fascicle.

EpimysiumEpimysium : a tougher overcoat of : a tougher overcoat of connective tissue surrounds many fascicles.connective tissue surrounds many fascicles.

The epimysia blend into the strong, cord- The epimysia blend into the strong, cord- like tendons, or into sheet-like like tendons, or into sheet-like aponeurosisaponeurosis..

FunctionFunction: :

1-Attaching the muscle to bone….1-Attaching the muscle to bone….

2-Providing durability 2-Providing durability

3-Conserving space 3-Conserving space

Muscles & the SkeletonMuscles & the Skeleton

Skeletal muscles cause the skeleton to move Skeletal muscles cause the skeleton to move at jointsat joints

They are attached to skeleton by tendons.They are attached to skeleton by tendons. Tendons Tendons transmittransmit muscle force to the bone. muscle force to the bone. Tendons are made of collagen fibres & are Tendons are made of collagen fibres & are

very strong & stiffvery strong & stiff

Muscle functionMuscle function

Providing movementProviding movement Maintaining postureMaintaining posture Stabilizing joint Stabilizing joint Generating heatGenerating heat

Skeletal MuscleSkeletal Muscle Functions of Skeletal Functions of Skeletal

MuscleMuscle– Produce MovementProduce Movement– Maintain postureMaintain posture– Stabilize jointsStabilize joints– Generate HeatGenerate Heat

Sites of Muscle Sites of Muscle AttachmentAttachment– BonesBones– CartilageCartilage– Connective tissue Connective tissue

coveringscoverings

Muscle Fibers blend into a Muscle Fibers blend into a connective tissue attachmentconnective tissue attachment– Tendon—cordlike structureTendon—cordlike structure– Aponeurosis—sheet-like Aponeurosis—sheet-like

structurestructure Properties of MuscleProperties of Muscle

– Irritability – ability to Irritability – ability to receive and respond to a receive and respond to a stimulusstimulus

– Contractibility – ability to Contractibility – ability to shorten when an adequate shorten when an adequate stimulus is receivedstimulus is received

– Extensibility – ability to Extensibility – ability to lengthen when an adequate lengthen when an adequate stimulus is receivedstimulus is received

– Elasticity – ability to return Elasticity – ability to return to normal shapeto normal shape

Muscles:Muscles:

Are responsible for almost all the movements Are responsible for almost all the movements in animalsin animals

OriginOrigin : is the point where the muscle is : is the point where the muscle is attached to immovable or less movable attached to immovable or less movable bone.bone.

InsertionInsertion : is the point where the muscle : is the point where the muscle attached to movable bone.attached to movable bone.

Prime mover Prime mover : the muscle that has the major : the muscle that has the major responsibility for causing a movement.responsibility for causing a movement.

AntagonistAntagonist : the muscle that reverse a : the muscle that reverse a movement.movement.

Antagonistic Muscle ActionAntagonistic Muscle Action

Muscles are either contracted or relaxedMuscles are either contracted or relaxed When contracted the muscle exerts a When contracted the muscle exerts a

pulling force, causing it to shortenpulling force, causing it to shorten Since muscles can only pull (not push), they Since muscles can only pull (not push), they

work in pairs called work in pairs called antagonistic musclesantagonistic muscles The muscle that bends the joint is called the The muscle that bends the joint is called the

flexorflexor musclemuscle The muscle that straightens the joint is The muscle that straightens the joint is

called the called the extensorextensor muscle muscle

Elbow JointElbow Joint The best known example of antagonistic The best known example of antagonistic

muscles are the biceps & triceps musclesmuscles are the biceps & triceps musclesElbow joint flexed

Flexor m uscles contractedExtensor muscles re laxed

Elbow joint extendedExtensor muscles contracted

Flexor m uscles relaxed

biceps

triceps

Section through arm

Flexorm uscles

Extensor m uscles

Hum erusBone

Naming Skeletal musclesNaming Skeletal muscles DirectionDirection of the muscle fibers: Orbicularis of the muscle fibers: Orbicularis

oris, Occuli oris, Occuli Relative Relative sizesize of the muscle: Gluteus of the muscle: Gluteus

maximus, medius, minimus…Major, minor.maximus, medius, minimus…Major, minor. LocationLocation of the muscle:Obturator internus of the muscle:Obturator internus NumberNumber of the origin:Biceps, Triceps of the origin:Biceps, Triceps Location of the muscle’s Location of the muscle’s originorigin and and

insertioninsertion: Occipitofrontalis: Occipitofrontalis ShapeShape of the muscle:Deltoidof the muscle:Deltoid ActionAction of the muscle:Pronator Quadratus of the muscle:Pronator Quadratus

Types of body movementsTypes of body movements

Flexion&extensionFlexion&extension

in sagittal planein sagittal plane

angle of the jointangle of the joint

RotationRotation

It is the movement of a bone around its It is the movement of a bone around its long axislong axis

atlas around the dens of axisatlas around the dens of axis

Abduction &adductionAbduction &adduction

moving the limb away or toward the moving the limb away or toward the midline of the bodymidline of the body

Circumduction is a combination ofCircumduction is a combination of

flexion,extension,abduction and adductionflexion,extension,abduction and adduction

Special movementSpecial movement

Dosiflexion&planter flexionDosiflexion&planter flexion Inversion and evasionInversion and evasion Supination and pronation Supination and pronation oppositionopposition

Head musclesHead muscles

Facial MusclesFacial Muscles (Frontalis, Orbicularis oculi (Frontalis, Orbicularis oculi Orbicularis oris, Buccinator,Zygomaticus) .Orbicularis oris, Buccinator,Zygomaticus) .

Chewing MuscleChewing Muscle (Buccinator,Masseter, (Buccinator,Masseter, Temporalis).Temporalis).

Facial musclesFacial muscles

FrontalisFrontalis : It covers the frontal bone: It covers the frontal bone It raise the eyebrowsIt raise the eyebrows It wrinkle the foreheadIt wrinkle the forehead

Orbicularis oculi Orbicularis oculi : It has fibres that run in : It has fibres that run in circles around the eyes.circles around the eyes.

It closes the eyes, squint, blink.It closes the eyes, squint, blink.

Orbicularis oris Orbicularis oris : it is a circular muscle of : it is a circular muscle of the lips.the lips.

It closes the mouth It closes the mouth It protrude the lipsIt protrude the lips

BuccinatorBuccinator : it runs horizontally across the : it runs horizontally across the cheek and inserts into orbicularis oris.cheek and inserts into orbicularis oris.

It flatten the cheek. It flatten the cheek.

ZygomaticusZygomaticus It extends from the corner of the mouth to It extends from the corner of the mouth to

the cheekbone.the cheekbone.

Chewing Muscle Chewing Muscle

BuccinatorBuccinator Masseter : it covers the angle of lower jawMasseter : it covers the angle of lower jaw It closes the jaw by elevating the mandibleIt closes the jaw by elevating the mandible Temporalis : it is a fan shaped muscle overlying Temporalis : it is a fan shaped muscle overlying

temporal bone temporal bone It is synergist of the masseter in closing the jaw.It is synergist of the masseter in closing the jaw.

Neck musclesNeck muscles

Sternocleidomastoid : it is a paired muscles Sternocleidomastoid : it is a paired muscles with two headed muscles, one from each with two headed muscles, one from each side of the neck.side of the neck.

platysmaplatysma

Trunk musclesTrunk muscles

Anterior musclesAnterior muscles Muscles of the abdominal wallMuscles of the abdominal wall Posterior muscles (Post. Antigravity Posterior muscles (Post. Antigravity

muscles)muscles)

Anterior muscles : Anterior muscles :

Pectoralis major : a large fan shaped Pectoralis major : a large fan shaped muscle covering the upper part of the chest. muscle covering the upper part of the chest. It adduct and flex the arm. It forms the It adduct and flex the arm. It forms the anterior wall of the axillaanterior wall of the axilla

Intercostal musclesIntercostal muscles

Muscles of the abdominal wall : Muscles of the abdominal wall : Rectus abdominisRectus abdominis External oblique External oblique Internal obliqueInternal oblique Transversus abdominisTransversus abdominis

Posterior muscles : Posterior muscles :

Trapezius Trapezius : It is the most superficial muscles : It is the most superficial muscles of posterior neck and upper trunk.of posterior neck and upper trunk.

Diamond –shaped.Diamond –shaped.

Extend the head &antagonist Extend the head &antagonist sternocleidomastoid.sternocleidomastoid.

Also,it can elevate, depress, adduct , and Also,it can elevate, depress, adduct , and stabilize the scapula.stabilize the scapula.

Latissmus DorsiLatissmus Dorsi

Large, flat muscle pair that cover the lower back.Large, flat muscle pair that cover the lower back.

Extends and adducts the humerus.Extends and adducts the humerus.

Erector spinaeErector spinae

Prime mover of back extentionPrime mover of back extention

Paired musclesPaired muscles

Deep muscles of the back.Deep muscles of the back.

Spasm of these muscles lead to lower back pain.Spasm of these muscles lead to lower back pain.

DeltoidDeltoid

Fleshy, triangle-shaped musclesFleshy, triangle-shaped muscles

Favorite injectionFavorite injection

Prime movers of arm abduction. Prime movers of arm abduction.

Muscle of the upper limbMuscle of the upper limb

The first group include muscles that arise The first group include muscles that arise from the shoulder girdle and cross the from the shoulder girdle and cross the shoulder joint to insert into the humerus shoulder joint to insert into the humerus (pectoralis major, latissimus dorsi, and (pectoralis major, latissimus dorsi, and deltoid).deltoid).

The second group causes movement at the The second group causes movement at the elbow joint (Biceps elbow joint (Biceps brachii,brachialis,brachioradialis, and brachii,brachialis,brachioradialis, and triceps brachii)triceps brachii)

The third group causes movement at the The third group causes movement at the wrist joint (flexor carpi and flexor wrist joint (flexor carpi and flexor digitorum)digitorum)

(extensor carpi and extensor digitorum) (extensor carpi and extensor digitorum)

Muscles of lower limbMuscles of lower limb

Muscles causing movement at the hip jointMuscles causing movement at the hip joint Muscles causing movement at the knee Muscles causing movement at the knee

jointjoint Muscles causing movement at the ankle and Muscles causing movement at the ankle and

foot jointfoot joint

Muscles causing movement at the hip joint Muscles causing movement at the hip joint (gluteus maximus,gluteus (gluteus maximus,gluteus medius,illiopsoas ,adductor muscles)medius,illiopsoas ,adductor muscles)

Muscles causing movement at the knee Muscles causing movement at the knee joint (hamstring group,sartorius ,quadriceps joint (hamstring group,sartorius ,quadriceps group)group)

Muscles causing movement at the ankle and Muscles causing movement at the ankle and foot joint (tibialis anterior,extensor foot joint (tibialis anterior,extensor digitorum longus,fibularis digitorum longus,fibularis muscles,gastrocnemius,soles)muscles,gastrocnemius,soles)