Musculature SystemMusculature System

So what do muscles do?So what do muscles do?

Muscles move cows, snakes, worms and Muscles move cows, snakes, worms and humans. Muscles move you! humans. Muscles move you!

Without muscles you couldn't open your Without muscles you couldn't open your mouth, speak, shake hands, walk, talk, or mouth, speak, shake hands, walk, talk, or move your food through your digestive move your food through your digestive system. system.

There would be no smiling, blinking, There would be no smiling, blinking, breathing. You couldn't move anything inside breathing. You couldn't move anything inside or outside you. or outside you.

Do I have lots of muscles?Do I have lots of muscles?

On average, probably 40% of your On average, probably 40% of your body weight is in muscles. body weight is in muscles.

You have over 630 muscles that You have over 630 muscles that move you. move you.

Muscles can't push. They pull. Muscles can't push. They pull. Muscles often work in pairs so that Muscles often work in pairs so that they can pull in different or opposite they can pull in different or opposite directions. directions.

How do muscles move?How do muscles move?

The cells that make up muscles contract and then The cells that make up muscles contract and then relax back to original size. relax back to original size.

Tiny microscopic fibers in these cells compress by Tiny microscopic fibers in these cells compress by sliding in past each other like a sliding glass door sliding in past each other like a sliding glass door being opened and then shut again.being opened and then shut again.

The cells of your muscles use chemical energy The cells of your muscles use chemical energy from the food you eat to do this.from the food you eat to do this.

Without food, and particular kinds of nutrients, Without food, and particular kinds of nutrients, your muscles wouldn't be able to make the your muscles wouldn't be able to make the energy to contract! energy to contract!

Some muscles are known as "voluntary" -- that is, Some muscles are known as "voluntary" -- that is, they only work when you specifically tell them to.they only work when you specifically tell them to.

Do you want to say something? Or swing a bat? Or Do you want to say something? Or swing a bat? Or clap your hands? These are voluntary movements. clap your hands? These are voluntary movements.

Others, like the muscular contracting of your heart, Others, like the muscular contracting of your heart, the movement of your diaphragm so that you can the movement of your diaphragm so that you can breathe, or blinking your eyes are automatic. breathe, or blinking your eyes are automatic. They're called involuntary movements. They're called involuntary movements.

And how do any of these muscles move? Through And how do any of these muscles move? Through signals from your nerves, and, in some cases, your signals from your nerves, and, in some cases, your brain, as well. brain, as well.

Can you hurt muscles?Can you hurt muscles?

YesYes If you hear someone say that they If you hear someone say that they

"pulled" a muscle, they have, in fact, "pulled" a muscle, they have, in fact, torn a muscle in the same way that torn a muscle in the same way that you can tear a ligament or break a you can tear a ligament or break a bone. bone.

Muscle FactsMuscle Facts

You have over 30 facial muscles which You have over 30 facial muscles which create looks like surprise, happiness, create looks like surprise, happiness, sadness, and frowning. sadness, and frowning.

Eye muscles are the busiest muscles in Eye muscles are the busiest muscles in the body. Scientists estimate they may the body. Scientists estimate they may move more than 100,000 times a day! move more than 100,000 times a day!

The largest muscle in the body is the The largest muscle in the body is the gluteus maximus muscle in the gluteus maximus muscle in the buttocks. buttocks.

3 Types of Muscles3 Types of Muscles

1. CARDIAC MUSCLE:1. CARDIAC MUSCLE: The cardiac muscles is the muscle of the brain itself. The cardiac muscles is the muscle of the brain itself. The cardiac muscle is the tissue that makes up the The cardiac muscle is the tissue that makes up the

wall of the heart called the mydocardium. Also like wall of the heart called the mydocardium. Also like the skeletal muscles, the cardiac muscle is striated the skeletal muscles, the cardiac muscle is striated and contracts through the sliding filament method.and contracts through the sliding filament method.

However it is different from other types of muscles However it is different from other types of muscles because it forms branching fibers. because it forms branching fibers.

Unlike the skeletal muscles, the cardiac muscle is Unlike the skeletal muscles, the cardiac muscle is attached together instead of been attach to a bone. attached together instead of been attach to a bone.

2. SKELETAL MUSCLE:2. SKELETAL MUSCLE:

The skeletal muscle makes up about 40 % of an adults The skeletal muscle makes up about 40 % of an adults body weight. body weight.

It has stripe-like markings, or striations. It has stripe-like markings, or striations. The skeletal muscles is composed of long muscle fibers. The skeletal muscles is composed of long muscle fibers. Each of these muscles fiber is a cell which contains Each of these muscles fiber is a cell which contains

several nuclei. several nuclei. The nervous system controls the contraction of the The nervous system controls the contraction of the

muscle. muscle. Many of the skeletal muscle contractions are automatic. Many of the skeletal muscle contractions are automatic.

However we still can control the action of the skeletal However we still can control the action of the skeletal muscle. And it is because of this reason that the muscle. And it is because of this reason that the skeletal muscle is also called voluntary muscle. skeletal muscle is also called voluntary muscle.

3. SMOOTH MUSCLE:3. SMOOTH MUSCLE:

Much of our internal organs is made up of Much of our internal organs is made up of smooth muscles.smooth muscles.

They are found in the urinary bladder, They are found in the urinary bladder, gallbladder, arteries, and veins.gallbladder, arteries, and veins.

Also the digestive tract is made up of smooth Also the digestive tract is made up of smooth muscle as well. muscle as well.

The smooth muscles are controlled by the The smooth muscles are controlled by the nervous system and hormones. We cannot nervous system and hormones. We cannot consciously control the smooth muscle that is consciously control the smooth muscle that is why they are often called involuntary muscles. why they are often called involuntary muscles.

DELTOIDDELTOID

ORIGINORIGINLateral third of clavicle, acromion, spine of Lateral third of clavicle, acromion, spine of scapula to deltoid tubercle scapula to deltoid tubercle

INSERTIONINSERTIONMiddle of lateral surface of humerus (deltoid Middle of lateral surface of humerus (deltoid tuberosity) tuberosity)

ACTIONACTIONAbducts arm, anterior fibers flex and medial Abducts arm, anterior fibers flex and medial rotate, posterior fibers extend and lateral rotate rotate, posterior fibers extend and lateral rotate NERVENERVEAxillary nerve (C5, 6) (from posterior cord) Axillary nerve (C5, 6) (from posterior cord)

TRAPEZIUSTRAPEZIUS

ORIGINORIGINMedial third superior nuchal line, ligament nuchae, Medial third superior nuchal line, ligament nuchae, spinous processes and supraspinous ligaments to spinous processes and supraspinous ligaments to T12T12

INSERTIONINSERTIONUpper fibers to lateral third of posterior border of Upper fibers to lateral third of posterior border of clavicle; lower to medial acromion and superior lip clavicle; lower to medial acromion and superior lip of spine of scapula to deltoid tubercleof spine of scapula to deltoid tubercle

ACTIONACTIONlaterally rotates, elevates and retracts scapula. If laterally rotates, elevates and retracts scapula. If scapula is fixed, extends and laterally flexes neckscapula is fixed, extends and laterally flexes neck

NERVENERVESpinal accessory nerve (C1-5)(spinal nerves C3 and Spinal accessory nerve (C1-5)(spinal nerves C3 and C4 for proprioception)C4 for proprioception)

STERNOCLEIDOMASTOIDSTERNOCLEIDOMASTOID

ORIGINORIGINAnterior and superior manubrium and superior Anterior and superior manubrium and superior medial third of claviclemedial third of clavicle

INSERTIONINSERTIONLateral aspect of mastoid process and anterior Lateral aspect of mastoid process and anterior half of superior nuchal linehalf of superior nuchal line

ACTIONACTIONFlexes and laterally rotates cervical spine. Flexes and laterally rotates cervical spine. Protracts head when acting together . Extends Protracts head when acting together . Extends neck when neck already partially extendedneck when neck already partially extended

NERVENERVESpinal accessory nerve (lateral roots C1-5)Spinal accessory nerve (lateral roots C1-5)

PECTORALIS MAJORPECTORALIS MAJOR

ORIGINORIGINClavicular head-medial half clavicle. Sternocostal head-Clavicular head-medial half clavicle. Sternocostal head-lateral manubrium and sternum, six upper costal cartilages lateral manubrium and sternum, six upper costal cartilages and external oblique aponeurosisand external oblique aponeurosis

INSERTIONINSERTIONLateral lip of bicipital groove of humerus and anterior lip of Lateral lip of bicipital groove of humerus and anterior lip of deltoid tuberositydeltoid tuberosity

ACTIONACTIONClavicular head:flexes and adducts arm. Sternal head: Clavicular head:flexes and adducts arm. Sternal head: adducts and medially rotates arm . Accessory for inspirationadducts and medially rotates arm . Accessory for inspiration

NERVENERVEMedial pectoral nerve (from medial cord) and lateral Medial pectoral nerve (from medial cord) and lateral pectoral nerve (from lateral cord) (C6, 7, 8)pectoral nerve (from lateral cord) (C6, 7, 8)

EXTERNAL ABDOMINAL EXTERNAL ABDOMINAL OBLIQUEOBLIQUE

ORIGINORIGINAnterior angles of lower eight ribs Anterior angles of lower eight ribs

INSERTIONINSERTIONOuter anterior half of iliac crest, inguinal lig, public Outer anterior half of iliac crest, inguinal lig, public tubercle and crest, and aponeurosis of anterior tubercle and crest, and aponeurosis of anterior rectus sheathrectus sheath

ACTIONACTIONSupports abdominal wall, assists forced expiration, Supports abdominal wall, assists forced expiration, aids raising intraabdominal pressure and, with aids raising intraabdominal pressure and, with muscles of opposite side, abducts and rotates trunkmuscles of opposite side, abducts and rotates trunk

NERVENERVEAnterior primary rami (T7-12) Anterior primary rami (T7-12)

GLUTEUS MAXIMUSGLUTEUS MAXIMUS

ORIGINORIGINOuter surface of ilium behind posterior gluteal line Outer surface of ilium behind posterior gluteal line and posterior third of iliac crest lumbar fascia, and posterior third of iliac crest lumbar fascia, lateral mass of sacrum, sacrotuberous ligament and lateral mass of sacrum, sacrotuberous ligament and coccyx coccyx

INSERTIONINSERTIONDeepest quarter into gluteal tuberosity of femur, Deepest quarter into gluteal tuberosity of femur, remaining three quarters into iliotibial tract remaining three quarters into iliotibial tract (anterior surface of lateral condyle of tibia)(anterior surface of lateral condyle of tibia)

ACTIONACTIONExtends and laterally rotates hip. Maintains knee Extends and laterally rotates hip. Maintains knee extended via iliotibial tractextended via iliotibial tract

NERVENERVEInferior gluteal nerve (L5, S1,2)Inferior gluteal nerve (L5, S1,2)

GLUTEUS MEDIUSGLUTEUS MEDIUS

ORIGINORIGINOuter surface of ilium between posterior and Outer surface of ilium between posterior and middle gluteal linesmiddle gluteal lines

INSERTIONINSERTIONPosterolateral surface of greater trocanter of femurPosterolateral surface of greater trocanter of femur

ACTIONACTIONAbducts and medially rotates hip. Tilts pelvis on Abducts and medially rotates hip. Tilts pelvis on walkingwalking

NERVENERVESuperior gluteal nerve (L4,5,S1) Superior gluteal nerve (L4,5,S1)

BICEPS FEMORISBICEPS FEMORIS

ORIGINORIGINLong head: upper inner quadrant of posterior surface of Long head: upper inner quadrant of posterior surface of ischial tuberosity. Short head:middle third of linea ischial tuberosity. Short head:middle third of linea aspera, lateral supracondylar ridge of femur aspera, lateral supracondylar ridge of femur INSERTIONINSERTIONStyloid process of head of fibula. lateral collateral Styloid process of head of fibula. lateral collateral ligament and lateral tibial condyle ligament and lateral tibial condyle

ACTIONACTIONFlexes and laterally rotates knee. Long head extends hipFlexes and laterally rotates knee. Long head extends hip

NERVENERVELong head: tibial portion of sciatic nerve. Short head: Long head: tibial portion of sciatic nerve. Short head: common peroneal portion of sciatic nerve (both L5, S1) common peroneal portion of sciatic nerve (both L5, S1)

PERONEUS LONGUSPERONEUS LONGUS

ORIGINORIGINUpper two thirds of lateral shaft of fibula , head of Upper two thirds of lateral shaft of fibula , head of fibula and superior tibiofibular joint fibula and superior tibiofibular joint INSERTIONINSERTIONPlantar aspect of base of 1st metatarsal and Plantar aspect of base of 1st metatarsal and medial cuneiform, passing deep to long plantar medial cuneiform, passing deep to long plantar ligamentligament

ACTIONACTIONPlantar flexes and everts foot. Supports lateral Plantar flexes and everts foot. Supports lateral longitudinal and transverse archeslongitudinal and transverse arches

NERVENERVESuperficial peroneal nerve (L5,S1)Superficial peroneal nerve (L5,S1)

TIBIALIS ANTERIORTIBIALIS ANTERIOR

ORIGINORIGINUpper half of lateral shaft of tibia and Upper half of lateral shaft of tibia and interosseous membraneinterosseous membrane

INSERTIONINSERTIONInferomedial aspect of medial cuneiform Inferomedial aspect of medial cuneiform and base of 1st metatarsaland base of 1st metatarsal

ACTIONACTIONExtends and inverts foot at ankle. Holds up Extends and inverts foot at ankle. Holds up medial longitudinal arch of footmedial longitudinal arch of foot

NERVENERVEDeep peroneal nerve (L4, 5)Deep peroneal nerve (L4, 5)

VASTUS LATERALISVASTUS LATERALIS

ORIGINORIGINUpper intertrochanteric line, base of greater Upper intertrochanteric line, base of greater trochanter, lateral linea aspera, lateral trochanter, lateral linea aspera, lateral supracondylar ridge and lateral intermuscular supracondylar ridge and lateral intermuscular septum septum

INSERTIONINSERTIONLateral quadriceps tendon to patella, via Lateral quadriceps tendon to patella, via ligamentum patellae into tubercle of tibialigamentum patellae into tubercle of tibia

ACTIONACTIONExtends kneeExtends knee

NERVENERVEPosterior division of femoral nerve (L3,4)Posterior division of femoral nerve (L3,4)

VASTUS MEDIALISVASTUS MEDIALIS

ORIGINORIGINLower intertrochanteric line, spiral line, Lower intertrochanteric line, spiral line, medial linea aspera and medial medial linea aspera and medial intermuscular septum intermuscular septum

INSERTIONINSERTIONMedial quadriceps tendon to patella and Medial quadriceps tendon to patella and directly into medial patella, via ligamentum directly into medial patella, via ligamentum patellae into tubercle of tibiapatellae into tubercle of tibia

ACTIONACTIONExtends knee. Stabilizes patellaExtends knee. Stabilizes patella

NERVENERVEPosterior division of femoral nerve (L3,4)Posterior division of femoral nerve (L3,4)

TRICEPSTRICEPS ORIGINORIGIN

Long head: infraglenoid tubercle of scapula. lateral Long head: infraglenoid tubercle of scapula. lateral head: upper half posterior humerus (linear origin). head: upper half posterior humerus (linear origin). medial head: lies deep on lower half posterior humerus medial head: lies deep on lower half posterior humerus inferomedial to spiral groove and both intermuscular inferomedial to spiral groove and both intermuscular septa septa

INSERTIONINSERTIONPosterior part of upper surface of olecranon process of Posterior part of upper surface of olecranon process of ulna and posterior capsuleulna and posterior capsule

ACTIONACTIONExtends elbow. Long head stabilizes shoulder joint. Extends elbow. Long head stabilizes shoulder joint. medial head retracts capsule of elbow joint on medial head retracts capsule of elbow joint on extensionextension

NERVENERVERadial nerve (C7, 8) (from posterior cord ), four Radial nerve (C7, 8) (from posterior cord ), four branchesbranches

LATISSIMUS DORSILATISSIMUS DORSI ORIGINORIGIN

Spine T7, spinous processes and supraspinous Spine T7, spinous processes and supraspinous ligaments of all lower thoracic, lumbar and sacral ligaments of all lower thoracic, lumbar and sacral vertebrae, lumbar fascia, posterior third iliac vertebrae, lumbar fascia, posterior third iliac crest, last four ribs (interdigitating with external crest, last four ribs (interdigitating with external oblique abdominis) and inferior angle of scapulaoblique abdominis) and inferior angle of scapula

INSERTIONINSERTIONFloor of bicipital groove of humerus after spiraling Floor of bicipital groove of humerus after spiraling around teres majoraround teres major

ACTIONACTIONExtends, adducts and medially rotates arm. Extends, adducts and medially rotates arm. Costal attachment helps with deep inspiration Costal attachment helps with deep inspiration and forced expirationand forced expiration

NERVENERVEThoracodorsal nerve (C6, 7, 8) (from posterior Thoracodorsal nerve (C6, 7, 8) (from posterior cord)cord)