Muscular System Part 2

•An Overview of the Major Skeletal Muscles

Figure 7-11(a)

•An Overview of the Major Skeletal Muscles

Figure 7-11(b)

Muscles of the head and neck

• Muscles of the Head and Neck

Figure 7-12(a)

•Muscles of the Head and Neck

Figure 7-12(b)

• Muscles of the Head and Neck

Figure 7-12(c)

Head & Neck Muscles

• Frontalis: elevate eyebrows

• Orbicularis Oculi: close eyelid

• Zygomaticus: draw angle of lip upward

• Buccinator: draws cheeks against teeth

• Orbicularis Oris: closes mouth

• Platysma: draws lower lip down & back

• Cranial Aponeurosis: connects frontalis to occipitalis

• Temporalis: elevates mandible

• Occipitalis: draws scalp back

• Masseter: elevates mandible

• Sternocleidomastoid:– Flexes head– Draws head toward

shoulder

Muscles of Mastication

• Masseter: elevates mandible

• Temporalis: elevates mandible

• Medial pterygoid: elevates mandible

• Lateral pterygoid: depresses mandible

Key Muscles of Facial Expression

• Smiling Muscles– Orbicularis Oculi– Nasalis– Levator Labii

Superioris– Levator Anguli

Superioris– Zygomaticus– Risorius

• Frowning Muscles– Frontalis– Orbicularis Oris– Depressor Anguli Oris– Depressor Labii

Inferioris– Mentalis– Platysma

• Muscles of the Anterior Neck

Figure 7-13

Muscles of the Axial Skeleton

Muscles of the Axial Skeleton

• Intrinsic Muscles– Erector Spinae:

maintain posture of back/extension

• Spinalis• Longissimus• Iliocostalis

– Oblique Muscles: rotation of the vertebrae

• Semispinalis• Multifidus• Rotatores

• Muscles of Quiet Respiration– Diaphragm– External Intercostals– Internal Intercostals—deep

breaths• Abdominal Muscles

– External Obliques– Internal Obliques– Transverse Abdominus– Rectus Abdominus

• Quadratus Lumborum

•Muscles of the Spine

Figure 7-14

Figure 7-15(a)

•Oblique and Rectus Muscles and the Diaphragm

•Oblique and Rectus Muscles and the Diaphragm

Figure 7-15(b)

•Oblique and Rectus Muscles and the Diaphragm

Figure 7-15(c)

• Muscles of the Shoulder

Figure 7-17(a)

• Muscles of the Shoulder

Figure 7-17(b)

Muscles of Scapular Stabilization

• Trapezius:– Retraction– Elevation– Depression – Upward Rotation

• Rhomboid—retraction

• Levator Scapular—Elevation

• Pectoralis Major—Protraction

• Serratus Anterior—Protraction

Upper Limbs

• Muscles that Move the Arm

Figure 7-18(a)

• Muscles that Move the Arm

Figure 7-18(b)

Anterior Muscles of Shoulder

• Deltoid– Flexion /Extension – Abduction /Adduction– Internal /External Rotation

• Pectoralis Major– Adduction– Flexion– Extension– Internal Rotation

• Biceps Brachii—Flexion

Posterior Muscles of Shoulder

• Teres Major– Adduction– Extension– Internal Rotation

• Latissimus Dorsi– Adduction– Extension– Internal Rotation

• Triceps Brachii– Adduction– Extension

Rotator Cuff Muscles (SITS)

• Supraspinatus– Abduction

• Infraspinatus– External Rotation

Teres Minor External Rotation

Subscapularis Internal Rotation

• Muscles That Move the Forearm and Wrist

Figure 7-19

Muscles of the Elbow/Forearm

• Triceps Brachii—Extension

• Bicep Brachii—– Flexion– Supination

• Brachialis—Flexion• Brachioradialis—

– Flexion– Pronation

• Pronator Teres• Pronator Quadratus• Supinator Longus

Muscles of the Wrist & Hand

• Flexor Carpi Ulnaris• Flexor Carpi

Radialis• Flexor Digitorum• Extensor Carpi

Ulnaris• Extensor Carpi

Radialis• Extensor Digitorum

Anterior (Palmar) View Posterior (Dorsal) View

Lower Extremity Muscles

• Muscles That Move the Thigh

Figure 7-20(a)

Muscles of Hip: Gluteal Muscles

• Gluteus Maximus—Extension

• Gluteus Medius—Abduction

• Gluteus Minimus—Abduction

• Tensor Fasciae Latae—– Flexion– Abduction

** Gluteus Minimus is under the Gluteus Medius

•Muscles That Move the Thigh

Figure 7-20(b)

Muscles of Hip:Anterior Muscles

• Medial/Adductor Muscles:– Adductor Magnus– Adductor Longus– Adductor Brevis– Gracilis

• Anterior Muscles– Iliopsoas—Flexion– Pectineus—

• Flexion• Adduction

– Sartorius—• Flexion• Lateral Rotation

Figure 7-21

• Muscles That Move the Leg

Muscles of Anterior Thigh

• “Quadriceps”– Rectus Femoris—

• Hip flexion• Knee extension

– Vastus Lateralis—knee extension

– Vastus Medialis—knee extension

– Vastus Intermedius—knee extension

– Sartorius—• Hip & Knee Flexion• Lateral Hip Rotation

**Vastus Intermedius is beneath Rectus Femoris

Muscles of Posterior Thigh

• “Hamstrings”– Responsible for

Knee Flexion & Hip Extension

– Semimembranosus– Semitendinosus– Biceps Femoris

• Gastrocnemius– Knee Flexion

• Muscles That Move the Foot and Toes

Figure 7-22(a)

Figure 7-22(b)

•Muscles That Move the Foot and Toes

Muscles of the Lower Leg

• Anterior Compartment– Tibialis Anterior—Dorsiflexion &

inversion– Extensor Digitorum Longus– Fibularis Tertius—dorsiflexion &

eversion• Posterior Compartment

– Gastrocnemius—plantarflexion, knee flexion

– Soleus—plantarflexion• Lateral Compartment

– Fibularis Longus—plantarflexion & eversion

– Fibularis Brevis—plantarflexion & eversion

Figure 7-22(c)

•Muscles That Move the Foot and Toes

Figure 7-22(d)

•Muscles That Move the Foot and Toes

Location of Muscles

• SkeletalMuscles– Anterior

view

Quadriceps Quadriceps groupgroup

Rectus abdominisRectus abdominis

Quadriceps GroupQuadriceps Group

External ObliquesExternal Obliques

FrontalisFrontalis

MasseterMasseter

Tibialis AnteriorTibialis Anterior

DeltoidDeltoidPectoralis MajorPectoralis Majorbiceps brachiibiceps brachii

BrachioradialisBrachioradialis

Locationof Muscles

• SkeletalMuscles– Posterior

view

Hamstring group

TrapeziusTrapezius

Hamstring Hamstring groupgroup

GastrocnemiusGastrocnemius

Latissimus dorsiLatissimus dorsi

Gluteus Gluteus maximusmaximus

Triceps brachiiTriceps brachii

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Muscles You Need to Know• 1. brachioradialis• 2. biceps brachii• 3. deltoid• 4. external oblique• 5. frontalis• 6. gastrocnemius• 7. gluteus maximus• 8. hamstring group• 9. latissimus dorsi• 10. masseter• 11. pectoralis major• 12. quadriceps group• 13. rectus abdominis• 14. tibialis anterior• 15. trapezius• 16. triceps brachii

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Disease Conditions in Muscles

Muscle Disorders

• A sprain is a wrenching, twisting or stretching injury to a ligament.

Sprains often affect theankles, knees, or wrists.

SprainSprain

Muscle Disorders

• A strain is an injury to a muscle or tendon, and is often caused by overuse, force, or stretching.

StrainStrain

Muscle Disorders

• A muscle tear may be partial or complete and caused either by a direct blow or by overexertion.

Muscle RupturesMuscle Ruptures

Muscle Disorders

• Muscle pull- very slight tear

• Chronic tear- gradual onset of pain

• Acute tear- sudden dramatic pain

Muscle PullMuscle Pull Muscle TearMuscle Tear

Muscle Muscle TearsTears

Muscle Disorders

• Muscle spasm- when A muscle (or even a few fibers of a muscle) involuntarily contract

• Muscle cramp- involuntarily + forcibly contracted muscle that does not relax

CrampsCrampsSpasmsSpasms

Muscle Disorders

Caused by bacteria that enters the body through the skin

• Found in soil, dust and manure • Toxin bacteria produces interferes with nerve

transmission to your muscles and causes them to seize up in painful spasms.

TetanusTetanus

Muscle Disorders

• Produced naturally by the body to support such functions as fighting stress and promoting growth and development

• Referred to as roids, juice, hype, weight trainers, gym candy, arnolds, stackers, or pumpers

• People use steroid pills, gels, creams, or injections to improve their sports performance or the way they look.  

• Anabolic steroids cause many different types of problems

Anabolic SteroidsAnabolic Steroids

Muscle Disorders

• Cerebral palsy is a group of disorders that affect a person's ability to move and to maintain balance and posture.

• The disorders appear in thefirst few years of life, and usually don’t get worse over time.

Cerebral PalseyCerebral Palsey

Muscle Disorders

• Muscular Dystrophy- most well known of hereditary diseases

• A genetic condition that describes over 20 genetic and hereditary muscle diseases.

Muscular DystrophyMuscular Dystrophy

Muscle Disorders

• Myasthenia gravis- chronic autoimmune neuromuscular disease characterized by varying degrees of weakness of the skeletal muscles

Myasthenia GravisMyasthenia Gravis

Muscle Disorders• Poliomyelitis, often

called polio is an acuteviral infectious disease which is spread fromperson-to-person via the fecal-oral route.

PolioPolio

Old PolioAsymmetric atrophy & weaknessAtrophic right leg (arrow) in patient with paralytic polio 70 years in past

Umbilical hernia

Epigastric hernia

Animations…

• Muscles – Descriptions– http://www.innerbody.com/image/musfov.html

• Muscles – Locations and Actions– http://www.getbodysmart.com/ap/muscularsys

tem/menu/menu.html