Download Muscles and Body Movements

Chapter 6
The Muscular System
Lecture Presentation by
Patty Bostwick-Taylor
Florence-Darlington Technical College
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Muscles and Body Movements
 Movement is attained as a result of a muscle
moving an attached bone
 Muscles are attached to at least two points
1. Origin: attachment to a moveable bone
2. Insertion: attachment to an immovable bone
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Figure 6.12 Muscle attachments (origin and insertion).
Muscle
contracting
Origin
Brachialis
Tendon
Insertion
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Types of Body Movements
 Flexion
 Decreases the angle of the joint
 Brings two bones closer together
 Typical of bending hinge joints (e.g., knee and
elbow) or ball-and-socket joints (e.g., the hip)
 Extension
 Opposite of flexion
 Increases angle between two bones
 Typical of straightening the elbow or knee
 Extension beyond 180° is hyperextension
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Figure 6.13a Body movements.
Flexion
Hyperextension
Extension
Flexion
Extension
(a) Flexion, extension, and hyperextension of the shoulder and knee
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Figure 6.13b Body movements.
Hyperextension
Extension
Flexion
(b) Flexion, extension,
and hyperextension
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Types of Body Movements
 Rotation
 Movement of a bone around its longitudinal axis
 Common in ball-and-socket joints
 Example: moving the atlas around the dens of axis
(i.e., shaking your head “no”)
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Figure 6.13c Body movements.
Rotation
Lateral
rotation
Medial
rotation
(c) Rotation
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Types of Body Movements
 Abduction
 Movement of a limb away from the midline
 Adduction
 Opposite of abduction
 Movement of a limb toward the midline
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Figure 6.13d Body movements.
Abduction
Adduction
Circumduction
(d) Abduction, adduction,
and circumduction
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Types of Body Movements
 Circumduction
 Combination of flexion, extension, abduction, and
adduction
 Common in ball-and-socket joints
 Proximal end of bone is stationary, and distal end
moves in a circle
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Figure 6.13d Body movements.
Abduction
Adduction
Circumduction
(d) Abduction, adduction,
and circumduction
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Special Movements
 Dorsiflexion
 Lifting the foot so that the superior surface
approaches the shin (toward the dorsum)
 Plantar flexion
 Depressing the foot (pointing the toes)
 “Planting” the foot toward the sole
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Figure 6.13e Body movements.
Dorsiflexion
Plantar flexion
(e) Dorsiflexion and plantar flexion
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Special Movements
 Inversion
 Turning sole of foot medially
 Eversion
 Turning sole of foot laterally
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Figure 6.13f Body movements.
Inversion
(f) Inversion and eversion
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Eversion
Special Movements
 Supination
 Forearm rotates laterally so palm faces anteriorly
 Radius and ulna are parallel
 Pronation
 Forearm rotates medially so palm faces posteriorly
 Radius and ulna cross each other like an X
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Figure 6.13g Body movements.
Pronation
(radius rotates
over ulna)
Supination
(radius and ulna
are parallel)
S P
(g) Supination (S) and pronation (P)
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Special Movements
 Opposition
 Moving the thumb to touch the tips of other fingers
on the same hand
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Figure 6.13h Body movements.
Opposition
(h) Opposition
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Types of Muscles
 Prime mover—muscle with the major responsibility
for a certain movement
 Antagonist—muscle that opposes or reverses a
prime mover
 Synergist—muscle that aids a prime mover in a
movement and helps prevent rotation
 Fixator—stabilizes the origin of a prime mover
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Naming Skeletal Muscles
 By direction of muscle fibers
 Example: rectus (straight)
 By relative size of the muscle
 Example: maximus (largest)
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Naming Skeletal Muscles
 By location of the muscle
 Example: temporalis (temporal bone)
 By number of origins
 Example: triceps (three heads)
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Naming Skeletal Muscles
 By location of the muscle’s origin and insertion
 Example: sterno (on the sternum)
 By shape of the muscle
 Example: deltoid (triangular)
 By action of the muscle
 Example: flexor and extensor (flexes or extends a
bone)
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Figure 6.15 Relationship of fascicle arrangement to muscle structure.
(a)
(b)
(a) Circular
(orbicularis oris)
(e)
(c)
(b) Converent
(pectoralis major)
(d)
(e) Multipennate
(deltoid)
(f)
(g)
(c) Fusiform
(biceps brachii)
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(d) Parallel
(sartorius)
(f) Bipennate
(rectus
femoris)
(g) Unipennate
(extensor digitorum
longus)
Table 6.3 Superficial Anterior Muscles of the Body (See Figure 6.22) (1 of 3).
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Figure 6.16 Superficial muscles of the face and neck.
Frontalis
Cranial
aponeurosis
Temporalis
Orbicularis
oculi
Occipitalis
Zygomaticus
Buccinator
Orbicularis
oris
Masseter
Sternocleidomastoid
Trapezius
Platysma
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Table 6.3 Superficial Anterior Muscles of the Body (See Figure 6.22) (2 of 3).
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Figure 6.17a Muscles of the anterior trunk, shoulder, and arm.
Clavicle
Deltoid
Sternum
Pectoralis
major
Biceps
brachii
Brachialis
Brachioradialis
(a)
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Figure 6.17b Muscles of the anterior trunk, shoulder, and arm.
Pectoralis
major
Rectus
abdominis
Transversus
abdominis
Internal
oblique
External
oblique
Aponeurosis
(b)
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Table 6.3 Superficial Anterior Muscles of the Body (See Figure 6.22) (3 of 3).
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Figure 6.20c Pelvic, hip, and thigh muscles of the right side of the body.
12th
thoracic vertebra
12th rib
Iliac crest
Iliopsoas
Psoas major
Iliacus
5th
lumbar vertebra
Anterior superior
iliac spine
Quadriceps
Sartorius
Adductor
group
Rectus femoris
Vastus lateralis
Vastus medialis
Patella
Patellar
ligament
(c)
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Figure 6.21a Superficial muscles of the right leg.
Fibularis longus
Fibularis brevis
Tibialis anterior
Extensor digitorum
longus
Fibularis tertius
(a)
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Tibia
Soleus
Figure 6.20d Pelvic, hip, and thigh muscles of the right side of the body.
Inguinal
ligament
Adductor
muscles
Sartorius
Vastus
lateralis
(d)
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Table 6.4 Superior Posterior Muscles of the Body (Some Forearm Muscles Also Shown) (See Figure 6.23) (1 of 3).
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Figure 6.18a Muscles of the posterior neck, trunk, and arm.
Occipital bone
Sternocleidomastoid
Trapezius
Spine of scapula
Deltoid (cut)
Deltoid
Triceps
brachii
Latissimus
dorsi
(a)
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Humerus
Olecranon
process of
ulna (deep
to tendon)
Figure 6.18b Muscles of the posterior neck, trunk, and arm.
C7
T1
Erector spinae
• Iliocostalis
• Longissimus
• Spinalis
Quadratus
lumborum
(b)
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Figure 6.19 The fleshy deltoid muscle is a favored site for administering intramuscular injections.
Deltoid
muscle
Humerus
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Table 6.4 Superior Posterior Muscles of the Body (Some Forearm Muscles Also Shown) (See Figure 6.23) (2 of 3).
© 2015 Pearson Education, Inc.
Figure 6.18a Muscles of the posterior neck, trunk, and arm.
Occipital bone
Sternocleidomastoid
Trapezius
Spine of scapula
Deltoid (cut)
Deltoid
Triceps
brachii
Latissimus
dorsi
(a)
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Humerus
Olecranon
process of
ulna (deep
to tendon)
Figure 6.22 Major superficial muscles of the anterior surface of the body.
Facial
• Temporalis
• Masseter
Shoulder
• Trapezius
• Deltoid
Facial
• Frontalis
• Orbicularis oculi
• Zygomaticus
• Orbicularis oris
Neck
• Platysma
• Sternocleidomastoid
Thorax
• Pectoralis minor
• Pectoralis major
• Serratus anterior
• Intercostals
Arm
• Triceps brachii
• Biceps brachii
• Brachialis
Forearm
• Brachioradialis
• Flexor carpi radialis
Abdomen
• Rectus abdominis
• External oblique
• Internal oblique
• Transversus abdominis
Pelvis/thigh
• Iliopsoas
Thigh (Quadriceps)
• Rectus femoris
• Vastus lateralis
• Vastus medialis
Leg
• Fibularis longus
• Extensor digitorum longus
• Tibialis anterior
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Thigh
• Sartorius
• Adductor muscle
• Gracilis
Leg
• Gastrocnemius
• Soleus
Figure 6.23 Major superficial muscles of the posterior surface of the body.
Neck
• Occipitalis
• Sternocleidomastoid
• Trapezius
Arm
• Triceps brachii
• Brachialis
Forearm
• Brachioradialis
• Extensor carpi radialis
longus
• Flexor carpi ulnaris
• Extensor carpi ulnaris
• Extensor digitorum
Shoulder/Back
• Deltoid
• Latissimus dorsi
Hip
• Gluteus medius
• Gluteus maximus
• Iliotibial tract
Leg
• Gastrocnemius
• Soleus
• Fibularis longus
Calcaneal
(Achilles)
tendon
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Thigh
• Adductor muscle
• Hamstrings:
Biceps femoris
Semitendinosus
Semimembranosus