BIO 210
Chapter 10 Part 2
Important Skeletal Muscles
Warm Up

Define & give an example of each of the
following.
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Prime mover
Synergist
Antagonist
Fixator muscles
Name the muscles of the Quadriceps Group
 Name the muscles of Hamstring Group
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Warm Up

Define & give an example of a muscle that does
each of the following.
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Prime mover-provides most of the force for a
movement, forearm flexion, biceps brachii.
Synergist-assists, i.e.contract at same time as prime
movers, and move the joint the same direction.
Brachialis.
Antagonist-muscle that extends the prime mover.
Triceps brachii is antagonist for biceps.
Fixator muscles-stabilize a joint. Deltoid.
 Name
Group
the muscles of the Quadriceps
 Rectus
femoris
 Vastus medialis
 Vastus lateralis
 Vastus intermedius
 Name
the muscles of Hamstring Group
 Semitendenosus
 Semimembranosus
 Biceps
femoris
Important Skeletal Muscles

When we talk about muscle actions of
the following muscles, we are referring to
the action of the prime mover.

Remember that muscles work together.
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Prime mover
Synergist
Antagonist
Fixator muscles
MUSCLES OF FACIAL EXPRESSION
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ORBICULARIS OCULI

ZYGOMATICUS MAJOR

ORBICULARIS ORIS

BUCCINATOR
ORBICULARIS OCULI: Closes Eyes
(Blinking)
ZYGOMATICUS MAJOR: Pulls Corners of Mouth
Upward (Laughing)
ORBICULARIS ORIS:
Puckers Mouth (Kissing)
BUCCINATOR: Presses Lips and Cheeks
Against Teeth (Blowing, Whistling)
MUSCLES OF MASTICATION


TEMPORALIS: Same as Masseter
MASSETER Elevates Mandible (Closes Jaw)
MUSCLES THAT MOVE THE HEAD

STERNOCLEIDOMASTOID
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Flexes Head ("Prayer Muscle") (When Both Contract)
Turns Head to Side (When Each Contracts Alone)
TRUNK MUSCLES - MUSCLES OF THE THORAX
NOTE: All of These Muscles Play an Important Role in Respiration.
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EXTERNAL
INTERCOSTALS
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INTERNAL
INTERCOSTALS
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Elevates Ribs
Depresses Ribs
DIAPHRAGM
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Enlarges Thorax
(Causes
Inspiration)
TRUNK MUSCLES - MUSCLES OF THE ABDOMINAL WALL

EXTERNAL OBLIQUE

INTERNAL OBLIQUE

TRANSVERSUS
ABDOMINUS

RECTUS ABDOMINUS
CAT ABS!

EXTERNAL
OBLIQUE

INTERNAL OBLIQUE

TRANSVERSUS
ABDOMINUS

RECTUS
ABDOMINUS
Functions of Muscles of the Abdominal Wall
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All Four of These Muscles Have the Following
Functions:
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Compress (Tighten) Abdomen
Rotate Trunk Laterally
Abdominal muscles play important roles in posture; they pull
pelvis upward which flattens lumbar curve of the spine.

They also aid in defecation, forced expiration, childbirth, etc.

Rectus abdominus flexes the trunk of the body.
UPPER LIMB MUSCLES –MUSCLES ACTING ON THE
SHOULDER GIRDLE: Trapezius & Serratus anterior

TRAPEZIUS

Raises and Lowers
Shoulders (Shrugs
Shoulders)
CAT TRAPEZIUS, DELTOID, ETC.
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1. External oblique
2. Latissimus dorsi
3. Spinotrapezius
4. Acromiotrapezius
5. Clavotrapezius
6. Levator scapulae ventralis
7. Spinodeltoid
8. Acromiodeltoid
9. Clavodeltoid
10. Triceps brachii (lateral
head)
11. Triceps brachii (long head)
UPPER LIMB MUSCLES –MUSCLES ACTING ON THE
SHOULDER GIRDLE: Trapezius & Serratus anterior
SERRATUS
ANTERIOR
•Pulls Shoulder
Forward and
Upward (Punching
Movements)
CAT-SERRATUS ANTERIOR
UPPER LIMB MUSCLES
MUSCLES THAT MOVE THE UPPER ARM
 Pectoralis
major
 Latissimus dorsi
 Deltoid
PECTORALIS MAJOR
Flexes Upper Arm
 Adducts Upper Arm Anteriorly
(Draws It Across Chest)

CAT PECS
Clavodeltoid
 Pectoantebrachialis
 Pectoralis major
 Pectoralis minor
 Xiphihumeralis

LATISSIMUS DORSI
Extends Upper Arm
 Adducts Upper Arm
 Posteriorly (Draws It Across Back)

CAT-LATISSIMUS DORSI
DELTOID
Assists with Flexion and Extension of Upper Arm
Abducts Upper Arm
CAT TRAPEZIUS, DELTOID, ETC.
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1. External oblique
2. Latissimus dorsi
3. Spinotrapezius
4. Acromiotrapezius
5. Clavotrapezius
6. Levator scapulae ventralis
7. Spinodeltoid
8. Acromiodeltoid
9. Clavodeltoid
10. Triceps brachii (lateral
head)
11. Triceps brachii (long head)
MUSCLES THAT MOVE THE FOREARM

BICEPS BRACHII
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
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Supinates Forearm and
Hand
Flexes Supinated
Forearm
BRACHIALIS

Flexes Pronated
Forearm
&
MUSCLES THAT MOVE THE FOREARM

BRACHIORADIALIS
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Supinates Forearm
and Hand
Flexes Forearm
(Semipronated or
Semisupinated)
TRICEPS BRACHII
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Extends Forearm
MUSCLES THAT MOVE THE WRIST,
HAND, AND FINGERS

SUPERFICIAL
FLEXORS
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FLEXOR CARPI
RADIALIS
 Flexes Hand
PALMARIS LONGUS
 Flexes Hand
FLEXOR CARPI
ULNARIS
 Flexes Hand
MUSCLES THAT MOVE THE WRIST,
HAND, AND FINGERS

FLEXOR
DIGITORUM
(SUPERFICIALIS)
 Flexes Fingers
MUSCLES THAT MOVE THE WRIST, HAND,
AND FINGERS

EXTENSOR CARPI
RADIALIS
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Extends Hand
Abducts Hand (Moves
Toward Thumb Side
When Hand Supinated)
MUSCLES THAT MOVE THE WRIST,
HAND, AND FINGERS:
EXTENSOR CARPI
ULNARIS
•Extends Hand
•Adducts Hand (Moves
Toward Little Finger
Side When Hand
Supinated)
EXTENSOR DIGITORUM
• Extends Fingers
MUSCLES THAT MOVE THE WRIST, HAND,
AND FINGERS

OPPONENS POLLICIS

Opposes Thumb to Fingers
LOWER LIMB MUSCLES
MUSCLES THAT MOVE THE THIGH:
ILIOPSOAS

Flexes Thigh Flexes
Trunk
LOWER LIMB MUSCLES
THAT MOVE THE THIGH:
RECTUS FEMORIS
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Flexes Thigh
Extends Lower Leg
LOWER LIMB MUSCLES
MUSCLES THAT MOVE THE THIGH:
GLUTEAL GROUP
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MAXIMUS
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MEDIUS
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Extends Thigh
Abducts Thigh
MINIMUS

Abducts Thigh
Lower Limb Muscles continued…
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TENSOR FASCIAE LATAE
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PECTINEUS
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Adducts Thigh
Flexes Thigh
ADDUCTOR GROUP
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Abducts Thigh
BREVIS
LONGUS
MAGNUS
ALL of These Muscles Adduct the
Thigh.
GRACILIS


Adducts Thigh
Flexes Lower leg
TENSOR FASCIAE LATAE
Abducts Thigh
1. Sartorius 2. Tensor fasciae latae
3. Gluteus maximus 4. Gluteus
medius 5. Caudofemoralis
6. Vastus lateralis
7. Biceps femoris
8. Gastrocnemius
9. Soleus
TENSOR FASCIAE LATAE-CAT
Abducts Thigh
1. Sartorius
2. Tensor fasciae latae
3. Gluteus maximus
4. Gluteus medius
5. Caudofemoralis
6. Vastus lateralis
7. Biceps femoris
8. Gastrocnemius
9. Soleus
PECTINEUS
Adducts Thigh
Flexes Thigh
PECTINEUS-CAT
ADDUCTOR GROUP
ALL of These Muscles Adduct the Thigh.
BREVIS
LONGUS
MAGNUS
ADDUCTOR GROUP-CAT
NOTE DIFFERENCES BETWEEN CAT AND HUMAN BEING
ADDUCTOR LONGUS
ADDUCTOR FEMORIS
GRACILIS
Adducts Thigh Flexes Lower leg
GRACILIS-CAT
MUSCLES THAT MOVE THE LOWER LEG
 QUADRICEPS
FEMORIS GROUP
 RECTUS FEMORIS
 Extends Lower leg
 Flexes Thigh
 VASTUS LATERALIS
 VASTUS MEDIALIS
 VASTUS
INTERMEDIUS
 ALL Muscles in the
Vastus Group Extend
Lower Leg
QUADRICEPS FEMORIS GROUP
 RECTUS FEMORIS
 Extends Lower leg
 Flexes Thigh
 VASTUS LATERALIS
 VASTUS MEDIALIS
 VASTUS
INTERMEDIUS
 deep to rectus femoris
 ALL Muscles in the
Vastus Group Extend
Lower Leg
QUADRICEPS FEMORIS
GROUP
 VASTUS
INTERMEDIUS
 deep to rectus femoris
 ALL Muscles in the
Vastus Group Extend
Lower Leg
QUADRICEPS FEMORIS
GROUP-CAT
VASTUS LATERALIS
RECTUS FEMORIS
VASTUS INTERMEDIUS
VASTUS MEDIALIS
MUSCLES THAT MOVE THE LOWER LEG
 SARTORIUS
 Flexes Lower Leg
 Permits Sitting
in Tailor Fashion
 HAMSTRING GROUP
 BICEPS FEMORIS
 Flexes Lower Leg
 Extends Thigh
 SEMITENDINOSUS
 Extends Thigh
 SEMIMEMBRANOSUS
 Extends Thigh
SARTORIUS-Flexes Lower Leg
SARTORIUS
Permits Sitting in Tailor Fashion
HAMSTRING GROUP
 BICEPS FEMORIS
 Flexes Lower Leg
 Extends Thigh
 SEMITENDINOSUS
 Extends Thigh
 SEMIMEMBRANOSUS
 Extends Thigh
HAMSTRING GROUP-CAT

BICEPS FEMORIS

SEMITENDINOSUS
 REFLECTED IN THIS PIC
 Flexes Lower Leg
 Extends Thigh
 Extends Thigh

SEMIMEMBRANOSUS
 Extends Thigh

http://www.mhhe.com/
biosci/ap/cat_dissect/c
at_demo/muscular_sy
stem/Biceps_femoris_
reflected/Biceps_femo
ris_reflectedindex.html
MUSCLES THAT MOVE THE FOOT
 TIBIALIS ANTERIOR
 Flexes Foot (Dorsiflexion)
 Inverts Foot (Inversion)
 GASTROCNEMIUS
 Extends Foot (Plantar Flexion)
 Flexes Lower Leg
 SOLEUS
 Extends Foot
TIBIALIS
ANTERIOR
Flexes Foot
(Dorsiflexion)
 Inverts Foot
(Inversion)

GASTROCNEMIUS
Extends Foot
(Plantar
Flexion)
 Flexes Lower
Leg

SOLEUS Extends Foot
MUSCLES THAT MOVE THE FOOT-CAT
 TIBIALIS ANTERIOR
 GASTROCNEMIUS
 SOLEUS