Download Anterior muscles of the leg

THE MUSCULAR
SYSTEM
Part 2:
Identification
OBJECTIVES
Identify the major skeletal muscle
of the human body
Explain each identified skeletal
muscle’s function or role
MUSCLES OF THE HEAD & FACE
 Occipitofrontalis
… Raises the eyebrows
 Orbicularis oculi
… Closes the eye lid
 Zygomaticus minor
… Raises the upper lip
 Zygomaticus major
… Pulls corner of the mouth up & out
MUSCLES OF THE HEAD & FACE
 Orbicularis oris
… Narrows mouth & purses lips
 Buccinator
… Pulls back the angle of the mouth &
flattens the cheek area
… Aids whistling and smiling
… In babies it is used to suckle
 Masseter
… Lifts the lower jaw & closes the mouth
Smiling
 Requires only 4
muscles
 Levator labii
superioris
 Zygomaticus minor
 Zygomaticus major
 Risorius
Frowning
 Requires 8 muscles!
 Occipitofrontalis
 Corrugator supercilii
 Orbicularis oculi
 Dilator naris
 Platysma
 Depressor anguli oris
 Depressor labii
inferioris
 Mentalis
MUSCLES OF THE HEAD & FACE
m. occipitofrontalis
MUSCLES OF THE NECK
 Splenius capitis
… Moves the head & twists the neck
 Levator scapulae
… Lifts & twists the shoulder
 Sternocleimastoid
… Tilts & twists the neck
 Sternohyoid
… Depresses the larynx
MUSCLES OF THE NECK
 Scalenus anterior, medius, & posterior
… Aid in breathing & neck flexion
… The anterior and middle scalene muscles
elevate the first rib and rotate the neck to
the same side
… The posterior scalene elevates the second
rib and tilts the neck to the opposite side
 Trapezius
… Rotates, elevates and retracts the shoulder
blade
MUSCLES OF THE NECK
m. sternocleimastoid
m. scalenus anterior
m. sternohyoid
ANTERIOR MUSCLES OF THE TORSO
 Deltoid
… Raises arm away from the body to front,
side, and rear
 External intercostals
… Elevate the ribs
 Pectoralis major
… Draws arm toward the body and rotates
upper arm inward
 Biceps brachii
… Flexes forearm at the elbow and turns the
palm upward
ANTERIOR MUSCLES OF THE TORSO
 Serratus anterior
… Pulls shoulder blades away from the spine
 External oblique abdominal
… Flexes and rotates trunk
 Rectus abdominis
… Flexes spine and draws pelvis forward
 Pyramidalis
… Tenses the linea alba
… It is absent in 20% of normal humans
ANTERIOR MUSCLES OF
THE TORSO
m. deltoid
m. external
intercostals
Linea alba
m. external oblique
abdominal
POSTERIOR MUSCLES OF THE TORSO
 Infraspinatus
… Rotates arm & stabilizes the shoulder
 Teres major & teres minor
… Lifts & twists arm, stabilizes the shoulder
 Triceps brachii
… Moves arm down towards the body and
contracts to straighten the arm
POSTERIOR MUSCLES OF THE TORSO
 Latissimus dorsi
… Extends, rotates and lowers arm, pulls
shoulder back
… Largest surface area of any muscle in the
body
 Gluteus maximus
… Raises thigh away from body at the hip,
rotates the thigh, and tilts the pelvis when
walking
POSTERIOR MUSCLES
OF THE TORSO
ANTERIOR MUSCLES OF THE ARM
 Pronator teres
… pronates the forearm, turning the hand
posteriorly
 Brachioradialis
… Flexes arm at the elbow
 Flexor carpi radialis
… Flexes hand at wrist
 Flexor digitorum superficialis
… Flexes joints of hand and wrist
ANTERIOR MUSCLES OF THE ARM
POSTERIOR MUSCLES OF THE ARM
 Brachialis
… Flexes the elbow
 Extensor carpi radialis longus
… Extends the wrist at the joint & abducts
the hand at the wrist
… Is a set of 5 muscles together
 Extensor digitorum
… Extends all finger joints
POSTERIOR MUSCLES OF THE ARM
ANTERIOR MUSCLES OF THE HAND
 Abductor pollicis brevis
… Pulls thumb in toward the palm
 Flexor pollicis brevis
… Flexes the thumb at the first metacarpal
joint
 Abductor digiti minimi
… Abducts the little finger
 Flexor digiti minimi brevis
… Flexes the little finger
ANTERIOR MUSCLES OF THE HAND
ANTERIOR MUSCLES OF THE LEG
 Iliopsoas
… Flexes the thigh at the hip
 Pectineus
… Flexes & draws thigh in toward the body
 Adductor longus
… Rotates and draws the thigh in toward the
body
 Gracilis
… Flexes and rotates the leg
ANTERIOR MUSCLES OF THE LEG
 Sartorius
… Flexes thigh at the hip and leg at knee joint,
and turns thigh outward
 Rectus femoris
… Flexes the thigh at the hip and with other
muscles extends the knee
 Vastus lateralis & vastus medialis
… Help to extend the knee
 Peroneus brevis
… Flexes the foot downward and stops it from
turning inward
ANTERIOR MUSCLES OF THE LEG
 Peroneus longus
… Flexes the foot downward and turns it
outward
 Tibialis anterior
… Flexes the foot upward and inward, &
supports the arch of the foot when running
or walking
 Extensor hallucis longus
… Extends the big toe
 Extensor digitorum longus
… Extends toes & ankle
ANTERIOR MUSCLES OF THE LEG
POSTERIOR MUSCLES OF THE LEG
 Adductor magnus
… Rotates, flexes & extends the thigh
 Biceps femoris, Semitendinosus, &
Semimembranosus
… Extends the thigh at the hip, flexes and
rotates the leg
… All three muscles make up the hamstrings
 Plantaris
… Assists in knee flexion
POSTERIOR MUSCLES OF THE LEG
 Gastrocnemius
… The main calf muscle
… It contracts to flex the ankle and pull up the
heel, as when standing on tip–toe and flexes
your knee
 Tibialis posterior
… Is the main muscle in turning the foot
inward
 Fibularis longus & fibularis brevis
… Flex and turn the foot outward
 Soleus
… Flexes the foot and it needed for walking and
running
POSTERIOR MUSCLES OF THE LEG
 Achilles (calcaneal) tendon
… It serves to attach the plantaris,
gastrocnemius, and soleus muscles to
the calcaneus (heel) bone
POSTERIOR MUSCLES OF THE LEG
Achilles
(calcaneal)
tendon