Download 10 - Dr. Par Mohammadian

PowerPoint® Lecture Slides
prepared by
Barbara Heard,
Atlantic Cape Community
College
CHAPTER
10
The Muscular
System:
Revised by Dr.
Par
Mohammadian
© Annie Leibovitz/Contact Press Images
© 2013 Pearson Education, Inc.
Naming Skeletal Muscles
• Muscle location—bone or body region with which
muscle associated (intercostal=between the ribs)
• Muscle shape—e.g., deltoid muscle (deltoid =
triangle)
• Muscle size—e.g., maximus (largest), minimus
(smallest), longus (long), brevis (short)
• Direction of muscle fibers or fascicles—e.g.,
rectus (fibers run straight), transversus (fibers run at
right angles), and oblique (fibers run at angles to
imaginary defined axis)
Naming Skeletal Muscles
• Number of origins—e.g., biceps
(2 origins) and triceps (3 origins)
• Location of attachments—named
according to point of origin and insertion
(origin named first)
• Muscle action—named for action they
produce, e.g., flexor or extensor
• Several criteria can be combined, e.g.,
extensor carpi radialis longus
Arrangement of Fascicles (bundles of fibers)
Circular (Fascicles arranged in
concentric rings) (orbicularis oris)
Convergent (Broad origin;
fascicles converge toward single
insertion (pectoralis major)
Fusiform (Spindle-shaped
with parallel fibers)
(biceps brachii)
Parallel
(sartorius) Fascicles
parallel to long axis
Multipennate
(deltoid)
(a)
(b)
(c)
(e)
(d)
(f)
Bipennate
(rectus femoris)
(g)
Pennate (feather)
Unipennate – fascicles attach only
to one side of tendon
Bipennate – fascicles insert from
opposite sides of tendon
Multipennate –appears as
feathers inserting into one tendon
Unipennate
(extensor digitorum longus)
Major Skeletal Muscles: Anterior View
The 40 superficial
muscles here are
divided into 10
regional areas of the
body
Facial
Epicranius, frontal belly
Head
Temporalis
Masseter
Shoulder
Trapezius
Deltoid
Arm
Triceps brachii
Biceps brachii
Brachialis
Forearm
Pronator teres
Brachioradialis
Flexor carpi radialis
Palmaris longus
Pelvis/thigh
Iliopsoas
Pectineus
Thigh
Rectus femoris
Vastus lateralis
Vastus medialis
Leg
Fibularis longus
Extensor digitorum
longus
Tibialis anterior
Orbicularis oculi
Zygomaticus
Orbicularis oris
Neck
Platysma
Sternohyoid
Sternocleidomastoid
Thorax
Pectoralis minor
Pectoralis major
Serratus anterior
Intercostals
Abdomen
Rectus abdominis
External oblique
Internal oblique
Transversus abdominis
Thigh
Tensor fasciae latae
Sartorius
Adductor longus
Gracilis
Leg
Gastrocnemius
Soleus
Major Skeletal Muscles: Posterior View
Arm
Triceps brachii
Brachialis
Forearm
Brachioradialis
Extensor carpi radialis
longus
Flexor carpi ulnaris
Extensor digitorum
Extensor carpi ulnaris
The 27
superficial
muscles here are
divided into seven
regional areas of
the body
Iliotibial tract
Leg
Gastrocnemius
Soleus
Fibularis longus
Calcaneal
(Achilles) tendon
Neck
Epicranius, occipital belly
Sternocleidomastoid
Trapezius
Shoulder
Deltoid
Infraspinatus
Teres major
Rhomboid major
Latissimus dorsi
Hip
Gluteus medius
Gluteus maximus
Thigh
Adductor magnus
Hamstrings:
Biceps femoris
Semitendinosus
Semimembranosus
Overview of muscles
• Head
– Facial Expression (Face & Scalp)
– Mastication & Tongue movement
• Neck & Throat (swallowing)
• Neck & Vertebral Column
– Head movement
– Trunk extension
• Deep thorax muscles (Breathing)
• Abdominal Wall
• Superficial muscles of thorax (movement of scapula & Arm)
Anterior & posterior
•
•
•
•
•
Muscles crossing the shoulder joint (movement of arm)
Muscles crossing the elbow (Flexion & extension of the forearm)
Muscles of the forearm (movements of the wrist, hand & fingers)
Muscles crossing the hip & knee joints (movements of the thigh & leg)
Muscles of the leg (movement of the ankle & toes)
Muscles of the Head
• Two groups
– Muscles of facial expression (Scalp & face)
• Insert into skin
• Important in nonverbal communication
• All innervated by cranial nerve VII (facial nerve)
– Muscles of mastication and tongue movement
Muscles of Facial Expression: The Scalp
• Epicranius (occipitofrontalis)
– Bipartite muscle consisting of
• Galea aponeurotica—cranial aponeurosis connecting
two bellies
• a) Frontal belly
– O: epicranial aponeurosis
– I: skin of eyebrows & root of nose
– Action: raises eyebrows
• b) occipital belly
a)
– O: Occipital & temporal bones
– I: epicranial aponeurosis
– Action: fixes aponeurosis & pulls scalp posteriorly
b)
Muscles of Facial Expression: The Face
Epicranial
aponeurosis
Corrugator supercilii
*Orbicularis oculi
Levator labii superioris
Frontal
belly
Occipital
belly
Temporalis
Epicranius
***Zygomaticus
minor and major
Buccinator
Risorius
**Orbicularis oris
Mentalis
Depressor
labii inferioris
Depressor anguli oris
(draws corners of mouth down
- tragedy mask!)
Masseter
Sternocleidomastoid
Trapezius
Splenius
capitis
Platysma
(tenses the skin of neck as during shaving)
*closes eyes
**closes mouth
***smiling muscle - raises lateral corners of the mouth upward
Muscles of the head: Mastication
•
Four pairs involved in mastication; all innervated by
cranial nerve V (trigeminal nerve)
– Prime movers of jaw closure
• Temporalis and masseter
– Grinding movements
• Medial and lateral pterygoids
– Chewing role - holds food between teeth
• Buccinator
Temporalis
O: temporal
fossa
I: coronoid
process of
mandible
Orbicularis
oris
Buccinator
(compresses cheek
– as in whistling and sucking- facial nerve)
Masseters
(chewer)
O: Zygomatic bone
I: angle &ramus of
mandible)
Muscles of the Anterior Neck and Throat Swallowing
•
Two groups
– Suprahyoid muscles
(pulls the hyoid bone
toward the mandible =>
widens the pharynx to
receive food)
– Infrahyoid muscles
(pulls hyoid to the inferior
position as swallowing
ends)
Mylohyoid
Stylohyoid
Hyoid bone
Omohyoid
(superior belly)
Sternohyoid
Sternocleidomastoid
Omohyoid
(inferior belly)
Muscles of the Neck and Vertebral Column:
Head Movement
• Sternocleidomastoid and scalenes—
lateral head movements
• Splenius capitis and cervicis portions head extension, rotation, and lateral
bending
• Semispinalis capitis—synergist with
sternocleidomastoid
1st cervical
vertebra
Sternocleidomastoid
Base of
occipital bone
Mastoid
process
Middle
scalene
Anterior
scalene
Posterior
scalene
Anterior
Muscles of the Neck and Vertebral Column:
Trunk Extension
• Deep (intrinsic) back muscles
– Erector spinae (sacrospinalis) group—
prime movers of back extension and lateral
bending (when touching fingertips to floor…)
• Iliocostalis
• Longissimus
• Spinalis
– Semispinalis and quadratus lumborum—
synergists in extension and rotation
Mastoid process
of temporal bone
Longissimus capitis
Iliocostalis cervicis
Longissimus cervicis
Iliocostalis thoracis
Ligamentum
nuchae
Semispinalis
capitis
Semispinalis
cervicis
Semispinalis
thoracis
Longissimus thoracis
Spinalis thoracis
Iliocostalis
Erector Longissimus
spinae
Spinalis
Iliocostalis
lumborum
External oblique
Multifidus
Quadratus
lumborum
Deep Muscles of the Thorax: Breathing
• Muscles of respiration (inspiration & expiration)
• External intercostals—more superficial muscles;
elevate ribs for inspiration
• Internal intercostals—deeper muscles; aid forced
expiration
• Diaphragm
– Partition between thoracic and abdominal cavities
– dome shaped
– Most important muscle in inspiration (contraction => flattens
=> increase the volume of the thoracic cavity)
– Innervated by phrenic nerves
Muscles of Respiration
• The primary function of
deep thoracic muscles is
to promote movement for
breathing
• External intercostals –
more superficial layer that
lifts the rib cage and
increases thoracic volume
to allow inspiration
Muscles of Respiration
• Internal intercostals –
deeper layer that aids in
forced expiration
Diaphragm – most important muscle in inspiration
Xiphoid process of sternum
Foramen for inferior
vena cava
Foramen for
esophagus
Costal cartilage
Central
tendon of
diaphragm
Foramen
for aorta
12th rib
Diaphragm
Lumbar
vertebra
Quadratus
lumborum
Psoas major
Central tendon of diaphragm
Body of thoracic vertebra
Aorta
Diaphragm (muscular part)
Inferior vena cava
Esophagus
Pericardial sac
Pericardium (cut)
Muscles of the Abdominal Wall: 4 paired
muscles
Pectoralis major
Serratus anterior
Linea alba
Tendinous intersection
Transversus abdominis
Rectus abdominis
Internal oblique
External oblique
Aponeurosis
of the external
oblique
Inguinal ligament
(formed by free inferior
border of the external
oblique aponeurosis)
Muscles of the Abdominal Wall
• Fascicles run at angles to one another, provide added strength
• All innervated by intercostal nerves
• Actions of these muscles
– Lateral flexion and rotation of trunk
– Help promote urination, defecation, childbirth, vomiting,
coughing, and screaming
– Relaxed during inspiration allowing the descending diaphragm to
push the abdominal viscera inferiorly
External
oblique
Iliac crest
Rectus
abdominis
Internal
oblique
Pubic tubercle
Lumbar
fascia
Transversus
abdominis
Inguinal
ligament
Lumbar
fascia
Superficial Muscles of the Thorax:
Movement of scapula & arm
• Most - extrinsic shoulder muscles
– Act in combination to fix shoulder girdle (mostly scapula);
move it to increase range of arm movements
– Actions - elevation, depression, rotation, lateral and
medial movements, protraction, and retraction
• Two groups of muscles: anterior and posterior
Sternocleidomastoid
Subclavius
Clavicle
Deltoid
Pectoralis major
Sternum
Biceps brachii
Subscapularis
Pectoralis minor
Coracobrachialis
Serratus anterior
Humerus
Muscles of anterior thorax
Pectoralis minor (O: ribs, I: coracoid process of scapula, A: draws scapula forward)
Serratus anterior (O: ribs, I: anterior surface of vertebral border of scapula, A: rotates
scapula)
Subclavius (O: rib 1, I: Clavicle, A: stabilizes pectoral girdle)
Levator
scapulae
Trapezius
Supraspinatus
Clavicle
Deltoid
Rhomboid
minor
Spine of
scapula
Infraspinatus
Rhomboid
major
Teres minor
Teres
major
Humerus
Latissimus dorsi
• Posterior shoulder muscles
– Trapezius (O: occipital bone, spinous process of C7 and T; I: acromion, spine of scapula, clavicle; A: rotates,
stabilizes, raises scapula)
– Levator scapulae (O: transverse process of C1-C4; I: medial border of scapula; A: elevates/adducts scapula)
– Rhomboids (major and minor): (O: spinous process of C7 & T; I: medial boarder of scapula; A: stabilizes
scapula)
Muscles Crossing the Shoulder Joint:
Movement of the Arm – Humerus)
• Nine muscles cross shoulder joint; insert
on and move humerus
• Some originate from scapula; others from
axial skeleton
• Actions include flexion, extension,
adduction
Muscles Crossing the Shoulder Joint
• Three prime movers of arm
– Pectoralis major (flexion, adduction)
– Latissimus dorsi (extension, adductor)
– Deltoid (abduction)
• Rotator cuff muscles: synergists and fixators; originate
on scapula; reinforce shoulder capsule; prevent
dislocation
– Supraspinatus & Infraspinatus
– Teres minor
– Subscapularis
• Coracobrachialis and teres major - synergists
Deltoid:
O: clavicle, acromion, scapula
I: deltoid tuberosity of humerus
Clavicle
Deltoid
Pectoralis major:
O: sternal end of
clavicle, sternum
I: greater tubercle of
humerus
Sternum
Pectoralis
major
Coracobrachialis
Triceps brachii:
Lateral head
Long head
Medial head
Biceps
brachii
Brachialis
Brachioradialis
Anterior view (muscles that originate anterior to the shoulder flex the arm)
Supraspinatus*
Spine of scapula
Deltoid (cut)
Latissimus dorsi:
O: iliac crest, lumbar
& thoracic vertebrae
I: spirals around teres
major to insert in
intertubercular sulcus
of humerus
(Latissimus &
pectoralis:
antagonistic)
Greater tubercle of humerus
Infraspinatus*
Teres minor*
Teres major
Triceps brachii:
Lateral head
Long head
Latissimus dorsi
Humerus
Olecranon
of ulna
Anconeus
Posterior view (muscles originating from posterior to the shoulder
extend the arm: latissimus & teres major)
Muscles Crossing the Shoulder
Chief medial rotator
Flexes & adducts humerus
Muscles Crossing the Elbow Joint: Flexion & Extension of
Clavicle
the forearm
• Anterior flexor
Deltoid
Sternum
muscles
Pectoralis
major
Coracobrachialis
– Brachialis and
biceps brachii __ chief Triceps brachii:
Lateral head
forearm flexors
Long head
– Brachioradialis —
synergist and
stabilizer
Medial head
Biceps
brachii
Brachialis
Brachioradialis
Anterior view
Muscles Crossing the Elbow Joint: Flexion & Extension of
Supraspinatus*
the forearm
Spine of scapula
Deltoid (cut)
• Posterior
extensor
muscles
Greater tubercle
of humerus
Infraspinatus*
Teres minor*
– Triceps
brachii—prime
mover of forearm
extension
– Anconeus—
weak synergist
Teres major
Triceps brachii:
Lateral head
Long head
Latissimus dorsi
Humerus
Olecranon
of ulna
Anconeus
Posterior view
Muscles of the Forearm: Movements of the wrist,
hand, and fingers
• The two functional forearm muscle groups:
– wrist movement
– move the fingers & the thumb
• These muscles insert via strong ligaments (“wrist bands”: =
flexor retinacula & extensor retinacula)
• Two main compartments:
– Anterior flexors
– Posterior extensors
Superficial anterior view
The pronator teres
& pronator
quadratus are not
flexors, but pronate
the forearm. Pronation –
one of the important
movements of forearm.
Superficial
transverse
ligament of palm
Palmar
aponeurosis
Flexor
digitorum
superficialis
Flexor carpi
ulnaris
Palmaris
longus
Flexor
carpi radialis
Medial
epicondyle
of humerus
Medial head of
triceps brachii
Flexor
retinaculum
Pronator
quadratus
Flexor pollicis
longus
Extensor carpi
radialis longus
Brachioradialis
Pronator
teres
Tendon of
biceps brachii
Biceps brachii
Forearm: Deeper Anterior Compartment The supinator muscle
is synergist with the
biceps brachii in
supinating the forearm
1
2
6
3
4
Deep
5
Deepest
Forearm:
Superficial
Posterior
Compartment
• These muscles are
primarily extensors of
the wrist and fingers
1
9
2
8
7
3
4
5
6
Forearm:
Deep
Posterior
Compartment
1
2
3
• These muscles are
primarily extensors
of the wrist and
fingers and the
supinator
4
5
Muscles Crossing Hip and Knee Joints: Movements of
the thigh and leg
• The most important thigh flexors:
– iliopsoas (prime mover)
– tensor fasciae latae
– rectus femoris
• The medially located
adductor muscles
sartorius (straplike)
assist in flexion
1
2
3
4
5
10
6
11
7
8
9
12
Muscles Crossing Hip and Knee Joints: Movements of
the thigh and leg
• Thigh extension primarily effected by:
hamstrings
(biceps femoris, semitendinosus, & semimembranosus)
• Forceful extension is aided by
• gluteus maximus
Movements of the Thigh at the Hip:
Other Movements
• Abduction and rotation:
– gluteus medius
– gluteus minimus,
• and are antagonized by the lateral rotators
• Thigh adduction is the role of five adductor muscles
– adductor magnus
– adductor longus
– adductor brevis
– pectineus
– gracilis
1
2
*
*
3
4
5
6
Movements of the Thigh at the Hip:
Other Movements
1
2
7
4
8
5
6
9
3
Movements:
Knee Joint
• sole extensor of
the knee
– quadriceps
femoris
• flex the knee, and
are antagonists to
the quadriceps
femoris
– hamstrings
Muscles of the leg: Movements of the ankle & toes Anterior Compartment
primary toe extensors and
ankle dorsiflexors
– tibialis anterior
– extensor digitorum
longus
– extensor hallucis
longus
– fibularis (peroneus)
tertius
1
2
3
4
5
6
7
Muscles of the
Anterior
Compartment
ISOLATED
Figure 10.21b-d
Muscles of the
Lateral Compartment
plantar flex and evert the
foot
– fibularis longus
– fibularis brevis
1
2
3
4
5
6
8
9
7
Muscles of the Lateral Compartment - ISOLATED
Muscles of the
Posterior Compartment
1
primarily flex the foot and the
toes
– gastrocnemius
2
– soleus
– tibialis posterior
3
– flexor digitorum
longus
– flexor hallucis longus
4
Muscles of the Posterior Compartment
1
2
*
*
3
*
1
2
4
3
4
Deep
5
7
Deepest
6
5
6
Muscles of the Posterior Compartment - ISOLATED