Lab #15
Muscles
Muscles of the Head and
Neck
The Axial Muscles
• Divisions based on location and function:
– muscles of head and neck
– muscles of vertebral column
– oblique and rectus muscles
– muscles of pelvic floor
6 Muscle Groups of
the Head and Neck
• 1. Muscles of facial expression:
– originate on skull
• 2. Extrinsic (outside) eye muscles:
(don’t need to know)
6 Muscle Groups of
the Head and Neck
• 3. Muscles of mastication:
– move the mandible
• 4. Muscles of the tongue:
– names end in glossus (FYI)
• 5. Muscles of the pharynx:
– begin swallowing process (FYI)
• 6. Anterior muscles of the neck:
– control position of larynx
– depress the mandible
– support tongue and pharynx
Muscles of Facial Expression
• Orbicularis oris:
– constricts the mouth opening
• Buccinator:
– moves food around the cheeks
• Corrugator supercilli – wrinkles forehead
• Orbicularis oculi – sphincter of eye
Others
• Zygomaticus – pull skin of mouth up and
out when smiling
• Levator labii superiorus – raises upper
lip
• Depressor labii inferiorus – “pouting”
muscle
Muscles of the
Epicranium (Scalp)
• Temporoparietalis
• Occipitofrontalis:
– frontal and occipital bellies
– separated by epicranial aponeurosis
• Platysma:
– covers anterior surface of neck
Muscles of Facial Expression
Figure 11–4a
Muscles of Facial Expression
Figure 11–4b
Summary: Muscles of
Facial Expression
Table 11–2 (1 of 2)
Summary: Muscles of
Facial Expression
Table 11–2 (2 of 2)
3 Muscles of Mastication
• Masseter:
– the strongest jaw muscle
• Temporalis:
– helps lift the mandible
• Pterygoid muscles (FYI):
– position mandible for chewing
Muscles of Mastication
Figure 11–6
Summary: Muscles of
Mastication
Table 11–4
Muscles of the Tongue
Don’t need to
know any of
these
Figure 11–7
Muscles of the Neck
• Digastric:
– from chin to hyoid
– also hyoid to mastoid
• Platysma:
– covers anterior surface of neck
• Sternocleidomastoid:
– from clavicle and sternum to mastoid
Anterior Muscles of the Neck
Figure 11–9
Summary:
Anterior Muscles of the Neck
Table 11–7
Muscles of the chest and
abdomen
Lab 19: Muscles of the chest
and abdomen
• Remember: if it’s not on the list, you don’t
have to locate it or write about it in the lab
report
Muscles to know
•
•
•
•
•
•
•
•
•
•
pectoralis major
serratus anterior
intercostals (external, internal)
diaphragm
rectus abdominus
obliques (external, internal)
transverse abdominus
trapezius
latissimus dorsi
splenius capitus
Oblique and rectus muscles
• Lie within the body wall
• Generally:
– obliques groups are lateral
– rectus muscles lie on the anterior midline
Oblique and Rectus Muscles
• Oblique muscles:
– compress underlying structures
– rotate vertebral column
• Rectus muscles:
– flex vertebral column
– oppose erector spinae
Cervical Oblique Muscles
• FYI: Cervical region:
– scalene muscles
– flex the neck
Oblique and Rectus Muscles of the
Thoracic region
Figure 11–11a, b
Thoracic Oblique Muscles
• Thoracic region:
– intercostal muscles (external and internal
intercostals):
• respiratory movements of ribs
– FYI: transversus thoracis:
• cross inner surface of ribs
Thoracic Rectus Group
• Diaphragmatic muscle or diaphragm:
– divides thoracic and abdominal cavities
– performs respiration
Oblique and Rectus Muscles of the
Abdominopelvic region
Figure 11–11a, c
Abdominopelvic Oblique Muscles
• Abdominopelvic region (same pattern as
thoracic):
– external oblique muscles
– internal oblique muscles
• Transversus abdominis – deep to
internals
Rectus Group -Abdominopelvic
• Rectus abdominis:
– between xiphoid process and pubic
symphysis
– divided longitudinally by linea alba
– divided transversely by tendinous inscriptions
Summary: Oblique and
Rectus Muscles
Table 11–9 (1 of 2)
Muscles that Position
the Pectoral Girdle
Figure 11–14b
Muscles that Position the
Pectoral Girdle (1 of 3)
• Trapezius:
– HUGE
– superficial
– covers back and neck to base of skull
– inserts on clavicles and scapular spines
Muscles that Position the
Pectoral Girdle (2 of 3)
• Rhomboid and levator scapulae:
– deep to trapezius
– attach to cervical and thoracic vertebrae
– insert on scapular border
Muscles that Position the
Pectoral Girdle (3 of 3)
• Serratus anterior:
– on the chest
– originates along ribs
– inserts on anterior scapular margin
– “serrated”
Summary: Muscles that
Position the Pectoral Girdle
Tables 11–11
Muscles that Move the Arm
Figure 11–15b
Muscles that Move the Arm
of 3)
• Deltoid:
– the major abductor of arm
• Supraspinatus:
– assists deltoid
• Subscapularis and teres major:
– produce medial rotation at shoulder
(1
Muscles that Move the Arm
(2 of 3)
• Infraspinatus:
– produce lateral rotation at shoulder
Muscles that Move the Arm
(3 of 3)
• Pectoralis major:
– between anterior chest and greater tubercle of
humerus
– produces flexion at shoulder joint
• Latissimus dorsi:
– between thoracic vertebrae and humerus
– produces extension at shoulder joint
Shoulder flexion vs extension
• Pecs and portion of
delts
• Lats and portion of
delts
The Rotator Cuff
• Muscles involved in shoulder rotation
– supraspinatus, subscapularis, infraspinatus,
teres minor,and their tendons
Muscles that Position the
Pectoral Girdle
• Rhomboid and levator scapulae:
– deep to trapezius
– attach to cervical and thoracic vertebrae
– insert on scapular border
• Also saw trapezius and serratus anterior
Muscles of the shoulders,
arm, and hand
Muscles to know
•
•
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•
•
•
•
•
•
supraspinatus
infraspinatus
subscapularis
teres major
rhomboid
levator scapulae
deltoid
biceps brachii
brachialis
•
•
•
•
•
•
•
•
triceps brachii
flexor carpi radialis
flexor carpi ulnaris
flexor digitorum sup.
extensor carpi ulnaris
extensor digitorum
extensor carpi radialis
brachioradialis
Muscles that Move the Arm
Figure 11–15a
Muscles that Move the Arm
Figure 11–15b
Muscles that Move the Arm
(1 of 3)
• Deltoid:
– the major abductor
• Supraspinatus:
– assists deltoid
• Subscapularis and teres major:
– produce medial rotation at shoulder
Muscles that Move the Arm
(2 of 3)
• Infraspinatus:
– produce lateral rotation at shoulder
Muscles that Move the Arm
(3 of 3)
• Pectoralis major:
– between anterior chest and greater tubercle of
humerus
– produces flexion at shoulder joint
• Latissimus dorsi:
– between thoracic vertebrae and humerus
– produces extension at shoulder joint
The Rotator Cuff
• Muscles involved in shoulder rotation
– supraspinatus, subscapularis, infraspinatus,
teres minor,and their tendons
Summary:
Muscles that Move the Arm
Table 11–12
Muscles that Position the
Pectoral Girdle
• Rhomboid and levator scapulae:
– deep to trapezius
– attach to cervical and thoracic vertebrae
– insert on scapular border
Muscles that Move
the Forearm and Hand
• Originate on humerus and insert on
forearm
• Exceptions:
– the major flexor (biceps brachii)
– the major extensor (triceps brachii)
Extensors and Flexors
• Extensors:
– mainly on posterior and lateral surfaces of
arm
• Flexors:
– mainly on anterior and medial surfaces
Muscles that Move
the Forearm and Hand
• Biceps brachii:
– flexes elbow
– stabilizes shoulder joint
– originates on scapula and humerus
– inserts on radial tuberosity
Muscles that Move
the Forearm and Hand
• Triceps brachii:
– extends elbow
– originates on scapula (three spots)
– inserts on olecranon
• Brachialis and brachioradialis:
– assist in flexing elbow (synergists)
Muscles that Move
the Forearm and Hand -Extensors
Figure 11–16a
Muscles that Move
the Forearm and Hand - Flexors
Figure 11–16b
Muscles that Move
the Forearm and Hand
• Flexor carpi ulnaris:
– superficial
– flexes wrist
– adducts wrist
Muscles that Move
the Forearm and Hand
• Flexor carpi radialis:
– superficial
– flexes wrist
– abducts wrist
Muscles that Move
the Forearm and Hand
• Extensor carpi radialis:
– superficial
– extends wrist
– abducts wrist
Muscles that Move
the Forearm and Hand
• Extensor carpi ulnaris:
– superficial
– extends wrist
– adducts wrist
Figure 11–16a
Figure 11–16b
Summary: Muscles that
Move the Forearm and Hand
Table 11–13 (1 of 2)
Muscles of the Pelvis, Leg and
Foot
Muscles to know
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psoas major
iliacus
gluteus maximus
gluteus medius
sartorius
quadriceps femoris (4)
gracilus
adductor longus
biceps femoris
semitendinosis
semimembranosus
•
•
•
•
•
•
•
•
tibialis anterior
ext hallucis longus
ext digitorum longus
fibularis (peroneus)
longus
gastrocnemius
soleus
flexor hallucis longus
flexor digitorum longus
Muscles of the Pelvis
and Lower Limbs
• Pelvic girdle is tightly bound to axial
skeleton:
– permits little movement
– has few muscles
Muscles that Position
the Lower Limbs
1. Muscles that move the thigh
2. Muscles that move the leg
3. Muscles that move the foot and toes
Generally…
•
•
•
•
Muscles that are lateral are abductors
Muscles that are medial are adductors
flexors are on inner surface of joint
extensors are on outer surface of joint
Note: in legs and feet, look at each joint
individually (cf. arms)
Muscles that Move the Thigh
•
•
•
•
Gluteal muscles
Lateral rotators
Adductors
Iliopsoas group
Muscles of hip and thigh
•
•
•
•
•
psoas major
iliacus
gluteus maximus
gluteus medius
adductor longus
Gluteal Muscles (1 of 2)
• Cover lateral surfaces of ilia
• Gluteus maximus:
– largest, most posterior gluteal muscle
– produces extension and lateral rotation at
hip
– Originates on illiac crest, etc., inserts on
illiotibial tract and femur
Gluteal Muscles (2 of 2)
• Gluteus medius and [gluteus minimus]:
– originate anterior to gluteus maximus
– insert on trochanter of femur
Muscles that Move the Thigh
Figure 11–19a, b
Muscles that Move the Thigh
Figure 11–19c, d
Adductors
• Adductor longus:
– hip flexion and adduction
• Gracilis (UPPER LEG):
– hip flexion and adduction
Iliopsoas group
• 2 hip flexors insert on the same tendon:
– psoas major
• originates on lumbar vetebrae, inserts on femur
– iliacus
• originates on illium/fossa
Summary: Muscles that
Move the Thigh
Table 11–16 (1 of 2)
Summary: Muscles that
Move the Thigh
Table 11–16 (2 of 2)
Muscles that Move the Leg
• Flexors of the knee:
– originate on the pelvic girdle
– generally: hamstrings
• Extensors of the knee:
– originate on the femoral surface
– insert on the patella
– generally: quads
Flexors of the Knee
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•
•
•
Biceps femoris
Semimembranosus
Semitendinosus
Sartorius:
– originates superior to the acetabulum
– long, ribbon-like muscle
– traverses the quads and wraps around to the
back of the knee
Hamstrings
• Made up of:
– biceps femoris (long and short heads)
– semimembranosus
– semitendinosus
• All are knee flexors
Muscles that Move the Leg
Figure 11–20a
Extensors of the Knee
• 4 muscles of the quadriceps femoris:
– 3 vastus muscles:
• vastus lateralis
• vastus medialis
• vastus intermedius
– rectus femoris muscle
Muscles that Move the Leg
Figure 11–20b, c
Summary: Muscles that
Move the Leg
Table 11–17 (1 of 2)
Summary: Muscles that
Move the Leg
Table 11–17 (2 of 2)
Muscles that Move
the Foot and Toes
• Extrinsic muscles that move the foot and
toes include:
– muscles that produce extension at the ankle
(Plantar flexion)
– muscles that produce flexion at the ankle
– muscles that produce extension at the toes
– muscles that produce flexion at the toes
Muscles that Produce Extension
at the Ankle (Plantar flexion)
Calf muscles
Large posterior calf muscles, both insert on
Achilles):
• Gastrocnemius
• Soleus
• Fibularis longus
Muscles that Move
the Foot and Toes
Figure 11–21a, b
Muscles that Move
the Foot and Toes
Figure 11–21c, d
The Achilles Tendon
• The calcaneal tendon (Achilles tendon):
– shared by the gastrocnemius and soleus
Muscles that Produce
Flexion at the Ankle
• Tibialis anterior:
– opposes the gastrocnemius
Muscles that Move
the Foot and Toes
Figure 11–21a, b
Muscles that Move
the Foot and Toes
Figure 11–21c, d
Muscles that Produce
Extension at the Toes
• Extensor digitorum longus
• Extensor hallucis longus
Toe extensors are on top of foot
Note: there are no muscles in toes
themselves (only tendons)
The Intrinsic Muscles of the
Foot
Figure 11–22a
Muscles that Produce
Flexion at the Toes
• Flexor digitorum longus
• Flexor hallucis longus:
– oppose the extensors
Toe flexors are on bottom of foot
The Intrinsic Muscles of the
Foot
Figure 11–22b, c
Summary: Muscles that
Move the Foot and Toes
Table 11–18
Lab 15
• This is a huge lab (it covers ~3-4 labs
worth of material)
• Due on day of practical (11/22)