Download BIOL 4260 Human Evolutionary Anatomy Lecture 14: Shoulder, Arm

BIOL 4260
Human Evolutionary Anatomy
Lecture 14: Shoulder, Arm, Hand
Lecture 2: Fossil Record
Appendicular Musculature
—  Functions:
—  Stabilizing the pectoral and pelvic girdles
—  Moving the upper and lower limbs
—  Muscular connections between pectoral girdle and
axial skeleton and shock absorption
—  Account for roughly 40 percent of the skeletal
muscles in the body
—  Two major groups of appendicular muscles:
—  The muscles of the pectoral girdle and upper limbs
—  The muscles of the pelvic girdle and lower limbs
Muscles of the Pectoral Girdle and Upper Limbs
—  Muscle groups:
—  Muscles that stabilize the pectoral girdle
(scapula/clavicle)
—  Muscles that move the humerus (arm)
—  Muscles that move the forearm and hand
—  Muscles that move the hand and fingers
Anterior Muscles that stabilize the pectoral
girdle
—  Pectoralis Minor
—  Serratus anterior
Pectoralis minor
Subclavis
Posterior Muscles that stabilize the
pectoral girdle
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Posterior Muscles stabilize the pectoral
girdle
—  Posterior group
—  Trapezius
—  Posterior group
—  Rhomboid major
—  Rhomboid minor
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Muscles that stabilize the pectoral
girdle
—  Posterior group
—  Levator Scapulae
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Summary :
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Muscles That Move the Humerus
—  Anterior view (usually insert on humerus):
—  Coracobrachialis
—  Deltoid
—  Pectoralis major
—  Biceps brachii (short head and long head).
DOES NOT insert on humerus
—  Subscapularis
SUPERFICIAL
DEEP
Clavicle
Sternum
Ribs (cut)
Deltoid
Subscapularis
Pectoralis
major
Coracobrachialis
Teres major
Biceps brachii,
short head
Biceps brachii,
long head
T12
Anterior view
Pectoralis major
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Muscles That Move the Humerus
—  Posterior view (usually insert on humerus)
—  Supraspinatus
—  Deltoid
—  Infraspinatus
—  Teres Major
—  Teres Minor
—  Triceps brachii (long head). Does NOT insert
on humerus
—  Lattisimus Dorsi
SUPERFICIAL
DEEP
Vertebra T1
Supraspinatus
Infraspinatus
Supraspinatus
Deltoid
Teres minor
Teres major
Triceps brachii,
long head
Latissimus
dorsi
Triceps brachii,
lateral head
Thoracolumbar
fascia
Posterior view
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Summary of Attachments to the Scapula
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Muscles That Move the Forearm and Hand
—  Most of these muscles originate on the
humerus and insert upon the forearm and wrist
—  Exceptions include:
—  Long head of triceps brachii -originates on
the infraglenoid tubercle of scapula and
inserts on the olecranon
—  Long head of biceps brachii - originates on
the supraglenoid tubercle of scapula and
inserts of the radial tuberosity of the radius
Muscles That Move the Forearm and Hand
—  Flexors of the Elbow
—  Biceps brachii: flexes at the elbow and shoulder
—  Brachialis: flexes at the elbow
—  Brachioradialis: flexes at the elbow
Biceps brachii
Brachialis
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Muscles That Move the Forearm and Hand
Extensors at the Elbow
—  Anconeus: extension at the elbow
—  Triceps brachii
—  Lateral head: extension at the elbow
—  Long head: extension at the elbow and adduction at the
shoulder
—  Medial head: extension at the elbow
Muscles That Move the Forearm and Hand
—  Pronators and
Supinators
—  Pronator quadratus:
pronates the forearm
—  Pronator teres (B):
pronates the forearm
—  Supinator (A): supinates
the forearm
Muscles That Move the Wrist, Hand and fingers
—  Flexors of the wrist
—  Flexor carpi radialis: flex and abduct the wrist
—  Flexor carpi ulnaris: flex and adduct the wrist
—  Palmaris longus: flexion at the wrist
Coracoid process
of scapula
Humerus
Coracobrachialis
Biceps brachii,
short head
Biceps brachii,
long head
Triceps brachii,
long head
Triceps brachii,
medial head
Brachialis
Medial epicondyle
of humerus
Pronator teres
Brachioradialis
Flexor carpi
radialis
Palmaris
longus
Flexor carpi
ulnaris
Flexor digitorum
superficialis
Palmar carpal
ligament
Pronator
quadratus
Flexor
retinaculum
Superficial muscles of the right
upper limb, anterior view
Extensor
carpi radialis
longus
Anterior
view
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Posterior
view
Muscles That Move the Wrist, Hand and fingers
—  Extensors of the wrist
—  Extensor carpi radialis longus: extend and abduct at the wrist
—  Extensor carpi radialis brevis: extend and abduct at the wrist
—  Extensor carpi ulnaris: extension and adduction at the wrist
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Extensor carpi
ulnaris
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Muscles That Move the Hand and Fingers
—  Extrinsic Muscles of the Hand
—  Relatively large muscles that perform flexion and
extension at the joints of the fingers
—  Provide strength and crude control of the hand and
fingers
—  These muscles are found mostly on the anterior and
posterior surfaces of the forearm
—  Their tendons carpus enclosed in sheaths associated
with connective tissue thickenings called retinacula
Muscles That Move the Hand and Fingers
—  Intrinsic Muscles of the Hand
—  Smaller muscles that provide fine control of hand
—  Responsible for flexion and extension, and abduction
and adduction of the fingers at the
metacarpophalangeal joints
—  Responsible for opposition and reposition of the thumb
—  These muscles are found mostly in the palm or the back
of the hand
Extrinsic Muscles of the Hand
—  Flexor muscles
—  Flexor digitorum superficialis: flexion at the wrist
and some digits
—  Flexor digitorum profundus: flexion at the wrist and
some digits
—  Flexor pollicis longus: flexion of the thumb
Tendon of
biceps
brachii
Median nerve
Pronator teres (cut)
Brachial artery
Radius
Ulna
Brachioradialis
(retracted)
Flexor carpi
ulnaris (retracted)
Flexor digitorum
superficialis
Flexor pollicis
longus
Flexor digitorum
profundus
LATERAL
MEDIAL
Anterior view of the middle layer of
muscles. The flexor carpi radialis
muscle and palmaris longus muscle
have been removed.
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Supinator
Brachialis
Cut tendons of
flexor digitorum
superficialis
Flexor digitorum
profundus
Flexor pollicis
longus
Pronator
quadratus
(see Figure
11.8f)
LATERAL
MEDIAL
Anterior view of the deep layer of muscles
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Extrinsic Muscles of the Hand (continued)
—  Extensor/Abductor Group
—  Abductor pollicis longus: abduction of thumb
—  Extensor digitorum: extension of fingers and wrist
—  Extensor pollicis brevis: extension of thumb,
abducts the wrist
—  Extensor indicis: extension and adduction of index
finger
—  Extensor digiti minimi: extension of little finger,
extension of wrist
Summary for extensors of digits
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Anconeus
Extensor
digitorum
Extensor
digiti minimi
Tendon of
extensor
pollicis longus
MEDIAL
Abductor
pollicis longus
Extensor
pollicis brevis
LATERAL
Posterior view of the
middle layer of muscles
Anconeus
Supinator
Abductor
pollicis longus
Extensor
pollicis longus
Extensor indicis
Extensor
pollicis brevis
Ulna
Radius
Tendon of
extensor
digiti minimi
(cut)
Tendon of
extensor
digitorum
(cut)
MEDIAL
LATERAL
Intrinsic Muscles of the Hand
—  Thenar Muscles
—  Adductor pollicis : adducts the thumb
—  Abductor pollicis brevis: abducts the thumb
—  Opponens pollicis: opposition movement of the thumb
—  Flexor pollicis brevis: flex and adduct thumb
—  Hypothenar Muscles
—  Flexor digiti minimi brevis: flex little finger
—  Opponens digiti minimi: brings digits into opposition with the
small digit
—  Abductor digiti minimi: abducts little finger
—  Palmaris brevis: moves the skin on the medial side of the palm
Intrinsic Muscles of the Hand
—  Midpalmar Muscles
—  Lumbricals: flexion of the digits at metacarpophalangeal joints
—  Dorsal interosseus: abduction of digits 2–4
—  Palmar interosseus: adduction of digits 2, 4, and 5
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Tendon of flexor
digitorum profundus
Tendon of flexor
digitorum superficialis
First dorsal interosseus
Synovial
sheaths
Tendon of flexor
pollicis longus
Lumbricals
Palmar
interosseus
Adductor
pollicis
Tendons of flexor
digitorum (both
profundus and
superficialis)
Opponens digiti
minimi
Flexor pollicis
brevis
Opponens
pollicis
Flexor digiti
minimi brevis
Abductor pollicis
brevis
Palmaris brevis (cut)
Tendon of
palmaris longus
Abductor digiti
minimi
Flexor retinaculum
Tendon of flexor
carpi ulnaris
Tendon of
flexor carpi radialis
Anterior (palmar) view
Figure 11.11a Intrinsic Muscles, Tendons, and Ligaments of the Hand
Tendon of
extensor indicis
First dorsal
interosseus
muscle
Tendon of
extensor
digiti minimi
Abductor
digiti minimi
Tendon of
extensor
pollicis longus
Tendon of extensor
pollicis brevis
Tendon of
extensor
carpi ulnaris
Extensor
retinaculum
Tendon of extensor
carpi radialis longus
Tendon of extensor
carpi radialis brevis
Posterior (dorsal) view