The Muscles of the Upper Extremity
- A Visual Guide -
Anatomy & Physiology I
BIOL 121
Rob Swatski
Associate Professor of Biology
HACC - York Campus
Frontalis
Draws back scalp, wrinkles forehead,
raises eyebrows 2
Frontalis
3
Occipitalis
Draws back scalp, wrinkles forehead 4
Auricularis anterior
Moves the ear 5
Orbicularis oculi
Closes eyelids; used in blinking,
winking, and squinting 6
Orbicularis oculi
7
Zygomaticus major
Draws angles of mouth upward
and outward; major muscle
used in smiling and laughing 8
Zygomaticus major
9
Zygomaticus major
10
Orbicularis oris
Closes and protrudes lips;
the "kissing muscle“; used
in whistling and forming many letters
during speech 11
Orbicularis oris
12
Risorius
Draws angles of mouth
laterally; used in grinning 13
Depressor anguli oris (Triangularis)
Draws angles of mouth
downward and laterally when
opening mouth; used in
frowning 14
Depressor anguli oris (Triangularis)
15
Buccinator
Draws angles of mouth laterally;
compresses cheek;
used to create
sucking action 16
Mentalis
Elevates and protrudes lower lip;
used in pouting 17
Platysma
http://commons.wikimedia.org/wiki/File:Platysma.png
Draws down lower lip and angles of mouth; tenses skin of the neck; helps depress mandible 18
Masseter
Elevates mandible
when chewing and slightly protracts it 19
Masseter
20
Temporalis
Elevates, retracts, and assists in side-to-side movement of mandible 21
Genioglossus
http://commons.wikimedia.org/wiki/File:Genioglossus.png
Protracts and depresses tongue 22
Styloglossus
http://commons.wikimedia.org/wiki/File:Styloglossus.png
Retracts and elevates tongue 23
Stylohyoid
http://commons.wikimedia.org/wiki/File:Musculi_colli_stylohyoideus.svg
Retracts and elevates the hyoid bone 24
Sternocleidomastoid
Contraction of one side: laterally flexes neck, rotates head to opposite side Contraction of both sides together: flexes neck 25
Sternocleidomastoid
26
Semispinalis capitis
Extends head and rotates it to opposite side 27
Splenius capitis
Extends and hyperextends head; Contraction of only one side laterally flexes and rotates head and neck 28
Splenius capitis
29
Trapezius
Elevates, depresses,
retracts, and rotates scapula;
rotates arm 30
Trapezius
31
Trapezius
32
Latissimus dorsi
Extends, adducts, and medially rotates arm;
draws shoulder downward and
backward 33
Latissimus dorsi
34
Pectoralis major
Adducts and medially rotates arm; flexes and
extends humerus 35
Pectoralis major
36
Serratus anterior
Abducts and protracts scapula 37
Serratus anterior
38
Deltoid
Flexes, medially rotates, and abducts arm 39
Coracobrachialis Flexes and adducts humerus
40
Coracobrachialis
41
Supraspinatus
Abducts arm; stabilizes head of humerus in glenoid cavity; one of the "rotator cuff" muscles 42
Infraspinatus
Laterally rotates shoulder; stabilizes head of humerus in glenoid cavity; one of the "rotator cuff" muscles 43
Teres minor
Laterally rotates arm; one of the "rotator cuff" muscles 44
Teres major
Medially rotates and adducts arm 45
Biceps brachii
Flexes and supinates forearm 46
Biceps brachii
47
Brachialis
Flexes elbow 48
Triceps brachii
Extends forearm 49
Triceps brachii
50
Anconeus
Extends forearm and stabilizes elbow joint
51
Anconeus
52
Brachioradialis Flexes elbow
53
Pronator teres Pronates forearm and
assists in flexing elbow
54
Flexor carpi radialis Flexes wrist and abducts hand
55
Palmaris longus
Flexes wrist
56
Flexor carpi ulnaris
Flexes and adducts wrist
57
Extensor carpi radialis longus
Extends wrist and abducts hand
58
Extensor digitorum
Extends fingers and wrist
59
External intercostals
Elevates rib cage 60
Internal intercostals
Draws ribs together and depresses rib cage 61
Pectoralis minor
Elevates 3rd-5th ribs during forced inspiration 62
Diaphragm
Flattens on contraction,
increasing volume of
thorax during inspiration 63
External oblique
Compresses abdomen; laterally flexes and rotates vertebral column 64
External oblique
65
Internal oblique
Compresses abdomen; laterally flexes and rotates vertebral column 66
Transversus abdominis
Constricts abdomen and supports abdominal viscera 67
Transversus abdominis
68
Rectus abdominis
Compresses abdominal cavity and flexes vertebral column 69
Quadratus lumborum
Flexes lumbar region of vertebral
column laterally to the same
side; stabilizes and extends
lumbar vertebrae 70
Quadratus lumborum
71
Spinalis group of erector spinae
http://commons.wikimedia.org/wiki/File:Spinalis.png Extends vertebral column 72
Longissimus group of erector spinae
Extends and laterally flexes vertebral column 73
Iliocostalis group of erector spinae
http://commons.wikimedia.org/wiki/File:Longissimus.png
Extends and laterally flexes vertebral column 74
Levator ani
http://commons.wikimedia.org/wiki/File:Levator_ani.png
Forms floor of pelvic cavity; assists in defecation 75
Anconeus: 51-52 Auricularis anterior: 5 Biceps brachii: 46-47 Brachialis: 48 Brachioradialis: 53 Buccinator: 16 Coracobrachialis: 40-41 Deltoid: 39 Depressor anguli oris: 14-15 Diaphragm: 63 Extensor carpi radialis longus: 58 Extensor digitorum: 59 External intercostals: 60 External oblique: 64-65 Flexor carpi radialis: 55 Flexor carpi ulnaris: 57 Frontalis: 2-3 Genioglossus: 22 Iliocostalis group of erector spinae: 74 Infraspinatus: 43 Internal intercostals: 61 Internal oblique: 66 Latissimus dorsi: 33-34 Levator ani: 75 Longissimus group of erector spinae: 73 Masseter: 19-20 Mentalis: 17
Occipitalis: 4 Orbicularis oculi: 6-7 Orbicularis oris: 11-12 Palmaris longus: 56 Pectoralis major: 35-36 Pectoralis minor: 62 Platysma: 18 Pronator teres: 54 Quadratus lumborum: 70-71 Rectus abdominis: 69 Risorius: 13 Semispinalis capitis: 27 Serratus anterior: 37-38 Spinalis group of erector spinae: 72 Splenius capitis: 28-29 Sternocleidomastoid: 25-26 Styloglossus: 23 Stylohyoid: 24 Supraspinatus: 42 Temporalis: 21 Teres major: 45 Teres minor: 44 Transversus abdominis: 67-68 Trapezius: 30-32 Triceps brachii: 49-50 Zygomaticus major: 8-10
INDEX
Credits All photographs and labels by Rob Swatski, 2009-2012
http://robswatski.virb.com
This work bears an Attribution-Noncommercial Share Alike Creative Commons license.
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