Muscles of the Upper Body Abdominal Muscles Abdominal

Muscles of the Upper Body

Abdominal Muscles

Abdominal Muscles 1. 2. 3. Rectus abdominus External and internal obliques Transversus abdominus Axial Musculature Positions spinal column Does NOT play a role in movement or support of pectoral or pelvic girdles or appendages.

Rectus Abdominus (“straight”) �Action: depresses ribs, flexes vertebral column I O

External and Internal obliques �Oblique = diagonal �External obliques are superficial to internal �Action: compresses abdomen, depress ribs, lateral flexion of vertebral column O I

Transversus Abdominus �Action: compresses abdomen I

q. Rectus abdominus q. External obliques q. Internal obliques q. Transversus abdominus

Muscles that Stabilize the Pectoral Girdle INSERT ON SCAPULA

Muscles of the Pectoral Girdle 1. 2. 3. 4. 5. Trapezius Levator scapulae Pectoralis minor Rhomboid muscles Serratus anterior ALL have insertions on scapula and therefore cause movement of the scapula

Trapezius (“trapezoid”) �Broad superficial muscle of the back �Action: depends on the active region and state of other muscles I O

Levator Scapulae (“elevates”) �Action: elevates scapula EX: shrugging shoulders O I

Pectoralis Minor �Action: depresses and protracts the shoulder, rotates scapula laterally EX: pressing shoulders downward I O

Rhomboid Muscles �Action: retraction (adduction) EX: pinching shoulder blades together O I

Serratus Anterior �Action: protraction, abduction and rotates scapula upward O I

Muscles of the pectoral girdle q. Trapezius q. Pectoralis minor q. Serratus Anterior

Muscles of the pectoral girdle q. Trapezius q. Rhomboid q. Levator scapulae

clavotrapezius Levator scapulae acromiotrapezius spinotrapezius Differences in the cat: External obliques • Trapezius muscle is 3 distinct muscles named… clavotrapezius, acromiotrapezius and spinotrapezius • Levator scapulae in cats is superficial

Muscles that move the arm

Muscles that move the arm 1. 2. 3. 4. 5. 6. 7. 8. Deltoid Pectoralis major Lattisimus dorsi Teres Major Supraspinatus Infraspinatus Teres minor subscapularis ALL have insertions on humerus and therefore cause movement of the humerus

Deltoid (“triangular”) �Action: major abductor O I

Pectoralis Major �Between sternum and greater tubercle of humerus �Produces flexion, adduction and O medial rotation I

Latissimus dorsi (dorsi = back) �Between thoracic vertebrae and humerus �Action: extension, adduction, medial rotation I O I

Teres Major �Action: adduction, medial rotation I O

Supraspinatus �Assists the deltoid in abduction �Rotator cuff muscle O I

Infraspinatus �Rotator Cuff Muscle �Action: lateral rotation O I

Teres minor �Rotator Cuff Muscle �Action: lateral rotation I O

Subscapularis �Rotator Cuff Muscle �Action: medial rotation I O

Muscles that move the arm q. Deltoid q. Latissimus dorsi q. Supraspinatus q. Infraspinatus q. Teres minor q. Teres major

Muscles that move the arm q. Deltoid q. Pectoralis major

Muscles that move the forearm, wrist and hand

Muscles that move the forearm 1. 2. 3. 4. 5. Biceps brachii Brachialis Brachioradialis Triceps brachii Pronator teres ALL originate on the humerus and insert on forearm Exception: triceps and biceps originate on the scapula Flexors = anterior/medial Extensors = posterior/lateral

Biceps brachii (“two origins”) �Two origins short head long head �Primary action: flexion at elbow and supination �Secondary action: flexion at shoulder

Brachialis �Assists biceps �Action: flexion at elbow

Brachioradialis �Assists biceps �Action: flexion at elbow

Triceps brachii (“three origins”) �Action: extension at elbow

Pronator Teres �Action: pronation

Muscles that move the wrist and hand FLEXORS (anterior/ventral) 1. Flexor carpi radialis 2. Flexor carpi ulnaris 3. Palmaris longus 4. Flexor digitorum EXTENSORS (posterior/dorsal) 1. Extensor carpi radialis 2. Extensor carpi ulnaris 3. Extensor digitorum ALL have insertions on the carpals and metacarpals and therefore cause movement of the hand at the wrist

Deltoid Biceps brachii Pectoralis major Brachialis Pronator teres Brachioradalis Palmaris longus Flexor carpi radialis Flexor carpi ulnaris

Triceps brachii brachioradialis Extensor carpi radialis Extensor digitorum Extensor carpi ulnaris

sternocleidomastoid Pectoralis Minor Internal Intercostals Trapezius Deltoid Pectoralis Major Serratus Anterior Rectus Abdominus Connective tissue Internal obliques External obliques Transverse Abdominus Tendinous sheet

Trapezius Deltoid Levator Scapulae supraspinatus infraspinatus Teres minor Teres Major Rhomboid Major Latissimus dorsi