Anterior Trunk: Origin, Insertion, and Action

Question 1

Serratus Anterior

Answer 1

Origin: ribs 1-8/9
Insertion: medial border of scapula
Action: rotates glenohumeral joint upward

Question 2

External Obligue

Answer 2

Origin: external surface of ribs 5-12
Insertion: anterior iliac crest, linea alba
Action: flection and rotation of trunk; laterally flexes abdomen

Question 3

Internal Oblique

Answer 3

Origin: anterior iliac crest, lateral half of inguinal ligament
Insertion: costal cartilages of ribs 8-12; linea alba
Action: flexes and rotates trunk; laterally flexes abdomen

Question 4

Transverse abdominis

Answer 4

Origin: anterior iliac crest; cartilages in ribs 6-12
Insertion: xiphoid process, public synthesis, linea alba
Action: compression of abdomen

Question 5

Rectus Abdominis

Answer 5

Origin: pubic crest, pubic synthesis
Insertion: fifth through seventh costal cartilages, xiphoid process
Action: flexes lumbar vertebrae

Question 6

Brachiordialis

Answer 6

Origin: upper lateral supracondylar ridge of humerus
Insertion: superior aspect of styloid process of radius, lateral half of radius
Action: flection of forearm

Question 7

Brachialis

Answer 7

Origin:distal half of humerus
Insertion: coronoid process of ulna
Action: flection of forearm

Question 8

Biceps Brachii

Answer 8

Origin: longhead= supraglenoid tubercle and superior portion of glenoid labrum, shorthead= coracoid process
Insertion: radial tuberosity
Action: flection and supranation of forearm, flection of shoulder

Question 9

Pectoralis Minor

Answer 9

Origin: anterior surface of ribs 3-5
Insertion: coracoid process of scapula
Action: scapular protraction, assists in scapular rotation

Question 10

Pectoralis Major

Answer 10

Origin: clavicular= medial half of clavicle; sternal head, costal cartilages of ribs 1-6
Insertion: lateral lip of intertubicular groove
Action: adduction of humerus, medial rotation of humerus, assists in shoulder flection

Question 11

Deltoid

Answer 11

Origin:ant=lateral 3rd of clavicle, middle=acromion, post= spine of scapula
Insertion: deltoid tuberosity
Action: abduction, shoulder flection, shoulder extension