M100 Muscles

Question 1

Origin: Short head- Coracoid. Long head- Supraglenoid tubercle of the scapula
Insertion: Radial tuberosity and bicipital aponeurosis
Actions: Flexion of humerus and elbow, supination of forearm (radioulnar joint)

Answer 1

Biceps Brachii

Question 2

Origin: Infraglenoid tubercle of scapula
Insertion: Olecranon process of ulna
Actions: All heads- Extension of elbow
Long head- Extension of the humerus and adduction of shoulder

Answer 2

Triceps Brachii

Question 3

Origin: Lateral epicondyle of humerus
Insertion: Olecranon process of ulna
Action: (Weak) Flexion of elbow

Answer 3

Anconeous

Question 4

Origin: Anterior shaft of humerus
Insertion: Ulnar tuberosity
Action: Flexion of elbow

Answer 4

Brachialis

Question 5

Origin: Later supracondylar ridge of humerus
Insertion: Styloid process of radius
Action:Flexion of elbow in neutral position
Assists in pronation and supination of forearm (antagonist to itself) when these movements are resisted

Answer 5

Brachioradialis

Question 6

Origin: Coracoid process of the scapula
Insertion: Medial surface of the mid-humeral shaft
Actions: Flexion and adduction of the shoulder (at the glenohumeral joint)

Answer 6

Coracobrachialis

Question 7

Origin: Lateral epicondyle of the humerus and ligamentous tissues around the ulna
Insertion: Anterior lateral surface of the proximal 1/3 of the radial shaft
Actions: Supinates the forearm

Answer 7

Supinator

Question 8

Origin: Humeral head- medial epicondyle of the humerus
Ulnar head- coranoid process of the ulna
Insertion: Middle of the lateral surface of the radius
Actions: Pronation of the forearm. Assists in flexing the elbow

Answer 8

Pronator teres

Question 9

Origin: Medial anterior surface of the distal ulna
Insertion: Lateral anterior surface of the distal radius
Actions: Pronates the forearm at the Distal radioulnar joint

Answer 9

Pronator Quadratus

Question 10

Origin: Inferior border of the rib above
Insertion: Superior border of the rib below
Actions: External- elevate ribs in inhalation
Internal- depress ribs in exhalation
Both: maintain interstitial space

Answer 10

Intercostals (internal and external)

Question 11

Origin:Pubic crest and pubic symphysis
Insertion: Costal cartilage of ribs 5,6,7 and xiphoid process
Actions: Flexion of trunk, posterior pelvic tilt, supports compression of abdominal contents

Answer 11

Rectus Abdominis

Question 12

Origin: External surface of ribs 5-12
Insertion: Illiac crest and abdominal aponeurosis to linea alba
Actions: Bilaterally- flexion of trunk& compression of abd contents. Unilaterally- Lateral flexion and rotation to the opposite side

Answer 12

External Oblique

Question 13

Origin: Illiac crest and inguinal ligament
Insertion: Ribs 10-12, Abdominal aponeurosis to linea alba
Actions: Bilaterally- Flexion of trunk, compression of ABD contents
Unilaterally- Lateral flexion, rotation of trunk to the opposite side

Answer 13

Internal obliques

Question 14

Origin: Lower ribs, iliac crest& fascia
Insertion: pubic bone and linea alba
Actions: Compression of abdominal contents

Answer 14

Transverse abdominis

Question 15

Which direction do the fibers of internal obliques go?

Answer 15

Up and medial

Question 16

Which direction do the fibers of the external obliques go?

Answer 16

Down and medial