regional and functional anatomy - elbow to digits

Question 1

What muscles comprise the anterior compartment of the arm?

Answer 1

Biceps brachii (long head and short head)
Brachialis
Brachioradialis

Question 2

Biceps brachii

Answer 2

Long head
Origin: supraglenoid tubercle
Insertion: radial tuberosity

Short head
Origin: coracoid process of scapula
Insertion: radial tuberosity

Question 3

Brachialis

Answer 3

Mainly responsible for elbow flexion
Origin: distal half of anterior humerus shaft
Insertion: coranoid process of ulna

Question 4

Brachoradialis

Answer 4

Origin: lateral supracondylar ridge of humerus
Insertion: radial styloid process

Question 5

Cubital fossa

Answer 5

Soft tissue depression in anterior elbow, contains veins and arteries, common site for venepuncture of superficial veins

Question 6

What muscles comprise the posterior compartment of the arm?

Answer 6

Triceps brachii (long, medial and lateral head)

Question 7

Triceps brachii

Answer 7

Long head: infraglenoid tubercle
Medial head: distal posteromedial humerus
Lateral head: proximal posteriomedial humerus

Insertion: olecranon process of ulna

Question 8

Radioulnar joint

Question 9

Which muscles are involved in pronation and where do they originate?

Answer 9

Pronator muscles originate in the anterior forearm (pronator teres and pronator quadratus).

Question 10

Pronator teres

Answer 10

Origin: Medial supracondylar ridge
Insertion: lateral radius

Question 11

Pronator quadratus

Answer 11

Origin: distal anterior ulnar
Insertion: distal anterior radius

Question 12

Muscles of the wrist

Answer 12

Anterior (flexion): originate from the medial epicondyle of the humerus
posterior (extension): originate from the lateral epicondyle of the humerus

Question 12

Supinator muscles

Answer 12

Supinator
Origin: lateral epicondyle and supinator chest of ulna
Insertion: anterolateral radius

Question 13

Anterior compartment (flexor carpi radialis)

Answer 13

Origin: medial epicondyle of humerus
Insertion: anterior base of 2nd and 3rd metacarpal

Question 14

Anterior compartment (palmaris longus)

Answer 14

Origin: medial epicondyle of humerus
Insertion: palmer aponeurosis

Question 15

Anterior compartment (flexor carpi ulnaris)

Answer 15

Origin: medial epicondyle of humerus
Insertion: medial carpals and anterior base of 5th metacarpal

Question 16

Posterior compartment (extensor carpi radialis longus)

Answer 16

Origin: lateral epicondyle of humerus
Insertion: posterior base of 2nd metacarpal

Question 17

Posterior compartment (extensor carpi radialis brevis)

Answer 17

Origin: lateral epicondyle of humerus
Insertion: posterior base of 3rd metacarpal

Question 18

Extensor carpi ulnaris

Answer 18

Origin: lateral epicondyle of humerus
Insertion: posterior base of 5th metacarpal

Question 19

Muscles of the digits

Answer 19

Anterior compartment (flexor digitorum superficialis, flexor digitorum profundus and flexor pollicus longus).

All originate from the deep antero-medial aspect of forearm

Posterior compartment (extensor digitorum, extensor indicis, extensor digiti minimi, extensor pollicus longus and extensor pollicus brevis).

All originate from the deep posterolateral aspect of forearm

Question 20

Flexor digitorum superficialis

Answer 20

Insertion: intermediate phalanges (2-5)

Question 21

Flexor digitorum profundus

Answer 21

Insertion: distal phalangaes (2-5)

Question 22

Flexor pollicus longus

Answer 22

Insertion: distal phalanx of thumb

Question 23

Extensor digitorium

Question 24

Extensor indicis

Answer 24

Insertion at the index

Question 25

Extensor digiti minimi

Answer 25

Extensor of the #5 phalange (pinky)

Question 26

Extensor pollicus longus

Answer 26

Insertion at the base of the distal phalanx, acts on the interphalangeal and metacarpohalangeal joints of the thumb.

Question 27

Extensor pollicus brevis

Answer 27

Insertion at the base of the proximal phalanx