Anatomy- Anterior Arm, Anterior Forearm and Cubital Fossa

Question 1

what muscles are in the anterior compartment of the arm

Answer 1

biceps brachii, brachialis, coracobrachialis

Question 2

what is the innervation of the anterior compartment of the arm

Answer 2

musculocutaneous nerve

Question 3

what are the actions of the anterior compartment of the arm

Answer 3

flexion of the arm and forarm

Question 4

what is the extra role of the biceps brachii

Answer 4

also supinates the forearm

Question 5

what muscles are in the superficial layer of the anterior compartment of the forearm

Answer 5

pronator teres,

flexor carpi radialis, palmaris longus, flexor carpi ulnaris

Question 6

what muscles are in the intermediate layer of the anterior compartment of the forearm

Answer 6

flexor digitorum superficialis

Question 7

what muscles are in the deep layer of the anterior compartment of the forearm

Answer 7

flexor digitorum profundus, flexor pollicis longus, pronator quadratus

Question 8

what is the innervation of the anterior forearm

Answer 8

all median nerve expect:
-flexor carpi ulnaris
-medial half of flexor digitorum superficialis (digits 4 & 5)
which are ulnar nerve

Question 9

what are the actions of the anterior forearm muscles

Answer 9

• flexion of the wrist and digits
• pronation
• abduction and adduction of the wrist

Question 10

how can the superficial muscles of the anterior forearm attach more proximal than the deep layer

Answer 10

as split to allow deep layer to go through

Question 11

what does the biceps brachii consist of

Answer 11

long and short head (plus tendon of long and short head),

two distal tendons- biceps tendon and bicipital aponeurosis

Question 12

what are the proximal attachments of biceps brachii

Answer 12

long head= supraglenoid tubercle of the scapula

short head- coracoid process of the scapula

Question 13

what three muscles attach to the coracoid process

Answer 13

pectoralis minor, coracobrachialis, short head of biceps

Question 14

what is the path of the tendon of the long head of the biceps

Answer 14

passes superiorly in the intertubercular (bicipital) groove/ sulcus of the humerus

then becomes enclosed within the fibrous layer of the shoulder joint capsule

reaches the supraglenoid tubercle of the scapula

Question 15

why might palpation of the tendon of the long head of biceps be painful

Answer 15

biceps tendinitis- causes shoulder pain, caused by movement of the ligament in the groove

Question 16

what are the two distal attachments of the biceps brachii

Answer 16

the biceps tendon- attaches to the the radial tuberosity

the bicipital aponeurosis- blends with the deep (antebrachial) fascia on the medial side of the proximal forearm

Question 17

what does the biceps deep tendon (myotactic) reflex test

Answer 17

• confirms the function of the muscle
• its peripheral nerve supply
• central connections at the spinal chord level (reflex arc) and above (descending controls)

Question 18

what are the peripheral nerves supplying the biceps brachii (and its nerve roots)

Answer 18

musculocutaneous (C5 and C6)

Question 19

how is the biceps deep tendon reflex tested

Answer 19

placing the examiners thumb on the biceps tendon (within the cubital fossa) and then striking briskly the examiners thumb with a tendon hammer

this conveys a sudden stretch of the biceps tendon and should elicit an involuntary (reflex) contraction of the muscles (patient will flex their forearm at the elbow)

Question 20

where does the coracobrachilalis attach proximally and distally

Answer 20

coracoid process of the scapula

medial surface of the humerus

Question 21

where is coracobrachialis in relation to the other muscles of the anterior arm

Answer 21

deep to biceps brachii and medial to brachialis

Question 22

what separates the coracobrachialis from the triceps

Answer 22

medial intermuscular septae

Question 23

what is the origin and insertion of the brachialis

Answer 23

humerus

coronoid process of ulnar

Question 24

where is brachialis in relation to the other muscles of the anterior arm

Answer 24

deep to biceps brachii and lateral to coracobrachilis

Question 25

what separates the brachialis from the triceps

Answer 25

lateral intermuscular septae

Question 26

what do the muscles of the anterior compartment of the arm span

Answer 26

the shoulder and elbow joint biceps brachii also spans the proximal radioulnar joint

Question 27

what muscle is the most powerful supinator of the forearm

Answer 27

biceps brachii

Question 28

what are the actions of the muscles of the anterior compartment of the forearm

Answer 28

flexion, abduction and adduction of the wrist (carpus) flexion of the fingers (digits 2-5: index-little) flexion of the thumb (muscles named pollicis) pronation of the forearm at the proximal and distal radioulnar joints

Question 29

where do the muscles in the superficial anterior forearm originate

Answer 29

to the medial epicondyle of the humerus via the common flexor tendon

Question 30

where does pronator teres attach distally

Answer 30

lateral surface of the radius

Question 31

where does the palmaris longus attach distally

Answer 31

to the palmar aponeurosis

Question 32

where does the flexor carpi radialis attach distally

Answer 32

metacarpals on the radial side

Question 33

where does the flexor carpi ulnaris attach distally

Answer 33

metacarpals on the ulnar side

Question 34

where does the intermediate layer of the anterior forearm attach to proximally

Answer 34

medial epicondyle of humerus, coronoid process of ulna and radial head

Question 35

where does flexor digitorum superficialis attach distally (intermediate compartment)

Answer 35

has four muscle bellies/ tendons for the medial four digits- attaches at middle phalanges

Question 36

where do the deep muscles of the anterior forearm attach proximally

Answer 36

to the anterior surfaces of the radius or ulnar

Question 37

where does the flexor digitorum profundus attach proximally and distally

Answer 37

ulnar distal phalanges of digits 2-5

Question 38

where does the flexor pollicis longus attach proximally and distally

Answer 38

radius distal phalanx of the thumb

Question 39

where does the pronantor quadratus attach proximally and distally

Answer 39

anterior surface of ulnar to anterior surface of radius

Question 40

what holds the tendons of the muscles in the anterior compartment of the forearm in place as they pass into the wrist and hand

Answer 40

palmar carpal ligament - at wrist joint | flexor retinaculum - at carpus

Question 41

where does the common flexor tendon attach proximally

Answer 41

medial epicondyle of the humerus

Question 42

what is golfers elbow

Answer 42

medial epicondylitis | -pain felt in area of medial epicondyle as a result of tendonitis of the common flexor tendon

Question 43

what is the superior boundary of the cubital fossa

Answer 43

a transverse line between the epicondyles of the humerus

Question 44

what is the medial boundary of the cubital fossa

Answer 44

pronator teres

Question 45

what is the lateral boundary of the cubital fossa

Answer 45

brachioradialis

Question 46

what are the superficial contents of the cubital fossa

Answer 46

``` median cubital vein, cephalic vein, basilic vein distal tendon (deep and lateral) and aponeurosis (medial) of biceps brachii are palpable in the fossa ```

Question 47

what are the deep contents of the cubital fossa

Answer 47

median nerve (medially), brachial artery, radial nerve (laterally)

Question 48

where does the median nerve after the cubital fosa

Answer 48

continues into the anterior compartment of the forearm

Question 49

what happens to the brachial artery at the cubital fossa

Answer 49

bifurcates into radial and ulnar arteries at the apex of the triangle

Question 50

what happens to the radial nerve at the cubital fossa

Answer 50

radial nerve divides into its superficial and deep branches when deep to brachialis deep branch pierces supinator to enter to to entrt the foresr

Question 51

what is the cubital fossa

Answer 51

triangular space between skin and the anterior aspect of the capsule of the shoulder joint

Question 52

what is the funny bone

Answer 52

where the ulnar crosses the posterior surface of the medial epicondyle of the humerus

Question 53

how does the ulnar nerve reach the anterior compartment of the forearm

Answer 53

passes through flexor carpi ulnaris (in cubital tunnel)