Arm and Forearm

Question 1

What is the single long bone of the upper arm?

Answer 1

Humerus

Question 2

Where does the deltoid muscle insert?

Answer 2

The deltoid tuberosity on the humerus

Question 3

On the distal end of the humerus, the _________ articulates with the ulna, while the _________ articulates with the radius.

Answer 3

Trochlea articulates with the ulna while the capitulum articulates with the radius

Question 4

What is the fascia of the arm called?

Answer 4

The brachial fascia

Question 5

Name the upper arm compartments.

Answer 5

Anterior, posterior

Question 6

Where does the triceps muscle insert?

Answer 6

The olecranon of the ulna

Question 7

Which nerve innervates the posterior arm compartment?

Answer 7

Radial nerve

Question 8

Name the muscles of the posterior arm compartment.

Answer 8

Triceps, that’s it!

Question 9

Name the muscles of the anterior arm compartment.

Answer 9

Coracobrachialis
Biceps brachii
Brachialis

Question 10

Which nerve innervates the anterior arm compartment? Is it classified as a preaxial, or postaxial nerve?

Answer 10

Musculocutaneous nerve. Preaxial nerve because it is a innervates flexor muscles.

Question 11

As the musculocutaneous nerve travels distally into the lateral forearm, it supplies cutaneous innervation to the ________ and is renamed the _________ _________ nerve of the forearm.

Answer 11

supplies cutaneous innervation to the lateral forearm and is renamed the lateral cutaneous nerve of the forearm! That is why it is called the musculo cutaneous nerve!

Question 12

What are the compartments of the forearm?

Answer 12

Anterior and posterior

Question 13

The deep fascia of the forearm separates the anterior from the posterior compartments and at the wrist forms a fibrous flexor and extensor _________ similar to the ankle joint. In the palm, the deep fascia forms the palmar _________.

Answer 13

extensor retinacula

palmar aponeurosis

Question 14

Name the subdivisions of the anterior/flexor forearm compartment muscles.

Answer 14

Deep, intermediate, superficial

Question 15

The middle and deep muscles of the anterior/flexor compartment of the forearm act to _______ the ________.

Answer 15

flex the digits

Question 16

The superficial muscles of the anterior/flexor compartment of the forearm act to ______ the ______.

Answer 16

flex the wrist

Question 17

Name the muscles of the deep muscle group of the anterior/flexor forearm compartment.

Answer 17

Flexor digitorum profundus and flexor pollicis longus.

Question 18

Name the muscle of the intermediate muscle group of the anterior/flexor forearm compartment.

Answer 18

Flexor digitorum superficialis

Question 19

Name the muscles of the superficial muscle group of the anterior/flexor forearm compartment.

Answer 19

Pronator teres, flexor carpi radialis, flexor palmaris longus, flexor carpi ulnaris

Question 20

What nerve supplies the anterior/flexor forearm compartment muscles?

Answer 20

Trick question! It isn’t that easy!

Superficial: Flexor carpi radialis and palmaris longus are supplied by median nerve. Flexor carpi ulnaris is supplied by ulnar nerve.

Intermediate: Flexor digitorum superficialis is supplied by the median nerve.

Deep: Flexor pollicis longus is supplied by the median nerve. The radial half of flexor digitorum profundus is supplied by the median nerve and the ulnar half is supplied by the ulnar nerve.

Question 21

How am I going to remember the innervation of the anterior forearm?

Answer 21

The median nerve supplies everything except 1.5 muscles: The flexor carpalis ulnaris and the ulnar half of the flexor digitorum profundus.

Question 22

Name the three major arteries of the forearm.

Answer 22

1. Radial artery
2. Ulnar artery
3. Anterior interosseous artery

Question 23

Which arteries travel distally into the hand from the forearm to become the palmar arches?

Answer 23

The radial and ulnar arteries

Question 24

Which artery supplies the deep flexor muscles?

Answer 24

Anterior interosseous artery - it runs deep to the muscles along the interosseous membrane

Question 25

What are the subdivisions of the extensor/posterior forearm muscles?

Answer 25

Superficial, deep

Question 26

There are ____ superficial posterior/extensor forearm muscles and ____ deep posterior/extensor muscles. (how many?)

Answer 26

8

4

Question 27

Which nerve innervates the extensor/posterior muscles of the forearm?

Answer 27

Radial nerve innervates all of them!

Question 28

The brachioradialis muscle is a member of the _______ forearm compartment. It crosses the ______ joint and acts to ______ the elbow.

Answer 28

member of the posterior forearm compartment. Crosses the elbow joint and acts to flex the elbow.

Question 29

Which muscle is the “beer drinker’s muscle?”

Answer 29

Brachioradialis

Question 30

Aside from brachioradialis, what is the other posterior forearm muscle that crosses the elbow joint?

Answer 30

Anconeus

Question 31

What happens to the radial nerve as it travels distally down the forearm?

Answer 31

It divides into a superficial (cutaneous) branch and a deep (motor) branch also known as the posterior interosseous nerve.

Question 32

If a patient has “wrist drop” (can’t extend the hand and digits), then which nerve is likely damaged?

Answer 32

Radial nerve

Question 33

Carpal tunnel syndrome results from compression of which nerve?

Answer 33

Median nerve

Question 34

Which nerve is affected by cubital tunnel syndrome?

Answer 34

Ulnar nerve

Question 35

Erb’s palsy is characterized by an injury to the _____ and _____ nerve roots of the brachial plexus. It can happen during childbirth.

Answer 35

C5, C6

Question 36

Klumpke’s palsy results from injury to the ____ and ____ nerve roots of the brachial plexus.

Answer 36

C8, T1

Question 37

What is the “carrying angle?” What is a normal carrying angle?

Answer 37

angle between humerus

and ulna – normally 10-15 degrees

Question 38

What is a Colles’ fracture? What is a Smith’s fracture?

Answer 38

Colles’ fracture is a distal radius fracture from falling on an extended wrist. The distal radius is displaced posteriorly. Results in a dinner fork deformity.

Smith’s fracture is a distal radius fracture from falling on a flexed wrist. The distal radius is displaced anteriorly.

Question 39

Does the scaphoid heal easily? Why or why not?

Answer 39

No, poor blood flow.

Question 40

List the posterior/extensor muscles of the forearm (8 superficial, 4 deep).

Answer 40

Superficial group:

1. Brachoradialis
2. Anconeus
3. Extensor carpi radialis longus
4. Extensor carpi radialis brevis
5. Extensor carpi ulnaris
6. Extensor digitorum
7. Extensor digiti minimi
8. Supinator

Deep group:

1. Extensor indicis
2. Extensor pollicis longus
3. Extensor pollicis brevis
4. Abductor pollicis longus

Question 41

The flexor carpi radialis tendon in the wrist is used to locate which artery? Where does this artery lie in relation to the tendon?

Answer 41

The radial artery lies lateral to the flexor carpi radialis tendon.

Question 42

The ______ artery is an often used arterial puncture for blood gas analysis.

Answer 42

radial

Question 43

Lateral epicondylitis (tennis elbow) is caused by chronic inflammation of the common tendon of the ________ muscles.

Answer 43

extensor muscles

Question 44

Golfer’s elbow (medial epicondylitis) is caused by irritation and inflammation of the _______ muscles of the forearm. Which nerve is at risk for compression from inflammation of these tendons?

Answer 44

flexor muscle inflammation can compress the ulnar nerve

Question 45

Why doesn’t paresthesia occur over the thenar eminence of the skin in the setting of carpal tunnel syndrome?

Answer 45

This area is supplied by the palmar cutaneous branch of the median nerve that branches off before the carpal tunnel.

Question 46

Through which muscle does the deep branch of the radial nerve travel through in the posterior forearm?

Answer 46

The supinator