The arm and the forearm

Question 1

Four main segments of the upper limb

Answer 1

shoulder
arm
forearm
hand

Question 2

Where is the clavipectoral region

Question 3

what is the cubital region

Answer 3

anterior to the elbow

Question 4

What is the main difference between the upper and lower limb

Answer 4

Stability of the lower limbs versus mobility of the upper limbs

• The iliac bones are anatomically connected posteriorly (at the sacroiliac joint); as a result, movement of one lower limb affects movement of the other lower limb
  *The scapulae are not connected posteriorly, such that the upper limbs can move relatively
  independently
  *In addition, although both are ball and socket joints, the hip has a much deeper bony
  articulation than the glenohumeral joint

Question 5

Function of the clavicle

Answer 5

• acts as a mobile strut keeps the upper limb away from the thorax to improve range of motion
• attaches the upper limb to the trunk

Question 6

can you tell the difference between the ends and surfaces of the clavicle?

Answer 6

conoid tubercle and trapezoid line are on the under side toward the acromial end

allow for attachment of the respective named ligaments

the inferior surface is rough whereas the top can be described as smooth

Question 7

Clavicular fracture types

what ligaments can be affected

what may be required?

Answer 7

displaced (unaligned fragment from main bone) and non displaced (broken bone but still aligned with main bone)

coracoclavicular ligament (trapezoid and conoid)

surgical stabilization and perhaps ligament fixing

Question 8

Where does the humerus tend to break?

Answer 8

surgical neck

Question 9

What fascia surround the structures of the upper arm and forearm?

Answer 9

brachial fascia: proximal to elbow
antebrachial fascia: distal to elbow

Question 10

what divides the space inside the brachial fascia into anterior and posterior components

Answer 10

intermuscular septa and the humerus

Question 11

what divides the space inside the antebrachial fascia into anterior and posterior components

Answer 11

interosseous membrane and radius and ulna

Question 12

what does the antebrachial fascia divide into

Answer 12

palmar carpal ligament, flexor retinaculum, extensor retinaculum

both retinaculum are important for flexion and extension of hand and digits at the wrist and the interphalangeal and metacarpal joints

Question 13

Describe the layers of the arm proximal to the elbow, distal to the elbow, and at the wrist

Answer 13

see slide

Question 14

what is the importance of the transverse carpal ligament/ flexor retinaculum

Answer 14

forms the roof of the carpal tunnel

Question 15

Describe the contents of the carpal tunnel

Answer 15

flexor retinaculum/transverse carpal ligament
- contains 9 tendons and the median nerve

• 4 flexor digitorum profundus
• 4 flexor digitorum superficialis
• 1 flexor pollicis longus
• median nerve

Mnemonic: my (median) fingers (FDP) funny (FDS) for (FPL) many (median) nights (9 tendons total)

Question 16

What muscles flex the forearm

Answer 16

biceps brachii (short and long head)

brachialis

brachioradialis

pronator teres (not main action)

palmaris longus

Question 17

Muscle: Biceps brachii
* origin
* insertion
* action
* innervation

Answer 17

origin:
Long head: Supraglenoid tubercle of the scapula
Short head: coracoid
process of scapula

insertion: Radial tuberosity + bicipital aponeurosis

action:
Both heads: Flexion of forearm, supination of forearm
Long head: Flexion of arm
(weakly)

innervation: musculocutaneous nerve

Question 18

Muscle: brachialis
* origin
* insertion
* action
* innervation

Answer 18

origin: body of humerus

insertion: ulnar tuberosity

action: flexion of forearm

innervation: musculocutaneous nerve and radial nerve

most powerful forearm flexor; loses power in supination

Question 19

Muscle: triceps brachii
* origin
* insertion
* action
* innervation

Answer 19

origin:
* Long head: infraglenoid tubercle of scapula
* Lateral head: Body of the humerus, superior to the radial groove
* Medial head: Body of the humerus, inferior to the radial groove

insertion: Posterior olecranon process of the ulna

action:
All heads: Extension of forearm
Long head: Extension of arm; adduction of arm

innervation: radial nerve

Question 20

Muscle: Pronator teres
* origin
* insertion
* action
* innervation

Answer 20

origin: medial epicondyle of the humerus

insertion: lateral surface of the radius

action: pronation and flexion of forearm

innervation: median nerve

Question 21

Muscle: flexor carpi radialis
* origin
* insertion
* action
* innervation

Answer 21

origin: medial epicondyle of the humerus

insertion: base of 2nd metacarpal

action: flexion of hand/ abduction/radial deviation of hand

innervation: median nerve

Question 22

Muscle: palmaris longus
* origin
* insertion
* action
* innervation

Answer 22

origin: Medial epicondyle of humerus

insertion: Palmar aponeurosis

action:
Flexion of hand;
Weak flexion of forearm
Tenses palmar aponeurosis

innervation: median nerve

Question 23

Muscle: flexor carpi ulnaris
* origin
* insertion
* action
* innervation

Answer 23

origin:
Medial epicondyle of humerus and olecranon of ulna

insertion: Base of the 5th metacarpal;
hook of the hamate; pisiform bone

action: Flexion of hand;
adduction/ulnar deviation of
hand

innervation: ulnar nerve

Question 24

Can you describe all the veins, arteries and nerves in the upper arm’s cross section

Answer 24

biceps brachii most superficially,
brachialis deep to biceps brachii. musculocutaneous nerve between

within the lateral intermuscular septum that separates barchialis and lateral head of triceps: radial nerve

medial to brachialis and deep to biceps brachii: median nerve, brachial artery, basilic vein, ulnar nerve.

posterior compartment: triceps (lateral, medial, and long head)

see notes for that picture

Question 25

Describe the articulations of the elbow joint and what stabilizes them (ligaments)

Answer 25

3 articulations * humeroulnar joint: trochlear of humerus and trochlear notch of the ulna * humeroradial joint: capitulum of humerus and the head of radius * proximal radioulnar joint: head of radius and radial notch of ulna; mediates pronation and supination of the forearm at the elbow * radial collateral ligament, ulnar collateral ligament * anular ligament (stabilizes proximal radial ulnar joint)

Question 26

what muscles cause pronation

Answer 26

pronator teres and pronator quadratus

Question 27

What muscles cause supination

Answer 27

supinator and biceps brachii contract

Question 28

distal radioulnar joint * articulation

Answer 28

* head of ulna and ulnar notch of radius the ulnar notch of the radius slides anteriorly over the head of the ulna to produce pronation

Question 29

What permits pronation

Answer 29

* interosseous membrane + proximal and distal radioulnar joint

Question 30

Anterior compartment of the forearm: * What is a good tip for remembering flexor origination? * what movements are done by muscles here * what are the nerves that innervate these muscles

Answer 30

* The superficial ones originate at the medial epicondyle humerus * flexion and pronation * median and ulnar nerve (only one is innervated by ulnar)

Question 31

What muscles are in the superficial layer of the forearm anterior compartment; intermediate layer, and deep layer

Answer 31

Superficial layer (medial to lateral): * pronator teres * flexor carpi radialis * palmaris longus * flexor carpi ulnaris Intermediate layer: flexor digitorum superficialis Deep layer (medial to lateral): * flexor pollicis longus * flexor digitorum profundus * pronator quadratus

Question 32

Muscle: flexor digitorum superficialis * origin * insertion * action * innervation

Answer 32

**origin**: Medial epicondyle of humerus, coronoid process of ulna, upper surface of radius **insertion**: Middle phalanges of digits 2-5 **action**: Flexion of proximal and middle phalanges of digits 2-5, flexion of hand, (weak) flexion of forearm **innervation**: median nerve

Question 33

Muscle: Flexor pollicis longus * origin * insertion * action * innervation

Answer 33

**origin**: anterior surface of the radius; interosseous membrane **insertion**: distal phalanx of digit 1 (thumb) **action**: Flexion of proximal and distal phalanges of digit 1 (thumb); abduction of hand/radial deviation; flexion of hand **innervation**: median nerve

Question 34

Muscle: Flexor digitorum profundus * origin * insertion * action * innervation

Answer 34

**origin**: Anterior surface of the ulna; interosseous membrane **insertion**: distal phalanges of digits 2-5 **action**: Flexion of proximal, middle and distal phalanges of digits 2-5, flexion of hand **innervation**: Median nerve (laterally); ulnar nerve (medially)

Question 35

How can we differentiate the actions of flexor digitorum profundus and flexor digitorum superficialis

Answer 35

Digit flexion occurs via a pulley system, in which the tendons of FDP pierce the tendons of FDS to reach the distal phalange. Thus, proximal and distal digital flexion can be used to differentiate between the actions of FDP and FDS.

Question 36

What is jersey finger?

Answer 36

hyperextension of the first finger joint (distal interphalangeal joint) caused by grabbing another player's jersey and getting your distal joint jerked. causes flexor digitorum profundus avulsion

Question 37

List the muscles in the posterior compartment superficial layer and deep layer

Answer 37

**Superficial** (7) lateral to medial: * Brachioradialis * Extensor carpi radialis longus * Extensor carpi radialis brevis * Extensor digitorum * Extensor digiti minimi * Extensor carpi ulnaris * Anconeus lateral to medial **Deep** (5) * Supinator * Abductor pollicis longus * Extensor pollicis brevis * Extensor pollicis longus * Extensor indicis

Question 38

Muscle: brachioradialis * origin * insertion * action * innervation

Answer 38

**origin**: Lateral supracondylar ridge of the humerus **insertion**: Styloid process of the radius **action**: Flexion of forearm; pronation and supination of forearm (depending on position of forearm) **innervation**: Radial nerve

Question 39

Muscle: Extensor carpi radialis longus * origin * insertion * action * innervation

Answer 39

**origin**: Lateral supracondylar ridge of the humerus **insertion**: Dorsal base of second metacarpal **action**: Extension of hand; abduction/radial deviation of hand **innervation**: Radial nerve

Question 40

Muscle: Extensor carpi radialis brevis * origin * insertion * action * innervation

Answer 40

**origin**: Lateral epicondyle of the humerus **insertion**: Dorsal base of the third metacarpal **action**: Extension of the hand at the wrist; Abduction/radial deviation of the hand **innervation**: Radial nerve

Question 41

Muscle: Extensor digitorum * origin * insertion * action * innervation

Answer 41

**origin**: Lateral epicondyle of the humerus **insertion**: Dorsal bases of distal and middle phalanges of digits 2-5 **action**: Extension of digits 2-5; abduction of fingers **innervation**: Radial nerve

Question 42

Muscle: Extensor digiti minimi * origin * insertion * action * innervation

Answer 42

**origin**: Lateral epicondyle of the humerus **insertion**: Dorsal aponeurosis (middle and distal phalanges) of 5th digit **action**: Extension of 5th digit; adduction/ulnar deviation of hand; extension of hand **innervation**: Radial nerve

Question 43

Muscle: Extensor carpi ulnaris * origin * insertion * action * innervation

Answer 43

**origin**: Lateral epicondyle of the humerus; Posterior surface of the ulna **insertion**: Dorsal base of 5th metacarpal **action**: Extension of hand; adduction/ulnar deviation of hand **innervation**: Radial nerve

Question 44

Muscle: Supinator * origin * insertion * action * innervation

Answer 44

**origin**: Lateral epicondyle of the humerus; Supinator crest of the ulna **insertion**: Posterior surface of radius **action**: Supination of the forearm **innervation**: Radial nerve

Question 45

Muscle: Anconeus * origin * insertion * action * innervation

Answer 45

**origin**: Lateral epicondyle of the humerus **insertion**: Olecranon and superior posterior surface of the ulna **action**: Extension of forearm; stabilization during pronation/ supination (very weakly tho. probably primarily a stabilizer) **innervation**: Radial nerve

Question 46

Muscle: Abductor pollicis longus * origin * insertion * action * innervation

Answer 46

**origin**: Dorsal surface of radius and ulna and adjacent interosseus membrane **insertion**: Lateral side of the base of 1st metacarpal **action**: Abduction of thumb; abduction/radial deviation of hand **innervation**: Radial nerve

Question 47

Muscle: Extensor pollicis brevis * origin * insertion * action * innervation

Answer 47

**origin**: Posterior surface of the radius; Interosseous membrane **insertion**: Dorsal base of the 1st proximal phalanx **action**: Extension of the thumb; abduction/radial deviation of hand **innervation**: radial nerve

Question 48

Muscle: Extensor pollicis longus * origin * insertion * action * innervation

Answer 48

**origin**: Posterior surface of the ulna; Interosseous membrane **insertion**: Dorsal base of the 1st distal phalanx **action**: Extension of the thumb; abduction of the hand/ radial deviation **innervation**: Radial nerve

Question 49

Muscle: Extensor indicis * origin * insertion * action * innervation

Answer 49

**origin**: Posterior distal ulna; Interosseous membrane **insertion**: Distal aponeurosis of the 2nd digit **action**: Extension of digit 2, extension of the hand **innervation**: Radial nerve

Question 50

list the hand bones

Answer 50

Some Lovers Try Positions They Can't Handle Scaphoid Lunate Triquetrum Pisiform Trapezium Trapezoid Capitate Hamate

Question 51

List the bone subtypes from proximal to distal

Answer 51

carpal metacarpal proximal phalanges intermediate phalanges distal phalanges

Question 52

Muscle: pronator quadratus * origin * insertion * action * innervation

Answer 52

**origin**: distal ulna **insertion**: distal radius **action**: pronator of forearm **innervation**: median nerve