The forearm and cubital fossa

Question 1

Articulations between the ulna and radius? (2)

Answer 1

Proximal radioulnar joint- radius articulates with radial notch of ulna=pivot join. Allows pronation and supination (radius crossover ulna in pronation)

Distal radioulnar joint: Near wrist between ulnar head and ulnar notch of radius

Question 2

What membrane lies between the radius and ulna?

Features of membrane (2)

Answer 2

Interosseous membrane- thick and fibrous

Question 3

Supination- what is it how is this achieved?

Answer 3

Palm up. Supinator(post forearm m) and biceps brachii (ant forearm m) contact and the elbow is flexed

Question 4

Pronation- what is it how is this achieved?

Answer 4

Palm Down- Pronator teres and pronator quadrates contract (ant arm muscles)

Question 5

Cubital fossa- what is it

Answer 5

triangular depression anterior to elbow joint contains superficial veins used for IV connotations and blood samples

Question 6

Superior border of cubital fossa

Answer 6

imaginary border between lateral and medial epicondyles

Question 7

Floor of cubital fossa

Answer 7

Brachialis

Question 8

lateral border of cubital fossa

Answer 8

Brachioradialis

Question 9

Medial border of cubital fossa

Answer 9

Pronator teres

Question 10

Superficial muscles of anterior arm

Answer 10

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

Question 11

Intermediate muscles of anterior arm

Answer 11

Flexor Digitorum Superficialis

Question 12

Deep muscles of anterior arm

Answer 12

Flexor digitorum profundus, flexor pollicus longus, Pronator quadratus

Question 13

Action of most of the muscles in the anterior forearm

Answer 13

Flexors of the wrist, fingers and thumb

Question 14

Origin of the superficial flexors

Answer 14

Medial epicondyle of humerus

Question 15

PT, FCU,FCR,PL which order are they in from the most lateral

Answer 15

PT, FCR, PL, FCU

Question 16

Pronator teres- attachment, action and innervation

Answer 16

Laterally to mid shaft of radius, pronates forearm, Median N

Question 17

Flexor carpi radialis- attachment, action and innervation

Answer 17

Base of metacarpal 2&3. Flexion and abduction at wrist, Median N

Question 18

Palmaris longus - attachment, action and innervation

Answer 18

Absent in 15% population, inserts onto the flexor retinaculum (palmar aponeurosis(which band of CT in wrist)) Flexion of wrist. Median N

Question 19

Flexor carpi ulnaris - attachment, action and innervation

Answer 19

Attaches onto the pisiform carpal bone. Flexion and abduction at wrist. Ulnar N

Question 20

what muscles are vulnerable when the palmar spect of the hand is injured

Answer 20

Muscles of the anterior arm

Question 21

Flexor digitorum superficialis- origin, attachment, action and innervation

Answer 21

from medial epicondyle and radius. Gives rise to 4 tendons that travel under flexor retinaculum through carpal tunnel and attach to middle phalanges of the 4 fingers.
Flexes metacarpopharengeal joints and proximal interpharengeal joints of 4 fingers and flexes the wrist.

Innervation: Median N (by 2nd finger
Ulnar NV bundle lies medial to FDS and radial NV bundle lies lateral

Question 22

Flexor digitorum profundus- origin, attachment, action and innervation

Answer 22

From ulna and Interosseous membrane. Gives rise to 4 tendons that travel under flexor retinaculum through carpal tunnel and attach to distal phalanges of the 4 fingers.
Only m that flexes distal interpharengeal joints of 4 fingers. Also flexes the wrist.

Medial 1.5 (4th and 5th finger)- Ulnar N the rest by anterior interosseous N (deep branch of median N)

Question 23

Flexor pollicus longus- origin, attachment, action and innervation

Answer 23

Lateral to FDP. Originates from ant radius and Interosseous membrane. Inserts onto distal phalanx of thumb. Flexes thumb
anterior interosseous N (deep branch of median N)

Question 24

Pronator quadratus- origin, attachment, action and innervation

Answer 24

From ant radius and inserts onto ant ulna.
Pronates the forearm
Anterior interosseous N (deep branch of median N)

Question 25

Superficial muscles of posterior forearm

Answer 25

``` Brachioradialis Extensor carpi radialis longus (ECRL) Extensor carpi radialis brevis (ECRB) Extensor digitorum (ED) Extensor digiti minimi (EDM) Extensor carpi ulnaris (ECU) ```

Question 26

Innervation of the posterior forearm muscles

Answer 26

Radial Nerve

Question 27

Origin of the posterior forearm muscles

Answer 27

lateral epicondyle of the humerus - the common extensor origin.

Question 28

Extensor carpi radialis longus- attachment and action

Answer 28

metacarpal 2&3. Extension and adduction or wrist | Principle wrist extensor

Question 29

Extensor carpi radialis brevis- attachment and action

Answer 29

metacarpal 2&3. Extension and adduction or wrist | Principle wrist extensor

Question 30

Extensor carpi ulnaris- attachment and action

Answer 30

Base of metacarpal 5. Extension and adduction or wrist

Question 31

Extensor digitorum- attachment and action

Answer 31

lies centrally in post forearm gives rise to 4 tendons that travel under flexor retinaculum through carpal tunnel and attach to extensor hood of the 4 fingers. Main extensor of fingers. Also extends wrist

Question 32

Extensor digiti minimi- attachment and action

Answer 32

Part of ED. Tendon attaches to extensor hood of the 5th digit. Extends finger and wrist

Question 33

Brachioradialis- origin, attachment and action

Answer 33

most lateral post m. on border of ant compartment. originates from supracondylar ridge of the humerus and extends to the distal radius, and is therefore a flexor of the elbow joint. It does not flex the wrist as it does not cross the wrist joint. It is important in returning the forearm to the mid-prone position from either full supination or pronation

Question 34

what muscles are vulnerable when the dorsal spect of the hand is injured

Answer 34

Muscles of the posterior arm

Question 35

What is the extensor hood

Answer 35

Fibrous tissue band overlying the dorm of the digits - helps to keep extensor tendons on midline of the digits and serves as insertion point for some hand muscles

Question 36

Anconeus

Answer 36

small muscle situated on the posterior aspect of the elbow.

Question 37

Deep muscles of posterior forearm

Answer 37

``` Extensor indicis (EI) Extensor pollicis longus (EPL) Extensor pollicis brevis (EPB) Abductor pollicis longus (APL) ```

Question 38

Origin of Deep muscles of posterior forearm

Answer 38

The shaft of the radius and ulna and the interosseous membrane

Question 39

Action of Deep muscles of posterior forearm

Answer 39

abduction and extension of the thumb and extension of the index finger.

Question 40

Injury to the Extensor indicis would affect movement of?

Answer 40

index finger

Question 41

Injury to the Extensor pollicis longus/ Extensor pollicis brevis/ Abductor pollicis longus would affect movement of?

Answer 41

thumb

Question 42

Innervation of the deep posterior muscles

Answer 42

Posterior interosseous N (deep branch of Radial N)

Question 43

Extensor indicis-attachment and action

Answer 43

Extensor hood of index finger | extends index finger

Question 44

Extensor pollicis longus-attachment and action

Answer 44

Distal phalanx of thumb | Extends carpometacarpal, interpharengeal and metacarpopharangeal joints of the thumb

Question 45

Extensor pollicis brevis-attachment and action

Answer 45

Attaches to base of proximal phalanx of thumb. | Extends carpometacarpal and metacarpopharangeal joints of the thumb

Question 46

Abductor pollicis longus-attachment and action

Answer 46

Attaches to lateral base of thumb | Abducts thumb

Question 47

Supinator muscle- where is it, origin, insertion and action

Answer 47

Lies in floor of cubital fossa. 2 heads one from lateral epicondyle one from posterior ulna. Inserts on posterior radius Supinates forearm

Question 48

Where is the anatomical snuffbox ?

Answer 48

Area between the tendons of abductor pollicis longus, extensor pollicis longus and extensor pollicis brevis form a distinctive depression at the wrist

Question 49

When is the the anatomical snuffbox best seen

Answer 49

Best seen with the thumb in full extension

Question 50

what lies in the floor of the anatomical snuffbox ?

Answer 50

The scaphoid bone

Question 51

Which artery can be palpated in the snuffbox?

Answer 51

Radial Artery

Question 52

Which vein can be accessed in the snuffbox?

Answer 52

Cephalic Veinb

Question 53

Medial border of the anatomical snuffbox

Answer 53

Extensor pollicis longus

Question 54

Lateral border of the anatomical snuffbox

Answer 54

Extensor pollicis brevis (EPB) | Abductor pollicis longus (APL)

Question 55

What is Colles fracture

Answer 55

Fracture of the distal radius. most common in elderly and Middle Ages women and those with osteoporosis. Usually result of falling onto outstretched forearm Ulnar styloid may also be avulsed Rich blood supple so usually heals well.

Question 56

What is Guyons canal? What does it contain?

Answer 56

allows passage of ulnar A and N (AKA ulnar canal)

Question 57

What are indications for carpal tunnel surgery?

Answer 57

Weakness of thumb, atrophy in thenar region, inability to oppose thumb due to thenar m paralysis due to a trapped of median N that cannot provide innervation Dinner fork abnormality

Question 58

What is the aim of carpal tunnel surgery?

Answer 58

Cut flexor retinaculum to release median N so it can provide innervation to thenar muscles.

Question 59

What is circumduction?

Answer 59

Flexion and extension

Question 60

What type of joint in the radoiocarpal joint?

Answer 60

Synovial ellipsoid joint. Radius articulates with carpal bones. Radoiocarpal ligaments strengthen the joint anteriorly and posteriorly.