anterior & posterior compartments of the arm & cubital fossa

Question 1

what** 3 bones **does the **humerus articulate with **and as a result, what joints do they form?

Answer 1

• scapula - glenohumeral joint
• radius & ulna - elbow joint

Question 2

what are the 2 necks of the humerus called & which one is more likely to fracture?

Answer 2

• anatomical
• surgical neck
• surgical neck is more likely to fracture -this can cause damage to the axillary nerve

Question 3

what is the spiral groove of the humerus and what does it contain?

Answer 3

• groove on the posterior aspect of the humerus and it contains the radial nerve and deep artery of the arm

Question 4

what is the quadrangular space in the arm?

Answer 4

• a space in the posterior axilla region
• it provides a passageway for structures to pass between the axilla and the posterior compartment of the arm - ie the axillary nerve

Question 5

what is the elbow joint?

Answer 5

• synovial joint in the upper limb formed by the articulation between the humerus, the radius and the ulna
• flexion and extension movements

Question 6

what are the 2 joints in the elbow joint?

Answer 6

• humeroulnar joint - joint between the trochlea on the medial aspect of the distal end of the humerus and the trocheal notch on the proximal ulna

Question 7

what is a** good mnemonic **that can helop with remembering the articulations in the elbow joint?

Answer 7

CRAzy TULips
* Capitulum = RAdius (capitulum of the humerus articulates with the head of the radius)
* Trochlea = ULnar (trochlea of the humerus articulates with the trochlear notch of the ulna)

Question 8

what occurs at the proximal ends of the radius and ulna ?

Answer 8

• they articulate with eachother and form the proximal radioulnar joint (seperate articulation from the elbow joint)
• pivot joint - allows rotational movement of the radius on the ulna

Question 9

what is the ulnar collateral ligament?

Answer 9

• one of the ligaments of the elbow
• extends from the medial epicondyle of the humerus to the coronoid process of the ulna
• composed of 3 parts - anterior inferior and posterior

Question 10

other than the ulnar collateral ligament,** what are the other ligaments of the elbow**?

Answer 10

• anular ligament
• radial collateral ligament
• quadrate ligament

Question 11

what is the anular ligament ?

Answer 11

ligament that holds the radius and ulna together at the proximal articulation

Question 12

what compartment of the arm is involved in flexion of the arm?

Answer 12

• the anterior compartment of the arm

Question 13

what compartment of the arm is involved in extension of the arm?

Answer 13

the posterior compartment

Question 14

what are the** 3 muscles of the anterior compartment** of the arm?

BBC

Answer 14

• biceps brachii
• brachialis
• coracobrachialis

Question 15

how many heads does the biceps brachii muscle have?

Answer 15

2 - long and short head

Question 16

where does the long vs short head of the biceps brachii originate from?

Answer 16

• long head - supraglenoid tubercle of the scapula
• short head- coracoid process of the scapula

Question 17

where do both of the heads of biceps brachii insert?

Answer 17

• the muscle (both heads) insert via a single tendon onto the radial tuberosity
• NB there is a continuation of this tendon on the forearm as flattened connective tissue sheath - called the** bicipital aponeurosis **

Question 18

what nerve innervates the bicep brachii muscle?

Answer 18

• musculocutaneous nerve

Question 19

what are the origins and insertions of the brachialis muscle?

brachialis muscle = deep to biceps brachi muscle

Answer 19

• originates from the distal/**lower half of the humeus **
• forms a singular tendon that inserts onto the ulnar tuberosity

Question 20

what nerve innervates the brachialis muscle?

hint: same as biceps brachii

Answer 20

the musculocutaneous nerve

Question 21

what is the origin and insertion of the coracobrachialis muscle?

Answer 21

• origin - coracoid process
• inserts onto the midshaft of the humerus

Question 22

what nerve innervates the coracobrachialis muscle?

Answer 22

• musculocutaneous nerve

Question 23

what is the brachioradialis muscle?

Answer 23

a superificial muscle of the forearm- also involved in flexion of the forearm but also supination & pronation

Question 24

where does the brachioradialis originate and insert onto?

Answer 24

• originate - lateral supracondylar ridge
• inserts onto the distal styloid process of the radius

Question 25

what nerve innervates the brachioradialis muscle?

Answer 25

the radial nerve

Question 26

what muscle is involved in extension of the arm?

Answer 26

the triceps brachii

Question 27

what are the 3 heads of the triceps brachii?

Answer 27

• lateral head
• long head
• medial head

Question 28

what are the 3 origins of the 3 heads of the triceps?

Answer 28

1. scapula
2. lateral border of the upper humerus
3. lower half of the humerus

Question 29

where does the triceps insert onto?

Answer 29

• the olecranon of the ulna

Question 30

what nerve innervates the triceps muscle?

Answer 30

the radial nerve

Question 31

what is the anconeus muscle?

shape, what does it do?

Answer 31

• small triangular shaped muscle of the arm
• assists in extension of the forearm

Question 32

what is the origin and insertion of the anconeus muscle?

Answer 32

• O- lateral epicondyle
• I- dorsal proximal ulna

Question 33

what are the branches of the axillary artery?

Save The Lions And Protect Species

Answer 33

• superior thoracic artery
• Thoracoacromial artery
• Lateral thoracic artery
• Anterior humeral circumflex artery
• Posterior humeral circumflex artery
• Subscapular artery

Question 34

what is volkmann’s contracture?

Answer 34

• permanent shortening of the of the forearm muscles, usually resulting from an injury
• gives rise to a claw like looking hand

Question 35

what is the cubital fossa?

Answer 35

• triangular shaped area situated on the most proximal part of the anterior surface of the forearm
• contains several important neurovascular structures that pass between the arm and the forearm

Question 36

what are the contents of the cubital fossa?

My Blood Turns Red

Answer 36

• Median nerve
• Brachial artery
• Tendon of biceps brachii
• Radial nerve

Question 37

what are the boundaries of the cubital fossa?

Answer 37

• lateral border - brachoradialis muscle
• medial border - the pronator teres muscle
• superior border - imaginary line joining the epicondyles of the humerus
• floor -brachialis muscle and supinator muscle