Lecture 6: The Arm and the cubital fossa

Question 1

what nerve innervates the deltoid?

Answer 1

axillary n

Question 2

what is the origin and the insertion of the deltoid?

Answer 2

O- anatomical horseshoe
I-Deltoid tuberosity

Question 3

what is the main action of the middle deltoid fibers?

Answer 3

abducts arm

Question 4

What are the main actions of the anterior deltoid fibers?

Answer 4

flex shoulder/humerus
internally rotate arm
abduct/adduct arm with posterior fibers( depending on shoulder position)

Question 5

what is the function of the posterior deltoid fibers?

Answer 5

-extend shoulder
-externally rotate the arm
-abduct/adduct arm( depending on shoulder position)

Question 6

where does teres major muscle originate and insert?

Answer 6

O-inferior angle and lateral border of scapula(posteriorly)
I- medial lip of intertubercular groove

Question 7

what nerve innervates teres major?

Answer 7

lower subscapular nerve
(Teres major is located below scapula= lower subscapular)

Question 8

what are the actions of teres major?

Answer 8

internal rotation of the arm
adducts shoulder

Question 9

what are the 3 heads of triceps brachii?

Answer 9

long, lateral, and medial

Question 10

what are the origins and insertions of the triceps brachii heads?

Answer 10

long head:
“O”-infra glenoid tubercle
Lateral and medial heads:
“O”-Back of humerus

“I” for all 3: olecranon of ulna

Question 11

what nerve innervates the triceps brachii?

Answer 11

radial nerve

Question 12

what is the common group of muscles that radial nerve supplies?

Answer 12

extensor compartment of the arm

Question 13

what is the blood vessel that supplies tricep brachii?

Answer 13

branches of profunda brachii artery

Question 14

what nerve and artery pass through the quadrangular space?

Answer 14

axillary n
the posterior humeral circumflex artery

Question 15

what nerve and artery pass through the triangular space?

Answer 15

a branch of circumflex scapular artery

Question 16

where do the radial nerve and the profunda brachii emerge ?

Answer 16

from behind the triangular interval

Question 17

what is the origin and insertion of brachialis?

Answer 17

O- anterior humerus and intermuscular septa
I-ulnar tuberosity

Question 18

what nerve innervates the flexor compartment of the ARM?

Answer 18

musculocutaneous(anterior)

Question 19

what nerve innervates the extensor compartment of the ARM?

Answer 19

radial( posterior)

Question 20

on what epicondyle does the common flexor tendon of the forearm attach?

Answer 20

medial epicondyle. Muscles go to the anterior flexor compartent

Question 21

on what epicondyle does the common extensor tendon of the forearm attach?

Answer 21

lateral. Muscles travel to the posterior extensor comp. of the forearm

Question 22

which muscle does not share the common tendon but belongs to the anterior/ flexor compartment of the forearm?

Answer 22

pronator teres

Question 23

‘O’ and ‘I’ of long and short heads of biceps brachii

Answer 23

‘O’ long head: supraglenoid tubercle
‘O’ short head: coracoid
‘I’: radial tuberosity and bicipital aponeuroses(blends with deep fascia of the forearm)

Question 24

‘O’ and ‘I’ of brachialis

Answer 24

‘O’- anterior surface of distal humerus( including the intermuscular septa)
‘I’-tuberosity of ulna

Question 25

'O' and 'I' of coracorachialis

Answer 25

'O'- coracoid 'I'-medial side of humerus(opposite deltoid tuberosity)

Question 26

what muscle works the most when carrying heavy loads?

Answer 26

coracobrachialis

Question 27

what is the function of the long head of biceps brachii

Answer 27

holds the humerus in place. prevents dislocation pushes the head of the humerus up against the glenoid fossa-> stabilisation

Question 28

what is this and what causes it?

Answer 28

"Popped muscle" due to rupture of long bicep head tendon with age-develop bony spores on the sides of the tubercle->friction can cause the tendon to rupture

Question 29

what are the actions of the coracobrachialis?

Answer 29

adduction of the shoulder flexion of shoulder

Question 30

what are the actions of brachialis?

Answer 30

main elbow flexor

Question 31

what are the actions of biceps brachii?

Answer 31

-supinator -elbow flexor -flexion of shoulder

Question 32

*EOM

Answer 32

1-cephalic vein 2-pectoralis major 3-musculocutaneous nerve 4-median nerve 5-brachial artery 6-basilic vein 7-ulnar nerve 8-arteria profunda brachii 9-radial nerve 10-biceps brachii 11/12-Corachobrachialis 13-humerus 14-medial head of triceps brachii 15-lateral head 16-triceps brachii 17-long head 18-deltoid

Question 33

*EOM

Answer 33

1-cephalic vein 2-musculocutaneous nerve 3-radial nerve 4-arteria profunda brachii 5-nerve to anconeus 6-middle collateral branch of arteria profunda brachii 7-ulnar nerve 8-superior ulnar collateral artery 9-medial cutaneous nerve of the forearm 10-basillic vein 11-median nerve 12-brachial artery 13-vena comitans 14-biceps brachii 15-brachialis 16-triceps brachii 17-humerus

Question 34

what are the actions of triceps brachii?

Answer 34

1- elbow extensor 2-shoulder adductor, shoulder extensor

Question 35

what are the most and least active parts of the triceps?

Answer 35

most- medial least-long

Question 36

'O' and 'I' of triceps brachii

Answer 36

'O' long head: infra glenoid tubercle 'O' of lateral and medial heads: back of the humerus 'I' of all three: olecranon of ulna

Question 37

Answer 37

1-axillary nerve 2-posterior circumflex humeral artery 3-profunda brachii artery 4-radial nerve( in radial or spiral groove) 5-inferior lateral cutaneous nerve of the arm 6-lateral intermuscular septa 7-posterior cutaneous nerve of forearm 8-ulnar nerve(posterior to medial intermuscular septa) 9-medial epicondyle 10- 11-circumflex scapular artery

Question 38

what nerve can get damaged if the intramuscular injection into the shoulder is too low?

Answer 38

axillary nerve

Question 39

what nerve and artery are at risk of getting damaged if there is a midshaft fracture in a humerus?

Answer 39

radial n and profunda brachii artery( lie close to the bone) most damaged to the forearm muscle

Question 40

what is the name of the muscle that is part of the forearm BUT contributes to elbow extension together with triceps?

Answer 40

anconeus

Question 41

what are the "Shunt muscles of arm"

Answer 41

Question 42

Answer 42

Question 43

Answer 43

Question 44

Answer 44

Question 45

Answer 45

Question 46

at what anatomical landmark does axillary artery become brachial artery?

Answer 46

inferior border of teres major

Question 47

what is the function of anastomosis?

Answer 47

Question 48

what are the boundaries of the cubital fossa?

Answer 48

superior: imaginary line between medial and lateral epicondyles medial: lateral edge of pronator teres lateral: medial boundary of brachioradialis floor: brachialis tendon roof: biceps tendon

Question 49

what nerve innervates the tricep brachii?

Answer 49

radial n

Question 50

Answer 50

Question 51

Answer 51

Question 52

why is the distal end of the humerus split into compartments?

Answer 52

some of the forearm muscles start originating at the humerus forearm muscles need to be long to generate enough strength. Forearm muscles provide strength for the hands as the hands themselves cannot accommodate powerful muscles.

Question 53

what nerve/s innervates the anterior compartment of the forearm?

Answer 53

ulnar & median n

Question 54

what nerve/s innervates the posterior compartment of the forearm?

Answer 54

radial n

Question 55

what nerve innervates teres major?

Answer 55

lower subscapular n

Question 56

Answer 56