Upper limb and back: Brachium

Question 1

What are the muscles of the arm? (4)

Answer 1

ANTERIORLY:
-Biceps brachii m.
-Coracobrachialis m.
-Brachialis m.
POSTERIORLY:
-Triceps brachii m.

Question 2

Common name of the:
a. Anterior brachial muscles
b. Posterior brachial muscles

Answer 2

a. Flexors
b. Extensors

Question 3

Sheath of deep fascia,
encloses arm?

Answer 3

Brachial fascia

Question 4

What is the brachial fascia continuous with both superiorly and inferiorly and what are the attachments of it?

Answer 4

-Superiorly continuous with the axillary, pectoral, deltoid and infraspinous fascia.
-Inferiorly continuous with the antebrachial fascia.
-Attached inferiorly to the epicondyles of the humerus and olecranon of ulna.

Question 5

Structures that divide the arm into the anterior and posterior compartments?

Answer 5

2 intermuscular septa

Question 6

Where do these septa extend from?

Answer 6

They extend from the deep surfaces of the brachial fascia to the medial and lateral supracondylar ridges of the humerus.

Question 7

Which nerve supplies the anterior brachial muscles?

Answer 7

Musculocutaneous nerve

Question 8

What do we call the aponeurosis from the tendon of biceps brachii, where does it attach to and why is it clinically important?

Answer 8

-We call it the bicipital aponeurosis.
-Attaches to the deep fascia of arm.
-It is NB bcs it:
-Forms the roof of the cubital fossa.
-Presses the median cubital vein against the skin, important for when you are drawing blood (identification).

Question 9

What is the origin, insertion and action of the biceps brachii muscle?

Answer 9

ORIGIN
-Long head: Supraglenoid tubercle
-Short head: Tip of the coracoid process.
INSERTION
-Radial tuberosity
ACTION
-Supination
-Flexion of the forearm at the elbow joint.
-Flexion of the arm at the shoulder.

Question 10

What is the origin, insertion and action of the coracobrachialis muscle?

Answer 10

ORIGIN
-Tip of the coracoid process.
INSERTION
-Mid-shaft of humerus
ACTION
-Flexion of the arm at the shoulder.

Question 11

What is the origin, insertion and action of the brachial muscle?

Answer 11

ORIGIN
-Lower half of anterior shaft of humerus
INSERTION
-Ulnar tuberosity
ACTION
-Flexion of the forearm at the elbow joint

Question 12

Innervation of the posterior brachial muscle (triceps)?

Answer 12

Radial nerve

Question 13

What is the origin, insertion and action of the triceps brachii muscle?

Answer 13

ORIGIN
-Long head: Infraglenoid tubercle
-Lateral head: Superior posterior surface of shaft.
-Medial head: Inferior posterior surface of shaft.
INSERTION
-Margin of olecranon
ACTION
-Extensor of the forearm at the elbow joint.
-Extensor of the arm at the shoulder joint (only long head).

Question 14

Which structures do you see when you reflect the lateral head of the triceps brachii muscle? (3)

Answer 14

-Medial head of the triceps brachii m.
-Radial nerve
-Profunda brachii artery.

Question 15

At which point does the axillary artery changes to brachial artery?

Answer 15

Inferior border of teres major m.

Question 16

At which point does the brachial artery bifurcate into the radial and ulna arteries?

Answer 16

At the elbow joint

Question 17

What are the branches of the brachial artery? (4)

Answer 17

-Profunda brachii artery
-Ulna collateral arteries
-Muscular branches
-Nutrient artery to humerus

Question 18

Which artery does the profunda brachii artery anastomose with?

Answer 18

The posterior humeral circumflex artery. (branch of the axillary artery)

Question 19

The profunda brachii a. bifurcate to form which vessels?

Answer 19

-Radial and middle collateral aa.

Question 20

Veins of the brachium.

Answer 20

-Basilic vein (medially)
-Cephalic vein (ant. laterally)

Question 21

Where does these veins drain into?

Answer 21

Axillary vein

Question 22

What forms the cubital fossa in terms of the:
a. Base
b. Medial border
c. Lateral border
d. Roof
e. Floor

Answer 22

a. Imaginary epicondylar line
b. Pronator teres m.
c. Brachioradialis m.
d. Skin, fascia, superficial nerves
Median cubital vein and bicipital aponeurosis
e. Brachialis m.

Question 23

What are the contents of the cubital fossa from lateral to medial? (3)

Answer 23

-Biceps brachii m.
-Brachial artery
-Median nerve

Question 24

Additional nerve that can be found in the cubital fossa (laterally)?

Answer 24

Radial nerve