Brachial muscles and their fasciae

Question 1

Brachial muscles

Answer 1

• Anterior: brachialis, coracobrachialis and biceps brachii
• Posterior: triceps brachii and anconaeus

Question 2

Brachialis

Answer 2

• Origin: Anterior side of the humeral body
• Insertion: tuberositas ulnae
• Innervation: musculocutaneous nerve
• Function: flexion in elbow joint
• It is an anterior brachial muscle

Question 3

Corachobrachialis

Answer 3

• Origin: coracoid process of the scapula
• Descends distally and laterally
• Insertion: medial side of the humeral body (half way down)
• Innervation: musculocutaneous nerve
• Function: adduction and partial anteflexion in shoulder joint
• It is an anterior brachial muscle

Question 4

Biceps brachii

Answer 4

• Origin:
  1. Caput longum: supraglenoid tubercle of the scapule
  2. Caput breve: coracoid process of the scapula (tendon passes through intertubercular groove, where its covered by the vagina synovialis intertubercularis)
• Join half was down the arm
• Insertion: Tuberositas radii
• Aponeurosis diverges distally and medially and blends with the antebrachial fascia
• Innervation: musculocutaenous nerve
• Function: antebrachial flexion in supinatory position, caput longum participates in arm abduction and caput breve praticipates in anteflexion and adduction of the arm
• It is an anterior antebrachial muscle

Question 5

Triceps brachii

Answer 5

• Three heads (origins)

1. Caput longum - infraglenoid tubercle of the scapula
2. Caput laterale - posterior side of the humeral body, proximally from the sulcus nervi radialis
3. Caput mediale - posterior side of the humeral body, distally from the sulcus nervi radialis

• All connect in distal part of the arm
• Insertion: olecranon ulnae
• Innervation: radial nerve
• Function: antebrachial extension and caput longum participates in ard adduction
• It is a posterior brachial muscle

Question 6

Anconaeus

Answer 6

• Origin: lateral epicondyle of the humerus
• Descends distally
• Insertion: olecranon ulnae
• Represents fourth head of the triceps brachii
• Innervation: radial nerve
• Function: extension in elbox joint

Question 7

Brachial fascia

Answer 7

• Covers brachial muscle
• Proximally adjoins to fascia deltoidea
• Distally passes into fascia antebrachii
• In the distal brachial area, on the ulnar and radial sides of the humerus, there are two existing fasciae, running from the humeral periosteum into the brachial fascia, they separate the anterior and posterior brachial muscles (Septum intermusculare brachii mediale et laterale)
• These septa pull the brachial fascia deeper, creating visible notches:

1. Sulcus m. bicipitis medialis - brachail vessels, median and ulnar nerve project through
2. Sulcus m. bicipitis lateralis - cephalic vein runs in its subcutaenous tissue