Write the Origin, Insertion, Action/s & Nerve Supply of Muscles of Anterior (Flexor) Compartment of Arm.
Muscles of anterior (flexor) compartment of arm, their origin, insertion, action/s and nerve supply are as follows:
Muscle Origin Insertion Action Nerve Supply Biceps brachii Short head - from tip of the coracoid process of scapula Tendon is inserted into the posterior rough part of radial tuberosity. Bicipital aponeurosis is attached to the fascia on the medial side of the forearm. Flexor of forearm Musculocutaneous Long head - from supraglenoid tubercle of scapula Supinator when the forearm is flexed Short head – Flexor of arm Long head – Prevents upward displacement of the head of humerus Corachobrachialis From tip of the coracoid process At the midle of the medial border of humerus Flexor of arm Musculocutaneous Brachialis Lower half of anterolateral and anteromedial surfaces of humerus incluing anterior border Coronoid process and ulnar tuberosity of ulna. Flexor of forearm Musculocutaneous and
Radial (proprioceptive)
Enumerate the Branches of Brachial Artery.
Brachial artery extends from lower border of the teres major muscle above to neck of radius below. Its branches are:
i. Profunda brachii
ii. Superior ulnar collateral
iii. Inferior ulnar collateral
iv. Muscular branches
v. Nutrient artery to humerus
vi. Terminal branches – Radial and ulnar arteries
Name the Branches of Profunda Brachii Artery.
i. Anterior descending (radial collateral)
ii. Posterior descending ( middle collateral)
iii. Deltoid (ascending)
iv. Nutrient artery to the humerus
Enumerate the Nerves Closely Related to Humerus.
i. Axillary nerve to surgical neck of humerus
ii. Radial nerve – radial groove
iii. Ulnar nerve – posterior aspect of medial epicondyle.
Name the tructures that Pierce Lateral Intermuscular Septum.
i. Radial nerve
ii. Anterior descending branch of profunda brachii artery.
Name the Structures that Pierce Medial Intermuscular Septum.
i. Ulnar nerve
ii. Superior ulnar collateral branch of brachial artery.
Draw labelled Diagram Showing Branches of Profunda Brachi Artery.
Name the Muscle of Extensor Compartment of Arm and Its Nerve Supply.
• Triceps – radial nerve
Name the Structures in the Spiral/radial Groove.
• Radial nerve
• Profunda brachii vessels
Enumerate the Muscles Supplied by Radial Nerve in the Arm.
• Triceps
• Brachioradialis
• Extensor carpi radialis longus
• Brachialis (propriceptive fibers)
Enumrate the Cutaneous Branches of Radial Nerve Given in the Arm.
• posterior cutaneous nerve of the arm
• lower lateral cutaneous nerve of the arm
• posterior cutaneous nerve of the forearm
Draw Labelled Diagram of Anastomosis Around Elbow Joint.
Applied Aspects
Volkman’s ischaemic contracture
The cause of Volkman’s ischaemic contracture is Injury/compression of brachial artery which could be due to :
- Supracondylar fracture of humerus
- Improper use of tourniquet
- Tight plaster cast
Volkman’s ischaemic contracture is characterised by:
Fibrosis and contracture of the muscles of forearm (especially flexor digitorum profundus and flexor pollicis longus) and as a result the deformity of hand presents: flexion at wrist and at interphalangeal joints.