Upper Limb Flashcards
Biceps brachii - attachments, innervation, action
Proximal: -Short head: tip of coracoid process.
-Long head: supraglenoid tubercle.
Distal: Tuberosity of radius and bicipital aponeurosis.
Innervation: Musculocutaneous nerve (C5, C6, C7).
Action: Supinates forearm, flexes forearm when it is supine, short head resists dislocation of glenohumeral joint.
Coracobrachialis - attachments, innervation, action
Proximal: Tip of coracoid process.
Distal: Middle third of medial surface of humerus.
Innervation: Musculocutaneous nerve (C5, C6, C7).
Action: Helps flexion and adduction of forearm, resists dislocation of glenohumeral joint.
Brachialis - attachments, innervation, action
Proximal: Distal half of anterior surface of humerus.
Distal: Coronoid process and tuberosity of ulna.
Innervation: Musculocutaneous and radial nerves.
Action: Flexes forearm in all positions.
Triceps brachii - attachments, innervation, action
Proximal: -Long head: Infraglenoid tubercle.
-Lateral head: Posterior surface of humerus, superior to radial groove. - Medial head: Posterior surface of humerus, inferior to radial groove.
Distal: Proximal end of olecranon of ulna, and fascia of forearm.
Innervation: Radial nerve (C6, C7, C8)
Action: Chief extensor of forearm, long head resists dislocation of humerus.
Anconeus - attachments, innervation, action
Proximal: Lateral epicondyle of humerus.
Distal: Lateral surface of olecranon and superior part of posterior surface of ulna.
Innervation: Radial nerve (C7, C8, T1)
Action: Assists triceps in extending forearm, stabilizes elbow joint.
Branches of brachial artery - proximal to distal
Profunda brachii artery: -middle collateral -radial collateral Humeral nutrient artery. Superior ulnar collateral artery. Inferior ulnar collateral artery. Radial recurrent artery. Anterior ulnar recurrent artery. Posterior ulnar recurrent artery. Radial artery. Ulnar artery.
Peri-articular arterial anastomoses of the elbow is formed by which anastomosing arteries?
Superior ulnar collateral+Posterior ulnar recurrent+Inferior ulnar collateral.
Inferior ulnar collateral+Anterior ulnar recurrent.
Main superficial veins of the arm.
Cephalic vein.
Basilic vein.
(Connected at cubital fossa by median cubital vein)
Medial cubital vein used for venipuncture.
Deep veins of the arm
Paired deep veins, collectively constitutes the Brachial vein accompanying brachial artery. Merges with basilic vein to form Axillary vein.
Main nerves of the arm
Median
Ulnar
Musculocutaneous
Radial
- Musculocutaneous nerve innervates…?
2. Emerges lateral to biceps as which branch that innervates what?
- Muscles of the anterior compartment of the arm (biceps brachii, brachialis, coracobrachialis).
- Lateral antebrachial cutaneous nerve: Skin of lateral aspect of forearm.
- Muscles of anterior compartment of upper arm.
2. Muscle of posterior compartment of upper arm.
- Biceps brachii, Brachialis, Coracobrachialis. (Flexors)
2. Triceps brachii. (Extensor)
- Radial nerve innervates…?
2. Anterior to lateral epicondyle, radial nerve divides into…?
- Muscles in posterior compartment of arm and forearm.
- -Deep branch of radial nerve (Entirely muscular and articular in its distribution)
- Superficial branch of radial nerve (Entirely cutaneous, supplies dorsum of hand and fingers.)
Median nerve in arm innervates?
No branches in axilla and arm! But it has articular branches to the elbow joint.
Ulnar nerve in arm.
No branches in arm! But it supplies articular branches to the elbow joint.
It is superficial, easily palpated, and vulnerable to injury.
Boundaries of cubital fossa
Superiorly: an imaginary line connecting the medial and lateral epicondyles.
Medially: flexor muscles of the forearm arising from the medial epicondyle, specifically the Pronator teres.
Laterally: extensor muscles of the forearm arising from lateral epicondyle and supra-epicondylar ridge, specifically the Brachioradialis.
Floor: brachialis and supinator muscles.
Roof: brachial and antebrachial fascia reinforced by the bicipital aponeurosis.
Contents of the cubital fossa.
- Terminal part of the brachial artery and commencement of its terminal branches (radial and ulnar arteries).
- Deep accompanying veins of the arteries.
- Biceps brachii tendon.
- Median nerve.
- Radial nerve.
The tendons of most flexor muscles are located on the anterior surface of the wrist and held in place by which ligaments?
Palmar carpal ligament.
Flexor retinaculum.
Muscles of Superficial layer of anterior compartment of forearm.
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
Muscle of intermediate layer of anterior compartment of forearm
Flexor digitorum superficialis
Muscles of Deep layer of anterior compartment of forearm
Flexor digitorum profundus
Flexor pollicis longus
Pronator quadratus
Pronator teres - attachment, innervation, action
Ulnar head: Proximal - Coronoid process, Distal - middle convexity of lateral surface of radius.
Humeral head: Proximal - Medial epicondyle of humerus (common flexor origin), Distal middle convexity of lateral surface of radius.
Innervation: Median nerve.
Action: Pronates and flexes forearm.
Flexor carpi radialis - attachment, innervation, action
Proximal: Medial epicondyle of humerus (common flexor origin).
Distal: Base of 2nd metacarpal.
Innervation: Median nerve.
Action: Flexes and abducts hand at wrist.
Palmaris longus - attachment, innervation, action
Proximal: Medial epicondyle of humerus (common flexor origin).
Distal: Distal half of flexor retinaculum and apex of palmar aponeurosis.
Innervation: Median nerve.
Action: Flexes hand at wrist and tenses palmar aponeurosis.
Flexor carpi ulnaris - attachment, innervation, action
Humeral head: Proximal - medial epicondyle of humerus (common flexor origin), Distal - pisiform, hook of hamate, 5th metacarpal.
Ulnar head: Proximal - Olecranon and posterior border of ulna, Distal - pisiform, hook of hamate, 5th metacarpal.
Innervation: Ulnar nerve.
Action: Flexes and abducts hand at wrist.
Flexor digitorum superficialis - attachment, innervation, action
Humero-ulnar head: Proximal - Medial epicondyle of humerus (common flexor origin), Distal - Shafts of middle phalanges of medial four digits.
Radial head: Proximal - Superior half of anterior border, Distal - shafts of middle phalanges of medial four digits.
Innervation: Median nerve.
Action: Flexes middle phalanges of middle four digits, if acting more strongly it also flexes proximal phalanges.
Flexor digitorum profundus - attachment, innervation, action
Medial part: Proximal - proximal 3/4 of medial and anterior surfaces of ulna and interosseous membrane, Distal - bases of distal phalanges of 4th and 5th digits.
Lateral part: Proximal - proximal 3/4 of medial and anterior surfaces of ulna and interosseous membrane, Distal - bases of distal phalanges of 2nd and 3rd digits.
Innervation: Medial part - Ulnar nerve.
Lateral part - Anterior interosseous nerve, from median nerve.
Action: Medial part - Flexes distal phalanges at 4th and 5th.
Lateral part - Flexes distal phalanges at 2nd and 3rd.
Flexor pollicis longus - attachment, innervation, action
Proximal: Anterior surface of radius and adjacent interosseous membrane.
Distal: Base of distal phalanx of thumb.
Innervation: Anterior interosseous nerve, from median nerve.
Action: Flexes phalanges of 1st digit (thumb).
Pronator quadratus - attachment, innervation, action
Proximal: distal quarter of anterior surface of ulna.
Distal: distal quarter of anterior surface of radius.
Innervation: Anterior interosseous nerve, from median nerve.
Action: Pronates forearm, deep fibers bind radius and ulna together.
Which muscles attach to the common flexor origin?
Pronator teres (humeral head), Flexor carpi radialis, Palmaris longus, Flexor carpi ulnaris (humeral head), Flexor digitorum superficialis.
