Arm & Forearm Flashcards
Where does radial nerve run in humerus?
In the spinal groove
Medial epicondyle
Where the flexors originate on humerus
Lateral epicondyle
Where extensors originate on humerus
Ulna
Flexes and extends forearm by wrapping around humerus. Places olecranon process in olecranon fossa and moving around trochlea
Radius
Rolls around capitulum for pronation and supination
Interosseous membrane
Connects radius and ulna
C6 Dermatome inervates
Lateral Arm, Forearm & Thumb
C7 Dermatome inervates
Back of Arm, Back of Forearm, 2nd & 3rd digits
C8 Dermatome inervates
Medial Arm, Forearm
Basillic Vein
Runs down medial side of upper arm
Caphalic vein
Runs does lateral side of upper arm
Which sides are short and long head of bicep on and where do they attach?
Short - medial - looks longer - attaches to coracoid process
Long - Lateral - attaches to scapula on superglenoid tubercle making it longer
The bicipital aponeurosis
Thickening of bicep fascia overlies & protects median nerve & brachial artery. Supports median cubital vein during venipuncture.
What must the bicep do before it can engage in flection?
Supinate
What holds the bicep tendon in place and where is it held?
Held in the intertubercular groove by the transverse humeral ligament and the Pec Major m
Insertion of Bicep, Brachialis?
Raidus, Unla. Brachialis is main flexor of forearm as it attaches to ulna which is main bone that moves forearm
What nerve pierces corachobrachealis? And where does it go?
Musculocutaneous - innervates biceps from deep side, lays on top brachealis,
Which tricep arm is least/ most active?
Least: Long, extends arm (on inside of arm)
Most: Medial, general smaller motions
Lateral is strongest generator of force but functions against active resistance (not during passive motions) only when doing large motion like push up
What can long tricep head do that others cant?
Aid in extension of arm as it crosses glenohumeral joint
What is the brachial artery a continuation of and what does it divide into?
Axillary artery dividing into radial and ulnar at cubital fossa
3 Muscles Brachial A. Lies on?
Long head triceps, coracobrachialis, brachialis
3 main branches of Brachial artery ?
Deep brachial (profunda brachii; runs in radial groove posteriorly), the superior ulnar collateral, and inferior ulnar collateral arteries.
What does injury to muculocutaneous cause?
Great loss of flexion of elbow, although not complete due to brachioradialis and flexor forearm muscles.
Where does radial nerve travel?
Radial groove on back of humerus traveling with deep brachial artery
If you break humerus low will triceps still work?
Yes! Radial nerve innervates triceps high on humerus
Relation of Median nerve to brachial artery in arm?
Starts laterally, then moves medially
Boundaries of cubital fossa?
Superior - line connecting epicondyles.
Medial - forearm flexors (pronator teres m.)
Lateral - forearm extensors (brachioradialis m.)
Floor - brachialis and supinator mm.
Roof - brachial and antebrachial fascia reinforced by bicipital aponeurosis
Contents of Cubital Fossa?
Terminal part of the brachial artery Deep veins in the area Tendon of the biceps brachii m. Median n. Radial n.
What does the extensor retinaculum do?
Extends obliquely across distal forearm preventing tendons from bowstringing
What does the flexor retinaculum do?
Same as extensor. Also covers carpal tunnel. If tunnel compressed, median nerve that travels through will have issues.
Which nerve innervates ring and pinky finger?
Ulnar
Difference between flexor digitorum superficialis & profundus?
Superficial goes to intermediate phalanges. Deep to distal.
Innervation of Flexor digitorum profundus?
Digits 2-3: Median
Digits 4-5: Ulnar
What does pollicis mean in latin?
Thumb
Contents of Snuff box
Floor - Radial artery
Roof - Branches of superficial radial nerve
Palpations - Styloid process of radius
Boundaries of snuff box
Laterally - abductor pollicis longus and extensor pollicis brevis
Medially - extensor pollicis longus tendon
Common Interosseous artery
Trunk off the ulnar a. extending laterally. 2 branches:
Anterior interosseous. Travels down forearm superficial to the interosseous membrane. Continues under pronator quadratus to palm
Posterior interosseous. Passes immediately deep to the interosseous membrane to supply the posterior forearm
Where does median nerve enter forearm? Path?
Enters forearm between heads of pronator teres. Gives off Anterior interosseous. Lies deep to the FDS. Becomes superficial in the distal forearm. Found between tendons of Flexor digitorum superficialis and Flexor carpi radialis mm. Passes deep and medial to Palmaris longus tendon, enters carpal tunnel deep to flexor retinaculum. Supplies thenar muscles and 1st & 2nd Lumbricals in hand. Gives off palmar branch to skin of palm.
Anterior interosseous branch of median nerve destinations
Supplies:
Flexor pollicis longus m.
Pronator quadratus m.
Where do ulnar A / N enter hand?
Canal of Guyon
Where is the capitulum and what does it do?
Distal lateral end of humerus
Articular surface with radius
Difference between dermatome and cutaneous nerve?
Dermatome: area of skin innervated by one spinal cord element
Cutaneous nerve: carry fibers from multiple spinal cord segments to target skin area
Difference between extrinsic and intrinsic hand muscles?
Extrinsic: arise in forearm
Intrinsic: Arise in hand
What is a tuberosity?
Rough area on bone formed by muscle attachment
What are bursae?
Small fluid-filled sac with inner layer of viscous fluid providing cushion between bones and tendons helping reduce friction
Styloid process of radius?
Lateral distal end of raidus
What does deep branch of radial nerve supply
Extensor brevis and supinator. After piercing supinator, called posterior interosseus and innervates rest of muscles. Radial proper innervates extensor radialus longus.
