Gross Anatomy - Antebrachium and Brachium

What muscles attach to the coracoid process?

It is the site of attachment for several structures: 1. The pectoralis minor muscle - to 3rd, 4th and 5th rib (origin) 2. The short head of biceps brachii muscle - to Radial tuberosity (origin) 3. The coracobrachialis muscle - to medial humerus. Ligaments: The coracoclavicular ligament - to the clavicle. (The ligament is formed by the conoid ligament and trapezoid ligament.) The coracoacromial ligament - to the acromion The coracohumeral ligament - to the humerus The superior transverse scapular ligament - from the base of the coracoid to the medial portion of the suprascapular notch

Lister's tubercle

Lister's tubercle serves as a pulley for the tendon of flexor pollicis longus muscle that wraps around its medial side then takes a 45 degree turn towards the thumb

Where do the long head of the biceps insert onto?

Long head of biceps - bicepital groove or intertuberacular groove

Which arm muscle often ruptures?

Long head of biceps ruptures more often -> tendon rupture -> bulge at the distal aspect of arm (popeye's effect)

What artery travels with the radial n?

Mid-shaft fracture: Radial nerve travels with the deep brachii artery

What nerves make up the posterior compartment of the forearm?

ONLY radial n

What is the innervation of brachioradialis?

brachioradialis is innervated by the radial nerve. The brachioradialis (Venke's muscle) is a muscle of the forearm that flexes the forearm at the elbow. It is also capable of both pronation and supination, depending on the position of the forearm. It is attached to the distal styloid process of the radius, and to the lateral supracondylar ridge of the humerus.

Where is the capitulum and trochlea in relation to the humerus?

capitulum - lateral side trochea - medial side

What is the action of the Coracobrachialis?

coracobrchialis: simple flexor of the forearm

Where does the deltoid muscle onto?

deltoid tuberosity

What muscle is tested when the middle finger is partially bent or flexed?

flexor digitorum profundus muscle test

What muscle is tested when the middle finger is completely bent or flexed?

flexor digitorum superficialis muscle test

What are the 4 superficial muscles of the forearm?

forearm: 1.Pronator teres - assist pronator quadratis with protonation of the forearm 2.Flexor carpi radialis 3.Palmaris longus 4.Flexor carpi ulnaris

Which artery travels with the median nerve?

medial nerve and brachial artery

What nerve innervates the superficial and deep muscles of the anterior forearm?

median nerve -runs in the cubital fossa

What nerves make up the anterior compartment of the forearm?

radial and ulnar nerve

Which nerve innervates the superficial extensor muscles?

radial n

Which nerve is responsible for supination?

radial nerve

What muscle or tendon inserts onto to the radial or bicipital tuberosity?

radial or bicipital tuberosity - insertion for the short head of the biceps brachii

What does carpi mean?

runs at the wrist

What does the humerus articulate with?

the scapula at the glenoid cavity

What is the stabilizing bone of the forearm?

ulnar bone

HIGH YIELD: What nerve is affected when the medial epicondyle is fractured?

ulnar nerve

Which nerve travels through the cubital fossa?

ulnar nerve (flexion) (at the elbow)

What are 2 anterior arm muscles?

1. biceps brachii 2. brachialis

Exception: What nerve innervates the Flexor digitorum profundus muscle?

Flexor digitorum profundus - innervated by both ulnar and median nerve median n: ONLY index & middle finger side; radial half: through anterior interosseous nerve branch ulnar n: ONLY ring & little finger side; ulnar half

What is the function of the annular ligament?

The lateral fan-like radial collateral ligament extends from the lateral epicondyle of the humerus and blends distally with the annular ligament of the radius. The annular ligaments encircles and holds the head of the radius in the radial notch of the ulna, forming the proximal radio-ulnar joint and permitting pronation-supination of the forearm.

What are the actions of the biceps brachii?

biceps brachii: powerful flexors of the arm and forearm. -also a supinator

A builder is unable to pronate his fore-arm. Which nerve is affected?

median nerve

What movement occurs at the radiohumeral joint?

protonation/supination OCCURS ONLY AT THE ELBOW due to the annular ligament which attaches the radius to the ulnar bone at the radial notch

What is the supinator muscle innervated by?

radial nerve

What ligament spans the bicpital groove (or intertabercular groove) in the proximal humerus

*The transverse humeral ligament* spans the bicipital groove in the proximal humerus converting the groove into a canal for the tendon of the long head of biceps. The short of head of biceps originates from the coracoid process of the scapula (along with coracobrachialis and pectoralis minor).

What does the lister's tuberacle acts as a pulley for which muscle?

-found on the posterior side of the radius -also known as the dorsal tuberacle of the radius flexor pollicis longus muscle -Lister's tubercle serves as a pulley for the tendon of flexor pollicis longus muscle that wraps around its medial side then takes a 45 degree turn towards the thumb

What are the functions of the vena comitans?

1) they travel alongside the arterial supply of the limb 2) drain both the thick walls of larger arteries, and the surrounding tissues 3) Pulsations of artery help with venous return

What are the deep muscles of forearm?

1. Flexor digitorum profundus 2. Flexor pollicis longus 3. Pronator quadratus

What are the deep extensor muscles?

1. abductor pollicis longus 2. extensor pollicis longus 3. extensor pollicis brevis 4. extensor indicis

What are the deep muscles of the forearm?

1. coracobrachialis 2. brachialis

What are the superficial muscles of the posterior forearm? (2) attach supra-epicondylar region

1. extensor carpi radialis longus 2. brachioradialis

What are the superficial muscles of the posterior forearm? (4) attach to lateral condyle

1. extensor carpi ulnaris 2. extensor digitorum 3. extensor carpi radialis brevis 4. extensor digiti minimi all these muscles attach the lateral condyle

What are the movements at the wrist?

1. flexion/extension 2. abduction (radial deviation) 3. adduction (ulnar deviation) 4. combine to produce circumduction

Which muscles insert onto the greater trochanter of the femor?

1. gemilli 2. obturator internus 3. pirformis 4. gluteus medius 5. gluteus minimus

What are the branches of the brachial artery?

1.Anterior and posterior circumflex humeral a 2.Profunda brachii a 3. Superior ulnar collateral artery 4. Inferior ulnar collateral artery

What are the upper and lower limits of the brachial artery?

It begins at the inferior border of the teres major and ends in the cubital fossa where it divides into the radial and ulnar arteries.

What is the scapulo-humeral rhythm?

First 120 degrees - abduction of humerus Beyond 120 degrees - glenoid fossa of the scapula

What the intermediate muscle of the anterior forearm?

Flexor digitorum superficialis (attaches to the medial epicondyle)

What is the floor, nerve, and vessel of the anatomical Snuff Box?

Floor- scaphoid and trapezium Nerve - superficial branch of the radial n Vessel - radial a

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

From lateral to medial the contents of the cubital fossa are: Radial nerve as it passes around the supinator muscle, dividing around the muscle into a 1)superficial branch that can be found running beneath brachioradialis muscle (see illustration B) and 2)a deep branch which pierces supinator and makes its way to the posterior, extensor compartment to become the posterior interosseous nerve supplying all the extensors in the forearm. Biceps brachii tendon Brachial artery enters the base of the fossa and leaves as the radial and ulnar aa. (much of their local branching occurs within the fossa) Median nerve runs straight through the fossa 1. median n 2. deep and superficial branches of radial n

What is the head of the radius enshealthed with?

Head of radius - enshealthed with an annular ligament (bone rotates in the ligament)

What the quadrangular space?

In the quadrangular space, the axillary nerve and posterior circumflex humeral artery can be compressed or damaged It is bounded by: above/superior: the teres minor below/inferior: the teres major medially: the long head of the triceps brachii laterally: the surgical neck of the humerus

What are the insertions of the gluteus maximus?

Insertions: Gluteal tuberosity of the femur and iliotibial tract

What attaches the interosseous crest?

Interosseous membrane

Which veins run down the anterior aspect of the forearm?

The two main superficial veins are the cephalic and basilica that course along the lateral and medial aspects of the arm, respectively.

What does the anterior interosseous nerve branch innervate?

anterior interosseous nerve branch (from median n) deep muscles of the anterior forearm

Which side has the deltoid tuberosity?

anterior side

Which side is the interosseous crest and ulnar tuberosity found on?

anterior side

What is cubital tunnel syndrome?

Compression of the ulnar nerve in the cubital tunnel posterior to the medial epicondyle (funny bone). Tunnel comprised by medial epicondyle, ulnar collateral ligament, two heads of flexor carpi ulnaris (superficial muscle).

What are the actions of the coracobrachialis muscle (in relation to the arm)?

Coracobrachialis: helps to flex and adduct the arm -stabilizes the glenohumeral joint

What is Lateral Humeral Epicondylitis?

Also known as tennis elbow -inflammation at the lateral epicondyle -Results from continued forced flexion/extension -Strain of common extensor tendon

What is Medial Humeral Epicondylitis?

Also known golfer's elbow -inflammation of the medial epicondyle

What are the tendons of the anatomical snuff box?

Anatomical snuff box Boundaries are medial, tendon of extensor pollicis longus, and laterally by tendons of extensor pollicis brevis and abductor pollicis longus

What is the drainage of the basilic v and median cubital v?

Basilic (medial aspect) and median cubital v drain into -> axillary vein -> subclavian v

Radial nerve is damaged. Supination is still possible through contraction of what muscle?

Biceps brachii biceps brachii innervated by Musculocutaneous nerve Supinator is innervated by the radial nerve!

HIGH YIELD: Which muscle is the only one that flexes powerfully in the supine position?

Biceps brachii: only flex powerfully in supine position

What are the boundaries of the cubital fossa?

Bounded by muscles on either side: brachioradialis m. laterally pronator teres m. medially they also form the apex distally and an imaginary line connects across the top to complete the triangle

What are the actions of brachialis?

Brachialis is the muscle that lies deep to biceps brachii. It is a simple flexor of the forearm, able to flex forearm in all positions. innervated by the musculocutaneous nerve (follows very similar trends as short head of biceps brachii)

What is the articulation for the head of the radius?

Captulum - articulation for the head of the radius

What is carpel tunnel syndrome?

Carpal tunnel syndrome (CTS) is when symptoms occur due to median nerve compression as it travels through the wrist at the carpal tunnel. Symptoms include: pain numbness and tingling in the 1. thumb 2. index finger 3. middle finger 4. thumb side of the ring finger

What is the function of the pronator quadratus?

Pronator quadratus- pronates forearm - deep fibers bind radius and ulna together. -Primary pronator of forearm.

contains the axillary nerve and posterior circumflex humeral artery

Quadrangular or axillary space

What does the radial nerve divide into?

Radial nerve divides into superficial (mainly sensory) and deep (motor to all extensor muscles, including brachioradialis- flexor muscle) branches. Deep branch passes to back of forearm by passing between heads of supinator. Once here it is renames the posterior interosseous nerve Superficial branch is cutaneous. It passes down with the radial artery, deep to brachioradialis to reach lower end of radius. It winds around to the back of the forearm, passing over the anatomical snuff box. It supplies skin on the back of the hand, thumb and lateral two and a half fingers (index, middle and half of ring) - it is the dorsal mirror image to the median nerve on the palmer aspect!

Which vein is used for blood to be drain?

Site of venipuncture is normally the median cubital vein: -Overlies bicipital aponeurosis -No nerves in proximity Median cubital vein - draw blood from this vein *Can accidently take blood from the brachial artery*

Exception: What nerve innervates the Flexor carpi ulnaris muscle ?

Superficial muscle of the anterior compartment: Flexor carpi ulnaris- innervated by ulnar nerve

What is the function of the supinator muscle?

Supinator - supinates forearm - rotates radius to turn palm anteriorly or superiorly

What artery travels with the median n?

Supracondylar fracture: Median nerve travels with the brachial artery