Week 6 Flashcards
The brachial plexus is the innervation to the __ and ___
The brachial plexus is the innervation to the shoulder and upper extremity
What forms the brachial plexus?
Formed by ventral primary rami C5 – C8 and part of T1
What are the parts that the brachial plexus can be divided into?
- Roots (ventral primary rami)
- Trunks
- Divisions
- Cords
- Terminal Branches
The cords of the brachial plexus are named in relationship to the ___
The cords of the brachial plexus are named in relationship to the axillary artery in the axilla
What are the terminal branches of the brachial plexus?
- Musculocutaneous
- Axillary
- Radial
- Median
- Ulnar
What roots in the brachial plexus forms the superior trunks?
Ventral primary rami of C5 and C6
What roots in the brachial plexus forms the middle trunks?
Ventral primary rami of C7
What roots in the brachial plexus forms the inferior trunks?
Ventral primary rami of C8 and T1
The 3 posterior divisions of the brachial plexus, forms the ___ cord
The 3 posterior divisions of the brachial plexus, forms the posterior cord
The anterior division of the upper and middle trunks of the brachial plexus forms the ___ cord
The anterior division of the upper and middle trunks of the brachial plexus forms the lateral cord
The anterior division of the lower trunk of the brachial plexus forms the ____ cord
The anterior division of the lower trunk of the brachial plexus forms the medial cord
What terminal branches does the lateral cord give rise to?
- Musculocutaneous nerve
- Lateral part of the Median nerve
What terminal branches does the medial cord give rise to?
- Medial part of the Median nerve
- Ulnar nerve
What terminal branches does the posterior cord give rise to?
- Axillary nerve
- Radial nerve
What are the nerve roots of the phrenic nerve?
C3, C4, and C5
Why do we think of the phrenic nerve as part of the brachial plexus?
Because of its C5 nerve root
What is the nerve root of the dorsal scapular nerve?
C5
What is the nerve root of the long thoracic nerve?
C5, C6, C7
What are the other branches of the ventral primary rami?
- Phrenic nerve
- Dorsal scapular nerve
- Long thoracic nerve
What are the branches that comes off the upper trunk of the brachial plexus?
- Suprascapular nerve
- Nerve to the subclavius
What are the branches that comes off the middle and lower trunk of the brachial plexus?
NONE
What are the branches that comes off the medial cord of the brachial plexus?
- Medial pectoral nerve
- Medial brachial(arm) cutaneous
- Medial antebrachial(forearm) cutaneous
What are the branches that comes off the lateral cord of the brachial plexus?
- Lateral pectoral nerve
What are the branches that comes off the posterior cord of the brachial plexus?
- Upper/superior subscapular nerve
- Lower/inferior subscapular nerve
- Thoracodorsal nerve
The medial pectoral nerve sends branches to the ____
The medial pectoral nerve sends branches to the pec minor
What 2 structures does the lateral pectoral nerve tend to send branches to?
- Deep branch – sternal head of pec major
- Sup branch – clavic head of pec major
What are the nerve roots of the musculocutaneous nerve?
C5-C7
What are the nerve roots of the median nerve?
C6-C8, T1
What are the nerve roots of the radial nerve?
C5- C8, T1
What are the nerve roots of the ulnar nerve?
C7-C8, T1
Where do you mostly see the trunks of the brachial plexus?
In the inter-scalene space, between middle and anterior scalene
When do the trunks of the brachial plexus becomes divisions?
When they pass over the 1st rib
When do the divisions of the brachial plexus becomes cords?
Relative to the 2nd part of the axillary artery, behind the 2nd part of pec minor
The musculocutaneous nerve terminates as the ____
The musculocutaneous nerve terminates as the lateral antebrachial cutaneous nerve
What type of joint does the interosseous membrane between the radius and ulnar bones create?
A fibrous joint
What type of joints are the superior radio-ulnar joint and inferior radio-ulnar joint?
Synovial joints
What does the presence of the superior radio-ulnar joint and inferior radio-ulnar joint along with the joint created by the interosseous joint allow?
Allows for the radius to rotate around the stationary ulnar, during pronation and supination
The arm is enclosed in a sheath of fascia known as the ___
The arm is enclosed in a sheath of fascia known as the brachial fascia
The brachial fascia is continuous with the fascia of the ____ superiorly/proximally and the fascia of the ____ inferiorly/ distally.
The brachial fascia is continuous with the fascia of the *axilla superiorly/proximally and the fascia of the forearm inferiorly/ distally. *
The brachial fascia gives rise to ___ and ___ septa that divides the arm into anterior and posterior compartments.
The brachial fascia gives rise to medial and lateral intermuscular septa that divides the
arm into anterior and posterior compartments.
The anterior compartment of the arm is the ___ compartment, while the posterior compartment is the ___ compartment
The anterior compartment of the arm is the flexor compartment, while the posterior compartment is the extensor compartment
The nerve in the posterior compartment of the arm is the arm is the ___ nerve
The nerve in the posterior compartment of the arm is the arm is the radial nerve
The medial intermuscular septum separates the ___ from the ___
The medial intermuscular septum separates the basilic vein from the brachial vein and artery
How many muscles are in the arm and where are they?
- 4.
- 3 in the anterior compartment and 1 in the posterior
What are the muscles in the anterior compartment of the arm?
- Biceps brachii
- Coracobrachialis
- Brachialis
What are the muscles in the posterior compartment of the arm?
Triceps brachii
What is the origin of the biceps long head?
Supraglenoid tubercle of the scapula
What is the insertion of the biceps long head?
Tuberosity of the radius and bicipital aponeurosis
What is the origin of the biceps short head?
Coracoid process of the scapula
What is the insertion of the biceps short head?
Tuberosity of the radius and bicipital aponeurosis
What is the innervation of the biceps?
Musculocutaneous nerve
What is the action of the biceps?
Flexes and supinates forearm
What is the origin of Coracobrachialis?
Coracoid process of the scapula
What is the insertion of Coracobrachialis?
Middle third of the medial side of the humerus
What is the innervation of Coracobrachialis?
Musculocutaneous nerve
What is the action of Coracobrachialis?
Flexion and adduction of the arm
What is the origin of brachialis?
Distal half of anterior surface of the humerus
What is the insertion of brachialis?
Coronoid process and tuberosity of the ulna
What is the innervation of brachialis?
Musculocutaneous nerve
What is the action of brachialis?
Flexes forearm (elbow)
What is the origin of the long head of the triceps brachii?
– Infraglenoid tubercle of the scapula
What is the origin of the medial head of the triceps brachii?
Posterior surface of the humerus, inferior to the spiral groove
What is the origin of the lateral head of the triceps brachii?
Posterior surface of the humerus, superior to the spiral groove
What is the insertion of the triceps brachii?
Olecranon process of the ulna
What is the innervation of the triceps brachii?
Radial nerve
What is the action of the triceps brachii?
Extends the forearm
___ muscle is a very strong supinator of the arm
Biceps brachii muscle is a very strong supinator of the arm
The ___ muscle helps pull down the coracoid process, and tips the scapula. If it overworks, it’ll cause a winging of the scapula
The coracobrachialis muscle helps pull down the coracoid process, and tips the scapula. If it overworks, it’ll cause a winging of the scapula
___ muscle is the work horse of the arm
Brachialis muscle is the work horse of the arm
The ___ muscle is tested with the forearm supinated
The biceps muscle is tested with the forearm supinated
The ___ muscle is tested with the forearm pronated
The brachialis muscle is tested with the forearm pronated
The ___ muscle is tested with the forearm mid-pronated/supinated
The coracobrachialis muscle is tested with the forearm mid-pronated/supinated
___ muscle is not considered a muscle of the posterior compartment of the arm, because it sits further down below the elbow joint
Anconeus muscle is not considered a muscle of the posterior compartment of the arm, because it sits further down below the elbow joint
What is the origin of anconeus?
Lateral epicondyle of the humerus
What is the insertion of anconeus?
Lateral surface of the Olecranon process and posterior surface of the ulna
What is the innervation of anconeus?
Radial n.
What is the action of anconeus?
Extension of the forearm
What does the anconeus also help to do?
It pulls of capsule of elbow joint to prevent it being pinched during extension
___ nerve supplies all the muscles of the anterior brachium
Musculocutaneous nerve supplies all the muscles of the anterior brachium
Where does the musculocutaneous nerve arise from?
Arises from the lateral cord of the brachial plexus
___ nerve supplies the posterior muscles of the brachium and continues into the forearm
Radial nerve supplies the posterior muscles of the brachium and continues into the forearm
Where does the radial nerve arise from?
Arises from the posterior cord of the brachial plexus
The brachial artery gives rise to the ___ artery, which travels to the posterior brachium with the radial nerve to supply the posterior compartment
The brachial artery gives rise to the profunda brachii artery, which travels to the posterior brachium with the radial nerve to supply the posterior compartment
How many brachial veins accompanies the brachial artery?
2
Where does the terminal branch of the musculocutaneous nerve come out through?
Between brachialis and biceps
What are the venous drainage of the arm?
Cephalic and basilic veins
__ and ___ are two superficial veins that are located along the lateral and medial
borders of the arm
Cephalic and basilic veins are two superficial veins that are located along the lateral and medial borders of the arm
___ vein runs along the anterior lateral surface of the biceps and empties into
the axillary vein near the deltopectoral triangle
Cephalic veins runs along the anterior lateral surface of the biceps and empties into the axillary vein near the deltopectoral triangle
___ vein runs along the inferior, medial surface. It enters deep to the brachial fascia at the middle of the arm and becomes the axillary vein
Basilic vein runs along the inferior, medial surface. It enters deep to the brachial fascia at the middle of the arm and becomes the axillary vein
___ is the communication of the cephalic and basilic in the cubital fossa
Median cubital vein is the communication of the cephalic and basilic in the cubital fossa
___ vein is where nurses like to stick you with their evil needles and take your blood sample for their witchcraft
Median cubital vein is where nurses like to stick you with their evil needles and take your blood sample for their witchcraft
What is the superior boundary of the cubital fossa?
Imaginary line between the epicondyles of the humerus
What is the lateral boundary of the cubital fossa?
Brachialradialis
What is the medial boundary of the cubital fossa?
Pronator teres
What is the medial boundary of the floor of the cubital fossa?
Brachialis
What is the lateral boundary of the floor of the cubital fossa?
Supinator
What is the roof of the cubital fossa?
Cubital fascia
What are the contents of the superficial layer of the cubital fossa?
- Basilic vein
- Cephalic vein
- Median cubital vein
- Bicipital aponeurosis
What are the contents of the deep layer of the cubital fossa?
- T – Tendon of the Biceps Brachii (most laterally)
- A – Brachial artery (in the middle)
- N – Median nerve (most medially)
- Also the radial and ulnar nerves can be found near by, but not in the cubital fossa
The deep branch of the radial nerve goes in the supinator through the ___
The deep branch of the radial nerve goes in the supinator through the arcade of frohse
What is the origin of the supinator?
Lateral epicondyle of the humerus
What is the insertion of the supinator?
Lateral, posterior and anterior surfaces of the proximal third of the radius
What is the innervation of the supinator?
Deep branch of the radial nerve
What is the action of the supinator?
Supinates the forearm
What is the origin of the Brachioradialis?
Proximal two-thirds of the lateral supracondylar ridge of humerus
What is the insertion of the Brachioradialis?
Lateral surface of the distal end of the radius
What is the innervation of the Brachioradialis?
Radial nerve
What is the action of the Brachioradialis?
Flexes forearm
What are the superficial muscles of the forearm?
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor digitorum superficialis
- Flexor carpi ulnaris
What are the deep muscles of the forearm?
- Flexor digitorum profundus
- Flexor pollicis longus
- Pronator Quadratus
What is the origin of pronator teres?
– Medial epicondyle of the humerus and coronoid process of the ulna
What is the insertion of pronator teres?
Middle of lateral surface of the radius
What is the innervation of pronator teres?
Median nerve
What is the action of pronator teres?
Pronates and flexes forearm
What is the origin of Flexor carpi radialis?
– Medial epicondyle of humerus
What is the insertion of Flexor carpi radialis?
Base of the second metacarpal bone
What is the innervation of Flexor carpi radialis?
– Median nerve
What is the action of Flexor carpi radialis?
Flexes and radial deviates hand
What is the origin of palmaris longus?
Medial epicondyle of humerus
What is the insertion of palmaris longus?
Flexor retinaculum and palmar aponeurosis
What is the innervation of palmaris longus?
Median nerve
What is the action of palmaris longus?
Flexes hand
What is the origin of Flexor digitorum superficialis?
Medial epicondyle of the humerus, coronoid process of the ulna and the anterior border of the radius
What is the insertion of Flexor digitorum superficialis?
– Bodies of the middle phalanges of the medial four digits
What is the innervation of Flexor digitorum superficialis?
Median nerve
What is the action of Flexor digitorum superficialis?
Flexes the middle phalanges of the medial four digits, the proximal phalanges and hand
What is the origin of Flexor carpi ulnaris?
– Medial epicondyle of humerus, olecranon and ulna
What is the insertion of Flexor carpi ulnaris?
– Pisiform, hook of the hamate and 5th metacarpal
What is the innervation of Flexor carpi ulnaris?
Ulnar nerve
What is the action of Flexor carpi ulnaris?
– Flexes hand, ulnar deviates hand
What is the origin of Flexor digitorum profundus?
Proximal three-fourths of medial and anterior surface of the ulna and interosseous membrane
What is the insertion of Flexor digitorum profundus?
Base of the distal phalanges of the medial four digits
What is the innervation of Flexor digitorum profundus?
Medial part is ulnar, Lateral part is median
What is the action of Flexor digitorum profundus?
Flexes the distal phalanges of the medial four digits
What is the origin of Flexor pollicis longus?
Anterior surface of the radius and interosseous membrane
What is the insertion of Flexor pollicis longus?
Base of the distal phalanx of the thumb
What is the innervation of Flexor pollicis longus?
Anterior interosseous nerve
What is the action of Flexor pollicis longus?
Flexes phalanges of thumb
What is the origin of Pronator Quadratus?
– Distal, anterior surface of ulna
What is the insertion of Pronator Quadratus?
– Distal, anterior surface of the radius
What is the innervation of Pronator Quadratus?
Anterior interosseous nerve
What is the action of Pronator Quadratus?
– Pronates the forearm
___ nerve enters the forearm via the cubital fossa and travels along the lateral aspect of
the anterior forearm.
Median nerve enters the forearm via the cubital fossa and travels along the lateral aspect of the anterior forearm.
The median nerve gives off the ___ which runs deep to the superficial muscle of the forearm. It innervates the deep muscles of the forearm.
The median nerve gives off the anterior interosseous nerve, which runs deep to the superficial muscle of the forearm. It innervates the deep muscles of the forearm.
___nerve passes posterior to the medial epicondyle of the humerus and enters the
forearm medial to the flexor carpi ulnaris
Ulnar nerve passes posterior to the medial epicondyle of the humerus and enters the
forearm medial to the flexor carpi ulnaris
The ulnar nerve dives deep and runs with the ____ to the wrist
The ulnar nerve dives deep and runs with the ulnar artery to the wrist
___ nerve enters the forearm by passing anteriorly over the lateral epicondyle of the
humerus
Radial nerve enters the forearm by passing anteriorly over the lateral epicondyle of the
humerus
The superficial branch of the radial nerve is responsible for ___, and the deep branch of the radial nerve is responsible for
__ and ___ innervation
The superficial branch of the radial nerve is responsible for sensory, and the deep branch of the radial nerve is responsible for
motor and joint innervation
When does the radial nerve split into superficial and deep branches?
Once in the forearm it divides into superficial and deep branches
Brachial artery divides into the radial and ulnar arteries in the ___
Brachial artery divides into the radial and ulnar arteries in the inferior aspect of the
cubital fossa
___ artery runs along the lateral aspect of the anterior surface of the forearm and is the common site for measuring pulse rate
Radial artery runs along the lateral aspect of the anterior surface of the forearm and is the common site for measuring pulse rate
The radial artery terminates in the hand as ____
The radial artery terminates in the hand as part of the palmar arch
____ artery arises from the radial artery just distal to the brachial artery
Radial recurrent artery arises from the radial artery just distal to the brachial
artery
The radial recurrent artery ascends the arm to anastomose with the____ a branch of the profunda brachii
The radial recurrent artery ascends the arm to anastomose with the radial collateral artery a branch of the profunda brachii
___ artery arises in the inferior cubital fossa and descends the anterior, medial aspect of
the forearm and enters the hand to form part of the palmar arch
Ulnar artery arises in the inferior cubital fossa and descends the anterior, medial aspect of the forearm and enters the hand to form part of the palmar arch
What are the branches that the ulnar artery gives off?
- Anterior ulnar recurrent
- Posterior ulnar recurrent
- Common interosseous
The anterior ulnar recurrent artery arises just inferior to the elbow and ascends to anastomose with the ___
The anterior ulnar recurrent artery arises just inferior to the elbow and ascends to anastomose with the inferior ulnar collateral artery
The posterior ulnar recurrent artery arises just distal to the anterior ulnar recurrent and ascends posteriorly to anastomose with the ____
The posterior ulnar recurrent artery arises just distal to the anterior ulnar recurrent and ascends posteriorly to anastomose with the superior ulnar collateral artery
The common interosseous divides into ___ and ___ interosseous arteries
The common interosseous divides into anterior and posterior interosseous arteries
The anterior interosseous artery runs deep on the anterior surface of the interosseous membrane supplying structures of the ___
The anterior interosseous artery runs deep on the anterior surface of the interosseous membrane supplying structures of the deep forearm
The posterior interosseous artery passes posterior to the interosseous membrane and supplies structures in the ___
The posterior interosseous artery passes posterior to the interosseous membrane and supplies structures in the posterior compartment of the forearm
What is the origin of the Extensor carpi ulnaris?
Lateral epicondyle
What is the insertion of the Extensor carpi ulnaris?
Base of the 5th metacarpal
What is the innervation of the Extensor carpi ulnaris?
– Posterior Interosseous nerve
What is the action of the Extensor carpi ulnaris?
Extends and ulnar deviates the wrist
What is the origin of the Extensor carpi radialis brevis?
Lateral epicondyle
What is the insertion of the Extensor carpi radialis brevis?
Base of the 3rd metacarpal
What is the innervation of the Extensor carpi radialis brevis?
Deep radial nerve
What is the action of the Extensor carpi radialis brevis?
Extends and radial deviates hand
What is the origin of the Extensor carpi radialis longus?
Lateral supracondylar ridge
What is the insertion of the Extensor carpi radialis longus?
– Base of the 2nd metacarpal
What is the innervation of the Extensor carpi radialis longus?
Radial nerve
What is the action of the Extensor carpi radialis longus?
Extends and radial deviates hand
What is the origin of the Extensor digitorum?
Lateral epicondyle of the humerus
What is the insertion of the Extensor digitorum?
Extensor expansions
What is the innervation of the Extensor digitorum?
Posterior Interosseous nerve
What is the action of the Extensor digitorum?
Extend fingers digits 2 through 5
What is the origin of the Extensor digiti minimi?
Ulnar side extensor digitorum
What is the insertion of the Extensor digiti minimi?
Extensor expansion of digit 5
What is the innervation of the Extensor digiti minimi?
Posterior Interosseous nerve
What is the action of the Extensor digiti minimi?
Extends the 5th digit
What does the deep branch of the radial nerve changes its name to, once it comes out of the supinator muscle?
Posterior Interosseous nerve
How does the supinator supinate the forearm?
It contracts along with the biceps. They function together to supinate
What bone movement is occurring during supination of the forearm?
The radius rotates around the ulnar
How does the forearm pronate?
Pronator teres and quadratus function together to pronate
Flexor digitorum profundus passes through the tunnels created by ___
Flexor digitorum profundus passes through the tunnels created by flexor digitorum superficialis
What branch of the median nerve innervates the median part of the flexor digitorum profundus?
Anterior interosseous nerve
___ is the terminal branch of the median nerve
Anterior interosseous nerve is the terminal branch of the median nerve
What are the superficial muscles of the flexor compartment of the forearm?
- Brachioradialis
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor carpi ulnaris
What are the intermediate muscles of the flexor compartment of the forearm?
Flexor digitorum superficialis
What are the deep muscles of the flexor compartment of the forearm?
- Flexor pollicis longus
- Flexor digitorum profundus
What are the deepest muscles of the flexor compartment of the forearm?
Pronator Quadratus
What is the anterior boundary of the anatomical snuffbox?
Tendons of the abductor pollicis longus and extensor pollicis brevis
What is the posterior boundary of the anatomical snuffbox?
Tendon of the extensor pollicis longus
What is the content of the anatomical snuffbox?
Radial artery
What is the origin of the Abductor pollicis longus?
– Posterior surface of the middle ulna, radius and interosseous membrane
What is the insertion of the Abductor pollicis longus?
Base of the 1st metacarpal
What is the innervation of the Abductor pollicis longus?
Posterior Interosseous nerve
What is the action of the Abductor pollicis longus?
Abducts thumb
What is the origin of the Extensor pollicis brevis?
Middle one third posterior surface or radius and interosseous membrane
What is the insertion of the Extensor pollicis brevis?
Base of the proximal phalanx of the thumb
What is the innervation of the Extensor pollicis brevis?
– Posterior Interosseous nerve
What is the action of the Extensor pollicis brevis?
Extends thumb
What is the origin of the Extensor pollicis longus?
Middle one third of the posterior surface of the ulna and interosseous membrane
What is the insertion of the Extensor pollicis longus?
Base of the distal phalanx of the thumb
What is the innervation of the Extensor pollicis longus?
– Posterior interosseous nerve
What is the action of the Extensor pollicis longus?
Extends the thumb
What is the origin of the Extensor indicis?
– Posterior surface of the ulna and interosseous membrane
What is the insertion of the Extensor indicis?
Extensor digitorum tendon to index finger
What is the innervation of the Extensor indicis?
Posterior interosseous nerve
What is the action of the Extensor indicis?
Extends the index finger
The radial nerve enters the forearm by crossing anteriorly to the lateral epicondyle between the ___ and ___ muscles. At this point the nerve divides into the superficial and deep branches
The radial nerve enters the forearm by crossing anteriorly to the lateral epicondyle between the Brachialis and the Brachioradialis muscles. At this point the nerve divides into the superficial and deep branches
____ continues from its division with the deep to travel underneath the Brachioradialis muscle and then emerges superficial near the distal end of the forearm. It then provides innervation to the skin and joints of the hand.
Superficial branch of the radial nerve continues from its division with the deep to travel underneath the Brachioradialis muscle and then emerges superficial near the distal end of the forearm. It then provides innervation to the skin and joints of the hand.
___ is the cutaneous and articular innervation of the dorsum of the hand
Superficial branch of the radial nerve is the cutaneous and articular innervation of the dorsum of the hand
___ artery supplies the posterior aspect of the forearm and is a branch of the common interosseous
Posterior interosseous artery supplies the posterior aspect of the forearm and is a branch of the common interosseous
What are the superficial muscles of the externsor compartment of the forearm?
- Extensor carpi ulnaris
- Extensor Carpi Radialis Brevis
- Extensor Carpi Radialis Longus
- Extensor Digitorum Communis
- Extensor Digiti Minimi
What are the deep muscles of the extensor compartment of the forearm?
- Abductor Pollicis Longus
- Extensor Pollicis Brevis
- Extensor Pollicis Longus
- Extensor Indicis
What does the dorsal tubercle of the radius/ lister’s tubercle do?
It creates a trochlear for the extensor pollicis longus, so that it doesn’t slip of place when the thumb is moved up
What does the radial artery do after going through the anatomical snuff box and before going through the 1st dorsal interosseous?
It sends off princeps pollicis artery and radialis indicis artery
The tendons of the superficial extensor muscles passes underneath the ___
The tendons of the superficial extensor muscles passes underneath the Abductor pollicis longus and extensor pollicis brevis at the de quervain
What are vincula?
Ligamentous attachments that come from the ulnar aspect of the digits into the long tendons of the finger
What happens if there is an injury to the volar plate of the finger?
The finger will not bend and there won’t be proper function of the fingers
What muscles are included in the wad of 3?
- Extensor carpi ulnaris
- Extensor Carpi Radialis Brevis
- Extensor Carpi Radialis Longus
What are the intrinsic muscles on the dorsum of the hand?
There are none
What are the de quervain muscles and their tendons are called de quervain’s tendons?
- Abductor Pollicis Longus
- Extensor Pollicis Brevis
What do the de quervain’s muscle and tendon have their names?
Because they overlap and their tendons run over Extensor Carpi Radialis Brevis, and Extensor Carpi Radialis Longus