Upper Extremity Myology Flashcards
Muscles can only do what?
Contract. Get smaller
Pectoralis Major M
Attachments
Attachments- [clavicle, sternum and the sheath of the rectus abdomnius–> intertubercular groove on the humerus]
Pectoralis Major M
Action
- Medially rotate humerus
- Adduct
- Flex the humerus
- Protract the scapula
Pectoralis major m.
Innervation
- Medial pectoral n.
2. Lateral pectoral n.
Pectoralis major m
blood supply
Pectorial branch of the thoracoacromial trunk
Pectoralis Minor M
Attachments
Coracoid process of the scapula–> 3-5 ribs
Pectoralis Minor M
Action
- stabilize the scapula to the thoracic cavity
Pectoralis Minor M
Innervation
Medial pectoral n.
Will pierce right through to get to pec major
Pectoralis Minor M
B.S
Pectoral trunk of the thoracoacromial trunk
Subclavius Muscle (WONT SEE)
Attachments
Bottom part of the clavicle–> 1st rib
Subclavius Muscle
Action
Depress the clavicle
Subclavius M.
Innervation
Nerve of the Subclavius
Subclavius M
B.S
Clavicular branch of the thoraccromial trunk
Serratus Anterior M.
Attachment
Deep part of the medial border of the scapula–> lateral part of the ribs
Serratus Anterior M
Action
- Stabilize the scapula in the thoracic wall
- Protract the scapula
- Rotate the glenoid cavity upwards
Serratus Anterior M
I
Long thoracic N
Serratus Anterior M
B.S
Lateral thoracic A
What causes winging of the scapula?
That pec minor and serratus anterior m will stabilize the scapula.
When the long thoracic n of the [SERRATUS ANTERIOR M] is damaged, it paralyzes the the muscle. thus, the scapula is not stabilzied.
This makes ABDUCTING hard. REMEMBER WE SAID THAT 1 JOB OF THE SERRATUS ANTERIOR MUSCLE WAS TO ROTATE THE GLENIOD CAVITY SUPERIORLY
Winged scapula makes _____ hard
abducting
because we said a job of the serratus anterior m was to lift the glenoid cavity superiorly
6 scapulohumeral muscles?
- Deltoid M
- SubscapulARIS m.
- Supraspinatus m.
- Infraspinatus m.
- Teres major m.
- Teres minor m.
Deltoid M
attachments
Scapular spine
Acromion
Clavicle
–> Deltoid tuberosity on the humerus
What kind of muscle is the deltoid?
multi-pennate
3 parts of deltoid axn
Anterior part
- Medially rotate shoulder
- Flex shoulder
Middle part of the deltoid
1. Abduct shoulder
Posterior part of the deltoid
- Laterally rotate shoulder
- Extend shoulders
Deltoid M
I
axillary N
Deltoid M
B.S
- Deltoid branch of the thoracoacromial trunk
2. PCHA: Posterior cirumflex humeral artery
Subscapularis M
Attachments
subscapular fossa–> lesser tubercle of the humerus (rmbr this faces anterior)
Subscapularis M
Axn
- Medial rotation of the humerus
2. Adduction of humerus
Subscapularis M
I
Upper subscapular n
Lower subscapular n
Subscapularis M
B.S
Subscapular a
Supraspinatus M
Attachment
Supraspinous fossa–> top of the greater tubercle of the humerus
(runs under the acromion)
Supraspinatus M
Axn
Abduction of the humerus
Supraspinatus M
I
Suprascapular N
Supraspinatus M
BS
Suprascapular A
Infraspinatus M
Attachment
Medial border of the infraspinous fossa–> greater tubercle of humerus
Infraspinatus M
Axn
External (lateral rotation)
Infraspinatus M
I
Suprascapular N
Infraspinatus M
B.S
Suprascapular A
Teres Major M.
Attachment
[inferior angle of the scapula]–> front of the humerus–> [intertubercular groove]
Teres Major M.
Action
Medial (internal) rotation of the humerus
Adduction
Teres Major M
I
Lower subscapular N
This makes sense because it is near the subscapularis M (which is also innervated by the lower subscapular N)
Teres Major M
BS
Circumflex scapular A
Teres Minor M
Attachment
Lateral border of scapula–> Greater tubercle of the humerus
Teres Minor M
Axn
Lateral rotation
Teres Minor M
I
Axillary N
same as deltoid
Teres Minor M
B.S
Circumflex scapular a.
Rotator Cuff Muscles
SITS Supraspinatus M. Infraspinatus M. Teres minor M. SubscapuLARIS N.
What do the rotator cuff muscles do?
Rotator cuff muscles will stabilize the glenohumeral joint. If any of these muscles become injured, it will destabilize the joint.
The most commonly injured rotator cuff muscle is what?
Supraspinatus M.
There are only 3 brachial muscles of the anterior component. What are they?
- Biceps Brachii M.
- Coracobrachialis M.
- Brachialis M.
Biceps Brachii M.
2 Parts:
- Short Head
2. Long head
Biceps Brachii M.
Actions:
Why?
- Flex the shoulder
- Flex the elbow
- Supinate
Because remember, it skips attaching to the humerus and goes from the [supraglenoid tubercle of the scapula–> radial tuberosity]
Biceps Brachii M.
Innervation:
Musculocutaneous N.
Coracobrachialis M.
Action:
Why?
- Flex the shoulder
- Adduct the shoulder
Remember; goes from coracoid process of scapula–> medial part of the humerus
Corachobrachialis M.
Innervations:
Musculocutaneous N.
Striking what should produce the bicipital myotactic reflex?
The Bicipital Tendon.
Patient David comes in and we conduct a bicipital myotactic reflex on his bicipital tendon. He does not exhibit the reflex. What can we suggest?
We can suggest that he has damage to his
[musculocutaneous n] or
[C5 and C6 anterior rami].
What is the Popeye Deformity?
The long head of the biceps brachii m. attaches to the supraglenoid cavity of the scapula. the tendon then goes through the intertubercular groove–> radial tuberosity.
Repetitive movement in this groove can cause inflammation of the tendon, called bicipital tendinitis and crepitus (cracking sound).
If that tendon gets out of the intertubercular groove, or separates from supraglenoid tubercle, it can cause a Popeyes deformity in the arm.
Brachialis M.
Action:
Why?
- Flex the elbow
Because it attaches from the humerus –> ulnar tuberosity.
Brachialis M.
Innervation
Musculocutaneous N.
All brachialis muscles in the anterior compartment are innervated by what?
Musculocutaneous N.
All brachial muscles in the POSTERIOR compartment are innervated by what?
Radial N.
What are the 2 brachial muscles in the POSTERIOR compartment?
- Triceps Brachii M.
2. Aconius M.
Triceps Brachii Heads
- Long head of the Tricep Brachii M.
- Medial head of the Tricep Brachii M.
- Lateral head of the tricep Brachii M.
Which is the only tricep brachii m. to attach to the shoulder joint?
Long head of the tricep brachii.
It will attach at the infraglenoid cavity of the scapula
All tricep muscles end up where?
Olecranon process of the ulna
Tricep Brachii M.
Action
- EXTEND the forearm
Because it goes from the infraglenoid tuberosity–> olecranon process of the ulna
Tricep Brachii M
Innervation
Radial nerve
Aconeus M features
WEEIIIRD because it is technically in the forearm, but called a brachial muscle.
It is located on the back of the elbow joint; it is small and triangular.
Goes from the lateral humeral epicondyle–> ulna
Aconeus M
Action
Extend the elbow
Aconius M
Innervation
Radial N
What are antebrachial muscle flexors
They are located in the anterior forearm.
Role: flex
What are the antebrachial flexors are going to be innervated by what nerve?
Median nerve.
EXCEPT the [flexor carpi ulnaris m] and the [flexor digitorum profundus m]
What innervated the flexor carpi ulnaris m
Ulnar n.
What innervates the flexor digitorum profundus
Lateral part: innervated by the [anterior interosseous n] (of the median nerve
Medial part: Ulnar nerve
What is so PROFOUND about the Flexor digitorum profundus?
It is innervated by both the MEDIAN and ULNAR NERVE.
Lateral part: Anterior interosseous N (of the median N)
Medial part: Ulnar nerve
Antebrachial flexors are
4 superficial flexors (P/F/P/F)
- Pronator teres M.
- Flexor Carpi Radialis M.
- Palmaris Longus M
- Flexor Carpi Ulnaris M
1 Intermediate Flexor
1. Flexor digitorum superficialis M
3 Deep Flexors
- Flexor Digitorum profundus
- Flexor Pollicis Longus M
- Pronator quadratus M.
Superficial flexors all begin at the
Medial humeral epicondyle of the humerus.
Thus, they will all work on your ELBOW
Pronator teres M
Action
Pronate the elbow
Pronator teres M
Innervation
Median Nerve
Flexor Carpi Radialis M
Action
- Abduct the wrist
- Flex the wrist
- Flex the elbow
Flexor Carpi Radialis M
Innervation
Median Nerve
Palmaris Longus M
Action
- Flex the elbow
- Flex the wrist
- Tenses the palmar aponeurosis
Palmaris Longus M. Goes where?
Palmaris longus will go from the medial humeral epicondyle to the PALMAR APONEUROSIS
Palmaris Longus M
I
Median N
Flexor Carpi Ulnaris M
Action
- Flex the elbow
- Flex the wrist
- Adduct the wrist
Flexor Carpi Ulnaris M
I
Ulnar N
Flexor digitorum Superficialis M features
Flexor digitorum superficialis m
is a [multi-caudal muscle]. It comes from everywhere on the front side of the arm and articulates to the intermediate phalanges of digits 2-5. Thus, it does not attach to the THUMB or the distal phalanges.
Where does the flexor digitorum superficialis m not go to?
- Distal phalanges (it stops at the intermediate phalanges)
2. It does not go to the thumb
Flexor Digitorum Superficialis M
Action
- Flex the forearm,
- Flex the wrist
- Flexes the proximal and intermediate phalanges of digits 2-5 at the MCP joint and PIP joint
Flexor Digitorum Superficialis M
I
Median N
Flexor Digitorum Profundus
Action
- Flex the wrist
2. Flexes all phalanges of digits 2-5 at the MCP, PIP, and DIP joints
Does the flexor digitorum profundus flex the elbow?
No. Because it does not attach to the medial humeral epicondyle. It begins at the
Does the flexor digitorum profundus m go to the thumb? Distal phalanges?
No- thumb.
Yes- distal phalanges
Flexor Pollicis Longus M
Feature
YAY! A muscle that finally goes to the thumb :)
Flexor Pollicis Longus M
Action
- Flex the wrist
- Abduct the 1st metacarpal at the carpometacarpal joint
- Flex both phalanges of the thumb at the INTERCARPAL joint
Flexor Pollicis Longus M
I
Anterior Interosseous N (of the median n)
Flexor Digitorum Profundus
I
Medial- Ulnar N
Lateral- Anterior Interosseous N (of median n)
Pronator Quadratus M
Action
- Pronation
2. Hold the ulna and radius together
Pronator Quadratus M
I
Anterior Interroseous N
B.S for
- Biceps Brachii M.
- Coracobrachialis m
Brachial A.
What are the SIX superficial extensors?
- Brachioradialis M.
- Extensor Carpi Radialis Longus M.
- Extensor Carpi Radialis Brevis M.
- Extensor Digitorum M.
- Extensor Digiti Minimi M.
- Extensor Carpi Ulnaris M.
What are the 2 extensors innervated by the RADIAL N?
- Brachioradialis M.
2. Extensor Carpi Radialis Longus.
What are the 2 extensors innervated by the DEEP RADIAL NERVE?
- Extensor Carpi Radialis Brevis M.
2. Supinator M.
All of the other extensors are innervated by what?
Posterior Interosseous N.
Brachioradialis M.
Action:
- Flex elbow, esp when it is mid-pronated
Brachioradialis M.
Innervation:
Radial N
Extensor Carpi Radialis Longus M.
Action:
Flexor Carpi Radialis goes to the base of the 2nd metacarpal
Action:
- Extend the wrist
- Abduct the wrist
Extensor Carpi Radialis Brevis M
Action
Starts a little bit lower on the arm than the extensor carpi radialis longus
- Extend the wrist
- Abduct the wrist (because it goes to the radial side)
Extensor Carpi Radialis Longus M
Innervation.
Radial N.
Extensor Carpi Radialis Brevis M
Innervation:
Deep Radial N.
Extensor Digitorum M
Fx
Lateral humeral Epicondyle–> Extensor hood (dorsal digital expansion of all joints in digits 2-5
Extensor digitorum M
Action
- Extend the wrist
2. Extend digits 2-5 at ALL joints
Extensor digitorum M
Innervation
Posterior Interosseous M.
Extensor Digiti Minimi M.
Action
- Extends the pinky
Extensor Digiti Minimi M.
Innervation:
Posterior Interosseous N
Extensor Carpi Ulnaris M
Action:
- Extend the wrist
2. Adduct the wrist
Extensor Carpi Ulnaris M
I:
- Posterior Interosseous N.
Where does the [brachioradialis M] and the [extensor carpi radialis longus m] attach?
- Lateral supracondylar ridge of the humerus
Where do the [extensor carpi radialis brevis m] [extensor digitorum m] [extensor digit minimi m] [extensor carpi ulnaris] come from?
Lateral humeral epicondyle
Tennis elbow is what?
Tennis elbow, also called lateral epicondidylitis, is pain of our lateral humeral epicondyle and down our posterior arm.
We get this from repetitive use of our SUPERFICIAL EXTENSORS.
Deep Extensors Muscles
- Supinator M
2. Extensor Indicis M.
Supinator M
Action
Supinate
Supinator M
I
Deep Radial N
Extensor Indicis M
Action
- Extend the wrists
- Extends the INDEX finger
Located at the bottom of the ulna
Extensor Indicis M
I
Posterior Interosseous N.
What extensors does the radial nerve innervate?
- Brachioradialis M.
2. Extensor Carpi Radialis Longus M/
What extensors does the DEEP RADIAL NERVE innervate?
- Extensor Carpi Radialis Brevis M.
2. Supinator M.
how does the radial nerve–> deep radial nerve–> posterior interosseous nerve?
The radial nerve will go to the [brachioradialis M] and the [extensor carpi radialis longus M] and then split into the deep radial nerve and the superficial radial nerve.
The deep radial nerve then goes to the [extensor carpi radialis brevis m] and deep into the [supinator m]
When it comes out, it runs with the [posterior interosseous m] so thats its new name.
What are the 3 antebrachial thumb muscles?
- Abductor Pollicis Longus M
- Extensor Pollicis Longus M
- Extensor Pollicis Brevis M.
Abductor Pollicis Longus M
Action
- Abduct the wrist
2. Abduct the thumb
Abductor Pollicis Longus M
I
- Posterior Interosseous N.
Extensor Pollicis Longus M
and the Extensor Pollicis Brevis M
Action
- Abduct the wrist
2. Extend the thumb
What is the difference between the extensor pollicis longus M and the extensor pollicis brevis M
Extensor pollicis Longus M goes to the base of the distal phalanx of the thumb
Extensor pollicis brevis M goes to the base of the promiximal phalanx of the thumb
Anatomical Snuff Box
There are two borders: lateral and medial borders
The lateral border: [extensor pollicis brevis t.] and your [abductor pollicis longus t.]
Them medial border: EPL [extensor pollicis longus tendon]
What is inside the anatomical snuff box?
- Radial nerve
2. Superficial Radial Nerve
What is Golfer’s elbow?
Medial humeral epicondyle strained and inflamed
What is Tennis Elbow?
Lateral humeral epicondyle is strained and inflamed because of overuse of the superficial extensors. As a result, lateral epicondidylitis will develop and you will have pain at the lateral epicondyle and the posterior side of the arm
What are your thenar muscles? Going from the bottom up?
- Abductor pollicis brevis m
- Flexor pollicis brevis m
- Opponens pollicis m
- Adductor pollicis m.
Abductor Pollicis Brevis M.
Action
Abduct the pollex
Abductor Pollicis Brevis M
I
Recurrent branch of the medial n
Flexor pollicis Brevis M
Action
Flexes the pollex
Flexor Pollicis Brevis M
I
Superficial head-
recurrent branch of the medial nerve
Deep head-
Deep ulnar nerve
Opponens Pollicis M
Located deep to the abductor pollicis brevis m. and the flexor pollicis brevis m
We may may have to look a little deep for it.
Located deep to the abductor pollicis brevis m. and the flexor pollicis brevis m
Opponens Pollicis M
Action
Opposes the pollex
Opponens Pollicis M
I
Recurrent branch of the medial nerve
Adductor Pollicis M.
Action
Adduct the pollex
Adductor pollicis M
I
Deep Ulnar N
Jimmy damaged his recurrent medial nerve. The damage was superficial. What problems, if any, will he suffer?
Jimmy will have trouble with opposition because he damaged his Opponens Pollicis M.
What does the adductor pollicis m have?
It is a pretty big muscle.
It will have a
Transverse head at the top
Oblique head at the bottom
What are the 3 Hypothenar muscles?
- Abductor Digiti Minimi M.
- Flexor Digiti Minimi M.
- Opponens Digiti Minimi M.
The [Abductor Digiti Minimi M] and the [Flexor Digiti Minimi m] both go to the proximal phalanx of the 5th digit
What innervates all hypothenar muscles?
Deep ulnar nerve
Abductor Digiti Minimi M
Action
Abduct the 5th digit
Flexor Digiti Minimi M
Action
Flex the proximal phalanx of the 5th digit
Opponens Digiti Minimi M
Action
Oppose the 5th digit
The opponens is located deep into the Flexor Digiti Minimi M and the Abductor Digiti Minimi M
1st and 2nd Lumbrical M
Action
Innervation
Action:
Flex the MCP
Extend the PIP
Extend the DIP
Innervation: Median N
3rd and 4th Lumbrical M
Action:
Innervation:
Action:
Flex the MCP
Extend the PIP
Extend the DIP
Innervation: Deep Ulnar N