Download Upper Limb Characterized by: - considerable mobility

Upper Limb
Characterized by:
- considerable mobility
- specialized for grasping and manipulating
Consists of 5 parts:
1- Shoulder
- marks junction between arm and trunk
- contains the clavicle and scapula
2- Brachium
- containg the humerus
3- Antibrachium (forearm)
- containing the radius and ulna
4- Wrist
- containing the 8 carpals
5- Hand
- containing the metacarpals and phalanges
Bones of the Pectoral Girdle:
-contains the only freely moveable synovial joint between and axial and appendicular skeletons
(sternoclavicular joint)
Clavicle
- connects the upper limb, which is appendicular division, to the trunk, which is axial division, of
the skeleton
- the medial end forms the sternoclavicular joint
- Lateral end articulates with the achromion of the scapula forming the acromioclavicular joint
- Medial 2/3 is convexed anteriorly
- Lateral 1/3 is concaved anteriorly
- Serves as a strut, keeping the upper limb away from the body allowing free movement
- transmits shocks from the upper limb to the axial skeleton
- fractures VERY EASILY – not much on top of it (exposed) and even less underneath it
**Scapula** (He loves this)
- triangular, thin, translucent shape bone
- runs from rib 2 to rib 7
- located on posteriolateral aspect of the thorax
- the concave anterior surface (the inside surface if the rib cage on the posterior portion of the
body) is the subscapular fossa
- the posterior surface is divided by the spine of the scapula into an infraspinous fossa and
supraspinous fossa
- the spine of the scapula ends in the acromion process
- just underneath the acromion, is a little beak like projection called the coracoid process
- Lateral surface of the scapula has a small depression called the glenoid fossa, into which the
head of the humerous fits in the glenohumeral joint
- The glenoid cavity is very shallow – which makes the joint a weak joint (structure of
joint is directly related to it’s function)
The Humerus
- articulates both with the scapula proximally and the radius and ulna distally
- the intertubercular groove (near the head of the humerous) separates the greater tubercle from
the lesser tubercle, provides a pathway for the tendon of the long head of the bicep muscle. The
tendon ascends to attach to the superior margen of the glenoid labrum
- the anatomical neck, which is very very short, separates the head of the bone from the tubercles
- distal to the tubercles is the surgical neck, where the bone narrows down to the form the shaft
**Look in atlas
Deltoid Tuberosity - anteriorly surface in middle of the humerus
Radial groove – on posterior surface
Moving down, the bone narrows to a ridge
These ridges refer to the medial and lateral supracondylar ridges
- these ridges end in the medial and lateral epicondyles
Distal end of the humerus has two articular surfaces:
- Laterally (to the radius)
- the capitulum – small articular surface serves for articulation with the radius
- Medially
- the trochlea – spool shaped condyle – for articulation with the ulna
Superior to the trochlea, on the anterior surface is the coronoid fossa
- for articulation with the coronoid process on the ulna
Superior to the trochlea, on the posterior surface is the olecranon fossa
- for articulation with the olecranon process of the ulna
**questions on exam about the orange above anatomical structures**
The Ulna
- the longer of the two forearm bones
- more medial in the anatomical position
- the proximal end has the olecranon posteriorly and the coronoid anteriorly
- and in between the olecranon posteriorly and coronoid anteriorly is the trochlear notch
- what the trochlea of the humerus fits into
- on the distal end, is the styloid process
- little extension to the bone
- helps to stabilize the wrist joint
The Radius
-small surface that articulates with capitulum of the humerus
- has a small styloid process on the distal end
- distally, has a notch into which the ulna approximates (comes close to the radius) that is
referred to as the ulnar notch
Eight Bones of the Carpals
**Know:
- recognize the names
- they are in two rows of 4
- be familiar with medial and lateral carpal in the proximal and distal row
-Proximal Row (starting from the medial side) (Plate 452)
**Pisiform** , Triquetrum , Lunate , Scaphoid (Navicular)
-Distal - Hamate , Capitate , Trapezoid , Trapezium
Most Medial - Pisiform and Hamate
Most Lateral - Trapezium and Navicular
From lateral to medial – Pneumonic Device
-New lovers Lovers Try Positions That They Can’t Handle
-Never lower tilly’s pants till tilly comes home
Metacarpals
- 1 for each digital - #1-5
#1 is associated with the thumb
Phalanges
- 14 of them
- 3 in each digit (Proximal, middle, distal)
- Thumb has ONLY 2 (proximal and distal)
Clavicle: make sure to know
- easy to palpate
- right and left clavicle articulate with the clavicular notch
- Point of the shoulder refers to the acromion
- Spine of the scapula is palpable
- the root of the spine (medial) is located at the level of T3
- Superior angle of the scapula at T2
- Inferior angle at T7
- Coracoid process (beak) of the scapular – located at the deltopecotral triangle – located
between the anterior border of the anterior deltoid muscle and the pectoralis major muscle
Fascia
IS VERY IMPORTANT BECAUSE IT ADDS STRENGTH AND HOLDS THINGS
TOGETHER
-invaginations of the fascia create compartments in the limbs of the body
- especially associated around hip joint and shoulder joint
- provide for spaces for infection, hold regions together
Pectoral Fascia
- fascia of the pectoral region is:
- Attached to the clavicle and the sternum
- Leaves the lateral border of the pectoralis major muscle to become the axillary fascia, which
then forms the floor of the axilla (armpit)
A layer of the fascia extends upward from the axillary region to form the clavopectoral fascia,
which goes underneath the pectoral muscles to attach to the clavicle
Brachial Fascia
- encloses the brachium
- wraps around the humerus and attaches itself to the medial and lateral epicondyles on the
humerus and attaches to the olecranon of the ulna
Invaginates to Divides the brachium into:
1 - anterior or flexor compartment
2 - posterior or extensor compartment
Antibrachial Fascia
- fascia of the forearm
- it surrounds the muscles of the forearm
- the forearm (or antibrachium) is divided into a posterior and anterior compartment by the
interosseous membrane between the radius and the ulna
**The Antibrachial Fascia THICKENS at the wrist to form the extensor retinaculum
posteriorly and the flexor retinaculum anteriorly
Flexor retinaculum converts the anterior cavity of the wrist into a carpal tunnel, through which
flexor tendons and the median nerve pass (not ulnar)
**When carpal tunnel is compressed due to fluid accumulation or tightening of flexor
retinaculum causing pressur on mostly the median nerve carpal tunnel syndrome**
Superficial veins of the upper limb
- easily accessible (venipunctures, IVs)
- include the cephalic and basilic
1 - cephalic – ascends along the lateral border of the wrist and along the anteriolateral
forearm and arm
- enters the deltopectoral triangle, where it participates in the formation of
the axillary vein
2 - basilica – ascends on the medial surface of the forearm and the brachium
- enters the deltopectoral triangle, and participates in forming the axillary
vein
Pectoral Muscles
Four Major Muscles: know what movement produced and joint it crosses
- all of which move the scapula and attach to the thoracic wall
1- Pectoralis Major
- covers the superior aspect of the thorax
- inferiolateral border forms the anterior axillary fold
- proximal attachment (for mental image) – along the lateral border of the sternum and the
clavicle
- distal attachment – intertubercular groove on the humerus
- adductor and medially rotates the upper limb
2- Pectoralis Minor
- smaller and underneath (anterior wall of thorax, covered by pectoralis major)
- runs from ribs 3, 4, 5 along the sternum to the coracoid of the scapula
- distal attachment – coracoid
- when it contracts – superior and anterior movement of the scapula (moves scapula up)
3- Subclavious Muscle
- runs underneath the clavicle
- protects the vessels underneath (subclavian artery)
- proximal attachment – rib 1 (can’t palpate rib 1)
- distal attachment – inner surface of the clavicle
- medial movement of the clavicle (doesn’t cross a joint)
4- Serratus Anterior
- serrated edge
- runs from the external outside of lateral surfaces of ribs 1-8 – proximal attach
- runs to the anterior surface of the scapula
- holds scapula against the posterior thoracic wall
Muscles that Attach the Upper Limb to the Vertebral Column
- latissimus dorsi
- levator scapula
- trapezius muscles
- rhomboids (major and minor)
Axilla
- armpit, pyramital area at junction of arm and thorax
- Apex of the axilla-located between rib 1, the clavicle, the subscapularis muscle –
- base of the axilla – formed by the fascia between the arm and the thoracic wall
- anterior wall of the axilla is formed by the pectoralis major and the pectoralis minor
- posterior wall of the axilla is formed by the scapula, the subscapularis muscle, the teres major
muscle and the latissimus dorsi
- lateral wall – intertubercular groove on the humerus
Axillary Artery
- continuation of the subclavian artery
- runs from rib1 to the inferior border of the teres major muscle  brachial artery
Three Divisions
1- Part One - WITHIN THE AXILLARY SHEATH, along with the axillary vein and the
cords of the brachial plexus
A- Superior thoracic artery
2- Part Two
A- Thoracoacromial
B- Lateral Thoracic Artery (comes off where subclavian becomes the axillary so can
either be said to come off axillary or subclavian)
3- Part Three
A- Subscapular
B- Anterior Circumflex Humeral
C- Posterior Circumflex Humeral
Axillary Vein
- continuation of the basilic vein
Axillary Lymph Nodes
Five Groups
**Pectoral, Lateral, Subscapula, Central, Apical**
Brachial Plexus (Plate 430)
Formed from:
- the ventral rami of C5, C6, C7, C8, and T1
- As these ventral rami enter the neck, they form three trunks
1- Superior Trunk – formed from C5 and C6
2- Middle Trunk – formed from C7
3- Inferior Trunk – formed from C8 and T1
Each trunk divides into an anterior and posterior division
**Anterior divisions supply anterior or flexor muscles of the arm**
**Posterior divisions suppler posterior or extensor muscles of the arm**
ALL posterior divisions unite to form a posterior cord
The anterior division of the superior and middle trunk form a lateral cord
The anterior division of the inferior trunk forms a medial cord
-all of these cords, give rise to 5 branches
Lateral Cord
Three Major Branches
1- Lateral Pectoral Branch – (not on the chart) associated with pectoralis major
2- **Musculocutaneous – innervates flexor muscles – coracobrachialis, brachialis, biceps
brachii
3- **Lateral Root of the Median Nerve – runs through the carpal tunnel
- associated with the flexor muscles of the forearm and part of the skin and muscles of the
hand
Medial Cord
Five Branches
1- Medial Pectoral Nerve
2- Medial Brachial Cutaneous
3- Medial Antibrachial Cutaneous
4- **Median Root of the Median Nerve
5- **Ulnar Nerve – runs along the posterior surface of the elbow
Posterior Cord
Five Branches
1- Upper Subscapula
2- Lower Subscapula
3- Thoracodorsal Nerve
4- **Axillary
5- **Radial
Plexus is divided into:
- a supraclavicular region, which can be approached through the neck
- a infraclavicular region, which can be approached through the axilla
**Know the 5 terminal branches of the brachioplexus; Hierarchy
PNEUMONIC DEVICE
Real Tired Drink Coffee Black
Roots, Trunks, Division, Cord, Branches**
Median nerve – only nerve that runs through carpal tunnel
Ulnar nerve – funny bone
Axillary Sheath
- within the axillary sheath, part of brachial fascia, is the:
- axillary vein
- axillary artery
- chords of the brachial plexus
- is just anterior to the subclavian artery
- results from folding of the fascia
Muscles
- broken into groups based on either location or action
Shoulder Muscles
Three Groups
1- Superficial Extrinsic Muscles
A - Trapezius – covers the posterior portion of neck and the trunk
- attached the pectoral girdle, via the scapula, to the skull and the vertebral
column
B - Latissimus Dorsi (2) – covers the inferior portion of the back
- runs from T6 to posterior iliac crest
- comes up to insert on the intertubercular groove (below head of
humerus)
2- Deep Extrinsic Muscles
A – Levator Scapula – elevates the scapula
B – Rhombdoid (major and minor) – runs from the medial surface of the scapula to the
vertebral column
C – Serratus Anterior
3- Intrinsic Muscles
- short muscles
- lots of them – about 6
A – Deltoid – caps the shoulder
- triangular
a- anterior
b- middle
c- posterior
- these abduct the arm
B – Teres Major – along with the deltoid, forms the posterior axillary fold
*****MUSCLES THAT FORM THE ROTATOR CUFF MUSCLES*****
C – Infraspinatus – in infraspinatus fossa
D – Supraspinatus – in supraspinous fossa (fixes head of humerous in glenoid cavity,
doesn’t actually produce movement.
E – Subscapularis – in subscapular fossa
F – Teres Minor – lateral border of the scapula
- provide some rotation of the humerus around the glenohumeral joint
Teres minor and infraspinatus
- span the shoulder joint across the back to attach on to the head of the humerus near the greater
tubercle
- start on the scapula
- Lateral rotators
Subscapularis
- because of its proximal attachment, it runs underneath the axilla to attach in the front, near the
intertubercular groove
- Medial rotator
Supraspinatus
- runs from supraspinous fossa onto the head of the humerus (right across the top)
- stabilize the head of the humerus (holds the head in the glenoid cavity while the others rotate it)
- important muscle in stabilizing the joint
Damage to it:
– devasting to integrity of glenohumeral joint
Hypertrophy – increase in size of cells
Atrophy (decreasing in size of cells) of the deltoid muscles occurs when there is damage to:
- axillary nerve
- associated with innervating the deltoid muscles
- one of five terminal branches of the brachial plexus
- if damaged, can’t use the deltoid
Brachium (Arm)
Divided into:
1- Anterior Compartment
- aka flexor compartment
Consists of three muscles: all are flexors
A - brachialis
B - biceps brachii
C - corico brachii
ALL of these muscles are innervated by the musculocutaneous nerve
2- Posterior Compartment
- extensors
Primary Muscle – triceps brachii
Also part of extensors – anconeus (really in the forearm but works with the triceps)
- based on its function, extensor of posterior and compartment
- Both are supplied by the radial nerve (third of brachial plexus final branches)
Brachial Artery
- the principle arterial supply to the ENTIRE arm
- it begins at the axillary artery
- it ends in the cubital fossa (proximal end of radius)
- at its point of termination near the neck of the radius, it divides into:
- radial artery
- ulnar artery
- is palpable, medial to and anterior to the humerus it travels with the median nerve
- gives off lots of braches to supply the tissue of the brachium
Cubital (anticubital) Fossa
- the hollowed out area on the anterior surface of the elbow
In the cubital fossa:
- end of the brachial artery
- inferiorly bifurcates to the beginning of radial and ulnar arteries
- median cubital vein
- median nerve and the radial nerve
Forearm Muscles
Muscles of the forearm act on:
- elbow
- wrist
- digits
**The flexor-pronator group of muscles ALL arise from a common flexor tendon that
attaches to the medial epicondyle of the humerus**
** The extensor-supinator group arise from a common extensor tendon that attaches to the
lateral epicondyle of the humerus**
Flexors
- distally the tendons of the flexor muscles are on the anterior surface of the forearm and are held
in place by the flexor retinaculum around the wrist
- proximal attachment on medial epicondyle
Divided into two groups:
1- Superficial Group
ALL SUPERFICIAL FLEXORS HAVE A COMMON PROXIMAL ATTACHMENT (medial
epicondyle)
A – Pronator Teres – runs from medial epicondyle to lateral surface of the radius(distal
attachment) [gets shorter]
B – Flexor Carpi-radialis – distal attachment is on the 2nd metacarpal (index finger – on
radial side)
- flexes at the wrist
C – Palmaris Longus – distal attachment is the flexor retinaculum
- runs across the flexor retinaculum
- flexes at the wrist
D – Flexor Carpi-ulnaris – distal attachment is the posterior surface of the ulna,
pisiform, and the 5th metacarpal
- flexes at the wrist
- adducts the hand at the wrist
E – Flexor Digitorum Superficialis – runs down to the middle phalanges of digits 2, 3,
4, and 5
- flexes digits 2, 3, 4, and 5
2- Deep Group
- does NOT attach to the common flexor tendon
A – Flexor Digitorum Profundus – runs from the proximal ¾ of the ulna to the distal
phalanges of digits 2, 3, 4 and 5
- flexes the digits
B – Flexor Pollicis (thumb) Longus – runs from the anterior surface of the radius to the
base of the distal phalange of the thumb (digit #1)
- flexes the thumb
Pollicis – has to deal with the thumb
C – Pronator Quadratus – runs from the distal half of the ulna to the distal ¼ of the
radius
- much shorter
- radial end approximates the ulnar end  pronating
Extensors
Divided into three groups:
A – Muscles that extend and abduct OR adduct the hand at the wrist
a- Extensor Carpi-Radialis Longus – from the lateral supracondylar ridge to the
2nd metacarpal
- extends at the wrist
- abducts at the wrist
b- Extensor Carpi-Radialis Brevis – from the lateral epicondyle of the humerus
down to the 3 metacarpal
- shorter
- extensor
rd
c- Extensor Carpi-Ulnaris – from the lateral epicondyle of the humerus to the 5th
metacarpal (ulna side)
- extends
- adducts
B – Muscles that extend the medial 4 digits (2, 3, 4, 5)
a- Extensor Digitorum – from the common extensor tendon on the lateral
epicondyle to the extensor expansion of digits 2, 3, 4 and 5
- extends the digits
- activity in extending the wrist
b- Extensor Digiti Minimi – common tendon on the lateral epicondyle to the
extensor expansion on digit 5 (digiti minimi)
- extends your pinky
c- Extensor Indexis – runs from the posterior surface of the ulna to the extensor
expansion of digit 2
- extends the index finger (digit 2)
**KNOW WHAT THEY DO BASED ON NAME**
Metacarpal side – abd
Ulna side – add
C – Muscles that extend and/or abduct digit 1 (thumb)
a- Abductor Pollicis Longus – abducts the thumb
- abduct the thumb = extend the thumb
- runs from the posterior surface of the radius and ulna to the base
st
of the 1 metacarpal
b- Extensor Pollicis Brevis – extends the thumb
- runs from the back of the radius to the base of the proximal
phalange
c- Extensor Pollicis Longus – extends the thumb
- runs from the posterior surface of the ulna to the base of the distal
phalange
-all extensors and flexors held in place by retinaculum.
-Anatomical snuff box: formed by the tendons of the abductor pollicis longus and the extensor
pollicis brevis anteriorly, and the abductor pollicis longus posteriorly. The radial artery runs
through here.
Wrist and the Hand
Anatomical Landmark – anatomical snuff box
Formed by the tendons of:
- abductor pollicis longus
- extensor pollicis brevis
- extensor pollicis longus
Radial artery passes through the anatomical snuff box
Fascia of the Wrist and the Hand
- continuation of the flexor retinaculum (book refers to it as extensor)
- called the pulmar apopneurosis
- Distally, the pulmar apopneurosis divides to cover the bases of digits 2, 3, 4, and 5
- the hypothenar compartment - located between the medial border of the pulmar apopneurosis
and the 5th metacarpal
- contains the:
- hypothenar muscles
- the thenar compartment – located between the lateral border of the pulmar apopneurosis and
the 1st metacarpal
- contains the:
- thenar muscles
Between the two, is the central compartment – midpalmar space
- contains the:
- flexor tendons
- lumbricals
- digital vessels and nerves
There are TWO potential spaces called thenar and midpalamar spaces
- between the flexor tendons and the deep palmar muscles
- allow free movement of structures
- potential sites for infection and spread of infection
Muscles of the Hand
Divided into four groups: (based on actions)
1- Thenar Muscles in the Thenar Compartment
Including:
A – Abductor Pollicis Brevis
B – Flexor Pollicis Brevis
C – Small muscles called Oppones Pollicis
2- Adductor Pollicis
- adducts the thumb
3- Hypothenar Muscles
A – Abductor Digiti Minimi
B – Flexor Digiti Minimi Brevis
C – Oppones Digiti Minimi
4- Short Muscles of the Hand
A – Lumbricles – tiny little muscles
- located on the phalanges of the medial 4 digits (2, 3, 4, 5)
B – Interossei – located on all 5 digits
a – DAB (Dorsal Interossei – ABduct the digits)
b – PAD (Pulmar Interossei – ADduct the digits)
Nerves of the Hand
Median nerve
- passes underneath the retinaculum – through the carpal tunnel
Ulnar nerve – do NOT go through carpal tunnel
Radial nerve – do NOT go through carpal tunnel
Arteries
Radial and ulnar arteries supply ALL of the blood to the hand
There are two arches that are formed by these arteries:
1- Superficial Palmar Arch – formed from ulnar artery
2- Deep Palmar Arch – formed from radial artery
- These arches mix with eachother and send a pair of digital arteries to digits 2, 3, 4
- The thumb and the digiti minimi, 1st and 5th digits, each have an arterial supply directly off the
radial and ulnar arteries, respectively
**Carpal Tunnel Syndrome**
- any condition that decreases the space in the carpal tunnel AND/OR puts pressure in the
median nerve
The median nerve has TWO terminal branches supplying the skin of the hand, specifically, the
lateral 3 ½ digits
- Pressure on these branches of the median nerve causes:
- paresthesia – tingling sensation
- anesthesia – absence of tactile stimuli
- And/or hypoesthesia - diminished sensation
- Progressive weakness in the thumb
- there are treatments, depending on severity
Joints of the Upper Limb
Sternoclavicular Joint
- between the sternum and the clavicle
- a gliding synovial joint
- articulation is between the medial surface of the clavicle to the manubrium of the sternum and
to the first costal cartilage
- has a joint capsule
- a TRUE synovial joint
- ONLY TRUE synovial joint between the axial and appendicular division of the skeleton
- reinforced by several ligaments:
- anterior and posterior sternoclavicular ligament
- small costo clavicular ligament – between first costal cartilage and the clavicle
- movement – anteriorly and posteriorly, superiorly and inferiorly
Acromioclavicular Joint
- plane synovial joint
- between the lateral end of the clavicle and the acromion (end of spine of scapula)
- reinforced by two important ligaments
- acromioclavicular ligament
- coricoclavicular ligament – between coracoid process and clavicle
- movement – rotation of the acromion as the scapula moves (rotates on clavicle)
- a shoulder separation has to do this acromioclavicular joint
- if both ligaments are ruptured/torn  SERIOUS injury (need reconstructive surgery)
Shoulder Joint
- ball and socket synovial joint
- between the head of the humerus and the glenoid cavity (not very deep) of the scapula
---- The integrity of the joint is based on architecture of the joint
- The glenoid cavity is deepened by a rim of fibrocartilage – glenoid labrum
- makes it a little more stable
- fibrous capsule – attaches:
- medially to the glenoid cavity
- laterally to the neck of the humerus
- Ligaments include:
- glenohumeral ligament – strengthens the anterior aspect of the joint capsule
- coricohumeral ligament – strengthens the joint capsule superiorly
- transverse humeral ligament
- strengthens the internal aspect of the capsule itself (holds the capsule together)
- goes across the tubercles (does NOT span two bones – all on humerus) – in
doing so, holds the tendon of the bicep muscles in the intertubercular groove
- Movements – flexion, extension, abduction, adduction, rotation, circumduction
- Injury to this joint involves lots of bleeding
Blood Supply
- Branches of the:
- suprascapular artery
- lateral thoracic artery
Nerve Supply
- Branches of the axillary nerve
Due to the weak architecture, and freedom of the movement, the joint is often dislocated
Most common location for dislocation – extension and lateral rotation
Elbow Joint
- hinge type synovial joint
- many similarities with knee joint
- articulation between the trochlear and capitulum on the humerus to the trochlear notch of the
ulna and the had of the radius
- joint capsule encloses the entire joint and continues downward to surround the radioulnar joint
- WEAK anteriorly and posteriorly
- STRONG laterally and medially
- Ligaments:
- radial collateral ligament – runs from the lateral epicondyle to the annular ligament
(thickened band of tissue that attaches to the radius)
- ulnar collateral ligament – runs from the medial epicondyle down to the coronoid and
olecranon of the ulna
Proximal Radioulnar Joint
- pivot synovial joint
- between the head of the radius and the radial notch on the ulna
- reinforced by the annular ligament (continuous with radial collateral joint), which surrounds
the joint
- movement – during pronation and supination
Distal Radioulnar Joint
- pivot synovial joint
- between the head of the ulna and the ulnar notch on the radius
- weak fibrous capsule
- movement – pronation and supination
****Look up Colles Fracture****
- the MOST COMMON fracture in people over 50 years of age
- occurs when an individual falls and tries to break their fall with their hand in a pronated
position
- results in a transverse fracture of the distal 2-3cm of the radius
- when that happens, the broken end is pulled UP (proximally)
- area of fracture resembles a dinner fork – dinner fork fracture