Download Anatomy of the upper Limb Upper limb

Anatomy of the upper Limb
Upper limb- characterized by considerable mobility, and is said to be specialized for grasping and
manipulating
Consists of 5 parts: Shoulder- marks junction b/w arm and trunk, contains clavicle and scapula
Brachium- (upper part of upper limb)- humerous and associated structures
Antebrachium- Radius + Ulna and their associated structures
Wrist- 8 Carpals and associated structures
Hand- Metacarpals + phalanges and associated structures
Pectoral Girdle
- contains only freely movable synovial joint b/w axial and appendicular skeletons (sternoclavicular joint)
Osteology
Clavicle
Connects upper limb and trunk. Medial end forms the sternal clavicular joint with the sternum and the
lateral end articulates with the acromion of the scapula. The medial 2/3rd of the clavicle is convex
anteriorly, lateral 1/3rd is concave anteriorly. The clavicle serves as a strut to keep the upper limb away
from the body to allow for free movement. It is also important in transmitting shocks from upper limb to
axial skeleton.
- Between left and right clavicle is the jugular notch.
Scapula
Located on posterior lateral surface of thorax from rib 2-7, it is triangular, thin, and translucent. It is
concave on its anterior surface. That concavity is called the subscapular fossa. The subscapular fossa is
occupied by the subscapularis muscle. The posterior surface is divided by the spine of the scapula into a
supraspinous fossa and infraspinous fossa, occupied by spinadous(tus?)[infra and supra] muscles. The
spine of the scapula laterally ends at the acromion, which articulates with the clavicle. The lateral
surface of the scapula is marked is marked by the slight indentation called the glenoid fossa- depression
into which the head of the humorous fits, called the scapulohumeral joint. The architecture of a joint is
directly related to its function. The glenoid cavity is a very shallow depression, its not a very stable joint
unlike the hipjoint. Around the ring of the glenoid fossa is a ring of fibrous tissue called the glenoid
labra. Above the glenoid cavity is the beak like projection called the coracoid process.
- Point of shoulder = acromion
- Root of spine of scapula is located at the level of T3.
- The inferior angle of the scapula is at T7
- Superior angle is at T2.
- The corocoid process of the scapula is located at the delto-pectoral triangle- right b/w the anterior
deltoid and the pectoralis major. You can palpate it.
- Fascia- holds things together, adds strength, invaginations (compartmentalize limbs in body).
Humerous
Articulates with scapula, radius and ulna. The interturbicular groove near the head which is located b/w
the greater and lesser tubercles, provides a pathway through which the tendon of the long head of the
bicep passes, as that tendon ascends to attach to the superior margin of the glenoid labrum(a?) The
short head of the biceps are for flexion, the short head is to hold it in place. The anatomical neck (very
short) of the humerous seperates the head of the humerous from the tubercles. More siginificant is the
surgical neck which is below distal to the tubercles, and it is where the shaft of the tubercle narrows.
Two prominent features on humerous; ridge about 1/3rd down, deltoid tuberosity (anterior surface) and
posteriorly there is a radial groove. As you move distally on the humerous, there is a sharp ridge on both
sides (anteriorly) called the supracondylar ridge (medial and lateral). Again moving distally the ridges
end in the medial and lateral epicondyles. The distal end of the humerous has two articular surfaces:
first, a small round articular surface for articulation with the radius called the capitulum. Medially has a
spool like surface called the trochlea for articulation with the ulna. Just above the trochlea anteriorly is
the coronoid fossa which is for articulation with the coronoid process of the ulna. Posteriorly on the
humerous is the olecranon fossa which articulates with the olecranon process. Its because of these
fossas that we are able to move our arms (flexion). The tendons of the triceps attach to the olecranon
process. Fractures to the olecranon process can restrict flexion.
The Ulna
Longer and more medial of the forearm bones. As we just discussed, on the proximal end posteriorly has
the olecranon process and the coronoid process anteriorly. Between those two is the trochlear notch
which sorrounds the trochlea on the distal end of the humerous allowing you to flex and extend at the
notch. Distally the ulna ends in a short styloid process.
Radius
The radius has very little outstanding structural components. It has a small articular surface superiorly
which articulates with the capitulum of the humerous and distally has a ulnar notch where the ulna
approximates the radius and also has a styloid process. The styloids add stability to the carpals (a little).
Carpals
Say Loudly to pam time to come home.
- Most medial and proximal in the medial and lateral sides.
- Proximal row- Lateral- Scaphoid (navicular), Lunate, Triquetrum, pisiform.-Medial -Anatomical Position
- Distal row-Lateral- Trapezium, Trapezoid, capitates, hamate- Medial
Never lower Tillie’s pants till Tillie comes home.
New lovers try positions that they can’t handle.
Metacarpals- number 1 is lateral, as the numbers go up it heads medial. Thumb is one, pinky is 5. In
digits 2,3,4,5 there are distal, middle and proximal phalanges. In thumb, only proximal and distal
phalanges.
Fascia
Fascia of the pectoral region is attached to the clavicle and the sternum. That pectoral fascia leaves the
lateral border of the perctoralis major muscle to become the axillary fascia. That axillary fascia forms the
floor of the axilla. A layer of the axillary fascia extends and is called the clavo-pectoral fascia which goes
around the pectoralis major muscle and the subclavius muscle( not very functionally important, but
right near subclavian artery) then attaches to the clavicle. Brachial fascia encloses the brachium (arm),
it’s a continuation of the axillary fascia and it attaches distally to the epicondyles of the humerous and
to the olecranon. The brachial fascia invaginates to divide the brachium into the anterior flexor
compartment and a posterior extensor compartment. The antebrachial fascia of the forearm
(antebrachium) sorrounds the muscles of the forearm. The muscles of the forearm are divided into a
anterior and posterior compartment by the interosseous membrane b/w radius and ulna.
- The antebrachial fascia thickens around the wrist to form the extensor retinaculum on the extensor
surface(posterior) and flexor retinaculum on the flexor or anterior surface. The flexor retinaculumconverts anterior surface into a carpal tunnel through which the flexor tendons and the median nerve
passes.
- Carpal tunnel syndrome- fluid accumulation in carpal tunnels causing pressure (inflammation of
retinaculum- puts pressure on median nerve and flexor surface(retinaculum).
Superficial veins of arm
Cephalic and basilic- superficial veins, not the brachial vein (deeper). There are communicating veins like
the antecubital.
Cephalic vein- ascends along the lateral border of the wrist, and ascends along the anterior lateral
surface of forearm and brachium, it ends in the deltopectoral triangle by merging into the axillary vein.
The basillic vein- runs medially on the forearm all the way up, emptying into the axillary vein. The more
readily accessible veins.
Pectoral Muscles
4 Major muscles for shoulder movement and attach to thoracic wall: Pectoralis major- covers the
superior thorax bilaterally and the inferior lateral border of the PM forms the anterior axillary fold.
Proximal attachment is the clavicle and sterum, and the distal attachement is the interturbicular groove
of the humerous- pulls arm in (adduction) and allows slight medial rotation at shoulder joint. Pectoralis
minor- located on anterior wall of thorax- covered by PM. Proximal attachment- ribs 3-5, distal
attachment is the corocoid process. Allows for superior/inferior movement of the scapula. The
subclavius muscle- under clavicle- protects blood vessels, mainly the subclavian artery. Small straight
muscle, proximal attachment- costal cartilage of rib 1 (can’t palpate), distal attachment is inner(inferior)
surface of clavicle. Allows for medial movement of clavicle. Serratous anterior- covers lateral surface of
thorax, has a serrated edge (jagged). Proximal attachment is the lateral surface of ribs 1-8, distal
attachment is the anterior surface of the scapula. Purpose- holds scapula against thorax. Group of
muscles which hold upper limb to the vertebral column, lattisimus dorsi, levator scapula, trapezius, and
the rhomboids.
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emphy
atelectasis- collapsed sun
bronchiectasis- inflammation of bronchioles and bronchus
Axilla
- Pyramidal shaped area @ junction of arm and thorax. Apex of axilla, is located between rib number 1,
clavicle, and subscapularis muscle. The base of the axilla is formed by the fascia of arm and thoracic wall.
Anterior wall- formed by pectoralis major and minor, posterior wall by scapula and subscapularis
muscle, teres major and lattisumus dorsi. Medial wall- ribs 1-4.
-Axillary artery- continuation of subclavian artery- runs from rib 1 to inferior border of the teres major
muscle. It then changes its name to the brachial artery. The axillary artery has 3 parts, (part 1 has 1
division, part 2 has 2, part 3 has 3 divisions).
Part 1- located within axillary sheath along with axillary vein and the cords of the brachial plexus and the
one major branch of this part of the artery is called the superior thoracic artery.
Part 2- 2 branches- Thoraco-acromial and lateral thoracic.
Part 3- Most distal, 3 branches; subscapular, anterior circumflex humeral, and posterior circumflex
humeral.
- plexus is formed from the rami of many spinal nerves. The peripheral nerves have a contribution from
all of the spinal nerves.
Brachial plexus
- Formed from ventral rami from C5, C6, C7, C8, T1. As these rami enter the neck, they form three
trunks, upper, middle and lower. The superior trunk (upper) is formed from C5 and C6. The middle from
C7. The lower (inferior from C8 and T1. Each trunk is divided into anterior and posterior division. *All
anterior divisions supply anterior or flexor muscles of arm, and posterior supply posterior or extensor
muscles of arm. All posterior divisions form a posterior cord. The anterior divisions of the superior and
middle trunk form a lateral cord, the anterior division of the inferior cord forms the medial cord. Finally,
the cords give rise to peripheral nerves (terminal branches). The lateral cord has three branches- Lateral
pectoral, the musculocuntaneous nerve- which innervates the chorocobrachialis, brachialis and the
biceps branchii. Third brach- Median nerve- from lateral root of nerve- goes through carpal tunnel,
innervates flexor muscles of forearm and part of the skin and muscles in the hand. The median cord
gives rise to 5 branches- median root of medial nerve and the ulnar nerve. The posterior cord gives rise
to radial and axillary nerves.
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Axillary Sheath
- Contains axillary artery, axillary vein the cords of brachial plexus and the sheath is located just in front
of the subclavian artery.
Muscles
Shoulder muscles
Grouped into 3 groups; superficial extrinsic muscles- include trapezius which attaches scapula, pectoral
girdle to skull and vertebral column and the lattisimus dorsi- T6 to iliac crest, inserts onto interturbicular
groove.
Group 2- deep extrinsic muscles- Levator scapula, rhomboid major/minor and serratous anterior.
Group 3- Intrinsic muscles- deltoid- insertion on humor, teres major- along with posterior deltoid form
posterior axillary fold. (something else forms anterior).
Scapular Muscles
- also known as rotator cuff muscles
- Supraspinatous (not really a rotator)- actual function is to fix the head of the humerous into the
glenoid cavity.
- Infraspinatous- run from infraspinous fossa to lateral border of scapula, attach on humerous superior
laterally. Lateral rotators.
- Teres Minor- run from infraspinous fossa to lateral border of scapula, attach on humerous superior
laterally. Lateral rotators.
- Subscapularis- from subscapular fossa- anterior surface of humorous which rotates medially.
- Weak joint.
Arm
- Brachium- upper part of upper limb. Divided into anterior and posterior compartment by fascia.
- Anterior compartment- brachialis, biceps brachii and coraco brachialis, all of which are flexors at the
elbow joint, and all of which are innervated by the musculocutaneous nerve. The posterior
compartment is composed primarily of the triceps brachii, and the anconieous (really in forearm, but it
works with tricep)- they are externsors supplied by radial nerve. Funny bone feeling- ulnar nerve.
- Brachial artery- BP artery. Principle arterial supply to arm, begins at axillary artery and it ends in the
cubidal fossa. It divides into a radial and ulnar artery, with careful articulation can be palpated, travels
along with the median nerve, medial and anterior to humorous. The cubidal fossa (or anti(e)cubidal)
contains the brachial artery superiorly and the radial and ulnar arteries inferiorly (bifricates there).
Median nerve and radial nerve pass through most notably and small veins pass through.
Forearm
Antebrachium- muscles of forearm act on elbow, wrists and digits. An important point- The flexor/
pronator group of muscles arise from a common flexor tendon which attaches to the medial epicondyle
of the humerous. The extensor/supinator group arises from a common extensor tendon attached to the
lateral epicondyle of the humerous.
Flexor/Pronator group- Tendons distally are held in place by the flexor retinaculum. Divided into groups;
superficial group- pronator teres- runs from medial epicondyle to lateral surface of radius. Flexor
carpiradialis- flexor associated with carpals and radials- Runs from medial epicondyle to second
metacarpal. 3- Palmaris Longus- Starts at Medial epicondyle to distal part of flexor reticulamun. flexes at
wrist.
Flexor Carpiulnaris- medial epicondyle to 5th metacarpal. Adduction.
Flexor Digitorum superficialis- Runs from medial epicondyle to middle phalanges of 2,3,4,5.
Deep Group- originate further down on the forearm.
- Flexor digitorum profundus- Originates on the proximal ¾ of the ulna, goes to distal phalanges of
2,3,4,5.
-Flexor Pallux(sis) Longus- anterior surface of radius to the distal phalanges of the thumb.
- Pronator quadrates- distal half of the ulna to distal ¼ of the radius (pronates).
-ExtensorsExtendor tendon on lateral epicondyle.
First group- Abduction at wrist- extensor carpi radialis longus, Extensor carpi radialis brevis (short
muscle). Run from lateral epicondyle. Longus to second metacarpal and brevis to the third. The third
one in this group was the extensor carpi ulnaris- runs along ulna from the lateral epicondyle to the fifth
metacarpal. – Adduction.
Second Group- Muscles that extend medial 4 digits.
1. Extensor digitorum- Originates on lateral epicondyle- runs down to extensor expansion (fascia of
posterior surface) of digits 2,3,4,5.
2. Extensor digitiminime- Pinky extension. Lateral epicondyle to 5th digit.
3. Extensor indices- Lateral epicondyle to 2nd digit.
Third group- muscles that work on pallux
1. Abductor pallux(es) longus- Posterior surface of radius and ulna to base of 1st metacarpal.
2. Extensor polluces brevis and long- Posterior surface of radius and ulna (both) to proximal
phalange(brevis) and distal phalange (longus). For extension.
Wrist/Hand
Always studied anatomical landmark- anatomical snuffbox. Formed by tendons of abductor palluxes
longus and extensor palluxes brevis anteriorly and by the tendon of the extensor palluxes longus
posteriorly. The radial artery runs through the snuff box (shove your cocaine here).
Fascia of hand
Continuation of flexor retinaculum, called palmar aponeruosis which spreads across the palm and covers
the flexor tendons. The palmar aponeurosis distally divideds to cover the base of digits 2-5. Hypothenar?
Compartment- located b/w medial border of aponeurosis and the fifth metacarpal. Contains hypothenar
muscles. Hypothenar- lump by your pinkyside of hand. Thenar- b/w lateral border of aponeurosis and
first metacarpal, contains thenar muscles. B/w the two, is the central compartment (midpalmar space)
containing the flexor tendons, lumbricals, also the digital blood vessels and nerves.
- Deepest muscular plane (or layer), adductor compartment- contains adductor palluses, there are two
potential spaces called the thenar and midpalmar spaces, located b/w flexor tendons and deep palmar
muscles- potential sites for infections.
Muscles of hand
The muscles of the hand are divided into 4 groups:
1. Thenar muscles in thenar compartment; 3 of them – Adductor palluses brevis, flexor palluses brevis,
opponens palluses. These three are associated with thumb. Functions are bolded.
2. Associated with thumb- Adductor Pallocis
3. Hypothenar muscles- Adbuctor digiti minime, flexor digiti minime brevis, opponens digiti minime.
4. Short muscles of hand; DAB, PAD. Lumbricles- small, located on medial 4 digits (not thumb), they are
responsible for flexion of the fingers at the phalanges. Interossei- movement of the phalanges. Dorsal
interossei- Abduction of digits, Palmar interossei- adduction .
Nerves
Ulnar, median and radial
Median- passes to he deep retinaculum- through the carpal tunnel. Ulnar and radial go above.
- Carpal tunnel syndrome- any condition that decreases the space in the carpal tunnels and puts
pressure on the median nerve.
-median nerve- 2 terminal branches supplying the skin of the hand, and compression of these branches
results in parasteia, anesthesia and or hypoesthesia. Occurs in lateral 3 and a half digits.
- Treatment= surgery relieving pressure.
Vessels
The radial and ulnar artery supply all blood to hand, there are 2 pulmar arches formed, the first is the
superficial pulmar arch, formed from radial artery., and the deep pulmar arch is from the ulnar artery.
These two arches anastamose with each other, and send pairs of digital arteries to digits 2,3,4. Thumb
and digit 5 have their own blood supply from the radial and ulnar arteries, respectively.
Pectoral Girdle (Joints)
Sternoclavicular Joint- Gliding synovial joint- freely movable. ONLY true synovial joint b/w appendicular
and axial skeleton. B/w manubrium of sternum, first costal cartilage Bilaterally, and medial end of
clavicle. There is a fibrous capsule which encloses the joint as with all synovial joints. The lining of that
capsules SnS’s synovial fluid. Syn(alike)ovium(egg)- like egg white. Ligaments associated with jointAnterior and posterior sternoclavicular ligaments. Small costoclaviculo ligament. Movements at this
joint are anterior, posterior, superior, inferior.
Acromioclavicular Joint- plane synovial joint, located b/w lateral and of clavicle and acromion of
scapula. Ligaments: Acromioclavicular ligament, coracoclavicular ligament. Movement: rotation type. A
shoulder separation is a location of the acromioclavicular joint. If all the ligaments are involved, it’s a
serious injury. For cereal.,
Shoulder Joint- ball and socket synovial joint- Articulation- head of humerous and glenoid cavity of
scapula, Let us remember that the glenoid cavity is made a little deeper by a ring of fibrous tissue called
the glenoid LABRUM. The capsule is a fibrous capsule that’s attached medially to the edge of the glenoid
cavity and laterally to the neck of the humerous (sorrounds that part). Ligaments: glenohumeral
ligament – strengthens the joint anteriorly (in the front), the corocohumeral strengthens the capsule
superiorly, and the third ligament which doesn’t do much in terms of strengthening capsule is the
transverse humeral ligament- b/w condyles- anchoring the large head of the bicep . Movementextension, flexion, Abduction, adduction, rotation. Blood supply is extensive, (too bad I missed it).
- Due to the tremendous amount of movement and its instability the joint is often dislocated, the most
common dislocation occurs which excessive extension and latero-rotation (like pitching or throwing).
Elbow Joint
Hinge type synovial joint- articulation is b/w trochlea on humerous and trochlear notch of the ulna, also
b/w capitulum and the head of the radius. The Capsule is unique, encloses the joint and then continues
downward (downward) to encapsulate the radio-ulnar joint. (lots of rambling). The joint is weak,
anteriorly and posteriorly, strong laterally and medially- because of collateral ligaments. The radial
collateral ligament runs from lateral epicondyle to a structure called the annular ligament- associated
with the proximal radio-ulnar joint. Ulnar collateral ligament- runs from medial epicondyle to coronoid
and olecranon of the ulna. Movement- Flexion and extension.
Proximal radioulnar Joint
PIVOT SYNOVIAL JOINT B/W HEAD OF RADIUS AND RADIAL NOTCH OF ULNA. Capsule is continous with
capsule from elbow JoInT. The only ligament associated with this joint is the annular ligament which
wraps the head of the radius to the notch of the ulna. Movement is slight, occurs during supination and
pronation (pronation).
Distal Radial ulnar joint
Pivot synovial joint. B/w head of ulna and ulnar notch on radius. Weak piece of shit capsule, and the
joint gets most of its flexability from the flexor & extensor retinaculum.
- Please try to be downstairs, its gonna be interesting.
Look for a picture of the colles FRACTURE- THE MOST COMMON FRACTURE IN PEOPLE who are 50
YEARS of age. It occurs when an individual falls and tries to break their fall with the pronation and
extension of the hands. Complete transverse fracture of distal 2-3cm of the radius. As a result, the
radius bone is pulled upwards proximally and orthopods always refer to this fracture as a dinner fork
fracture.
- Alright guys, See you Wednesday