lecture 12: the arm and elbow Flashcards
what is the top of the arm called
brachium
what is the bottom of the arm called
anti brachium
what are the skeletal components of the upper limb
humerus
ulna
radius
what are the aspects of the distal humerus and be able to label them
lateral and medial epicondyles
medial and lateral supracondylar ridge
shaft
capitulum
trochlea
coronoid fossa
radial fossa
olecrannon fossa
which is more lateral capitulum or trochea
capitlum
what bone articulates with the capitulum
radius
what bone articulates with the trochlea
ulna
what are the 2 articualr facets of the humerus that articular with the elvlow bones
capitum and throchela
what articular surface acts as a spool/pulley in the elbow
trochlea
which acts as a pulley: capitum or trochlea
trochlea
where does the ulnar nerve pass behind
medial epicondyle
what passes behind the medial condyle
ulnar
what is another name for the intertubercular groove and why
bicipital groove because boceps of tendon passes through
which epicondyle is larger : medial or lateral
medial
what are the 2 bones of the forearm
proximal radius and ulna
which bone is more medial: radius or ulna
ulna
ulna is medial or lateral
medial
radius is medial or lateral
lateral
which is the longer bone: radius or ulna
ulna
which bone fits with the trochlea
ulna
which bone fits with the capitulum
radius
where does the radial head articualr wit h
the capitulum of humerus
where do the trochlear notches articulate with
the trocheal
what two aspects make the radius look like a wrench
olecrannon and coronoid process
what are the tuberocities of the of the forearm
radial tuberocity
ulnar tuberocity
does the ulna have a neck>
no the radial does
radial head is proximal or distal
proximal
ulnar head is proximal or distal
distal
be able to identify the aspects of the radius and ulna
/
what type of jt is the elbow joint
synovial hinge joint
is the elbow joint considered a compound joint>
yes
explain why the elbow jt is compound joint
because there are three bones and three articulations
what tare the 3 bones that make up the elbow joint
humerus
radius
ulna
what are the 3 articulations of the elbow joint
humeroradial
humeroulnar
radioulnar
which are the artciulations most important for the flexion of the elbow joint
humeroulnar and humeroradial (no radioulnar)
what are the 3 fossas of the humerus
coronoid
radial
olecrannon
what is the function of the three fossa of the distal humerus
the 3 fossa accomodate processes on radius and ulna and prevent excessive ROM
what are the aspects that make up the humeroradial articulation
capitulum and head of the radius
what are the aspects that make up the humeroulnar articulation
trochea and trochlear notch
which makes up the largest impact of the hinge movement at the elvow
humeroulnar
(trochlear and thorclear notches)
since elbow joint is a hinge joint, which movements are the major ones
flexion and extension
coronoid and radial fossa prevent excessive flexion or extension
flexion
olecranon fossa prevent excessive flexion or extension
extension
where is the olecreannon locked
its locked i nthe olecreannon fossa
what are the 2 main accessory structures of the elbow
fat pads
olecrannon bursa
where are the fat pads of the elbow located
in the 3 humerus fossa to act as cushion
(on top of synovial membrane
ie: extramembranous but intracapsular)
what are the 4 main structures of synovial joints
membrane
articualr cartilage
fibrous capsule
synovial fluid
what is the function of the olecranon burs
ddecrease friction between skin and bone
what is the only structure superior to the olecrannon bursa
skin
what are the 3 main ligaments of the elbow joint
ulnar and radial collateral ligament
annular ligaments
which ligament of the elbow joints is a triangular shape
ulnar collateral
what motion does the ulnar colalteral prevent
excessive radial movememtn
what turns the radioulnar jt into a pivot
the annular ligament
what is the function of the annular ligament
turns the radioulnar into a pivot joint
what is the general meaning of nursemaids elbows
subluxation of radial head
explain nursemaids elbow
subluxation of radial head
=not fully dislocated but retuns back into the socket
=as radial head returns to the articulation with the capitulum it pinches the annular ligament (and structures)
the anterior comparement of the brachium is aka as
the flexor compartment
the posterior comparement of the brachium is aka as
extensor compartment
does the anterior or psoterior compartment do flexion
anterior
does the anterior or psoterior compartment do flexion
anterior
does the anterior or psoterior compartment do extension
posterior
what is the anterior compartment of the brachium innervated by
musculocutaneous nerve
what is the posterior compartment of the brachium inneravted by
radial nerve
what is the anterior compartment of the forearm responsible for
elbow flexion (aka flexion of forearm at the elbow)
what is the posterior compartment of the forearm responsible for
elbow extension (extension of the foream at the elbow)
what are the 3 muscles of the anterior compartment of thee brachium
biceps brachii
coracobrachilais
brachialis
what are the origins of the biceps brachio
long head: supraglenois tubercle of the scpula, tendon runs over humeral head through the biciptal groove
(passive stabilization of the shoulder
short head: radial tuberocity
which head of biceps origins at the coracoid process
short head of biceps
which head of biceps originates at the supragelnoid tujbercle
long head of the biceps
which head, long or short head runs through the intertub groove
long head
true or false, bicep brachii long head tendon acts as passive stabilization
true
what ist the function of the biceps brachii
flexion of the elbow joint
accessory flexion of the GH jt
supination
true or false: biceps only acts on elbow joint
false, also accessory flexion of the glenohumeral joint
what is bicitial aponeurosis
broad flat tendon of the biceps
what are the two deep muscles of the anterior compartment of the arm
coracobrachialis and brachial
what is the origin of the coracobrachilais
coracoid process
what is the insertion of the coracobrach
medial/anterior shaft of the humerus
what is the function of the coracobrachilalis
flexion, weak adduction and medial rotation at thee GH joint (does not cross elbow joint)
true or false and why: coracobrachialis acts on the ELBOW
false it does not cross the eblow
what is the pure flexor of the elbow
brachialis
what is the origin of the brachialis
anterior shaft of the humerus
what is the insertion of the brachialis
ulnar tub
true or false: the biceps inserts into the ulnar tuberocity
false, radial
what is the function of the brachilalis
flexion of the elbow joint
true or false: the brachialis m inserts into the radial tubercotiy
false, the ulnar tuberoctiy
what is the motor inneravtion of the anterior arm
musculocutaneous (from lateral cord)
where does the musculocutaneous nerve pierce/go
behind and pierces through the coracobrachialis
all three muscles of the anterior arm are inervated by..
musculocutaneous (c5-c7)_)
what would sensory and motor loss look like in amusculocutaneous n injury
loss of elbow flexion for motor
loss of sensation near lateral aspect of the antebrachium
where is motor innervation of the anterioa arm coming from
multiple cutaneous and mixed nerves
what are the sensory branches for the anterior compartment of the arm
axillary (c5-c6)
radial (c5-t1)
lateral cutaneous n of forearm
medial brachial cutaneus (medial cord, c8-t1)
medial antebrachial cuatenous (medial cord, c8-t1)
what are the muscle that makes up the posterior compartment of the arm
triceps brachii
anconenous
what are the origins of the triceps brachii
long head: infraglenois tubercle of the scapula (crosses the GH jt)
lateral: posteiror shaft of humerus above the radial groove
medial head: posterior shaft of the humerus below the radial groove
which head of the triceps originates at the infraglenoid tubercle of the scap
long head
which head of the triceps originates at the posterior shaft above the radial groove
lateral head
which head of the triceps originates at the posterior shaft below the radial groove
medial head
what is the insertion of the triceps
olecrannon process of the unla (single tendon)
tru or false: the heads of the triceps converge into one single tendon and insert into the ulnar tuberocity
false, they converge as one onto the olecrannon process
what are the functions of the triceps
elbow extension
(long head can also do GH adduction and extensiON)
true or false and explain: the triceps function at the elbow and the GH jt
yes because it starts on scpula
it does elbow extension but also adduction and extension at the GH jt (specifically long head)
what is the origin of the anconeus
posterior aspect of the lateral epicondyle of the humerus (dorsal)
what is the insertion of the anconeus
olecrannon process
what is the function of the ancoenous
elbow extension and stabilization
which muscle is antagonist with the biceps
triceps
true or false: the medial and lateral heads of the triceps are deep to the long head
true
where does the radial n travel
in the radial groove of the posterior hum
explain the pathway of the radial nerve
travels through radial groove on the posterior humerus
and then wraps around humeral shaft to end on the anterior to lateral epicondyle
tricps and ancoenous are innervated by…
radial n
whta is the brachial plexus contributions to the radial n
c5-t1
what nerve innervates around the surgical neck of the hum
axillary n
what passes in the quadrangular space of the scapula
axillary n and posterior circumflex humeral
what passes in the triangular interval
radial n and deep brachial a
what is sensory innevation of the triceps
axiallary (c5-c6)
radial n (c5-t1)
medial brachial cutaneous (c8-t1)
medial anterbrachial cutaenous (c8-t1)
lateral cutaneous n of the forearm
where does the axillary artery become the brachial artery
inferior to the teres major
inferior to the teres major, the axillary artery becomes the BLANK
brachial artery
what is the blood supply to the posterior ar m
deep brachial a (in radial groove)
what is the blood supply to the anterior arm
brachial a
what passes in the radial groove of the humerus with the radial n
the deep brachial (profunda brachii)
brachial artery branches to what to supply the posterior arm
deep brachial
brachial artery branches to form deep brachial and what other artery
posterior humeral circuflex
where does the brachial artery split
at the elbow psoterior
what does the brachial artery split into at the elbow
radial a
ulnar a
what are the terminal branches of the brachial artery
radial a (lateral)
ulnar a (medial)
brachioradialis muscle lies anterior and laterally, but is considered an exception, why
because it is not innervated by musculaocut but rather by radial
brachioradialis spans across the elbow joint but not the BLANK
carpus
what is the origin of the brachioradilais
lateral supracondylar ridge of the humeris
what is the insertion of the brachioradalis
styloid process of te radius
what is the function of the brachioradialis
elbow flexor (biceps.brachialis synergist),despite being innervated by radial n
the brachioradialis is a synnergist flexor for what muscles
biceps and brachialis
what is the cubital fossa
triangular space, in anterior elbow, apex pointing distally, forming a passage (funnel) for neurovascular strucutres from arm into forearm
what is the superior border of the cubital fossa
line between humeral epicondyles
what is the lateral border of the cubital fossa
brachioradialis
what is the floor border of the cubital fossa
brachialis (deep to the biceps brach00)
what is the medial border of the cubital fossa
pronator teres
what is the roof border of the cubital fossa
bicipital aponeurosis
ADD CARDS ABOUTHE CONTENTS OF THE CUBTAL FOSSA