Upper Limb Flashcards
what is the prehensile limb (upper limb) specialised to do?
to reach and grasp objects
less consideration for weight bearing
why is the upper limb susceptible to dislocation?
limited fixation to axial skeleton
what are the anterior and posterior connections between the axial skeleton and the upper limb?
anterior - sternoclavicular joint
posterior - vertebral column muscles
name the movements of the upper limb
flexion/extention
abduction/adduction
internal/external rotation
circumduction
name the movements of the elbow
flexion/extention
pronation/supination
name the movements of the wrist
flexion/extention
abduction/adduction
what is circumduction?
circular movement of any ball and socket joint
what is pronation and supination?
forearm rotation
moves palm from anterior to posterior facing
what is apposition?
gripping between fingers and thumb
where does the clavicle run?
runs from manubrium (sternum) to the acromiom (scapula)
what is the function and directions of sigmoid curves in the clavicle?
lateral - concave
medial - convex
gives space for vessels/nerves
what is the function of the clavicle?
acts as strut (resists compression)
transmits weight
describe the structure of the scapula
large flat triangular bone
name the processes of the scapula
acromiom process
spine of scapula
coracoid process
medial border
glenoid cavity
what muscles hold the scapula in place?
trapezius
levator scapulae
rhomboids major/minor
serratus anterior
pectoralis minor
describe the movements of the scapula
protraction/retraction
lateral/medial rotation
abduction/adduction
elevation/depression
name the landmarks of the axilla
apex
floor
medial/lateral walls
anterior/posterior walls
pectoralis major (clavicular head): origin and insertion
origin - anterior surface of medial clavicle
insert - intertubular sulcus of humerus
pectoralis major (clavicular head): actions and innervation
actions - flexes/adducts humerus, depresses scapula
innervation - medial pectoral nerve
pectoralis major (sternocostal head): origins and insert
origins - anterior sternum, costal cartilages 1-6, external oblique aponeurosis
insert - intertubular sulcus of humerus
pectoralis major (sternocostal head): actions and innervation
actions - extend/adducts humerus, depresses scapula
innervation - lateral pectoral nerve
pectoralis minor: origin and insertion
origin - ribs 3-5
insert - coracoid process of scapula
pectoralis minor: actions and innervation
actions - shoulder depression, pulls scapula and shoulder forward, raises ribs
innervation - medial pectoral nerve
serratus anterior: origin and insertion
origin - lateral ribs 1-8
insert - medial border of scapula (costal surface)
serratus anterior: actions and innervation
actions - rotates scapula, holds scapula on ribcage
innervation - long thoracic nerve
what is the brachial plexus?
ventral rami of C5-T1 spinal nerve roots
what and where does the brachial plexus supply?
sensory/motor/sympathetic nerve supply to pectoral girdle and upper limb
name the 5 nerves in the brachial plexus
musculocutaneous, axillary, median, radial, ulnar
where do the brachial plexus roots emerge?
between scalene anterior and medius muscles
where are the brachial plexus trunks located?
neck region
where do the anterior divisions of brachial trunks supply?
flexor muscles and skin on front of upper limb
where do posterior divisions of the brachial trunks supply?
extensors and skin on back of upper limb
name the 3 brachial cords and why they are named as such
medial, lateral and posterior
based on position around axillary artery
name the innervations of the lateral cord of the brachial plexus
musculocutaneous and median nerve
name the innervations of the medial cord of the brachial plexus
median nerve and ulnar nerve
name the innervations of the posterior cord of the brachial plexus
radial nerve and axillary nerve
name the 3 main supraclavicular branches of the brachial plexus and what they innervate
dorsal scapular - supplies rhomboids
long thoracic - supplies serratus anterior
suprascapular - supplies supraspinatus and infraspinatus
name the 3 main infraclavicular branches of the brachial plexus and what they innervate
medial/lateral pectoral - pectoralis muscles
upper/lower subscapular - supplies subscapularis (U/L) and teres major (L)
thoracodorsal - latissimus dorsi
name 2 injuries caused from the radial nerve
crutch palsy - prolongued use of crutches
drop wrist - cant extend hand
name an injury caused by median nerve damage
carpal tunnel syndrome - numbness/tingling and pain in palm/fingers
caused by repetitive wrist flexion
what are the 2 joints of the pectoral girdle?
sternoclavicular and acromioclavicular
what is the sternoclavicular joint?
ball and socket joint between manubrium of the sternum and the medial clavicle
what do ligaments do in the sternoclavicular joint?
prevents dislocation
what does the sternoclavicular ligament do?
thickens the anterior and posterior aspect of the synovial sternoclavicular joint
what does the interclavicular ligament do?
connects medial ends of each clavicle
what does the costoclavicular ligament do?
strengthens inferior aspect of joint from 1st rib to clavicle
what is the acromioclavicular joint?
joint lateral clavicle and acromion process of scapula
gliding synovial joint
what 3 ligaments is the AC joint strengthened by?
coracoclavicular
acromioclavicular
coracoacromial
what is the glenohumeral joint?
synovial joint from head of humerus and glenoid cavity of the scapula
multiaxial ball and socket joint
what are the problems of the glenohumeral joint?
limited stability due to poor bony fit
loose capsule and ligaments
where does the stability of the shoulder joint come from?
rotator cuff muscles
what increases the surface area of the glenoid fossa around the humerus head?
glenoid labrum
name the parts of the humerus from superior to interior at the shoulder level only
head
anatomical neck
surgical neck
greater tubercle
lesser tubercle
intertrubercle/bicipital groove
deltoid tuberocity
where does the distal humerus articulate?
articulates with forearm bones
medial - ulna (trochlea)
lateral - radius (capitulum)
what is the purpose of the medial and lateral epicondyles on the humerus?
muscle attatchment
describe the synovial capsule of the glenohumeral joint
attatches proximally to scapula (beyond supraglenoid tubercle and margin of labrum)
attaches distally to anatomical head of humerus
contains inner synovial membrane and outer fibrous layer
what structures are lined by synovial membranes?
non-articular surfaces
bursae (fluid filled sacs) found around most major joints to reduce friction
name 4 bursae in the shoulder
subacromial
subscapular
subdeltoid
subcoracoid
describe the flexion movement from the glenohumeral joint
caused by muscles passing anterior to joint
(pectoralis major and anterior deltoid fibres)
describe the extension movement of the glenohumeral joint
limited from anatomical position: posterior deltoid fibres and lat dorsi
returning to anatomical position:
lat dorsi, teres major, pec major
describe the abduction movement in the glenohmeral joint
15-30 degrees of movement initiated by supraspinatus
30 degrees to horizontal controlled by deltoid
limb to over head requires lateral rotation of scapula
describe the adduction movement of the glenohumeral joint
gravity centred
lat dorsi
pec major
describe the medial rotation of the glenohumeral joint
trunk to anterior humerus:
pec major and lat dorsi
scapula to anterior humerus: subscapularis and teres major
describe the lateral rotation of the glenohumeral joint
muscles from scapula to posterior humerus - infraspinatus, deltoid (post. fibres) and teres minor
name the muscles acting on the shoulder from a distance and what effect they have
deltoid, teres major, short head biceps brachii
mechanical impact
name the muscles acting closely to the shoulder and what effect they have
long head biceps, triceps brachii, rotator cuff
stabilises joint
what do the rotator cuff muscles join together?
scapula to humerus
what do the rotator cuff tendons do?
encircle joint and fuse with articular capsule
teres minor: origin, insertion, action and innervation
origin - lateral scapula
insert - greater tubercle of humerus
actions - lateral rotation and stabilisation
innervation - axillary nerve
infraspinatus: origin, insert, actions and innervation
origin - medial scapula
insert - greater tubercle of humerus (superior)
actions - lateral rotation and stabilisation
innervation - suprascapular nerve
supraspinatus: origin, insert, actions and innervation
origin - posterior scapula
insert - superior greater tubercle of humerus
actions - abduction and stabilisation
innervation - suprascapular nerve
subscapularis: origin, insert, actions and innervation
origin - anterior scapula
insert - lesser tubercle of humerus
actions - medial rotation and stabilisation
innervation - subscapular nerve
what kind of joints are in the elbow?
hinge synovial joint
what are the 3 main joints of the elbow?
humeroulnar
humeroradial
proximal radioulnar
what is the main stability of the elbow?
bony articulations:
trochlea (humerus) and olecranon (ulna)
explain the position of the ulna
medial - larger than radius
what landmarks are present at the proximal end of the ulna?
trochlear notch
2 processes:
olecranon (larger/posterior)
coronoid (smaller/anterior)
what landmarks are present at the distal end of the ulna?
head (anterior - articulates with radius)
styloid process - (post/med - articulates with wrist ligaments)
how does the radius lie?
lateral (near thumb)
what landmarks are present at the proximal end of the radius?
head (articulates with capitulum and radial notch of ulna)
radial tuberosity medially (attaches to biceps)
what landmarks are present on the distal end of the radius?
styloid process (laterally - articulates to wrist ligaments)
ulnar notch (medially)
where does the humeroulnar joint articulate?
between trochlea in humerus and trochlear ulnar notch
what is the humeroulnar joint reinforced by and what movement does it allow?
reinforced by ulnar collateral ligament
allows flexion/extention
where does the humeroradial joint articulate between?
between the capitulum on the humerus and the radial head
what is the humeroradial joint reinforced by and what movement does it allow?
reinforced by the radial collateral ligament
allows supination/pronation
biceps brachii (long head): origin and insertion
origin - supraglenoid tubercle of scapula
insert - radial tuberosity (distal), bicipital aponeurosis
biceps brachii (short head): origin and insertion
origin - coracoid process of scapula
insert - radial ruberosity (distal), bicipital aponeurosis
biceps brachii: actions and innervation
actions - forearm supination, arm flexion
innervation - musculocutaneous nerve
what is bicipital apneurosis?
a flat sheet of CT attaching biceps indirectly to posterior ulnar border
coracobrachialis: origin, insertion, actions and innervation
origin - coracoid process
insert - medial humerus
actions - shoulder flexion, weak adduction
innervation - musculocutaneous nerve
brachialis: origin, insertion, action and innervation
origin - anterior distal humerus
insert - coronoid process (ulna)
action - flexes elbow
innervation - musculocutaneous nerve
triceps brachii (long head): origin and insertion
origin - infraglenoid tubercle of scapula
insert - olecranon of ulna (one converged tendon)
triceps brachii (medial head): origin and insertion
origin - humerus (inferior to radial groove)
insert - olecranon of ulna (one converged tendon)
triceps brachii (lateral head): origin and insertion
origin - humerus (superior to radial groove)
insert - olecranon of ulna (one converged tendon)
triceps brachii: actions and innervation
actions - elbow extension, long head acts on shoulder to steady humerus
innervation - radial nerve
where does forearm rotation occur?
between forearm bones at radioulnar joint
around axis from radial head to ulna styloid process
below & independant of shoulder/elbow
explain the anatomical features of pronation
palm turned posteriorly
proximal radius lateral to ulna
distal radius medial to ulna
explain the anatomical features of supination
palm turned anteriorly
radius lateral and parallel to ulna
explain the structure of the superior radioulnar joint
pivot joint between radius head and radial notch on ulna
associated with elbow
held in place by radial annular ligament that runs around radial head
describe the structure of the inferior radioulnar joint
pivot synovial joint going from ulnar head to ulnar notch on radius
held together by articular disk and interosseus membrane
what is the interosseus membrane?
thin fibrous tissue separating bones (radius and ulna)
what does the interosseus membrane do?
site of attachment for forearm muscles
divides forearm into ant and post
when does the interosseus membrane change from relaxed to tense?
pronation -> supination
name the muscles in the anterior compartment of the forearm, and whether they are superficial, intermediate or deep
flexor carpi ulnaris (S)
palmaris longus (S)
flexor carpi radialis (S)
pronator teres (S)
flexor digitorum superficialis (I)
flexor pollicis longus (D)
flexor digitorum profundus (D)
pronator quadratus (D)
name the superficial muscles in the posterior compartment of the forearm
extensor carpi radialis longus/brevis
extensor digitorum
extensor carpi ulnaris
extensor digiti minimi
anconeus
brachioradialis
name the deep muscles in the posterior compartment of the forearm
supinator
abductor pollicis longus
extensor pollicis brevis/longus
extensor indicis
what is the cubital fossa?
a triangular depression anterior to elbow joint
what is the cubital fossa (triangular depression) bound by?
brachioradialis (laterally)
pronator teres (medially)
what does the brachial artery diverge into when it enters the base of the cubital fossa?
radial and ulnar arteries
explain the nerves in the cubital fossa
medial nerve runs through
radial nerve located laterally
explain the structure of the superficial forearm muscles
often long muscles
run from humerus to hand (acting on elbow/wrist) or humerus to digits (acting on elbow, wrist and digits)
explain the structure of the deep forearm muscles
arise from forearm bones and pass to digits (acting on wrist and digit joints)
anterior compartment forearm mucles: actions, innervations and arterial supply
actions - forearm pronation, wrist/finger flexion
innervations - median nerve
arterial supply - ulnar/radial artery
posterior compartment forearm muscles: actions, innervation and arterial supply
actions - wrist/finger extension
innervation - radial nerve
arterial supply - posterior interosseus artery
name the 2 muscles in the anterior forearm compartment that are innervated differently
flexor carpi ulnaris and flexor digitorum profundus (medial half)
innervated by ulnar nerve
teres major: origin and insertion
origin - posterior surface of scapula (inferior angle)
insert - intertubular sulcus of humerus (medial lip)
teres major: actions and innervation
actions - adducts/extends shoulder, medially rotates arm
innervation - lower subscapular nerve
deltoid: origins and insertion
origins - lateral clavicle, acromiom and scapula spine
insert - deltoid tuberosity of humerus (lateral)
deltoid: actions and innervation
actions:
anterior - flexion, medial rotation
posterior - extension, lateral rotation
middle - arm abduction
innervation - axillary nerve
