ALS Lecture 2 - Axilla and Brachial Plexus DONE Flashcards
axilla is the space between the
ribcage and humerus
through the space of the axilla passes
vessels, nerves, lymphatics
posterior of axilla
scapula, subscapularis muscles
anteriorly and superiorly part of axilla
clavicle, pectoral muscles
mediolateral part of axilla
ribcage
distolateral part of axilla
humerus
injury to the axilla is devastating to the upper limb because
important structures that serve upper limb pass through axilla
apex of axilla (triangle) is formed between
first rib, clavicle, superior margin of scapula
major nerves and vessels pass over
first rib, through apex to enter axilla
label the apex of the axilla
done
label the cadaveric section of the axilla
done
brachial plexus is wrapped around
axillary artery
brachial plexus is the
network of nerves, sends signals from spinal cord to shoulder
brachial plexus takes contributions from
C5-T1
label the drawn diagram of the axilla
done
axillary vein passes
under clavicle at junction of medial and middle third of clavicle
the axillary vein is quite
superficial
the subclavian artery and vein pass over
first rib behind clavicle
aim the needle
under junction of medial and middle third clavicle horizontal to body
we point needle horizontally so it enters the
subclavian vein rather than artery
5 groups of lymph nodes that drain breast and upper limb into axillary lymphatics
lateral, subscapular, pectoral, central, apical
the 5 groups of nodes are very important in breast cancer surgery as often if there has been
metastasis they spread here so surgeon will have to clear the nodes
if surgeon clears the lymph nodes due to breast metastases, this can cause
oedema in upper limb
brachial plexus gives
motor and sensation to upper limb
roots of brachial plexus
C5-T1
how many cervical vertebrae are there?
7
how many cervical nerves are there?
8
in cervical region we name the nerve for the vertebrae that lies
beneath them
in thoracic region we name the nerve for the vertebrae that lies
above them
C8 lies below the
seventh cervical vertebra
trunks of the brachial plexus
superior, middle, inferior
superior trunk of brachial plexus is formed by
C5 and C6 merging
middle trunk of brachial plexus is formed by
C7
inferior trunk of brachial plexus is formed by
C8 and T1 merging
divisions of brachial plexus
posterior and anterior
how does each trunk divide?
superior and middle have both superior halves move anteriorly and inferior has inferior half move anteriorly
cords of the brachial plexus
lateral, posterior, medial
lateral cord is made up of
anterior divisions of superior and middle trunks
posterior cord is made up of
posterior divisions of superior, middle and inferior trunks
medial cord is made up of
anterior division of inferior trunk
label the brachial plexus
done
label the brachial plexus diagram 2, including branches
done
lateral cord gives rise to which branches?
musculocutaneous and median
posterior cord gives rise to which branches?
axillary and radial
medial cord gives rise to which branches?
median and ulnar
the median nerve arises from which branches of the brachial plexus?
lateral and medial
arm
shoulder to elbow
forearm
elbow to wrist
hand
below wrist
radial nerve first supplies
arm extensors, triceps
radial nerve enters forearm by
radial groove
in the forearm the radial nerve supplies
many of extensors
finally, superficial radial nerve supplies
dorsum of hand
label the radial nerve diagram
done
label the musculocutaneous nerve
done
musculocutaneous nerve supplies
flexors/adductors of arm, coracobrachialis, biceps brachii, brachialis
anterior divisions of nerve plexuses give rise to nerves that supply muscles that are…
flexors or adductors
label the diagram of the median nerve
done
in the arm, the median nerve
passes with no branches
in the forearm, the median nerve supplies
flexor muscles
in the hand, the median nerve supplies
muscles on radial aspect
label the diagram of the ulnar nerve
done
in the arm, the ulnar nerve
passes with no branches
in the forearm, the ulnar nerve supplies
a few muscles
in the hand, the ulnar nerve supplies
muscles on ulnar aspect
label the diagram of the sensation of nerves in upper limb
done
label the cutaneous innervation of the hand palmar side
done
label the cutaneous innervation of the hand dorsal side
done
musculocutaneous nerve gives sensory supply to
lateral forearm
median nerve gives sensory supply to
radial side of hand - thumb, middle and half of ring finger
ulnar nerve gives sensory supply to
ulnar side of hand - half of ring finer and little finger
radial nerve gives sensory supply to
dorsum of hand (thumb back half)
to test sensation of median nerve we must touch
tip of index and middle finger
to test sensation of ulnar nerve we must touch
tip of little finger
to test sensation of radial nerve we must touch
webbing between thumb and index finger back of hand
radial nerve injury would cause
loss of sensation in radial area and weakness of wrist extensors so wrist drop
label the dermatomes diagram
done
dermatome is an area of skin whose sensory supply comes from
single nerve from spinal cord
fill in the myotome table
done
erb’s palsy is injury to
upper roots of brachial plexus, C5 and C6
erb’s palsy can occur during
birth due to traction
erb’s palsy results in
shoulder muscle paralysis so limp arm and no sensation C5 and C6
klumpke’s paralysis is due to injury to the
lower roots of brachial plexus
in klumpke’s paralysis , the main nerve affectes is
T1
in klumpke’s paralysis sensation is lost in
medial side of forearm
in klumpke’s paralysis motor is lost in
small muscles of hand so loss of hand function
