L3: the axilla and brachial plexus Flashcards
axilla=
armpit
muscle medial to axilla=
serratus anterior
muscle posterior to axilla=
subscapular muscles
muscles anterior to axilla=
pectoral muscles
where is the axilla apex
between the first rib and upper border of scapula
contents of axilla (3)
axillary vessels
Axillary lymphatics
Brachial plexus
large vein under clavicle=
subclavian vein
what 2 structures do axillary lymphatics drain
upper limb and breast
5 lymph node groups of axilla
- lateral
- subscapular
- pectoral
- Central
- Apical
dorsal roots carry
sensory information
ventral roots carry
motor information
when the spinal cord exits the vertebral column what does it split into
dorsal primary ramus and ventral primary ramus
where does the dorsal primary ramus supply sensation and muscles
all the way the back
where does the ventral primary rami supply
muscles of the anterior body wall and the limbs
how many cervical vertebrae
7
how many cervical nerves
8
what nerve comes off immediately as the ventral primary rami emerge
the long thoracic nerve
what are the ventral primary rami known as
the roots of the brachial plexus
superior trunk comes from
C5 and C6
middle trunk comes from
C7
inferior trunk comes from
C8 and T1
what do the trunks divide into
anterior and posterior divisions
what muscles does the anterior division supply
all flexors and adductors of the upper limb
what muscles does the posterior division supply
all extenders and abductors of the upper limb
the anterior divisions of the superior and middle trunks fuse to form
the lateral cord
the inferior trunk anterior division forms
the medial cord
what forms the posterior cord
the posterior divisions of the superior, middle and inferior trunks
lateral nerve and medial nerves form an M when they fuse in the middle what 3 nerves come off (lateral–> medial
Musculocutaneous
Median
Ulnar
2 nerves coming of the posterior cord
axillary nerve and radial nerve
where does the radial nerve travel
down the back of the upper limb and supplies all the extensors of it and the forearm
where does the axillary nerve travel
wraps around humerus and supplies deltoid
3 muscles musculocutaneous nerve supplies
coracobrachialis –> adductor
Biceps brachii –> flexor
Brachialis –> flexor
where does the median nerve supply
flexors of forearm on radial side + thumb
where does the ulnar nerve supply
- 2 flexors of forearm
- lots of small muscles in the hand
if you get weakness of muscles but not sensation then what HASN’T happened
peripheral nerve injury
radial nerve injury–>
- weakness of extensors
- Loss of sensation over dorsal web between thumb and index finger
shoulder myotome that abducts and laterally rotates
C5
shoulder Myotome that adducts and medially rotates
C6, C7 C8
elbow myotome that flexes
C5 C6
elbow myotome that extends
C7, C8
Forearm myotome that pronates
C6
forearm myotome that Supinate
C6
Wrist only myotome that flexes and extends
C6, C7
fingers and thumb myotomes that flex and extend
C7, 8
hand intrinsic muscles
T1
Erb’s palsy is injury off
tears of routes of the brachial plexus
what are symptoms are Erb’s palsy baby’s born with at birth
paralysis of upper shoulder and arm;
forearm pronates and hand hangs
what effect can Erb’s palsy have on limb
reduced limb growth
what is Klumpke’s paresis
tear of the lower roots of the brachial plexus
how do you tear the lower roots of the brachial plexus
by forcefully abducting the limb
what is often damaged in Klumpke’s paresis
T1
what does T1 supply
all intrinsic muscles of the hand and sensation over medial side of forearm
