upper limbs 2 Flashcards
what is a nerve plexus
A nerve plexus is formed when peripheral spinal nerve roots merge and split to produce a network of nerves from which new multi-segmental peripheral nerves emerge.
what are teh upper limbs innervated by
brachial plexus
what are the lower limbs innervated by
lumbo-sacral plexus
where do the roots enter the inferior neck
through teh spinal cord to form trunks, then enter the clavicle and form 6 divisions
, those merge to form 3 cords
what is teh superior trunk formed by
c5 c6
what forms middle trunk
c7
and inferior trunk
c8 and t1
how are anterior and posterior divisions formed
each s m i divide to give anterior and posterior
what forms the lateral cord
anterior of s m
what forms the medial
anterior inferior
and posterior
all 3 posterior forms post cord
nerves from lateral cord innervate…
lateral structures
what are Supraclavicular branches
from the roots and the trunks
e.g. dorsal scapular nerve, long thoracic nerve
branch from posterior part of plexus
superoiir to the clavicle
Infraclavicular branches
: side branches to pectoral girdle muscles and the main peripheral nerves.
e.g. branches to some scapular muscles, and the large terminal branches e.g. radial, ulnar, median
branch from distal part of plexus
inferior to clavicle
what 2 branches arise form the brachial plexus
Supraclavicular branches
clavicular branches
what cord does the Musculocutaneous Nerve
branch off from
lateral cord
what is the order of roots to bigger stuff
roots(C5 C6ect) trunks (superior mid inf) divisions (ant post) cords(lateral posterior medial) terminal branches (Musculocutaneous Nerve ect)
what does the Musculocutaneous Nerve
innervate
Muscular innervation to the anterior muscles of the arm
Cutaneous innervation of the lateral forearm
describe the route from the lateral cord
Pierces coracobrachialis to reach biceps and brachialis muscles.
Continues to cross the elbow joint to innervate the lateral arm
ulnar nerve braches of which cord
A terminal branch of the medial cord
does it innervate the arm
nope
where can it get easily damaged
Passes behind the medial epicondyle of the humerus – easily damaged here (“funny bone”)
what does it innervate
Cutaneous innervation of the medial hand
Branches to intrinsic hand muscles
how does it pass through the wrist
distally towards the wrist
what part of teh hand does it innervate
the medial aspect
the little finger and half the ring finger
does it innervate the foremarm
limited innervation - only 2 muscles
Median Nerve braches of which cord
cords- From lateral and medial cords
what does it innervate
Innervates most of the anterior forearm muscles
Innervates some intrinsic hand muscles
Cutaneous innervation of the lateral hand
what does it innervate in teh arm
no innervation in the arm
Cutaneous innervation to
of the lateral hand and 3½ digits
thumb, index finger, middle finger, and half of the ring finger
where is it commonly damaged
Commonly damaged at the wrist, and also in the distal arm
what are the nerves of the posterior cord
Radial and Axillary Nerves
which is larger
radial
what does the axillary nerve innervate
innervates deltoid muscle and upper lateral aspect of the arm
what does teh radial muscle supply
Innervates all arm and forearm posterior muscles, no intrinsic hand muscles
Cutaneous branches in arm and forearm
Cutaneous innervation of the lateral hand and 3½ digits
what is the differnce between teh superficial and deep branches to the
superficial is a sensory branch supplying teh back of teh hand
deep supplies motor to the posterior forearm musckes
where does teh radial nerve divide
at the elbow region
Superficial branch innervate
cutaneous to the dorsolateral hand
Deep branch
motor supply to the posterior muscles of the forearm
sensory innervation of the hadns nerves
stop median nerve
ulnar nerve
what does the ulnar nerve supply
medial one and half digit
little finger
half the ring finger
what does the median nerve supply
lateral 3 and a half digiits
thumb to half the ring finger
what part of the hand doees the radial nerve supply
the back of the hand
lateral aspect from the thumb to half teh middle only the hand not the digits themselves
what is most of the upper limb blood supply
(left and right) subclavian artery
what strcuture does it pass under
clavicle
what happens to teh artery then
becomes the axillary artery
what is the largest brach of the brachial artery
profunda brachii artery
where does the brachial artery cross the elbow
antecubital fossa
what braches then arise
radial and ulnar artery
what branches does the ulnar artery arise
common -> anterior, posterior interosseous artery
when arteries of the forearm cross the wrist, what do they form
arterial arches
what do the radial and ulnar arches form
2 palmar arches - superficial and deep
what does teh posterior interosseous artery form when crossing the wrist
dorsal carpal arch
what are teh 2 forms of venous return in the limbs
Deep (accompanying the arteries)
Superficial (on the limb surface)
What are venae comitantes?
Venae comitantes (VC)
= accompanying veins
Multiple veins form a network of smaller veins with arteries which they accompany
what do these allow
Connections between the VC
Allow heat exchange
Artery pulse promotes venous flow
what is teh pattern of The Superficial Veins
small veins in the digits drain into a superficial venous network on the dorsal of the hand
which, at teh wrist, forms Basilic (medial)
Cephalic (lateral)
which is the medial vien
basillic
whcih is the lateral
cephalic
what is a vein most people have in the elbow region
media cubital vein
what is this vein used for
venapuncture to take blood
what is the journey made by the cephalic vein
passes through the lateral aspect of the arm
passes between teh deltoid
and pectoral muscles –> axillary to subclavian
and the basillic
perices teh fascia to go deep to join the vena cominatantes of the the bracial vien and forms large bascilic vein
how do teh lympahtic and vein drainage link
In general, the lymphatic vessels run with the veins in most organs and tissues.
where are teh lymph nodes in teh upper limb
Cubital nodes – drain distal limb
Axillary nodes – drain limb and breast
where do teh cubital nodes drain
drain distal limb- hand and forearm
and axillary
drain limb and breast
