anatomy - Axilla, brachial plexus, and arm

Pyramid-shaped space that provides a passageway for vessels and nerves going to and from the upper limb .

axilla

the apex of the axilla

cervico-axillary canal

the apex of the axilla is made up of what 3 things?

clavicle, scapula, and 1st rib

the base of the axilla is the

axillary fossa

what 3 things make up the base of the axilla?

concave skin, subcutaneous tissue, and axillary fascia

what makes up the anterior border of the axilla?

pec major, minor, and clavipectoral fascia

what makes up the lateral border of the axilla?

intertubercular groove of the humerus

what makes up the posterior border of the axilla?

subscapularis, teres major, and latissimus dorsi

what makes up the medial border of the axilla?

lateral thoracic wall and serratus anterior

action for serratus anterior

protraction

boxing muscle

serratus anterior

how many roots in the brachial plexus?

5

how many trunks in the brachial plexus?

3

how many divisions in the brachial plexus?

6

how many cords in the brachial plexus?

3

how many terminal branches/nerves in the brachial plexus?

5

Roots of the brachial plexus pass between what 2 muscles in the neck

anterior and middle scalene muscles

the 5 roots of the brachial plexus is formed by the .... of C5-T1

ventral rami

upper trunk is formed by which root(s)?

C5-T1

middle trunk is formed by which root(s)?

C7

lower trunk is formed by which root(s)?

C8-T1

upper, middle, and lower trunks divide into .... and ... divisions

anterior and posterior

the divisions of the brachial plexus are found deep to what?

clavicle

which part of brachial plexus allows for mixing of nerve roots in the terminal branches

divisions

the cords are named by where they are in relation to the what?

Axillary Artery

cord: formed by anterior divisions of upper and middle trunks (C5-C7)

lateral

cord: formed by anterior division of lower trunk (C8-T1)

medial

cord: formed by the 3 posterior divisions (C5-T1)

posterior

how many cervical vertebrae are involved in the brachial plexus?

7

how many cervical spinal nerves are involved in the brachial plexus?

8

the lateral cord is made from what 2 trunks

superior and middle

all 3 trunks are going to have a ... and ..... division

anterior and posterior

which part of the brachial plexus can be described as supraclavicular?

roots and trunks

which part of the brachial plexus can be described as infraclavicular?

divisions and cords

the lateral cord has contributions from which spinal nerve roots?

C5-C7

the medial cord has contributions from which spinal nerve roots?

C8-T1

the posterior cord has contributions from which spinal nerves roots?

C5-T1

which cord has contributions from all of the spinal nerve roots?

posterior

once you get to terminal branches it is no longer the brachial plexus it is ...

individual nerves

terminal branches from the medial cord?

ulnar and median

terminal branches from the lateral cord?

median and musculocutaneous

terminal branches from the posterior cord?

radial and axillary n

the median nerve gets contributions from which 2 cords?

lateral and medial cords

When a nerve is injured, everything .... is affected!

down stream

Axillary artery is divided into 3 parts relative to which muscle?

pectoralis minor

axillary artery is a continuation of what artery

subclavian

axillary artery extends from the lateral border of ..... to inferior border of ...

rib 1; teres major m

proximal to pec minor is the ... part of the axillary artery

1st

deep to pec minor is the ... part of the axillary artery

2nd

lateral to pec minor is the ... part of the axillary artery

3rd

where does the name change from subclavian to axillary artery?

lateral border of 1st rib

where does the name change from axillary artery to brachial artery?

inferior border of teres minor

what does the subclavian artery change names into?

axillary artery

what does the axillary artery change names into?

brachial artery

1st part of axillary artery: what does the superior thoracic artery supply?

thoracic wall

what artery branches off the 1st part of the axillary artery?

superior thoracic A

what 2 branches come off of the 3rd part of the axillary artery?

Anterior and Posterior circumflex humeral A

Anterior and Posterior circumflex humeral A come off which part of the axillary artery

3rd

the Anterior and Posterior circumflex humeral A wrap around to create an anastamoses around what structure?

the shoulder

commonly known as a "stinger" or "burner"; Typically short lived, but repeated injuries can cause lasting deficits

brachial plexus traction injury

injury where shoulder is depressed and the neck is side bent away; lose control of upper extremity muscles; numbness and tingling

brachial plexus traction injury

in brachial plexus traction injury, shoulder is .... and the neck is ....

depressed; side bent away

what individuals are more prone to brachial plexus traction injury

individuals with longer necks

Also known as Erb-Duchenne Palsy

Erb's palsy

Erbs palsy involved damage to the .... trunk of the brachial plexu

upper/superior

MOI: shoulder depression with cervical sidebending, common in childbirth when the shoulder gets stuck on the pelvis of the mother

Erbs palsy

what does the upper extremity present with in Erb's palsy?

adducted, medially rotates, elbow extended. wrist flexed

Erbs palsy involves damage to what nerve roots?

C5-C6

Klumpke paralysis is a less common injury to the .... trunk

inferior

Klumpke paralysis involves damage to what nerve roots?

C8-T1

klumpke paralysis: MOI: hyper .... of the shoulder (ex. trying to catch yourself on something when falling), can occur at birth if a baby is pulled out by the arm

abduction

klumpke paralysis: present with what of the hand

claw hand

klumpke paralysis: present with .... of the MCP joints and ..... of the IP joints

hyperextension; flexion

movements of shoulder? (6)

- Flexion/Extension

- Abduction/Adduction

- Medial/Lateral Rotation

-circumduction

movements of elbow? (4)

- flexion/extension

-pronation/supination

shoulder is what kind of joint?

ball in socket

movement of elbow that mimics pouring out bowl of soup; turn palms down

pronation

movement of elbow that mimics holding a bowl of soup; turning palms up

supination

what 2 fascial compartments divide the posterior and anterior arm compartments?

- lateral intermuscular septum

-medial intermuscular septum

the muscles of the anterior compartment of the arm are primarily what?

flexors

what 3 muscles make up the anterior compartment of the arm?

biceps brachii m

coracobrachialis m

brachialis m

what nerve innervates the anterior arm compartnent?

musculocutaneous

the proximal attachment of the coracobrachialis muscle

coracoid process

the distal attachment of the coracobrachialis muscle

shaft of humerus

action of the coracobrachialis muscle?

shoulder flexion, adduction, resists dislocation

nerve innervation of the coracobrachialis muscle

musculocutaneous nerve

the proximal attachment of the long head - biceps brachii muscle

supraglenoid tubercle

the proximal attachment of the short head - biceps brachii muscle

coracoid process

the distal attachment of the long and short heads - biceps brachii muscle

redial tuberosity

what's the action of the biceps brachii muscle?

supinates forearm; flexion of elbow in supination; flexion of shoulder

our shoulder joint is known as the ... joint

glenohumeral

the tendon of the long head of the biceps brachii sits in what?

bicipital groove

have to attach to the .... to assist with supination

radius

which bone rotates in supination?

radius

nerve innervation of biceps brachii

musculocutaneous nerve

proximal attachment of the brachialis muscle

shaft of distal humerus

distal attachment of the brachialis muscle

tuberosity of the ulna

action of the brachialis muscle?

elbow flexion

what kind of curl targets the biceps muscle?

supinated curls

what kind of curl targets the brachialis muscle?

pronated curls