Shoulder and Brachial Plexus

Question 1

Pectoral Girdle

Answer 1

Attaches upper limb to our trunk
Unstable joints
Very mobile
Formed by manubrium, clavicles and scapulae
Attachment site for many upper limb muscles

Question 2

Glenoid Cavity

Answer 2

Joint cavity

Question 3

Coracoid process
Acromion

Answer 3

Prevent humerus from dislocating superiorly also serve as muscle ligament attachment sites

Question 4

Deltoid

Answer 4

Forms the contour of the shoulder
3 parts: clavicular, acromial and spinal
When is contracts it abductions occurs (arm moving away from body)
Innervated by axillary nerve

Question 5

Teres major

Answer 5

Adducts and medially rotates the humerus
stabilizing role of the humerus head along with the deltoid
Attaches from inferior portion of scapula to the humerus

Question 6

Rotator Cuff Muscles

Answer 6

Supraspinatus: assists the deltoid with arm abduction
Infraspinatus: laterally rotates arm
Teres minor: laterally rotates arm
Subscapularis: medially rotates and adducts arm

Question 7

Glenohumeral Joint

Answer 7

Ball and socket synovial joint
Articulation between large humeral head and shallow glenoid cavity
inferior portion of joint is the weakest

Question 8

Ligaments of Glenohumeral Joint

Answer 8

Glenohumeral Ligaments- strengthen it anteriorly: hold shoulder joint together
Coracohumeral ligament- reinforces superiorly: attaches coracoid process to humerus
Coraco- acromial ligament- prevents superior displacement

Synovial Bursa- accumulation of CT surrounding the bursal fluid that protects the joint

Question 9

Movements of Glenohumeral Joint

Answer 9

Flexion, extension, abduction, adduction, rotation, full circumdution

supraspinatus starts the abduction process then the deltoid follows. deltoid can not start this process

Question 10

Upward rotation of the scapula

Answer 10

joint cavity up
Medial side goes down
Descending and ascending portion of trapezius along with Serratus anterior

Question 11

Acromioclavicular Joint Dislocation

Answer 11

Joint is weak and injured, in some cases the joint and the coracoclavicular ligaments are torn resulting in separation of the shoulder from the clavicle

Question 12

Dislocation of the Glenohumeral Joint

Answer 12

Most happen in a inferior direction, head of humerus gets pushed forward

Clinicians say anterior or posterios
Anatomus anterior posterios but also inferior

Question 13

Brachial Plexus

Answer 13

Formed by ventral Rami C5-T1 that constitute the roots

Question 14

Trunks of Brachial Plexus

Answer 14

to 3 trunks (Superior C5-C6, middle C7, inferior C8-T1)
Anterior divisons supple anterior flexor compartments of upper limb
Posterior Divisons supply posterior extensor compartment

Question 15

Cords of Brachial Plexus

Answer 15

3 cords form within the axilla
Lateral (anterior division) - superior and middle trunk
Medial (anterior division) - inferior
Posterior - all three unite to create

Anterior: supple axon of nerves flexor compartments of arm and forearm, supply anterior portion of arm
Posterior: nerves supply extensor compartment muscle, backside, triceps, and forearm

Question 16

Branches of Brachial Plexus

Answer 16

Ulnar Nerve (comes off the medial cord)- innervates two muscles in the anterior foearm and the hypothenar copartments, the pinky compartment of the hand aw well as a couple of lumbracles
Musculocutaneous nerve comes off the lateral cord
Axillary nerve to the deltoid muscle and the radial nerve to the entire posterior compartment coming off the posterior cord
Median nerve comes off the medial and lateral cord- innervation for most of the anterior forearm and thumb compartment

Question 17

Dermatomes

Answer 17

Is an area of skin supplies by one spinal nerve

Question 18

Upper Brachial Plexus Injuries

Answer 18

Erb-Duchenne/Erb’s Palsy
- traction or tear of the upper trunk C5-C6
Limb hanged by the side, hand is flexed

Question 19

Lower Brachial Plexus injuries

Answer 19

Klumpke’s Palsy
- traction or tear of the lower trunk C8-T1
affects hand muscles innervated by median and ulnar nerves, resulting in Klumpke’s Total claw hand