Lecture 14: UE pt 3

Question 1

What are the two groups of muscles of the shoulder complex? What articulation/ joint does each aid in?

Answer 1

1) Extrinsic muscles: scapulothoracic articulation
2) Intrinsic muscles: glenohumeral joint

Question 2

What plexus forms the nerves of the axilla?

Answer 2

Brachial plexus

Question 3

1) What compartment forms the axilla?
2) Where is the axilla?

Answer 3

1) Pyramidal compartment
2) Junction of arm and thorax
(tip is above clavicle, follows ribs, goes to humerus)

Question 4

1) What is the passageway for vessels and nerves going to and from the upper extremity?
2) How many walls does the axilla have? How many are muscular?

Answer 4

1) Axilla
2) 4 walls, 3 of which are muscular

Question 5

List the 2 folds of the axilla and what muscle(s) make them up

Answer 5

1) Anterior fold: Pectoralis major
2) Posterior fold: Teres major & latissimus dorsi

Question 6

1) What makes up the medial wall of the axilla?
2) What makes up the lateral wall of the axilla?

Answer 6

1) Medial wall: Thoracic wall and overlying serratus anterior muscle.
2) Lateral wall: Boney wall; humerus

Question 7

1) What artery and vein are found in the axillary region?
2) What nerves and plexus branches are here?
3) What other vessels are here? Are there lymph nodes here?
4) What immediately surrounds all of these/ bundles them together?
5) What is this embedded in?

Answer 7

1) Axillary artery & vein
2) Nerves of the cord & br. of brachial plexus
3) Lymphatic vessels; lymph nodes
4) Axillary sheath
5) All embedded in axillary fat

Question 8

Give examples of the extensive arterial anastomosis of scapula region

Answer 8

1) Suprascapular and dorsal scapular arteries
2) Anastomosis with intercostal aa. and scapular artery branches

Question 9

1) What artery supplies the posterior arm w blood?
2) What artery supplies the medial and anterior arm?

Answer 9

1) Profunda brachii a.
2) Brachial a.

Question 10

The profunda brachii artery runs
__[anteriorly/ posteriorly]__along with the radial nerve in the __________ groove, & they are both
vulnerable from a _______-shaft _____________ fx.

Answer 10

posteriorly; radial; midshaft humeral fx.

Question 11

What are the two types of veins of the arm? Do they anastomose? Describe.

Answer 11

Superficial and deep; freely anastomosis

Question 12

List 3 superficial veins in the shoulder and arm. Where do they originate?

Answer 12

Cephalic, basilic, and antebrachial veins; in the dorsum of hand

Question 13

1) Where do the deep veins of the arm lie?
2) What are they collectively called at the elbow? Why?
2a) What does this form proximally?

Answer 13

1) Deep to the investing fascia
2) Brachial veins; union of the ulnar and radial veins
2a) Axillary vein

Question 14

Why do we care abt lymphatics of the arm and shoulder? (2 reasons)

Answer 14

1) Breast cancer’s spread to lymph nodes (spreads to axillary nodes v often).
2) Surgical staging

Question 15

List the 6 steps of the spread of breast cancer if it doesn’t go to the axillary nodes

Answer 15

Pectoral nodes > Central nodes > Apical nodes> Supraclavicular nodes > Subclavian trunk > Right lymphatic duct (if on right side; thoracic duct on left side)

Question 16

1) What nerves (i.e from what spinal levels) make up the brachial plexus? From what rami?
2) What type of fibers make up this plexus, post synaptic or pre? Parasymp. or symp?
3) Where is it located?
4) What are its 2 parts?

Answer 16

1) Anterior rami C5-T1 spinal n.
2) Post synaptic sympathetic fibers
3) Lateral region of neck over middle and anterior scalene m.
4) Supraclavicular vs. Infraclavicular parts

Question 17

List the 3 trunks formed by the roots (C5-T1) of the brachial plexus.
-Include what spinal levels form each

Answer 17

1) C5-6 form superior trunk
2) C7 middle trunk
3) C8-T1 inferior trunk

Question 18

What do each of the 3 trunks of the C5-T1 roots form?

Answer 18

Each divide and form 3 anterior & 3 posterior divisions

Question 19

1) C5-T1 [roots] form 3 trunks’ that have ant. and post. divisions; what do the posterior divisions form?
2) What does that form + where do they go? What are nerves are these called?

Answer 19

1) Posterior cord, which forms :
2) Terminal nerves to posterior arm/ forearm; axillary & radial nn.

Question 20

1) The anterior divisions of the 3 trunks of C5-T1 are from what two pts of the cord? What type of nerves do these form to the anterior arm and forearm?
2) What are the names of these 3 nerves? Where does each specifically go?

Answer 20

1) Lateral and medial; terminal nerves
2) Musculocutaneous n. to arm;
-Median & ulnar nn. to forearm and hand

Question 21

1) What is the dermatome of the Axillary nerve?
2) What is it the terminal branch of?
3) What joint does it supply?
4) List 2 specific muscles it supplies (highlighted)
5) Does it innervate any skin? Explain?

Answer 21

1) C5-6
2) Posterior cord
3) Shoulder joint
4) Teres minor and deltoid m.
5) Skin inferior deltoid region

Question 22

1) What is dermatomes are the radial nerve?
2) What is it a branch of?
3) What muscles does it supply? What do these muscles do?
4) What areas of skin does it supply? (3)

Answer 22

1) C5-8, T1
2) Posterior cord
3) All muscles posterior compartments of arm & forearm
-Extend elbow, wrist, fingers
4) Posterior lateral arm, forearm and laterodorsal hand and finger

Question 23

1) What nerve travels in radial groove with Profundis brachial a.?
2) What does this make it vulnerable to?

Answer 23

1) Radial
2) Fracture of mid shaft humerus.

Question 24

1) Where does the Lateral cutaneous n. of forearm come from and what is it called? What spinal cord levels?
2) What compartment of the arm does it supply w motor?
3) What 3 muscles specifically?

Answer 24

1) Lateral cord; musculocutaneous nerve C5-7.
2) Anterior (flexor) compartment of the arm
3) Coracobrachialis m, Biceps brachii m, Brachialis m.

Question 25

1) What spinal level is the median nerve? What pts of the cord does it come from?
2) What forearm compartment’s muscles does it supply w motor? What is the exception?
3) What does it supply w sensory? What shares this function?

Answer 25

1) C6-7-8, T1; lateral and medial cord
2) Anterior compartment of the forearm
-EXCEPT for flexor carpi ulnaris and ulnar halve of flexor digitorum profundus (ulnar n.)
-5 intrinsic m. of thenar half of palm
3) Palmar skin; ulnar n.

Question 26

1) What groups of muscles are supplied by the median nerve?
2) What distribution to the hand does it have?

Answer 26

1) Flexors of wrist and fingers
2) “Carpal Tunnel Syndrome” distribution to hand; aka lateral palm (first 3 fingers and half of 4th) and dorsal tips of those fingers.

Question 27

1) What spinal cord levels does the ulnar nerve come from? What pt of the cord?
2) What compartment does it supply?

Answer 27

1) C7-8, T1; medial cord
2) Anterior compartment (medial) of forearm

Question 28

1) What spinal nerves does the ulnar nerve come from?
2) What muscles does it innervate (3 main categories)

Answer 28

1) C7-8, T1
2) -Flexor carpi ulnaris
-Ulnar half of flexor digitorum profundus in forearm
-Most intrinsic hand muscles

Question 29

1) The ulnar nerve partially innervates the skin of the hand; where does it innervate the dorsal pt?
2) What abt the anterior pt?

Answer 29

1) Medial from axial line of digit 3
2) Medial from axial line digit 4

Question 30

Describe the distribution of the hand’s cutaneous innervation by the median nerve
Important

Answer 30

Lateral palm (first 3 fingers and half of 4th) and dorsal tips of those fingers.

Question 31

Describe the distribution of the hand’s cutaneous innervation by the ulnar nerve
Important

Answer 31

-Medial palm (pinky and half of ring finger).
-Dorsal hand, pinky, almost all of ring finger, small pt of middle finger

Question 32

Describe the distribution of the hand’s cutaneous innervation by the radial nerve
Important

Answer 32

Medial aspect of dorsal wrist.
Dorsal aspect of: thumb, adjacent two fingers (except tips), and back of hand.