Arm and Cubital Fossa

Question 1

humerus components

Answer 1

head
body
trochlea
capitulum
coronoid fossa
olecranon fossa
supracondylar ridges - medial and lateral

Question 2

humeral head

• articulates with
• components

Answer 2

articulares with glenoid cavity of the scapula
components
-greater tubercle
-lesser tubercle
-intertubercular groove (sulcus)

Question 3

humeral head

-anatomic vs. surgical neck

Answer 3

anatomical
-lies between head and the tubercles
surgical
-more likely region of breakage
-lies at beginning of body or shaft, distal to tubercles

Question 4

humeral body

• location
• components and description of each

Answer 4

ends distally at expansions (medial and lateral epicondyles)
deltoid tuberosity
-anterolateral “bump” indicating insertion of deltoid muscle
radial groove (spiral groove)
-posterior aspect; position of radial nerve

Question 5

trochlea of humerus

• function
• medial to trochlea…

Answer 5

articulates with ulna

medial to trochlea is a deep groove, sulcus for ulnar nerve - “funny bone”

Question 6

capitulum

-function

Answer 6

articulates with radius

Question 7

elbow articulations

Answer 7

humeroulnar
humeroradial
proximal radioulnar

Question 8

elbow ligaments

Answer 8

radial collateral ligament
ulnar collalteral ligament
-anterior head
-posterior head
-oblique head
annular ligament of radius
-proximal radioulnar joint

Question 9

muscles of the arm

-confined to

Answer 9

confined to anterior and posterior compartments

Question 10

anterior and posterior compartments of arm -formed by…

-separating structures attached at…

Answer 10

medial and lateral intermuscular septa from fascia encircling arm
attached at
-medial and lateral supracondylar ridges of humerus

Question 11

anconeus

• located primarily _____ due to…
• functions…

Answer 11

in forearm
due to insertion on ulna
functions along with medial head of triceps brachii
-anatomically is not always distinguishable

Question 12

what must occur at the ulna during pronation?

• why
• what happens if this does not occur?
• what does this mean for the humeroulnar joint?

Answer 12

ulna must abduct
maintains position of hand (as in turning a screw driver)
pronation without abduction results in change in placement of hand during pronation
humero-ulnar joint is necessarily loose-packed

Question 13

muscles of the cubital region

• primarily located where?
• where do they act

Answer 13

primarily located in forearm
action
-move forearm at elbow joint
-do not act on the hand or wrist

Question 14

arm blood supply

• entirity comes from…
• majority of arteries have…

Answer 14

entirity comes from brachial artery (axillary artery after passing teres major)
majority of arteries have a matching paired set of veins

Question 15

which veins are not matched to an artery?

Answer 15

cephalic
median cubital
median vein of forearm
basilic

Question 16

brachial veins (paired to artery) do what?

Answer 16

anastomose with each other and the superficial veins

Question 17

veins of the arm through the subclavian vein

• where are valves located
• number compared to LE
• size of vein compared to corresponding artery
• why this size?

Answer 17

valves located at the distal and proximal ends
not as many as LE
smaller than corresponding artery
-majority of venous return being handled by superficial venous plexus

Question 18

muscular branches of artery

• for anterior compartment where do they come from
• for posterior compartment where do they come from

Answer 18

anterior
-brachial artery
posterior
-deep brachial artery

Question 19

deep brachial artery

• splits into…
• what does it do around the lateral epicondyle

Answer 19

splits into anterior and posterior descending branches surrounding the lateral epicondyle of humerus to anastomose with collaterals from the brachial artery

Question 20

profunda brachii (deep brachial artery)

• relation to brachial
• location

Answer 20

first and largest branch

branches and follows the radial nerve posteriorly around the radial groove to the posterior surface of the humerus

Question 21

radial and ulnar arteries

• location
• formed from

Answer 21

found at the level of the cubital fossa

result of the brachial artery branching

Question 22

recurrent branches

-created by…

Answer 22

radial artery
-one recurrent branch
ulnar artery
-anterior and posterior recurrent branches

Question 23

anastomosis around the elbow

-formed from

Answer 23

anterior and posterior branches of deep brachial artery
radial recurrent artery
superior and inferior ulnar collaterals
anterior and posterior ulnar recurrent arteries

Question 24

superior and inferior ulnar collateral arteries

• arise from
• superior follows…

Answer 24

arise from brachial artery proximal to division within cubital fossa
superior follows ulnar nerve

Question 25

muscles of arm innervated by...

Answer 25

radial | musculocutaneous

Question 26

median and ulnar nerves - formed in... - location - function

Answer 26

formed in axilla descend along brachial artery through arm to reach forearm innervate muscles and skin of forearm

Question 27

radial nerve - size compared to other branches of posterior cord - location - function

Answer 27

``` largest location -curves posteriorly around the humerus in the radial groove (with deep brachial artery) innervates -triceps -anconeus -supinator -brachioradialis continues into forearm to innervate extensors of the wrist ```

Question 28

musculocutaneous nerve - formed from - function - continues into forearm as...

Answer 28

small branch of lateral cord innervates -muscles of the anterior compartment of the arm continues into forearm as lateral cutaneous nerve of forearm

Question 29

median and ulnar nerves | -location

Answer 29

travel down lateral and medial side of brachial artery, respectively

Question 30

median nerve protected in cubital fossa by...

Answer 30

lying deep to bicipital tendon

Question 31

ulnar nerve - begins... - where does it go?

Answer 31

begins in anterior muscular compartment | pierces the medial intermuscular septum to continue distally along the medial head of the triceps

Question 32

cubital fossa | -borders

Answer 32

``` superior -line crossing from medial to lateral epicondyles of humerus medial -pronator teres lateral -brachioradialis floor -brachialis -supinator roof -deep fascia -includes bicipital aponeurosis (covered by superficial fascia, loose CT, and skin) ```

Question 33

cubital fossa | -contains

Answer 33

``` bicipital tendon brachial artery -its terminal radial and ulnar brahcnes brachial veins parts of median and radial nerves ```

Question 34

median cubital vein in relation to cubital fossa

Answer 34

runs in loose CT superficial to deep fascia covering cubital fossa

Question 35

radial nerve | -pressure may result in...

Answer 35

may result in temporary to long term paralysis or weakness of the extensors muscles of the wrist in the forearm -called wrist drop

Question 36

musculocutaneous nerve damage in the axilla | -results in...

Answer 36

weakened flexion and supination of forearm | anesthesia of lateral forearm also possible

Question 37

damage to median nerve | -results in...

Answer 37

``` loss of sensation to lateral portion of palm loss of -pronation -flexion of wrist and digits -complex thumb movements ```

Question 38

damage to ulnar nerve - results in... - effect on forearm flexors compared to median nerve damage

Answer 38

weakened - flexion and adduction of wrist vs. median nerve - innervates less - flexion less severely affected

Question 39

sharp blow on medial side of elbow can result in...

Answer 39

tingling or anesthesia of the medial two digits if ulnar nerve is affected (in ulnar groove) this is the funny bone

Question 40

brachial/axillary artery damage - can result in - may lead to...

Answer 40

can result in loss of blood supply to forearm -results in paralysis of deep flexors of wrist permanent damage may occur -produces a permanent flexion contracture due to atrophy and shortening of deep flexor muscles

Question 41

anastomotic circulations and injury - work best when... - what will anastomotic circulations do if lack of perfusion is sudden and lasting

Answer 41

work best when -"rerouting" of blood takes place over time will allow minimal survival if lack of perfusion is sudden and lasting