Arm

Question 1

2 compartments of the arm

Answer 1

formed by the medial and lateral intermuscular septa which passes from each side of the humerus to the outer sleeve of deep fascia that surround the limb.

Anterior and Posterior compartments

Question 2

Anterior Compartment

Answer 2

Contains muscles that predominantly FLEX the elbow jt

Contains Brachial Artery

Contains peripheral nerves derived from the anterior divisions of the brachial plexus

All musculature is innervated by Musculocutaneous Nerve

Question 3

Posterior Compartment

Answer 3

contains muscles that predominatly EXTEND the elbow jt

Contains peripheral nerves derived from posterior division of the brachial plexus

All the musculature in the posterior arm are innervated by the Radial nerve

Question 4

Carrying Angle

Answer 4

Angualtion b/w the long axis of humerus and the long axis of the forearm

Due to the configuration of the articular surfaces

Slightly greater in women than in men

women= 10-15

men=5

Abnormal if outside these ranges and it is called cubitus valgus

Question 5

Bicipital Aponeurosis

Answer 5

Distal continuation of the common biceps tendon

Triangular membranous band

Connects biceps tendon to the deep fascia of the forearm

Fxn: provides protection for the brachial artery and the median nerve in the cubital fossa

Alters the force distribution and decreased the pressure of the biceps tendon on the radial tuberosity

Question 6

Brachial Artery

Answer 6

Fxn and Course:

• Provides main arterial supply to arm
• Continuation of the axillary artery: after passing the inferior border of teres major
• ends in the cubital fossa anterior to the brachialis
• initially lies medial in the arm passes inferolaterally to become anterior in the arm
• travels with the median nerve which initially lies anterior to the artery but becomes medial in the cubital fossa

Question 7

Brachial Profunda (deep artery of the arm)

Answer 7

Main branch off the brachial

provides blood supply to the posterior compartment of the arm

Question 8

Superior and inferior ulnar collateral artery

Answer 8

Participate in elbow anastomoses

Superior ulnar collateral connects with posterior ulnar recurrent

inferior ulnar collateral connects with the anterior ulnar recurrent

Question 9

Radial Artery

Answer 9

at or near the cubital fossa under the bicipital aponeurosis

Question 10

Ulnar artery

Answer 10

at or near the cubital fossa under the bicipital aponeurosis

Question 11

Middle collateral artery

Answer 11

participant from the brachial profunda artery

connects with the interrosseous recurrent artery

Question 12

Radial collateral a.

Answer 12

connects with radial recurrent artery

participant from the brachial profunda and radial artery

Question 13

Participants from ulnar artery

Answer 13

anterior and posterior ulnar recurrents

interosseous recurrent from the common interosseus artery off the ulnar artery

Question 14

Cephalic Vein

Answer 14

travels primarily on the lateral surface of the arm

travels superiorly to the deltopectoral groove

travels with the deltoid branch from the thoracoacromial trunk in the deltopectoral groove

Question 15

Basilic vein

Answer 15

ascends into the inferior medial arm

passes deeply, piercing the brachial fascia to merge with the accompanying veins of the brachial veins to form the axillary vein

Question 16

Median cubital vein

Answer 16

communication b/w the cephalic vein and the basilic vein

serves as the site for venous puncture for drawing blood

Question 17

Musculocutaneous Nerve

Answer 17

supplies all of the anterior compartment

pierces the coracobrachialis

travels b/w the biceps brachii and brachialis

becomes the lateral antebrachial cutaneous nerve

Question 18

Median nerve

Answer 18

initally lateral to the brachial artery

crosses anterior as it travels with the brachial artery

becomes medial to the brachial artery in the cubital gossa

Does not supply any muscles in the ARM

Question 19

Ulnar Nerve

Answer 19

medial to the brachial artery

around the middle of the arm pierces the medial intermuscular septum (with the superior ulnar collateral artery)

Passes posterior to the medial epicondyle (easily palpated at the “funny bone site”)

Question 20

Radial Nerve

Answer 20

Supplies the muscles in the posterior compartment of the arm

initally radial nerve is posterior to the brachial artery, medial to the huemrus, and anterior to the LH of the triceps brachii

Travels inferolaterally in the spiral line (radial groove) on the posterior humerus

provides motor innervation to the LH & lateral head of the triceps brachii prior to the spiral line

provides innervation to the medial head of the triceps brachii from the spiral line

pierces the lateral intermuscular septim and enters the anterior compartment of the arm

passes b/w the brachialis and brachioradialis

At the level of the lateral epicondyle the radial nerve divides deep and superifical branch

—deep branch=entirely muscular and articular and pierces the supinator

–superficial nerve is entirely cutaneous

Question 21

Cutaneous Innervation of the arm

Answer 21

Intercostobrachial nerve

Medial brachial cutaenous (from medial cord (C8-T1)

Superior lateral brachial cutaneous (From axillary)

Inferior lateral brachial cutaneous (from radial)

Posterior brachial cutaneous (from radial)

Question 22

Dermatomes of the arm

Answer 22

Question 23

Cubital Fossa Borders

Answer 23

Superiorly: an imaginary line connecting the medial & lateral epicondyles

Medially: pronator teres

Laterally: brachioradialis

Floor: brachialis & supinator muscles

Roof: deep fascia reinforced with the bicipital aponeurosis

Question 24

Cubital Fossa: Lateral to medial

Answer 24

Lateral: biceps Tendon

Middle: brachial Artery

Medial: median Nerve

Median cubital vein lies in the subcutaneous tissue overlying the cubital fossa

Question 25

Cubital Fossa Contents

Answer 25

Terminal part of the brachial artery Commencement of the radial and ulnar arteries Biceps brachii tendon Median Nerve

Question 26

Humeroulnar and humeroradial jts

Answer 26

Hinge joints Uniaxial diarthrodial jt 1 DOF Allows Flexion/Ext Humeroulnar: modified SELLAR Humeroradial: modified OVOID

Question 27

Proximal radioulnar jt

Answer 27

Uniaxial diarthrodial jt trochoid (pivot) type jt Modified OVOID 1 DOF allows for pronation/supination

Question 28

Elbow Jts Fxns

Answer 28

Elbow complex is designed to serve the hand in space can provide mobility and stability

Question 29

Trochlea

Answer 29

distal humerus covered with articular cartilage spool-shaped (hourglass) Trochlear groove: spirals obliquely around the trochlea and divides into a medial and lateral portion

Question 30

Articular surface of the distal humerus

Answer 30

sellar or saddle-shaped superior to the trochlea on the anterior surface of teh humerus=coronoid fossa Posteriorly=olecranon fossa

Question 31

Capitulum

Answer 31

covered with articular cartilage spherically shaped separated from the trochlea by the capitulotrochlear groove Superior to the capitulum on the anterior surface of humerus is the radial fossa

Question 32

Position

Answer 32

distal humerus is slightly internally rotated medial aspect of the trochlea is inferior with respect to the capitulum both the trochlea and capitulum are anterior to the shaft of the humerus

Question 33

Attachments of the Jt capsule

Answer 33

Anterior proximal: superior to the radial and coronoid fossa Anterior distal: inserted onto the ulna at the margin of the coronoid process Laterally: blends with the fibers of the LCL Medially: blends with fibers of the MCL Posteriorly: attached to the upper edge of the olecranon fossa Jt capsule is relatively weak antereriorly and posteriorly but it is reinforced medially and laterally by ligaments

Question 34

Medial (ulnar) collateral ligament of the elbow

Answer 34

Anterior medial collateral ligament Posterior medial collateral ligament Transverse (oblique) ligament

Question 35

Fxn of Anterior medial collateral ligament

Answer 35

This is the MOST IMPORTANT attaches tip of medial epicondyle of the humerus to the coronoid process of the ulna can be divided into fxnal bands limits primarily extension and resists valgus stress

Question 36

Fxnal consideration of posterior medial collateral ligament

Answer 36

attaches from the posterior surface of the medial epicondyle to the olecranon process and coronoid process of the ulna limits primarily flexion

Question 37

Lateral (radial) collateral ligament of the elbow

Answer 37

Fan shaped Poorly demarcated extends from inferior lateral epicondyle of the humerus to the annular ligament and to the lateral aspect of the olecranon process Fxn: resists varus stress