-
Region of arm
- Superiorly: communicates with the axilla
- Inferiorly: a number of important structures pass between the arm and forearm
-
2 compartments formed by the medial and lateral intermuscular septa
Anterior and posterior compartment
-
4 facts about anterior compartment
- Contains muscles that predominantly flex the elbow joint
- Contains brachial artery
- Contains peripheral nerves derived from the anterior divisions of the brachial plexus
- All the musculature is innervated by the musculocutaneous nerve
-
3 facts about the posterior compartment
- Contains muscles that predominantely extend the elbow joint
- Contains peripheral nerves derived from posterior divisions of the brachial plexus
- Musculature in this region is innervated by the radial nerve
-
Describe carrying angle of elbow
- Angulation between long axis of humerus and long axis of forearm
- Greater in women than men
- Abnormal cases outside this range is called cubitus valgus/varus (varus is gunstock)
-
The medial border of the humeral shaft continues distally and forms the:
Medial supracondylar ridge
-
The medial supracondylar shaft is:
A roughened surface for the attachmet of muscles found in the anterior compartment of the forearm
-
5 Borders of the shaft
- Medial border
- Lateral border
- Anteromedial surface
- Anterolateral surface
- Posterior surface
-
Where is the deltoid tuberosity located?
Anterolateral surface
-
What extends and form the lateral supracondylar ridge distally?
lateral border
-
Where is the radial groove located?
Posterior surface
-
What lies in the radial groove?
radial nerve and profunda brachii artery
-
What is the medial epicondyle?
A large bony protuberance, is the major palpable landmark on the medial side of the elbow. Bears a large oval impression for the attachment of muscles in the anterior compartment of the aforearm.
-
What holds the goove for the ulnar nerve?
Medial epicondyle
-
What is the lateral epicondyle?
Much less pronounced than medial epicondyle. Lateral to the capitulum and has a large irregular impression for the attachment of muscles in the posterior compartment of the forearm.
-
Name the three fossa of the distal humerus
- Radial fossa
- Coronoid fossa
- Olecranon fossa
-
2 facts about the radial fossa
- least distinct of the fossae
- Immediately superior to the capitulum of the anterior surface of the humerus
-
Describe the coronoid fossa
Adjacent to the radial fossa and is superior to the trochlea
-
2 facts about the olecranon fossa
- Larget of fossae
- Occurs immediately superior to the trochlea of the posterior surface of the distal end of the humerus
-
Describe the capitulum
- lateral in position and hemispherical in shape, it projects anteriorly and somewhat inferiorly and is not visible when the humerus is viewed from the posterior aspect
- Articulates with the radius
-
Describe the trochlea
- Articulates with the ulna
- Pulley shaped and lies medial to the capitulum
- Medial edge is is more pronounced than its lateral edge
-
Describe the shape of the head of the radius
- Thick, disc-shaped structure oriented in the horizontal plane.
- Circular superior surface, the fovea, is concave for articulation with the capitulum ofthe humerus
-
Where is the next of the radius?
Between the expanded head and the radial tuberosity on the shaft
-
Describe the radial tuberosity and what attaches to it
- Large blunt projection of the medial surface immediately inferior to the neck.
- Roghened attachment for the biceps brachii tendon
-
Describe olecranon process
- Large projection of bone that extends proximally from the ulna.
- Anterolateral surface is articular and contributes formation of trochlear notch (articulates with trochlea of humerus)
-
Describe the coronoid process
- Projects anteriorly from the proximal end of the ulna.
- Superolateral surface is articular and participates, with the olecranon, in forming the trochlear notch
-
Where is the ulnar tuberosity and what attaches there?
At the apex of the anterior surface and is the attachment site for the brachialis muscle.
-
Where is the radial notch?
Lateral surface of the coronoid process
-
Where is the supinator crest?
Posterior margin of the fossa inferior to the radial notch.
-
3 considerations of corachobrachialis
- Pierced by musculocutaneous n.
- Brachial pulse palpable, medial and posterior to muscle
- Proximal attachment blends with short head of biceps on corcoid process of scapula
-
4 considerations of biceps brachii
- Tendon for long head is intrascapular and extrasynovial
- Two joint muscle
- Transverse humeral ligament
- Deals with the bicipital aponeurosis
-
What is the bicipital aponeurosis?
Distal continuation of the common biceps tendon
-
2 functions of bicipital aponeurosis
- Provides protection for the brachial artery and the median nerve in the cubital fossa
- Alters the force distribution and decreases the pressure of the biceps tendon on the radial tuberosity
-
2 considerations for brachialis
- Musculocutaneous nerve is anterior
- Primary flexor of the elbow
-
2 facts of triceps brachii
- Head is primary elbow extender
- The long head of the triceps brachii is a joint muscle as it crosses the shoulder and the elbow
-
What is the function and course of the brachial artery?
- Provides the main arterial supply to the arm
- Continuation of the axillary artery (receives name after passing the inferior border of teres major)
- Ends in the cubital fossa anterior to the brachialis
- Lies medial in the arm and passes inferolaterally to become anterior to the arm
- Travels with median nerve which lies anterior to the artery, but becomes medial to it in the cubital fossa
-
Branches of the brachial artery
- Brachial profundus
- Superior and inferior ulnar collateral artery
- Radial artery
- Ulnar artery
-
Function of brachial profundus
Provides blood supply to the posterior compartment of the arm
-
Function of superior and inferior collateral ulnar artery
Participate in the elbow anastomoses
-
Function of radial artery
At or near the cubital fossa under the bicipital aponeurosis
-
Function of the ulnar artery
At or near the cubital fossa under the bicipital aponeurosis
-
Anastomoses of Superior ulnar collateral artery
Posteral ulnar recurrent artery
-
Anastomoses of Inferior collateral ulnar artery
Anterior ulnar recurrent artery
-
The middle collateral artery artery anastomoses with:
interosseus recurrent artery
-
The radial collateral artery anastomoses with the:
radial recurrent artery
-
Participants with the radial artery
Radial recurrent
-
Participants from the ulnar artery
- Anterior and posterior ulnar recurrents
- Interosseus recurrent from the common interosseus artery off the ulnar artery
-
3 functions of the Cephalic Vein
- Travels primarily on the lateral surface of the arm
- Travels superiorly to the deltopectoral groove
- Travels with deltoid branch from the thoracoacromial trunk in the deltopectoral groove
-
2 facts about the basilic vein
- 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
-
2 Functions of the Median cubital vein
- Commnication between the cephalic vein and the basillic vein
- Serves as the site for venous puncture for drawing blood
-
4 Functions of Musculocutaneous nerves
- Supplies all the muscles of the anterior compartment of the arm
- Pierces the coracobrachialis
- Travels between biceps brachii and brachialis
- Becomes the lateral antebrachial cutaneous nerve
-
4 functions of median nerve
- Initially lateral to the brachial artery
- Crosses anterior as it travels with the brachial artery
- Becomes medial to the brachial artery in the cubital fossa
- Does not supply any muscles in the ARM
-
3 Functions of the ulnar nerve
- Medial to 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 this site "funny bone")
-
What compartment does the radial nerve supply?
Posterior compartment of the arm
-
What does the radial nerve provide innervation for?
- long head & lateral head of the triceps brachii prior to the spiral line
- medial head of the triceps brachii from the spiral line
-
What septum does the radial nerve pierce?
intermuscular septum and enters the anterior compartment of the arm
-
Where does the radial nerve divide into branches?
Level of the lateral epicondyle
-
What does the radial nerve divide into?
Deep and superficial branches
-
What is the function of the deep branch of radial nerve?
Entirely muscular and articular and pierces the supinator
-
What is the function of the superficial branch of the ulnar nerve?
Superifical nerve is entirely cutaneous
-
Name the 5 distributions of the cutaneous innervation
- Intercostobrachial nerve
- Medial brachial cutaneous - from medial cord
- Superior lateral brachial cutaneous - from axillary n.
- Inferior lateral brachial cutaneous - from radial n.
- Posterior brachial cutaneous - from radial n.
-
Define cubital fossa
- Triangular area with 5 borders
- Superior - imaginary line connecting med & lat epicondyles
- Medially - pronator teres
- Laterally - brachioradialis
- Floor - brachiallis & supinator muscles
- Roof - deep fascia reinforced with the bicipital aponeurosis
-
Contents of cubital fossa
- Lateral - biceps brachii tendon
- Middle - brachial artery - commencement of radial and ulnar arteries
- Medial - Median nerve
-
Facts about humeroulnar and humeroradial
- ginglymoid or hinge joints
- uniaxial diarthrodial joint
- 1 DOF
- allows for flexion/extension
-
What type of joint is the humeroulnar joint?
Modified sellar
-
What type of joint is the humeroradial joint?
Modified ovoid
-
Facts about proximal radioulnar joint
- Uniaxial diarthrodial joint
- trochoid (pivot) type joint
- modified ovoid
- 1 DOF
- allows for pronation/supination
-
Describe the trochlea
- Covered with articular cartilage
- Spool-shaped
- trochlear groove spirals obliquely around the trochlea and divdes into a medial and lateral portion
-
What is superior to the trochlea and lies on the anterior surface?
coronoid fossa
-
What is on the posterior surface near the trochlea?
olecranon fossa
-
Describe the capitulum
- Covered with articular cartilage
- Spherically shaped
- Separated from the trochlea by the capitulotrochlear groove
-
Where is the radial fossa located?
Superior to the capitulum on the anterior surface of the humerus
-
Describe the trochlear notch
- Located on the anterior surface of the olecranon process
- Concave-shaped
- Contains a trochlear ridge that ridges in the trochlear groove
-
The ulna contains what two notches?
Trochlea and radial notches
-
The joint capsule encloses what 3 joints?
- Humerulnar joint
- Humeroradial joint
- Proximal radioulnar joint
-
The medial (ulnar) collateral ligament of the elbow contains two/three parts
- Anterior medial collateral ligament
- Posterior medial collateral ligament
- Transvere (oblique) ligament
-
Function of Anterior medial collateral ligament
- MOST IMPORTANT
- Attaches from the tip of the medial epicondyle of the humerus to the coronoid process of the ulna
- Can be divided into functional bands
- Limits primarily extension and resist valgus stress
-
Functional consideration of Posterior medial collateral ligament
- Attaches from the posterior surface of the medial epicondyle to the olcranon and coronoid process of ulna
- Limits primarily flexion
-
Functional consideration of Lateral (radial) collateral ligament of the elbow
- Fan-shaped
- Poorly demarcated
- Extends from inferior lateral epicondyle of the humerus to the annular ligament and to the lateral aspet of the olecranon process
- Resists varus stress
|
|
