Lecture 18 Flashcards
What is the Flexor compartment of the arm?
Anterior comartment
What is the Extensor compartment of the arm?
Posterior Compartment
What are the anterior and posterior compartments of the arm divided by?
Medial and Lateral intermuscular septae
What are 2x features of the intermuscular septae of the humerus?
Septa attached to medial and lateral supracondylar ridges(lines) of humerus
Septa fade out in upper part of arm
Continuous with deep fascia
What 3x muscles make up the bulk of the front of the arm?
Coracobrachialis
Brachialis
Biceps Brachii
-all innervated by the musculocutaneous nerve
What is the relative position of musculocutaneous nerve to the 3x muscles it innervates on the bulked front of the arm?
Coracobrachialis -through
Brachialis -lies on
Biceps Brachii - underneath
What 2x muscles originate from the coracoid process and are partially attached to one another?
Coracobrachilais
Short head of biceps
Where does the Long head of biceps Brachii originate from?
Supraglenoid tubercle
Where does brachialis originate from?
front of humerus
-oppostie deltoid tuberosity
What does brachialis cover and attach to?
Brachialis covers anterior aspects of elbow joint
attches to coracoid process and tuberosity of the ulna
Where are the 2x insertions of Biceps Brachii?
Strong tendinous insertion into the tuberosity of the radius
Bicepital aponeuorosis into the deep fascia onto the anterio-medial aspect of the forearm
What is the pathway of the ulna nerve?
Behind medial intermuscular septum in lower 1/3 of arm
accompanies superior ulnar collateral artery
Behing medial epicondyle of humerus
Enters Forearm between 2x head of flexor carpi ulnaris
What is the relationship between the median nerve and ulnar nerve and the arm?
Neither the median nerve or ulna nerve have any branches into the arm
What are the vena comitantes reinforced by?
Basilic vein
-which pierces deep fascia half way up the arm
Where does the basilic vein pierce the deep fascia?
Half way up the arm
What is the pathway of the cephalic vein?
Lies in subcutaneous tissue
Travels up anterolateral aspect of arm
Into the groove between the anterior fibres of deltoid and pectoralis major (deltopectoral groove)
joins axillary vein (via piercing clavipectoral fascia)
What 7 muscles run from the pectoral girdle –> arm?
- Deltoid
- Teres Major
- Coracobrachilais
Rotator Cuff Muscles - Supraspinatis
- Infraspinatis
- Teres Minor
- Subscapularis
What 2x muscles bypass the arm and run from the Pectoral girdle –> to the forearm?
Biceps Brachii
Triceps Brachii
What 2x muscles run from the Arm –> forearm?
Brachilais
Triceps - Lateral and Medial Head
Deltoid
Large powerful Lateral muscle
Delta = traingle
3x muscle fibres (Anterior, Posterior and Middle fibres)
Origin: anatomical Horseshoe (distal end of clavicle, acromium and spine)
Insertion: 1/2 way down humerus, on lateral deltoid tuberosity
-roughened area
Axillary Nerve
What are the Key features about the anterior fibres of deltoid?
Unipennate
=strong (non parallel arangement of fibres increasing/impacting on strength)
Primary: Flex shoulder + internally rotates arm
What are the Key features about the Posterior fibres of deltoid?
Unipennate
=strong
Primary: Extend shoulder Externally rotates arm
-almost complete antagonist to anterior fibres
What are the Key features about the middle fibres of deltoid?
Multipennate (very strong)
Abducts arm
How does the position of the limb affect the deltoid?
Position of the limb, affect whether with the middle fibres, the anterior and posterior fibres either help or not help with ABD abduction
- Alone: Middle fibres will ABDuct, and pass imaginary line/15 degree buffer zone with subscapularis firing
- stationary(behind imaginary line): posterior and anterior fibres with ABDuct
- already Abducted arm = Anterior and posterior fibres shorten and assist with abduction
Teres Major
O: inferior angle of scapula
I: Medial lip of inter tubercular groove
-twisting around Teres Major = Insertion of Lat Dorsi
Teres Major + Lat Dorsi= Posterior fold of axilla
-Internal Rotation + Extends shoulder
Teres Major inferior border= boundary between Axillary and Brachial structures
Lower Subscapular nerve