Upper Limb Flashcards
Name the muscles that connect the upper limb to the thoracic wall
Pectoralis major
Pectoralis minor
Subcalvius
Serratus anterior
Origin and insertion of the pectoralis major muscle
Origin: two heads claviclular head from medial half of the front of the clavicle and sternocostal head from sternum upper six costal cartilages and apponeurosis of external oblique muscle.
Insertion: lateral lip of bicepital groove of the humerus.
NS and NR of perctoralis major muscle
NS medial and lateral pectoral nerve
NR c5 c6 c7 c8 and t1
Action of pectoralis major muscle
Addiction and medial rotation of the arm
Clavicular head helps in flex ion of the arm (shoulder)
Pectoralis minor origin and insertion
Origin: from 3rd 4th and 5th ribs close to their costal cartilages.
Insertion: Coracoid process of the scapula
NS and NR of pectoralis minor
NS medial pectoral nerve from brachial plexus
NR c6 c7 c8
Action of pectoralis minor
Depression of the shoulder
Draws the ribs upwards and outwards during deep inspiration.
Origin and insertion of subclavius
Origin: first costal cartilage
Insertion: subcalvian groove in the middle 1/3 of the inferior surface of clavicle.
NS of subclavius
Nerve to sublclavius from upper trunk of brachial plexus
Action of subclavius
Fixes the clavicle during movement of the shoulder joint.
Serratus anterior origin and insertion
Origin: upper eight ribs
Insertion: anterior aspect of the medial border and inferior angle of scapula.
Serratus anterior NS
Long thoracic nerve.
Serratus anterior action
Draws the scapula forward in boxing (protrusion)
Rotates the scapula outwards in raising the arm above 90*
What is the clavipectoral fascia
It is a thickened membrane of deep fascia between the subclavius and perctoralis minor It is pierced by Lateral pectoral nerve Thoraco-acromial artery Cephalic vein Few lymph vessels
The root of brachial plexus
Formed by the anterior rami (branch) of c5, c6, c7, c8 and t1
Trunks of brachial plexus in details and divisions
Upper (superior) trunk: formed by the union of the anterior rami of c5 and c6
Middle trunk: anterior ramus of c7
Lower (inferior) trunk: formed by the union of the anterior rami of c8 and t1.
Division: each trunk is divided into anterior and posterior divisions.
Cords of brachial plexus in details
Lateral cord: formed by the union of the anterior divisions of the upper and middle trunk
Posterior cord: formed by the union of the posterior division of all trunks.
Medial cord: formed by the anterior division of the lower trunk
Describe the axilla in general
Known as the armpit a pyramid shape space between the upper part of the arm and the side of the chest. It’s a communication between the upper limb and the root of the neck.
Has an apex (inlet) base and four walls: anterior posterior medial and lateral.
The folds of the axilla are formed by
The anterior fold of the axilla is formed by the folded fibers of the pectoralis major muscle
The posterior fold of the axilla is formed by the folding of the latissimus dorsi over teres major muscle.
The anterior fold is higher than the posterior fold
The anterior wall of the axilla is formed by the
Pectoralis major
Pectoralis minor
Subclavius
Clavipectoral fascia
The posterior wall of the axilla is formed by the
Subscapularis
Teres major
Lattissimus dorsi
Proximal part of the long head of triceps
Openings in the posterior wall of the axilla the quadrangular space is bounded by… and transmits
Subscapularis
Surgical neck of the humerus
Teres major
Long head of triceps
And transmits the axillary nerve and posterior circumflex humeral artery.
Openings in the posterior wall of the axilla the triangular space is bounded by … and transmits
Long head of triceps
Subscapularis
Teres major
Transmits circumflex scapular artery and vein.
The medial wall of the axilla is formed by
Upper 4-5 ribs
Upper 4-5 intercostal spaces covered by the upper digitations of the Serratus anterior muscle.
The lateral wall of the axilla is formed by
It is the narrowest wall
Biciputal groove
Coracobrachialis
Biceps brachii
What are the contents of the axilla (7)
Axillary artery and it’s branches
Axillary vein and it’s tributaries
Axillary tail of the breast
Cords and terminal branches of the brachial plexus
Axillary lymph vessels and lymph nodes
Axillary fat
Lateral cutaneous branches of the upper intercostal nerves.
Begging course and termination of the axillary artery
Beginning: at the outer (lateral) border of the first rib as a continuation of the subclavian artery.
Corse: passes downwards in the axilla from the apex to the base.
Termination: ends at the lower border of the teres major muscle where it continuous as the brachial artery.
Parts of the axillary artery
Divided by pectoralis minor into three parts
First part: lies above the pectoralis minor
Second part: lies behind the pectoralis minor
Third part: lies below the pectoralis minor.
Relations o father first part of the axillary artery
The first part lies above the pectoralis minor
Anteriorly: the clavicular part of the pectoralis major the clavipectoral fascia and vessels and nerves superficial to it.
Posteriorly: first intercostal space, first digitation of the Serratus anterior and medial cord the brachial plexus.
Laterally: lateral and posterior cords of the brachial plexus.
Medially: axillary vein.
Relations of the second part of the axillary artery
The second part of the axillary artery lies behind the pectoralis minor
Anteriorly: the pectoralis minor and major
Posteriorly: the posterior cord of the brachial plexus and the Subscapularis muscle.
Laterally: the lateral cord of the brachial plexus.
Medially: the medial cord of the brachial plexus, medial pectoral nerve and axillary vein.
Relations of the third part of the axillary artery
The third part of the axillary artery lies below the pectoralis minor.
Anteriorly: upper part is covered by pectoralis major but it’s lower part is covered by skin, superficial and deep fascia. It’s crossed by the medial root of the median nerve.
Posteriorly: the Subscapularis, the lattismus dorsi and the teres major. The axillary and radial nerves also lies behind the artery.
Laterally: the coracobrachialis p, the biceps and the humerus. The lateral root of the median and musculocutaneous nerves also lie in the lateral side.
Medially: the ulnar nerve, axillary vein and the medial cutaneous nerve of the arm and the forearm.
Branches of the axillary artery in the first part
The superior thoracic artery.
Branches of the axillary artery in the second part
The thoracoacromial trunk
The lateral thoracic artery
The branches of the axillary artery in the third part
The Subscapular artery
The anterior circumflex humeral artery
The posterior circumflex humeral artery
The beginning and end of the axillary vein
Beginning: at the lower border of teres major as a continuation of basilic vein.
End: the outer border of the first rib where it becomes subclavian vein.
It lies on the medial side of the axillary artery.
The tributaries of the axillary vein
Two vanae comitantes of brachial artery, cephalic vein and other tributaries follow the axillary arterial branches.
Muscles that connect the scapula to the humerus (6)
Deltoid Supraspinatus Infraspinatus Teres major Teres minor Subscapulrais
Superficial muscles of the shoulder are
Trapezius and deltoid muscles. Together they provide the characteristic contour of the shoulder. The trapezius attaches the scapula and clavicle to the trunk. The deltoid attaches the scapula and clavicle to the humerus.
Deltoid muscle, origin insertion and NS, NR
Large and triangular in shape, with its base attached to the scapula and clavicle and it’s apex attached to the humerus.
Origin: lateral third of clavicle, acromion and spine of the scapula (U shaped).
Insertion: middle of the lateral surface of shaft of humerus (deltoid tuberosity).
NS: axillary nerve c5 and c6 (branch of posterior cord of the brachial plexus).
Action of deltoid muscle
Performs three functions because of the direction of its fibers
- posterior fibers extend and laterally rotate the arm (shoulder)
- middle fibers abducts arm 15 to 90
- Anterior fibers flex and Medially rotate arm 
Structures under cover of the deltoid muscle
Bone: Upper part of humerus Coracoid process Greater tuberosity Lesser tuberosity Intertuberculus sulcus (groove)
Bursa: subdeltoid
Subacromial bursa
Muscles: teres minor
Teres major
Lattismus dorsi
Triceps long head
Vessels: anterior and posterior circumflex humeral vessel.
Nerves: axillary nerve.
Trapezius origin, insertion and nerve supply
Origin: external occipital protuberance Superior nuchal line Ligamentum nuchae Spine of the 7th cervical vertebra Spines of all thoracic vertebrae and their supraspinous ligament
Insertion: U shaped insertion opposite to the origin of the deltoid.
Upper fiber into the posterior border of lateral third of clavicle.
Middle fibers, medial border of acromion and upper lip of the crest of the spine
Lower fibers, pass upward and laterally insert on medial end of the spine of the scapula.
Nerve supply: spinal part of accessory nerve (motor) XI
Ventral rami of C3 and c4 (sensory- proprioceptive)
Action of the trapezius muscle
Upper fibers along with lavator scapulae elevate the scapula
Middle fibers with rhomboids pull scapula Medially (retracts)
Lower fibers pull medial border of scapula downward, so upper and lower fibers acting together rotate scapula glenoid cavity face upward assisted by lower five digitations of Serratus anterior. 
