Muscles And Fasciae Of The Upper Limb part 1 Flashcards
Muscles are attached to the skeleton at two points/areas to carry out their actions on joints:
Point of Origin
Point of Insertion
Muscle attaches to a 💡more stable bone in the contraction.
💡More proximal/ nearer to the center of the body
💡Have greater mass
Point of Origin
The 💡opposite end that 💡tends to move while the body part of the 💡origin is stabilized.
💡More distal
Have 💡less mass
Example: Biceps brachii muscle of the arm
- Contraction of its muscle will bring the forearm or elbow into flexion.
Point of Insertion
Associated with the lateral aspect of the lower part of the neck; suspended from the trunk by muscles and the sternoclavicular joint
UPPER LIMB
It is a small 💡skeletal articulation 💡between the clavicle and the sternum
Sternoclavicular joint
It is the 💡area of the upper limb attachment to the trunk.
Shoulder
It is the part of the upper limb 💡between the shoulder and the elbow joint.
Arm
It is is 💡between the elbow joint and the wrist joint.
Forearm
It is 💡distal to the wrist joint
Hand
Three significant 💡areas of transition between the different parts of the limb:
Major structures pass though these areas:
Axilla
Cubital Fossa
Carpal tunnel
o Irregularly shaped 💡pyramidal area
o Formed by muscles and bones of the shoulder and the lateral surface of the thoracic wall
o Where 💡all major structures that pass between the neck and arm pass through
• Apex or Inlet - opens directly into the lower portion of the neck
• Floor - skin of the armpit.
Axilla
o 💡Triangularly shaped depression
formed by muscle 💡anterior to the elbow joint
💡Brachial artery
💡Radial nerve
Cubital Fossa
o Gate way of the palm of the hand
o Where the 💡median nerve and all the 💡long flexor tendons passing from the forearm to the digits of the hand pass through
o Its posterior, lateral, and medial walls form an arch - made up of 💡small carpal bones in the proximal region of the hand namely:
• 💡Pisiform and hamate- medially
• 💡Scaphoid and trapezium- laterally
o 💡Flexor retinaculum- provides roof of this tunnel
Carpal tunnel
MUSCLES OF THE SHOULDER
Trapezius Deltoid Levator scapulae Rhomboid major Rhomboid minor
SUPERFICIAL MUSCLES OF THE SHOULDER
Trapezius
Deltoid
It attaches the 💡scapula and clavicle to the trunk
Trapezius
It attaches the scapula and clavicle to the humerus
Deltoid
Origin of the trapezius
💡Skull (Occipital bone)
💡Spinous pocess of vertebrae (💡CI to TXII)
💡 CI to CVII, attaches to the vertebrae through the 💡ligamentum nuchae
INSERTION of the trapezius
Lateral third of the clavicle and acromion
Spine of scapula
ACTION of the trapezius muscle
Powerful 💡elevator of the shoulder; 💡rotates the scapula to extend the reach superiorly.
INNERVATION of the trapezius muscle
💡Accessory nerve [XI] and the 💡anterior rami of cervical nerves C3 and C4
A 💡large and 💡triangular muscle, with its 💡base attached to the scapula and clavicle and its 💡apex attached to the humerus.
Made up of 3 parts: Anterior, Middle, and Posterior
DELTOID
ORIGIN of the deltoid muscle
Long a continuous U-shaped line of attachment to the 💡clavicle and the 💡scapula, mirroring the adjacent insertion sites of the trapezius muscle
INSERTION of the deltoid muscle
💡Deltoid tuberosity on the lateral surface of the shaft of the humerus
ACTION of the deltoid muscle
▪ Anterior part: 💡Flexes & 💡medially rotates arm
o Middle part: 💡Abduction of the arm beyond the initial 15° accomplished by the supraspinatus muscle
o Posterior part: 💡Extends & 💡laterally rotates arm
INNERVATION of the deltoid muscle
💡Axillary nerve, a branch of the posterior cord of the brachial plexus; axillary nerve and posterior circumflex humeral artery and vein enter the deltoid by passing posteriorly around the surgical neck of the humerus
Fractures of the surgical neck of the humerus can lead to:
▪ 💡Paralysis of the deltoid muscle
▪ Anesthesia on the lateral aspect of the arm
▪ Because of 💡injury to the axillary nerve
💡Deep to trapezius, the scapula is attached to the vertebral column by 3 muscles:
** These muscles 💡work with the trapezius (and with muscles found anteriorly) to 💡position the scapula on the trunk.
▪ Levator scapulae
▪ Rhomboid minor
▪ Rhomboid major
ORIGIN OF LEVATOR SCAPULAE
Transverse processes of 💡CI to CIV vertebrae
INSERTION OF LEVATOR SCAPULAE
💡Posterior surface of the medial border of the scapula from the superior angle to the smooth triangular area of bone at the root of the spine
INNERVATION OF LEVATOR SCAPULAE
💡Dorsal scapular nerve and directly from 💡C3 and 💡C4 spinal nerves
ACTION OF LEVATOR SCAPULAE
💡Elevates the scapula
INNERVATION OF RHOMBOID MINOR AND MAJOR MUSCLE
💡Dorsal scapular nerve, which is a branch of the brachial plexus; branches direct from the anterior rami of 💡C3 and 💡C4 spinal nerves
ACTION OF RHOMBOID MINOR AND MAJOR MUSCLE
💡Retract and 💡elevate the scapula
ORIGIN OF RHOMBOID MINOR MUSCLE
💡Lower end of the ligamentum nuchae and the 💡spines of CVII and TI vertebrae
INSERTION OF RHOMBOID MINOR MUSCLE
Laterally into the smooth triangular area of bone at the root of the 💡spine of the scapula on the posterior surface
ORIGIN OF RHOMBOID MAJOR MUSCLE
Spines of vertebrae 💡TII to TV; intervening 💡supraspinous ligaments
INSERTION OF RHOMBOID MAJOR MUSCLE
Long the posterior surface of the medial border of the 💡scapula from the insertion of rhomboid minor to the inferior angle
This region occupies the 💡posterior aspect of the scapula and is located 💡deep to the trapezius and deltoid muscles.
POSTERIOR SUPRASCAPULAR REGION
The POSTERIOR SUPRASCAPULAR REGION contains 4 muscles, which pass between the scapula and proximal end of the humerus:
o Supraspinatus
o Infraspinatus
o Teresminor
o Teresmajor
This muscle, along with other muscles of the region and the humerus, participates in 💡forming several spaces through which 💡nerves and 💡vessels enter and leave the region.
Long head of the triceps brachii
The supraspinatus, infraspinatus, and teres minor muscles are components of the __, which stabilizes the glenohumeral joint.
Rotator cuff
They 💡form tendons that insert on the greater tubercle of the humerus
SUPRASPINATUS & INFRASPINATUS MUSCLE
ORIGIN OF SUPRASPINATUS MUSCLE
▪ Medial two-thirds of the 💡supra-spinous fossa
of the scapula and the deep fascia that covers the muscle
▪ The 💡tendon of suprapinatus passes:
o under the 💡acromion, where it is separated from the bone by a 💡subacromial bursa
o passes over the 💡glenohumeral joint
INSERTION OF SUPRASPINATUS MUSCLE
Most superior facet on the 💡greater tubercle of the humerus
INNERVATION OF SUPRASPINATUS MUSCLE
💡Suprascapular nerve [C4, C5, C6]
Arterial Supply: 💡suprascapular artery; 💡dorsalscapular artery
ACTION OF SUPRASPINATUS MUSCLE
Rotator cuff muscle; initiation of 💡abduction of arm to 15° at glenohumeral joint
Rotator Cuff Injuries and the Supraspinatus
o Injury or disease may damage the musculotendinous rotator cuff, producing 💡instability of the glenohumeral joint.
o Trauma may tear or rupture one or more of the tendons of the SITS muscles.
o 💡Tear of the supraspinatus is most commonly seen.
o A rotator cuff injury can make it 💡painful to lift your arm out to the side
o Abducted arm slowly lowered
• May be able to lower arm slowly to 90 degrees (deltoid function)
• Arm will then drop to side if with rotator cuff tear o
Positive test
• Patient unable to lower arm with control
• If able to hold at 90 degrees, pressure on wrist will cause arm to fall
▪ During arthroscopy, your surgeon inserts the arthroscope and small instruments into your shoulder joint
ORIGIN OF INFRASPANITOUS MUSCLE
▪ Medial two-thirds of the 💡infra-spinous fossa of the scapula and the 💡deep fascia that covers the muscle
▪ The tendon of infraspinatus passes:
o posteriorly to the glenohumeral joint
INSERTION OF INFRASPANITOUS MUSCLE
▪ Middle facet on posterior surface of the 💡greater tubercle of the humerus.
INNERVATION OF INFRASPANITOUS MUSCLE
▪ 💡Suprascapular nerve [C5, C6]
▪ Arterial Supply: 💡circumflex scapular artery;💡suprascapular artery
ACTION OF INFRASPANITOUS MUSCLE
▪ Rotator cuff muscle; 💡lateral rotation of arm at the glenohumeral joint
A 💡cord-like muscle
TERES MINOR
ORIGIN OF TERES MINOR MUSCLE
▪ Upper two-thirds of a flattened strip of bone on the posterior surface of the scapula immediately
▪ adjacent to the lateral border of the scapula below the infraglenoid tubercle
INSERTION OF TERES MINOR MUSCLE
▪ 💡Inferior facet of the greater tubercle of the
humerus
INNERVATION OF TERES MINOR MUSCLE
▪ 💡Axillary nerve [C5,6]
▪ Arterial Supply: 💡circumflex humeral artery; posterior circumflex humeral artery
ACTION OF TERES MINOR MUSCLE
▪ Rotator cuff muscle; 💡lateral rotation of arm
at the glenohumeral joint
A 💡broad ‘cord-like’ muscle that passes superiorly and laterally
TERES MAJOR
ORIGIN TERES MAJOR MUSCLE
From a large oval region on the posterior surface of the inferior angle of the scapula
INSERTION TERES MAJOR MUSCLE
💡Medial lip of the 💡intertubercular sulcus on the anterior surface of the humerus
INNERVATION TERES MAJOR MUSCLE
▪ 💡Inferior subscapular nerve [C5, C6, C7]
▪ Arterial Supply: 💡circumflex scapular artery; 💡subscapular artery;
💡posterior circumflex humeral artery
ACTION TERES MAJOR MUSCLE
💡Medially rotates and extends the humerus at the glenohumeral joint
ORIGIN LONG HEAD OF TRICEPS BRACHII MUSCLE
💡Infraglenoid tubercle
INSERTION LONG HEAD OF TRICEPS BRACHII MUSCLE
💡Common tendon of insertion with medial
and lateral heads on the 💡olecranon process of ulna
INNERVATION LONG HEAD OF TRICEPS BRACHII MUSCLE
▪ Radial nerve [C6, C7, C8]
▪ Arterial Supply: deep brachial artery; superiorulnar collateral artery; posterior circumflex humeral artery
ACTION LONG HEAD OF TRICEPS BRACHII MUSCLE
▪ 💡Primary extensor of the forearm at the elbow joint; 💡accessory adductor and extensor of the arm at the glenohumeral joint
▪ Its vertical course between teres minor and teres major, together with these muscles and the humerus, forms spaces through which nerves and vessels pass between regions.
- GATEWAYS TO THE POSTERIOR SCAPULAR REGION
o Suprascapular foramen
o Quadrangular Space
o Triangular Space
o Triangular Interval
Route through which structures pass 💡between the base of the neck and the 💡posterior scapular region.
SUPRASCAPULAR FORAMEN
SUPRASCAPULAR FORAMEN IS FORMED BY THE:
o 💡Suprascapular notch of the scapula
o 💡Superior transverse scapular (suprascapular) ligament which converts the notch into a foramen
INNERVATION SUPRASCAPULAR FORAMEN
▪ 💡Suprascapular nerve- passes through it
▪ 💡Suprascapular artery /suprascapular vein - pass immediately superior to the superior transverse scapular ligament
Provides a passageway for nerves and vessels passing between the 💡axilla and the 💡posterior scapular region
QUADRANGULAR SPACE
QUADRANGULAR SPACE boundaries are formed by:
o Inferior margin of teresminor
o Surgical neck of the humerus
o Superior margin of teres major
o Lateral margin of the long head of triceps brachii
Pass through QUADRANGULAR SPACE
o 💡Axillary nerve
o 💡Posterior circumflex humeral artery and vein
o 💡Hypertrophy of the quadrangular space muscles or fibrosis of the muscle edges may impinge on the axillary nerve.
o Uncommonly, this produces 💡weakness of the deltoid muscle
o Typically, it produces 💡atrophy of the teres minor muscle, which may 💡affect the control that the rotator cuff muscles exert upon shoulder movement.
Quadrangular space syndrome
▪ It is an area of communication between the 💡axilla and the 💡posterior scapular region
▪ The 💡circumflex scapular artery and vein pass through this gap
TRIANGULAR SPACE
TRIANGULAR INTERVAL is formed by the:
o Lateral margin of the long head of triceps brachii
o Shaft of the humerus;
o Inferior margin of teres major
The structures pass through TRIANGULAR INTERVAL
o Radial Nerve
o Profunda brachii artery and veins
Gateway to the upper limb, providing an 💡area of transition between the 💡neck and the 💡arm
▪ Irregularly shaped pyramidal space with:
o inletorapex
o floor(base)-skin of the arm pit
o four sides
AXILLA
Oriented in the horizontal plane and is somewhat triangular, with its apex directed laterally.
▪ Margins:
o Medial margin - lateralborderofribI
o Anterior margin - posterior surface of the clavicle
o Posterior margin - superior border of the scapula
Major vessels and nerves pass between the neck and the axilla by crossing over the lateral border of rib I and through the axillary inlet.
AXILLARY INLET
▪ Formed by fascia and a dome of skin that spans the distance between the inferior margins of the wall.
▪ Supported by 💡clavipectoral fasci
FLOOR OF AXILLA
FLOOR OF AXILLA ANTERIOR WALL
▪ Formed by the:
o Pectoralis major muscle
o Pectoralis minor muscle
o Subclavius muscle
FLOOR OF AXILLA MEDIAL WALL
Consists of the:
▪ Upper thoracic wall (the ribs [4,5] and related
intercostal tissues)
▪ Serratus anterior muscle
Narrow and formed entirely by the intertubercular sulcus of the humerus
FLOOR OF AXILLA LATERAL WALL
FLOOR OF AXILLA LATERAL WALL
Muscle attachment:
▪ Pectoralis major - lateral lip
▪ Teres major - medial lip
▪ Latissimus dorsi - floor of the intertubercular
sulcus
Complex; bone framework is formed by the
costal surface of scapula
Gaps between the muscles of the posterior wall form apertures through which structures pass between the axilla, posterior scapular region and posterior compartment of the arm
FLOOR OF AXILLA POSTERIOR WALL
MUSCLES OF THE ANTERIOR WALL OF AXILLA
PECTORALIS MAJOR
SUBCLAVIUS
PECTORALIS MINOR
▪ Largest and most superficial muscle of the anterior wall.
▪ Inferior margin forms the 💡anterior axillary fold, which marks the anteroinferior border of the axilla
PECTORALIS MAJOR
ORIGIN OF PECTORALIS MAJOR MUSCLE
The muscle has two heads:
▪ 💡Clavicular head - anterior surface medial half of the 💡clavicle
▪ 💡Sternocostal head - medial part of the anterior 💡thoracic wall (first seven costal cartilages; 💡sternal and of sixth rib; aponeurosis of external oblique)
INSERTION OF PECTORALIS MAJOR MUSCLE
▪ lateral lip of the 💡intertubercular sulcus of the humerus
ACTIONS OF PECTORALIS MAJOR MUSCLE
▪ 💡Flex, 💡adduct and 💡medially rotate the arm at
the glenohumeral joint
▪ Clavicular head 💡flexes the arm from an
extended position
▪ Sternocostal head 💡extends the arm from a
flexed position, particularly against resistance
INNERVATION OF PECTORALIS MAJOR MUSCLE
▪ Lateral and medial pectoral nerves
o 💡Clavicular head (C5,C6)
o 💡Sternocostal head (C6,C7,C8,T1)
▪ Arterial supply: pectoral branches of the 💡thoracoacromial artey; perforating branches of the internal thoracic artery; superior and lateral thoracic arteries
A small muscle that 💡lies deep to the pectoralis major muscle and passes between the 💡clavicle and 💡rib I.
SUBCLAVIUS
ORIGIN SUBCLAVIUS MUSCLE
▪ as a tendon, from 💡rib I at the junction between the rib and its costal cartilage
INSERTION SUBCLAVIUS MUSCLE
▪ An elongate 💡shallow groove on the inferior surface of the middle third of the clavicle
ACTION SUBCLAVIUS MUSCLE
▪ Pull the shoulder down by 💡depressing the clavicle
▪ 💡Stabilize the sternoclavicular joint by pulling the clavicle medially
INNERVATION SUBCLAVIUS MUSCLE
▪ 💡Subclavian nerve (C5, C6) from the superior trunk of the brachial plexus
▪ Arterial supply: 💡clavicular branch of the thoracoacromial artery; 💡suprascapular artery
A small triangular-shaped muscle that lies deep to the pectoralis major muscle and passes from the thoracic wall to the coracoid process of the scapula.
▪ Used as a 💡landmark for dividing the axillary artery into 3 parts:
o 1stpart-medial to pectoralis minor
o 2ndpart-lies behind pectoralis minor
o 3rdpart-lateral to pectoralis minor
PECTORALIS MINOR
ORIGINS OF PECTORALIS MINOR
▪ 3 muscular slips from the anterior surfaces
and upper margins of 💡ribs 3 to 5
▪ Deep fascia overlying muscles of the related
intercostal spaces
INSERTION OF PECTORALIS MINOR
▪ Medial and upper aspects of the 💡coracoid
process
ACTION OF PECTORALIS MINOR
▪ 💡Stabilizes the scapula by pulling the scapula
inferiorly and anteriorly against the thoracic
wall
▪ 💡Depresses the lateral angle of the scapula
INNERVATION OF PECTORALIS MINOR
▪💡 Medial pectoral nerve (C5, C6, C7, C8, T1)
▪ Arterial supply: pectoral and deltoid branches of the 💡thoracoacromial artery; superior and lateral 💡thoracic arteries
▪ A thick sheet of 💡connective tissue that connects the clavicle to the floor of the axilla
▪ 💡Encloses the subclavius and pectoralis minor muscles and spans the gap between them
CLAVIPECTORAL FASCIA
Important structures that pass between the subclavius and pectoralis minor muscle:
o Cephalic vein
o Thoraco-acromialartery
o Lateral pectoral nerve
MUSCLES OF THE MEDIAL WALL OF AXILLA
SERRATUS ANTERIOR
ORIGIN OF SERRATUS ANTERIOR
▪ Muscular slips from the lateral surfaces of
💡ribs I to IX.
▪ Intervening deep fascia overlying the related
intercostals
INSERTION OF SERRATUS ANTERIOR
Coastal surface of the medial border of the 💡scapula
INNERVATION OF SERRATUS ANTERIOR
▪ long 💡thoracic nerve, that passes through the axilla along the medial wall, and passes vertically down the serratus anterior muscle on its external surface, just deep to skin and superficial fascia [C5, C6, C7]
ACTION OF SERRATUS ANTERIOR
▪ 💡Protracts the scapula forward over the thoracic wall
▪ Facilitates 💡scapular rotation
▪ Keeps the costal surface of the scapula closely opposed to the thoracic wall
In the clinic: SERRATUS ANTERIOR
Injury to nerve > loss of function of SA > medial border & inferior angle of the scapula elevate away from thoracic wall
SIGN: OF SERRATUS ANTERIOR INJURY
💡‘WINGING’ of scapula, on pushing forward with the arm.
TREATMENT: SERRATUS ANTERIOR INURY
💡Pectoralis major transfer
o The pectoralis major is transferred around the chest to the lower part of the scapula, so it can substitute for the serratus anterior
▪ Result of Treatment
o Pectoralis major transfer generally improves both patient function and pain
MUSCLES OF THE SHOULDER
o Subscapularis muscle
o Distal parts of the latissimus dorsi and teres major muscles
o Proximal part of the long head of the triceps brachii muscle
It is a muscle of the shoulder that forms the 💡largest component of the posterior wall of the axilla
SUBSCAPULARIS
ORIGIN OF SUBSCAPULARIS
💡Subscapular fossa
INSERTION OF SUBSCAPULARIS
▪ 💡Lesser tubercle of the humerus
▪ The tendon crosses immediately anterior to the joint capsule of the glenohumeral joint
These are muscles that 💡stabilize the glenohumeral joint
Rotator cuff muscles
Rotator cuff muscles
▪ Supraspinatus
▪ Infraspinatus
▪ Teres minor
▪ SUBSCAPULARIS
INNERVATION OF SUBSCAPULARIS
💡Superior and 💡inferior subscapular nerve
ACTION OF SUBSCAPULARIS
▪ Rotator cuff muscle; 💡medial rotation of the arm at the glenohumeral joint
▪ Forms the inferolateral aspect of the posterior wall of the axilla.
▪ These two structures lie under the posterior axillary fold, which marks the posteroinferior border of the axilla.
TERES MAJOR AND LATISSIMUS DORSI
▪ The flat tendon of the latissimus dorsi muscle curves around the inferior margin of the teres major muscle on the posterior wall.
LATISSIMUS DORSI
ORIGIN OF LATISSIMUS DORSI
▪ 💡Spinous processes of lower six thoracic vertebrae and related inter-spinous ligaments
▪ Via the thoracolumbar fascia to the spinous processes of the lumbar vertebrae, related interspinous ligaments, and iliac crest
▪ Lower 3-4 ribs.
INSERTION OF LATISSIMUS DORSI
▪ Floor of the 💡intertubercular sulcus of the humerus
ACTION OF LATISSIMUS DORSI
▪ 💡Adduction, 💡medial rotation and 💡extension of the arm at the glenohumeral joint.
▪ The 💡axillary artery becomes the brachial artery of the arm as it crosses the inferior margin of the teres major muscle.
CONTENTS OF THE AXILLA
- Axillary artery and vein
- The infraclavicular part of the brachial plexus
- Intercostobrachial nerve and some lateral branches of some intercostal nerve
- The axillary group of lymph nodes and vessels
