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.