lecture 2 pg 34-44 Flashcards
which muscles cover the upper part of the anterior thoracic regions and spread posteriorly to cover most of the posterior thoracic region? (these muscles are divided into three distinct groups.)
Shoulder muscles
the three distinct divisions of the shoulder muscles?
- originate from the vertebral column or skull and insert on the shoulder girdle or humerus
- originate on the thoracic wall and insert on the shoulder girdle of humerus
- originate on the scapula and insert on the humerus
the five muscles that originate on the vertebral column?
- Trapezius
- Rhomboid Major
- Rhomboid Minor
- Levator Scapula
- Latissimus Dorsi
what is the large muscle that covers the posterior cervical and thoracic region. its named because the right and left muscles form a four sided figure known as a trapezoid?
Trapezius
which muscle has the origin of the external occipital protuberance, the superior nuchal line, ligamentous nuchae, and (C7-T12) spines of the thoracic vertebrae?
Trapezius
what is the origin of the Trapezius?
external occipital protuberance
superior nuchal line
ligamentous nuchae
(C7-T12) spines of the thoracic vertebrae
what is the insertion of the trapezius?
Clavicle
Acromion process and spine of the scapula
what is the muscle with the insertion at the clavicle and the acromion process and spine of the scapula?
trapezius
what are the three actions of the trapezius?
- stabilizes the scapula (holds in anatomical position)
- upper portion; elevates the scapula
- middle and lower portions: adducts the scapula
what is the motor innervation of the Trapezius?
the spinal accesory nerve
cranial XI
what is the sensory nerve innervation for the trapezius?
C4 and C5
what is trapezius palsy?
weakness of the muscle
- A deepening of the shoulder on the affected side.
- Shoulder drops on the affected side
which part of the trapezius is commonly involved in whiplash injuries?
the superior portion
describe the clinical examination to test for the XI Cranial nerve?
have patient elevate their shoulders against resistance. both sides should be tested at the same time, so weakness of one side can be evaluated relative to the other side.
what is the thin, flat muscle that is rhomboid in shape and lies deep to the trapezius?
Rhomboid Major
what is the origin of the Rhomboid Major?
(T2-T5) spines of the upper thoracic vertebrae
what is the insertion point of the rhomboid Major?
vertebral border of the scapula
what is the muscle that lies superior and parallel to the rhomboid major, with which it is sometimes fused?
Rhomboid minor
what is the origin of the rhomboid minor?
(C7,T1) spines of lower cervical and first thoracic vertebrae
what is the muscle found on the side of the neck, deep to the superior portion of the Trapezius?
Levator Scapula
what is the origin of the Levator Scapula?
(C1-C4) transverse process of the upper cervicals
what is the insertion of the Rhomboid Minor?
Vertebral border of the scapula
what is the insertion of the Levator scapula?
Superior Angle of the scapula
what are the three actions of the Levator Scapula?
- Elevates the scapula
- adducts the scapula
- stabilizes the scapula
what is the nerve innervation to the levator scapula?
Dorsal Scapular Nerve
C5
what will happen to the levator scapula when there is damage to the nerve?
- muscle atrophy
- difficulty in completely adducting the scapula
- scapula on affected side will be farther from the midline
what is the large, flat muscle that is found over the lower posterior thoracic and lumbar region?
Latissimus Dorsi
widest muscle of the back
its tendon along with the teres major helps to form the posterior fold of the axilla
what are the origin points of the latissimus dorsi?
spines of the lower thoracic and lumbar vertebrae
thoracodorsal fascia
crest of the ilium
lower ribs
what is the insertion of the latissimus dorsi?
intertubercular groove (lesser tubercle) of the humerus
what are the 2 actions of the latissimus dorsi?
extends, adducts and medially rotates the humerus
involved with forced expiration
what is the nerve innervation of the latissimus dorsi?
thoracodorsal nerve (C6, C7, and C8)
what happens when there is weakness or damage to the latissimuss dorsi?
it results in forward displacement of the shoulder
what is the lumbar triangle?
a depression found at the lower portin of the latissimus dorsi.
what are the borders of the lumbar triangle?
latissimuss dorsi
crest of the ilium
external oblique muscle
what is the clinical significance of the lumbar triangle?
hernias of the posterior abdominal wall may develop here
what is the triangle of auscultation?
a depression found at the superior border of the latissimuss dorsi
what are the borders of the triangle of auscultation?
latissimus dorsi
trapezius
vertebral border of the scapula
what is the clinical significance of the triangle of auscultation?
the relatively thin layer of tissue here allows the lungs sounds to be more easily heard with a stethoscope. The triangle can be enlarged by abducting the scapula (folding the arms across the chest).
what is the broad, muscular sheet which passes posteriorly around the thoracic cage from an extensive costal attachment to a more limited attachment on the scapula?
Serratus Anterior
the anterior portion lies immediately beneath the skin
what is the origin of the serratus anterior?
upper ribs
what is the insertion point of the serratus anterior?
vertebral border of the scapula
what are the 3 actions of the serratus anterior?
- abducts the scapula (prime mover)
- stabilizes the scapula
- involved with forced inspiration but only when the humerus is abducted
what is the nerve innervation of the serratus anterior?
Long Thoracic
C5, C6, and C7
explain long thoracic nerve palsy
the condition where the serratus anterior muscle is weakened due to damage to the long thoracic nerve or its segmental innervation. will cause winged scapula when the patient pushes against a wall.
three potential causes of long thoracic nerve palsy?
- trauma or subluxation
- traction injuries involving the shoulder joint
- recumbency for a long period of time
what are the muscles of the rotator cuff?
supraspinatus
infraspinatus
subscapularis
teres minor
what is the criteria to be classified as a rotator cuff muscle?
- tendon of insertion must contribute to forming a cuff around the proximal part of the humerus
- they participate in either lateral or medial rotation of the humerus.
what is the large, complex muscle that forms the roundness of the shoulder and is divided into three portions, each with a different origin and action?
Deltoid
what are the origins of the three portions of the deltoid?
clavicle (anterior portion)
acromion process (middle portion)
spine of scapula (posterior portion)
what is the insertion of the deltoid muscle?
deltoid tuberosity of the humerus
what is the action of the anterior portion of the deltoid muscle?
flexes and medially rotates the humerus
what is the action of the middle portion of the deltoid muscle?
abducts the humerus
what is the action of the posterior portion of the deltoid?
extends and laterally rotates the humerus
what is the nerve innervation of the deltoid?
axillary nerve
C5 and C6
atrophy of the deltoid (crutch paralysis) is injury to the axillary nerve, which can have what 3 causes?
- fracture of the surgical neck of the humerus (injury to nerve may be immediate or occur during healing)
- dislocation of the shoulder joint
- pressures of the crutch in the axilla
atrophy of the deltoid muscle will give the shoulder a _________ appearance.
flattened
the deltoid muscle is the most common site for?
intramuscular injections
when atrophy of the deltoid occurs due to axillary nerve damage there will be loss of sensation where?
the lateral aspect of the arm (due to the lateral brachial cutaneous branch of the axillary nerve being compromised)
abduction of the arm will be greatly impaired when there is damage to what?
the axillary nerve
the muscle that occupies the supraspinous fossa andf is deep to the trapezius?
supraspinatus
the muscle whose tendon passes under the acromion process and over the top of the shoulder to insert on the humerus?
supraspinatus
the tendon of the supraspinatus is separated from the acromion process (as it passes underneath) by what two structures?
subacromial bursae
subdeltoid bursae
the muscle that originates at the supraspinous fossa and inserts at the greater tuberosity of the humerus?
supraspinatus
what are the three actions of the supraspinatus?
- initiates abduction of the humerus
- laterally rotates the humerus
- stabilizes the shoulder joint
what is the nerve supply to the supraspinatus?
suprascapular nerve
C5 and C6
when there is an irritation and inflammation of the supraspinatus tendon and on of the most common causes of shoulder pain?
Rotator Cuff Tendinitis
also known as shoulder impingement syndrome
a twinge in the shoulder that progresses to a sharp or aching pain that usually occurs in the anterior or lateral aspect of the shoulder, combined with a possible hot or burning feeling are generally signs of?
Rotator Cuff Tendinitis
shoulder movements may appear weaker and inability to sleep on affected side
being born with a hooked acromion process can be a genetic cause of?
Rotator Cuff Tendinitis
Rotator Cuff tendinitis can be caused by weakness around the rotator cuff which will cause?
this causes the humerus to ride up and compress the tendons of the cuff
the most common cause of rotator cuff tendinitis in athletes is?
excess stress and repetition
what are the five common causes of rotator cuff tendinitis?
genetic weakness around the rotator cuff excess stress and repetition trauma/injury calcium deposits (in tendon, most common in elderly)
when the tendon is weakened by a combination of multifactorial conditions (age, repeated episodes of trauma, steroid injections)it may result in?
rotator cuff tears
when the rotator cuff tears it usually ruptures at or near the _________ and the tear may be partial or complete
Insertion
complete rotator cuff tears in younger individuals are almost always from?
a single traumatic injury
(shoulder dislocation)
over the age of 50, tears can occur with only minor trauma
what test is used to evaluate a patient that one suspects pf having a rotator cuff tear?
Drop test
the test where the patient is asked to lower the fully abducted limb slowly, the limb will drop suddenly to the patient’s side in an uncontrolled manner?
Drop test
when the shoulder pain is caused by inflammation of the bursae between the tendon and the acromion process it is known as?
bursitis
affects either the subdeltoid or subacromial bursae
bursitis of the shoulder might be more common than rotator cuff _______.
tendinitis
may be hard to distinguish
the muscle that occupies the infraspinous fossa of the scapula and is deep to the skin. it is often fused with the teres minor muscle.
Infraspinatus
the muscle that originates at the infraspinous fossa and inserts at the greater tuberosity of the humerus?
infraspinatus
what are the two actions of the infraspinatus?
- laterally rotates the humerus
2. stabilizes the shoulder joint
what is the nerve supply of the infraspinatus?
suprascapular
C5 and C6
the muscle occupies the ventral surface (subscapular fossa) of the scapula?
Subscapularis
what is the muscle that originates at the subscapular fossa of the scapula and inserts at the lesser tuberosity of the humerus?
Subscapularis
what are the 2 actions of the subscapularis?
- medially rotates the humerus
2. stabilizes the shoulder joint
what is the nerve supply of the subscapularis?
upper and lower subscapular
C5 and C6
the narrow muscles that is found parallel to the axillary border of the scapula, between the infraspinatus (with which it sometimes fuses) and the teres major?
teres minor
the muscle that originates at the axillary border of the scapula and inserts at the greater tuberosity of the humerus?
teres minor
the two actions of the teres minor?
- laterally rotates the humerus
2. stabilizes the shoulder joint
what is the nerve supply of the teres minor?
axillary nerve
C5 and C6
the well developed muscles which along with the latissimus dorsi helps form the posterior wall (fold) of the axilla?
Teres Major
the muscle that originates at the inferior angle of the scapula and inserts at the medial lip of the intertubercular groove of the humerus?
teres major
what are the two actions of the teres major?
- adducts and medially rotates the humerus
2. stabilizes the shoulder joint
what is the nerve supply of the teres major?
lower subscapular
C6
the space between the teres major and the teres minor is divided by the long head of the triceps brachii into what two sections?
Quadrilateral Space (the more lateral) Triangular Space (the more media)
The axillary nerve and humeral circumflex blood vessels (Artery and Vein) are found in which Space?
the more lateral (Quadrilateral space)
the circumflex scapular branch of the subscapular artery can be found in which space?
the more medial (triangular space)
the joint by which the upper limb articulates with the axial skeleton. it is the most stable joint of the upper extremity?
the Sternoclavicular Joint
The three articulations of the Sternoclavicular joint?
sternal end of the clavicle
clavicular notch and costal notches of the sternum
medial end of the first rib
the poorly adapted articulating surfaces of the sternoclavicular joint is overcome by a piece of cartilage known as? which is found in the middle of the joint cavity
articular disc
the disc divides the joint into two separate cavities and functions
the two functions of the sternoclavicular joint?
- prevents the clavicle from being displaced at its articulation with the sternum
- acts as a shock absorber of forces being transmitted along the clavicle
what is the joint classification of the sternoclavicular joint?
plane gliding (but does act like a ball and socket to some degree)
true or false
the capsular ligament of the sternoclavicular joint is very strong and completely surround the joint.
true
the ligaments that are found superficial to the capsular ligaments are classified as?
extrinsic or extracapsular
the ligaments that are found deep to the capsular ligament are known as?
intrinsic or intracapsular
ligaments prevent movement by acting either as a _____ or as a _____.
rope or as a wall
which extrinsic ligaments that acts like a wall and reinforces the capsular ligament, while preventing excessive forward and backward movement?
anterior and posterior sternoclavicular ligaments
which extrinsic ligament that acts like a rope, attaches to the sternal ends of both clavicles and functions to prevent displacement of the clavicle when one is carrying a heavy object?
interclavicular
which strong extrinsic ligament that acts like a rope, and attaches to the costal impression of the clavicle and the first rib, while reinforcing the capsular ligament and limits elevation at the medial end of the clavicle? (as when one hangs by their limbs)
Costoclavicular
what is the nerve supply to the sternoclavicular joint?
supraclavicular and the nerve to the subclavius
although the sternoclavicular joint is very strong and stable it is mobile enough to allow _________ movement and occurs when the scapula moves.
passive
the sternoclavicular joint is rarely dislocated due to?
- strength of the ligaments
- the articular disc
- how forces are transmitted along the clavicle
when dislocations do occur to the sternoclavicular joint it is usually the result of direct trauma to the?
anterior aspect of the sternal end
grade 1 to grade 3
dislocations to the sternoclavicular joint may be life threatening due to damage or compression of the________ or _______ vessels in the neck.
trachea and blood vessels
