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