Pectoral region, deltoid and axilla Flashcards
What forms the anterior border of the axilla
pectoralis major
What forms the medial boundary of the axilla
serratus anterior and underlying ribs
What 3 muscles form the posterior border of the axilla
teres major, subscapularis, latissimus dorsi
What does the serratus anterior connect to
the ribs and scapula
Where does the teres major extend from and to
the scapula to the anterior part of the humerus
Where is the subscapularis attached
on the anterior part of the scapula to the anterior part of the humerus
Where does the lattisimus dorsi attach on to
the anterior part of the humerus
What shape do those boundaries create
a triangular shape
What runs through the triangular shape
axillary artery, axillary vein, long thoracic nerve, lymph nodes and fat
What does the axillary artery do in the axilla
from the root of the neck it diverges in the axilla, then enters the arm and provides several branches on the axilla
What bones are associated with the axilla
humerus, scapula and ribs
What is the shape of the deltoid muscle
a roughly triangle shape
Anteriorly where does the deltoid originate
superior aspect of the lateral 1/3 of the clavicle
Laterally, where does the deltoid originate from
the lateral and superior part of the acromion process if the scapula
Posteriorly where does the deltoid originate from
inferior edge of the spine of the scapula
What are the 3 sets of fibres of the deltoid
The anterior, clavicular fibers , the lateral acromial fibers and the posterior, spinal fibers
When the 3 sets of fibres from the deltoid come together what do they form
a tendon that inserts onto the deltoid tuberosity on the lateral aspect of the humerus
Where do the fibres of the deltoid run in relation to the glenohumeral joint
anteriorly and posteriorly around it allowing the deltoid to produce several movements around it
What can the anterior fibres of the deltoid do
draw the arms forward to flex the shoulder and can medially rotate the humerus
What do the posterior fibres of the deltoid do
fibers extend the shoulder and cause lateral rotation of the humerus
What other muscles do the posterior fibres of the deltoid act synergistically with
trapezius and teres major
What do the lateral fibres of the deltoid do
abductors of the shoulder
What are the lateral fibres of the deltoid assisted by
the supraspinatus of the rotator cuff
What does the deltoid receive its blood supply from
by the acromial and deltoid branches of the thoracoacromial artery and the anterior and posterior circumflex humeral arteries. Can recieve supply from subscapular artery and deltoid branch of the profundo brachii
Which nerve innervates the deltoid
axillary nerve
Where does pectoralis major arise from
the medial third of the clavicle, from the front of the sternum and the front of the first 6 costal cartilages
Where does the pectoralis major insert on to
the anterior edge of the bicipital groove
What is the function of pectoralis major
abductor of the humerus, when its adducting effect is held in check by other muscles it produces internal rotation
Where does lattissimus dorsi originate
under the tail end of trapezius, at T7, and goes all the way down to the sacrum and out onto the posterior iliac crest. It also has some fibers arising from the lower 4 ribs and sometimes from the lower scapula
Where does latissimus dorsi insert on to
bicipital groove - to do this it has to spiral around teres major
How does latissimus dorsi spiral round
it spiral from the back to the front with the lowest fibres of origin ending up highest
What is the function of the latissimus dorsi
abductor of humerus. Acting through humerus it is a powerful depressor of the scapula (can overcome whole weight of body).
How many muscles move the scapula in relation to the trunk
6 - 4 on back, 1 in front and 1 on the side
What is the muscle underneath that moves the scapula
serratus naterior
Where does the serratus anterior arise from
side and front of the first 8 ribs, it runs back under the scapula and is inserted on the medial border of the scapula
When the whole serratus anterior contracts
it pulls the scapula forward around the rib cage (protusion)
What happens when the scapula’s upper or lower fibres contract separately
It produces downward or upward rotation of the scapula and stabilizes the scapula against the thoracic wall
What are the 4 muscles on the back which move the scapula
trapezius, levator scapulae, rhomboid minor and rhomboid major
Where does levator scapulae arise from
the outer most point of the first 3 cervical vertebra and inserts on the upper medial corner of the scapula
What does the levator scapulae do
helps elevate the scapula
Where do the rhomboids arise from
the 4th cervical to the 5th thoracic vertebrae, and insert along the medial border of the scapula
What is the function of the rhomboids
to elevate and retract the scapula
Which muscles does the trapezius overlie?
levator scapulae, rhomboid minor and major
Where does the upper and lower part of the trapezius converge
on the spine of the scapula
Where does the upper part of the trapezius arise from
arises from the occiput, and from the nuchal ligament, and from T1-T3 in the mid-line.
Where does the upper part of the trapezius insert
inserted along the upper edge of the spine of the scapula, around the acromion and along the lateral third of the clavicle
Where does the lower part of the trapezius arise
from T4 to T12 in the mid-line
Where does the lower part of the trapezius insert
on the lower edge of the spine of the scapula
What happens when the whole of the trapezius contracts
it retracts the scapula
What happens when only the upper part of the trapezius contracts
it elevates the scapula
What is the muscle in front that moves the scapula
pectoralis minor
Where does pectoralis minor arise between
the 2nd and 4th ribs
Where does pectoralis minor insert
coracoid process
What is the function of pectoralis minor
It produces depression of the scapula. It stabilizes the scapula against the thoracic wall and is an accessary muscle of respiration.
Where does the subclavius go
from the first rib to the clavicle
Where does the omohyoid arise
from the hyoid bone and inserts in the upper edge of the spine of the scapula
What does the omohyoid bone do
depresses the hyoid bone and the larynx do
Where does the cephalic vein run
in the groove between pectoralis major and deltoid, coming up from the arm
Which vein does the cephalic vein join
the subclavian vein
Where does the subclavian vein travel
comes up from the arm and passes beneath pectoralis minor then over the outer surface of the first rib and under the subclavius muscle and the clavicle
Where does the internal jugular vein join the subclavian vein
the medial border of the first rib, it is joined from above
What forms the brachiocephalic vein
subclavian and internal jugular vein
Where is the brachiocephalic vein located
medial to the first rib and enters the chest
Where does the dome of the pleura lie
immediately behind the brachiocephalic vein
What forms the superior vena cava
right and left brachiocephalic
Name the arteries of the axilla
posterior circumflex humeral artery, anterior circumflex humeral artery, subscapular artery, superior thoracic artery, thoracocromial artery, lateral thoracic artery
What are the 6 different types of synovial joints
pivot, hinge, saddle, plane, condyloid, ball anc socket
What are the 3 joints of the shoulder
the acromioclavocular joint, sternocalvicular joint and glenohumeral joint
Name the ligaments by the sternoclavicular joint
interclavicular ligament, anterior sternoclavicular ligament, costoclavicular ligament
Name the ligaments by the acromioclavicular joint
Acromioclavicular ligament, coracoacromial ligament, coracoclavicular ligament, conoid ligament, trapezoid ligament
