Week 7 - pectoral girdle Flashcards
3 parts of the trapezius muscle
Descending (superior)
Transverse
Ascending (inferior)
What does the descending part of the trapezius do
Retraction of the scapula
Elevation of the scapula
Movements of the transverse part of the trapezius
Retraction of the scapula
Elevation of the scapula
Movements of the ascending part of the trapzius
Retraction of the scapula
Depression of the shoulder
Levator scapulae
Connects the scapula with the spine
Deeper than the trapezius
Helps elevate the scapula
The Rhomboids (rhomboid minor and rhomboid major)
Connect the scapula with the spine from the medial border of the scapula
If the rhomboids major and minor contract together, what movement happens
Retraction of the scapula
Role of the subclavius
Stabilises the pectoral girdle during the movements of the glenohumeral joint
Actions of the pectoralis minor
Protraction of scapula and depression of shoulder
Actions of the pectoralis major
Shoulder depression
Actions of the serratus anterior
Protraction of the scapula
Similarities and differences between the pelvic and pectoral girdle
The bones involved articulate with each other
There is a gap in the pectoral girdle not found in the pelvic girdle
Bones in the pectoral girdle
Clavicle
Scapula
Sternum
Where is the gap located in the pectoral girdle and what does it do
Between the two scapula
Gives great mobility
What provides the closing of the girdle
The rhomboids
Pectoral girdle joints
3 true joints
2 other joints
Sternoclavicular joint (SCJ)
Acromioclavicular joint (ACJ)
Glenohumeral joint (GJ)
2 other:
scapulothoracic articulation
subacromial articulation
Sternoclavicular joint
Made of the articular surface of the manubrium of the sternum and the lateral surface clavicle articulates with the acromion of the scapula
Why is the shape of the clavicle important
The S shaped clavicle allows for 180 degrees of movement at shoulder
Articulation between the humerus and the scapula
Glenoid fossa
Where does the anterior aspect of the scapula articulate to
What does this provide
The thorax
Allows the scapuls to slide along the thorax - great mobility
Most prominent area of the scapula in the posterior view
What does it do
The spine of the scapula
Divides the posterior aspect of the scapula into the supraspinous and infraspinous fossae
Where is the suprascapular fossa
Large area on the anterior side of scapula
Where is the coracoid process
Superior aspect of scapula
Provides attatchment for ligaments and tendons
Features of the sternoclavicular joint
The articular disc - located on the sternum - where the clavicle connects to
Anterior sternoclavicular ligament - connects the sternum and clavicle
Interclavicular ligament - passes superiorly to the anterior sternoclavicular ligament
Posterior sternoclavicular ligament
Costoclavicular ligament - goes from cartilage of first rib to the clavicle
Features of the acromioclavicular joint
Disc - provides mobility
Acromioclavicular ligament - formed by cap of shoulder and collar bone - allows continuation of the clavicle
Trapezoid ligament - connects the coracoid process of the scapula to the trapezoid line
Conoid ligament
Glenohumeral joint
Labrum - provides stability for the humerus (surrounds the glenoid fossa)
Joint capsule - connects glenoid fossa to the ligaments
Tendon of the long head of the biceps brachii (stabilises humerus during elevation)
Transverse humeral ligament - overlying the tendon of biceps as it emerges from capsule of shoulder joint
Superior, medial, inferior glenohumeral ligament
Coracohumeral ligament - extracapsular
Conicoachronium ligament - reinforces the conico achronium arch. Acts as a roof for the movement of humerus
Several bursae - provides lubrication
Elevation and depression of the scapula
Elevation is the scapula gliding superiorly (shoulders up)
Depression is the scapula gliding inferiorly (shoulders down)
Protraction and retraction of the scapula
Protraction (or abduction) is when medial border of scapula moves away from spine
Retraction (or adduction) is the opposite (arms behind your back)
Upward and downward rotation of the scapula
Upward is abduction of the shoulder - inferior angle of scapula moves further away from midline
Downward is adduction of shoulder
Movements at the glenohumeral joint
Flexion
Extension
Lateral rotation
medial rotation
Abduction
Adduction
Circumduction
Scaption
Scpation is movements that keep the scapula in its resting position
How does the shoulder move 180 degrees
60 degree rotation of scapulothoracic joint
30 degree elevation of sternoclavicular joint
120 degree abduction of glenohumeral joint
Role and location of the intertubercular groove
On the humerus, separates the greater and lesser tubercle. It allows for the long tendon of the biceps brachii muscle to pass
Role and location of the deltoid tuberosity
Lies proximally about a third of the way to the elbow
Provides attachment for the deltoid
Muscles that create abduction
Middle deltoid and supraspinatus
Muscles that create adduction
Latissimus dorsi, teres major, coracobrachialis, pectoralis major
Muscles that create flexion at the shoulder
Anterior deltoid, pectoralis major, biceps brachii, coracobrachialis
Muscles that create extension at the shoulder
Posterior deltoid, LD, long head of triceps brachii
Muscles that create medial rotation at the shoulder
LD, subscapularis, pectoralis major, anterior deltoid
Muscles that create lateral rotation
Infraspinatus, teres major, posterior deltoid
Muscles that make up the rotator cuff
Supraspinatus, infraspinatus, teres minor, subscapularis
Insertion point of the rotator cuff muscles
The head of the humerus
