Flashcards in Pectoral Region_MSB Deck (76):
What is the pectoral region?
-Region external to the anterior thoracic wall
What does the pectoral region do?
Anchors Upper limb to trunk
What do the pectoral region consist of?
- Pectoral Muscles (movements of pectoral girdle and upper limb)
- Superficial Compartment (skin, superficial fascia, breast)
- Deep Compartment (muscles & associated neuromuscular structure)
What does the pectorals major muscle look like?
Large, fan shaped superficial muscle covering superior thorax
What are the two heads of the pectorals major muscle?
1) Clavicular head
2) Sternocostal head
Where does the clavicular head originate from?
Originates from medial 1/2 clavicle
What does the sternocostal head look like
large and the lateral border is at the anterior wall axilla
Where does the sternocostal head originate from?
Originates from medial parts of anterior thoracic wall
Where does the pectoralis major muscle insert into?
Lateral lip of the intertubercular sulcus /groove
What does the pectoralis major muscle do?
Helps for powerful adduction, flexion, medial rotation of the arm
What is the ORIGIN of the pectoralis major muscle?
- Median half of clavicle
- Sternum (anterior surface)
- Upper 7 Costal Cartilage
- External oblique aponeurosis
What is the INSERTION of the pectoralis major muscle?
- Lateral lip of intertubercular groove (bicipital groove(
- Muscle fibres with more superior origin, insert lower and more anteriorly on lateral lip than those of inferior origin
What is the INNERVATION of the pectoralis major muscle?
Medial and Lateral Pectoral Nerve
What is the ACTION of the pectoralis major muscle?
Adduction, Medial Rotation and Flexion of arm at the shoulder joint
How do you test the clavicular head of the pectoralis major muscle?
Abduct arm 90 degrees
Try to move arm anteriorly against resistance
The clavicular head can be seen and palpated
How do you test the sternoclavicular head of the pectoralis major muscle?
Abduct arm 60 degrees
Try to adduct arm against resistance
If acting normally, the sternocostal head can be seen and palpated
What is the ORIGIN of the pectoralis minor muscle?
Surfaces of ribs 3,4,5
What is the INSERTION of the pectoralis minor muscle?
Coracoid process of the scapula
What is the INNERVATION of the pectoralis minor muscle?
Medial Pectoral Nerve
What is the ACTION of the pectoralis minor muscle?
- Draws Scapula forward and down
- Assists in raising ribs during inspiration
What is the ORIGIN of the Serratus Anterior muscle?
External lateral surfaces of ribs 1- 8 or 1- 9
What is the INSERTION of the Serratus Anterior muscle?
Anterior surface of the medial border of the scapula
What is the INNERVATION of the Serratus Anterior muscle?
Long Thoracic Nerve
What is the ACTION of the Serratus Anterior muscle?
- Protracts and fixes scapula against the thoracic wall
- Assists in lateral rotation of the scapula
What is the ORIGIN of the Subclavius muscle?
Junction of 1st rib and its costal cartilage
What is the INSERTION of the Subclavius muscle?
Subclavian groove of clavicle
What is the INNERVATION of the Subclavius muscle?
Nerve to subclavius
What is the ACTION of the Subclavius muscle?
- Draws clavicle down and forward
- Stabilises the sternoclavicular joint
Where is the pectoral fascia?
Covers (Invests) pectoralis major
Continuous with anterior abdominal wall fascia inferiorly
Becomes axillary fascia laterally
Where is the clavipectoral fascia?
Deep to pectoralis major
Where does the calvipectoral fascia extends from?
From the clavicle
What does the clavipectoral fascia do?
Enclose subclavius and pectoralis minor
What is the clavipectoral fascia inferior to?
Pectoralis minor continues as the suspensory ligament of the axilla
What is the clavipectoral fascia pierced by?
What is a joint?
Site of articulation between bones
What is the synovial joints for?
Motion and Flexibility
What is the synovial joints separated by?
What are the characteristic features of the synovial joint?
- Cartilage covering articulating surfaces (Articular Hyaline cartilage)
- Joint capsule
What does the joint capsule contain?
1) Synovial membrane
2) Fibrous membrane
3) Articular Disks, Fat Pads, Tendons
What does the synovial membrane produce?
Produce synovial fluid
Where does the synovial membrane attach to?
Attaches at margin of joint surfaces between cartilage and bone
What does the synovial membrane contain?
Synovial bursae / tendon sheaths
What does the fibrous membrane do?
Surrounds and stabilises joint
Parts of the fibrous membrane may thicken to form ligaments
What do ligaments do?
Attach bone to bone
What do tendons do?
Attach muscle to bone
What are synovial joints described by?
Shape and movement
What does the synovial joints shapes include?
Hinge (e.g. elbow)
Ball and socket (e.g. shoulder)
What are the movements that the synovial joints are described by?
Uniaxial - movement in one plane
Biaxial - movement in two planes
Multiaxial - movement in three planes
What is the articulation of clavicle with axial skeleton called?
What is the articulation of clavicle and scapula with each other called?
What gives the upper limb its freedom of movements?
Movements at the Sternoclavicular, Acromioclavicular, and Shoulder (Glenohumeral) Joints
At the Sternoclavicular Joint, what are the articulating surfaces? 
2) Manubrium of sternum
3) Cartilage of 1st rib
Which type of joint is the Sternoclavicular joint?
Saddle type of synovial joint
What is the movement of the Sternoclavicular joint?
What does the sternoclavicular joint contain?
Name the ligaments that are in the sternoclavicular joint? 
1) Articular capsule
2) Anterior Sternoclavicular ligament
3) Posterior Sternoclavicular LIgament
4) Interclavicular Ligament
5) Costoclavicular Ligament
6) Articular Disk
Where is the Anterior Sternoclavicular ligament located?
Clavicle to anterior surface of manubrium
Where is the Posterior Sternoclavicular ligament located?
Between posterior surfaces of clavicle and manubrium
What does the Interclavicular Ligament do? 
Joins the superior surface of 2 clavicles across sternal notch
Limits depression of shoulder
Where is the Costoclavicular Ligament located?
From 1st costal cartilage to inferior surface of clavicle
What does the costoclavicular ligament do?
Limits elevation of shoulder
Where is the Articular Disk found?
Between sternum and clavicle
What does the Articular Disk do?
Limits depression of shoulder
What is the blood supply for the Sternoclavicular Joint?
Internal thoracic and Suprascapular Arteries
What is the innervation for the Sternoclavicular Joint?
Branches from nerve to Subclavius
What are the movements allowed because of the Sternoclavicular Joint as it is a very stable joint?
Elevation and Depression (Shrugging shoulders) of shoulders on the parasagittal axis
Protraction and Retraction (reaching for an object) of shoulders on the longitudinal axis
Which is more common: Clavicle fractures or SC joint dislocation?
What are the articulating surfaces of the Acromioclavicular Joint?
Acromion of the Scapula
What type of joint is the Acromioclavicular joint?
Planet type of synovial joint
What are the movements allowed because of the Acromioclavicular joint?
Allow scapula to move on the lateral end clavicle by rotating on 2 axes
What does the Acromioclavicular Joint have?
Name the ligaments that are part of the Acromioclavicular Joint. 
1) Articular capsule
2) Articular Disk
3) Superior Acromioclavicular Ligament
4) Inferior Acromioclavicular Ligament
Name the ligaments that are not part of the Acomioclavicular Joint.
1) Conoid Ligament
2) Trapezoid Ligament
3) Coracoclavicular Ligament - Keeps clavicle against acromion
What are the blood supply of the Acromioclavicular Joint.
Supraclavicular and thoracoacromial arteries
What are the innervation of the Acromioclavicular Joint
Branches from the lateral pectoral and axillary nerves