Session 1 - Pectoral Region Flashcards
Name the four sections of the pectoral region we need to know
- Pectoralis Major
- Pectoralis Minor
- Serratus anterior
- Subclavius Muscles
What is the name of the muscle in the image?
Pectoralis Major
Name A and and give the bone it attaches to
Clavicular head
Attaches to the clavicle (predictably)
Name B and give the bones it attaches to
Sternocostal head
Attaches to the sternum and ribs
What do fibres from both A and B attach to?
The intertubecular groove of the humerus
Describe how the two heads A and B can work and what bone they mediate the movement of?
Give a mechanism specific to A
1) Two heads can work independently and synergistically.
Together they act to adduct (draw towards the mid-line) and medially rotate (rotate towards the center) the humerus at the shoulder
Draws scapula anteriorly and inferiorly
2) The clavicular head also performs flexion (decrease in joint angle)
What is the muscle in the picture innervated by?
The medial and lateral pectoral nerves, derives from the brachial plexus (network of nerve fibres).
C5-C8 and T1
What is the name of muscle A in the image?
Pectoralis Minor
Where does the muscle lie?
Posterior to the pectoralis major
What do the pectoralis major and pectoralis minor together form?
The anterior wall (front) of the axilla
Where does muscle A originate from?
The anterior surfaces of ribs 3-5
Name B, where muscle A attaches
The corocoid process of the scapula
What lies under muscle A?
Vessels passing into the upper limb
What is the main action of muscle A?
Stabilises scapula by drawing it inferiorly and anteriorly against the thoracic wall
What is muscle A innervated by?
The medial pectoral nerve
What is muscle A?
The serratus anterior
Where is muscle A found and what does it form?
Laterally in the chest and forms the medial wall of the axilla
What does the muscle A attach to?
The costal (rib facing) surface of the medial border of the scapula and originates from 1st - 8th rib
What is the main innervation of muscle A?
Long thoracic nerve (C5, C6, C7)
What is the main action of muscle A?
To rotate the scapula, allowing the arm to be raised over 90 degrees.
Holds scapula against ribcage, useful when upper limb reaches anterioly
Name muscle A
Subclavius muscle
What is the attachment of muscle A?
Junction of 1st rib and costal cartilage
Attached to clavicle
What is the main innervation of A?
Nerve to subclavius (C5, C6)
What is the main action of muscle A?
Anchors and depresses clavicle
