The Thoracic Wall & Scapula Wk5 Flashcards
What is the importance of the thorax?
– Housesthelungs
– Housestheheartandgreatvessels
– Its musculature acts as the bellows that inflate and deflate the lungs
– It is a site for passage of major viscera between the pharynx and abdomen
– It is the site for attachments of upper limbs to the axial skeleton
– It is an important site for clinical procedures
• Chest compressions
• Auscultation of heart sounds
• Percussion of the lungs
• Imaging of the heart and lungs
• Harvesting of bone marrow
What are prominent features of the anterior thoracic wall?
– The Clavicle
– Roundedness of Shoulders (Left & Right Comparison) – Pectoralis Muscles
– Manubro-sternal Joint
– Sternoclavicular Joint
– Nipples - use for determining where things are
– Sternum or Breast Bone
– Suprasternal Notch
– Decreasing width of the chest with fall in height
What are prominent features of the posterior view of the thoracic wall?
– The Scapulae
• Blades of scapulae
• InferiorAnglesofscapulae
– Undulations of the vertebral column
• Trajectory of central gutter is important
• Central gutter is indicative of locations of spinous processes of vertebrae
– Back Muscles
– Vertebra Prominens
– Roundedness of the Shoulders (Left & Right Comparisons)
– Decreasing width of the chest with fall in height
What are the boundaries of the thorax?
• Superior – Superior Thoracic Aperture • Inferior – Thoracic Diaphragm • Antero-Latero-Posterior – Ribs • Anterior – Manubrium, Sternum & Xiphoid Process • Posterior – Thoracic vertebrae • Scapulae (shoulder blades)
What is the superior aperture of the thorax?
• Also known as the thoracic inlet • It is the obliquely truncated apex of thorax • The suprasternal notch is located here • It is also known as the – Jugular Notch – or – Fossa jugularis sternalis • Itis: – A large, visible dip in between the neck and the two collarbones in human anatomy – Occurs at the superior border of the manubrium of the sternum, between the clavicular notches – A site of clinical importance
What are the margins of the aperture?
– Body of first thoracic vertebra (T1)
– 1st ribs and their cartilages
– Manubrium of the sternum
– Suprasternal Notch
Tissue layers of the thorax overview
• They are a continuous series of layers of tissues
• They span from the skin to the parenchyma of the lung
• They can be artificially divided into 2 categories
– Tissues that constitute the thoracic wall
– Tissue that fill the cavity of the thorax
What are the 10 layers of tissues (superficial to deep)?
– Skin – Superficial Fascia – Pectoral Fascia – Pectoralis Major – Clavipectoral Fascia – Pectoralis Minor – External Intercostal Muscle – Internal Intercostal Muscle & Ribs – Innermost Muscle – Endothoracic Fascia The muscular layers vary according to the region of the chest wall - some muscles cover only limited territories e.g. may include pectoralis major or not etc.
What are the fascial layers of the thoracic wall?
• There are 3 layers of Thoracic fascia to note
– They are all part of the deep fascia of the thorax
• The most superficial 2 layers are collectively known as
– Fascia Pectoralis
• The deepest layer of fascia is known as
– Endothoracic Fascia
What is the fascia pectoralis?
• It is separable into 2 layers
– Superficial Layer of Fascia Pectoralis
– Deep Layer of Fascia Pectoralis
• Superficial Layer of Fascia Pectoralis
– It is known as Pectoral Fascia
– Surface sheet covers the outer surface of the pectoralis major muscle
– It separates the thoracic piece of the pectoralis major muscle from breast tissue
What is the deep layer of fascia pectoralis?
• It separates
– Pectoralis Major muscle
• from
– Pectoralis Minor muscle
• At the top, it is fused with the clavicle and coracoid process
• In the subclavian area from two sides surrounds a small chest muscle and subclavian muscle, forming a dense plot, called fascia clavipectoralis
• It also goes on to form fascia of the axilla (fascia axillaris).
Summary of fascia pectoralis?
The most superficial 2 layers of thoracic fascia are collectively known as – Fascia Pectoralis • It is separable into – Pectoral Fascia • Superficial layer of Fascia Pectoralis – Clavipectoral Fascia • Deeper layer of Fascia Pectoralis
What is endothoracic fascia?
- It is the 3rd and deepest layer of fascia of the thoracic region
- It is in itself, a layer of loose connective tissue deep to the intercostal spaces and ribs
- It separates the internal thoracic wall from the underlying pleura
- It forms the outermost membrane of the thoracic cavity
What is the bony thorax?
- Manubrium
- Sternum
- Xiphoid Process
- Coastal cartilages
- Clavicles
- Ribs
- Thoracic Vertebrae
- It is the bony skeleton of the body giving rise to what we commonly refer to as the chest
- It is formed by 12 pairs of ribs
- Thoracic vertebrae (n=12)
- Sternum (n=1)
- Manubrium of the sternum (n=1)
- Manubrosternal joint
What does a rib have?
- Head (two facets)
- Neck
- Tubercle(facet)
- Angle
- Proximal end–costal cartilage
What are the anterior articulations of ribs?
• Rib 1 to sternum (manubrium) – Fibrous joint – No movement • Ribs 2 – 7 true ribs – Synovial (gliding) joints – Radiate sternocostal ligaments • Ribs 8-10 = false, articulate with costal cartilage of rib 7 • 11-12 = false & floating ribs
Anatomy summary of sternum
Top to bottom
- jugular notch
- manubrium of sternum
- sternal angle (manubriosternal joint)
- transverse ridges
- body of sternum
- xiphoid process
What are the muscles of the thoracic region?
• Muscles of the thoracic region are divisible into 2 categories
– Muscles that attach the upper limb to the axial skeleton
– Muscles of Respiration
What muscles are associated with movements of the upper limb?
– Pectoralis Major – Pectoralis Minor – Subclavius – Serratus Anterior – Latissimus Dorsi – Rhomboid Major – Rhomboid Minor – Trapezius – Muscles of The Scapula – Terres Minor – Terres Major
What are the actions of pectoralis major muscle?
• Itisa: – Flexorofthearm – Adductorofthearm • Clavicular Part of Pectoralis Major • It elevates the shoulder • Draws the arm forward and medial-ward • Sternocostal Part of Pectoralis Muscle • Has same actions as the clavicular portion but also draws the shoulder downwards
What is the serratus anterior?
• It has a serrated presentation
• It attaches on
– Lateral surfaces of upper 8–9 ribs and deep fascia overlying the related intercostal spaces
– Costal surface of medial border of scapula
• It is supplied by the Long Thoracic Nerve (Root Values C5 to C7)
• Its actions are:
– Protraction and rotation of the scapula
– Keeps medial border and inferior angle of scapula opposed to thoracic wall
• Winging of the scapula
What is the neurovascular bundle of intercostal muscles?
- The neurovascular bundle of the intercostal muscles runs on the inferior aspect of the ribs
- It is housed under the cover of the sub-costal groove
- Any procedures on the thoracic wall must be carried out on the upper surface of the ribs
- This avoids damage to the neurovascular bundle
