Thoracic Wall

Question 1

Thoracic Inlet and Outlet

• Inlet boundaries
• Outlet boundaries

Answer 1

• Body of T1, the 1st pair of ribs, and the superior border of the manubrium
• Body of T12, and the 11th/12th pairs of ribs. Costal margin (cartilages of ribs 7-10). Xiphisternal joint.

Question 2

Sternum

• Jugular notch
• Clavicular notches
• Costal notches

Answer 2

• Single one at the top
• One at either side of the jugular notch
• Go down the sides for articulation with the ribs

Question 3

Rib Types (based on connection with sternum)

• True ribs
• False ribs
• Floating ribs

Answer 3

• Directly via their own cartilage (ribs 1-7)
• Indirectly via cartilage of the ribs above (ribs 8-10)
• No connection and end in the musculature of the posterior abdominal wall (ribs 11 + 12)

Question 4

Typical Ribs

• Which ones are typical?
• Head
• Neck
• Tubercle
• Body

Answer 4

• 3rd to 9th
• Head is wedge shaped and has 2 articular facets separated by a crest.
• Connects head and body at tubercle
• Articular and non-articular parts
• Thin, flat and curved

Question 5

Atypical Ribs (1+2)

• 1st Rib
• 2nd Rib

Answer 5

• Single facet on the head as it articulates with T1 only. Has grooves on the superior surface, either side of the scalene tubercle, which are to allow passage of the subclavian vessels.
• Rough surface (tuberosity) on the superior side for attachment of serratus anterior.

Question 6

Atypical Ribs (10-12)

• Ribs 10-12
• Ribs 11+12

Answer 6

• Single facet on head as they articulate with a single vertebra
• Short with no neck or tubercle

Question 7

Intervertebral Joints

• Location of intervertebral disk
• Zygapophyseal joint

Answer 7

• Between the bodies of the two vertebrae. 2nd degree cartilaginous joint.
• Between the articular facets - synovial plane joints

Question 8

Sternocostal Joints

• Rib 1
• Ribs 2-7
• Ribs 6-9
• Ribs 9+10

Answer 8

• No movement between the rib and the manubrium. Cartilaginous joint (synchondrosis)
• Synovial plane joints. Limited movement is allowed.
• All joined by interchondral joints. Synovial plane joints between 6+7, 7+8 and 8+9.
• Joined with a fibrous joint

Question 9

Respiratory Movements

• Anterior-Posterior
• Lateral
• Vertical

Answer 9

• Ribcage expands anteriorly and superiorly
• Lower ribcage moves laterally
• Diaphragm descends, increasing space for lungs. Is the primary muscle of respiration at rest.

Question 10

Upper Limb and Ant. Abdominal Wall Muscles

• Pectoralis Major
• Pectoralis Minor
• Serratus Anterior
• Rectus Abdominis
• External Oblique

Answer 10

• Medial (C8-T1) and Lateral (C5-C7) pectoral nerves
• Medial pectoral nerve (C8-T1)
• Long thoracic nerve (C5-C7)
• Anterior rami (T7-T12)
• Anterior rami (T7-T12)

Question 11

Serratus Posterior and Scalenes

• Scalene muscles (anterior, posterior and middle)
• Serratus posterior

Answer 11

• Work when you really need breath. Anterior (Anterior Rami C3-C7), Middle (Anterior Rami C4-C7) and Posterior (Anterior Rami C5-C7)
• There are serratus posterior superior (2nd - 5th intercostal nerves) and inferior (Anterior Rami T9-T12). Helpful in telling brain position of ribcage.

Question 12

Intercostal Space

• Location
• Contents
• Neurovascular plane
• Costal groove

Answer 12

• Between adjacent ribs
• Intercostal muscles
• Between internal and innermost intercostal muscles
• Intercotal vein, artery and nerve run in this.

Question 13

Blood Supply of Thoracic Wall

• Anterior intercostal arteries
• Venous drainage

Answer 13

• 1-6 come directly from the internal thoracic artery which runs down either side of the sternum. 7-9 comes from the musculophrenic artery.
• Anterior intercostal veins go into the internal thoracic vein. Posterior intercostal veins go into the azygos/hemiazygos venous system.

Question 14

Dermatomes and Breast

• Breast supply
• Lymphatics

Answer 14

• Lateral and medial mammary branches from lateral and internal thoracic arteries.
• Most drainage to axillary nodes, and the rest goes to the parasternal nodes.