Thoracic Wall Flashcards
What is the sternal angle and why do we feel for it during examination
Manubriosternal joint
It is where the Costal cartilage of the second rib attaches
How many ribs are there in total
12
What are the true ribs
First 7 ribs
Join to sternum via costal cartilage
False ribs
8th - 10th rib
Join to sternum via costal cartilage of 7th rib
Floating ribs
Ribs 11 and 12
Do not attach to sternum anteriorly
What makes first rib different to others
Shortest true rib
Single facet on head
Lacks angle and costal groove, has groove for subclavian artery and vein and a scalene tubercle
F,O,I of serratus posterior superior
F: Assists in elevating ribs during inhalation
O: Spinous processes of C7-T3 vertebrae
I:Upper borders of ribs 2-5
FOI of Serratus posterior inferior
F: Draws lower ribs downwards and backwards during exhalation
O: Spinous processes of T11-L2
I: Inferior border of ribs 9-12
FOI of external intercostles
Direction of muscle fibres
F: Elevate ribs during inhalation - increasing thoracic volume
O: Inferior border of rib above
I: Superior border of rib below
Muscle fibres of external intercostles run down and forwards (hands in pockets)
FOI of internal intercostles
Direction of muscle fibres of internal intercostals
F: Depress ribs during forced exhalation
O: Inferior border of rib above
I: Superior border of rib below
Muscle fibres of internal intercostles run down and backwards (perpendicular to externals)
FOI of innermost intercostles
Muscle fibres direction
F: Assist internal intercostles in forced expiration
O: Inferior border of rib above
I: Superior border of rib below
Muscle fibres of internal intercostles run down and backwards (perpendicular to externals and same to internals)
Subcostals FOI
F: Depress the ribs, aiding forced exhalation
O: Inner surface of one rib
I: Inner surface of rib 2-3 ribs below
FOI of transversus thoracis
F: Weakly depresses ribs during exhalation
O: Posterior surface of lower sternum
I: Internal surface of costal cartilage of ribs 2-6
Subclavius FOI
F: Stabilises and depresses clavicle
O: 1st rib and its costal cartilage
I: Inferior surface of clavicle
Pectoralis major FOI
F: Adducts, flexes and medially rotates humerus
O: clavicular head - median side of clavicle
Sternocostal head - sternum and costal cartilage of ribs 1-6
I: Lateral lip of bicepital (intertubercular) groove of Humerus
Pectoralis minor FOI
F: Stabilises scapular by drawing it anteriorly and inferiorly against thoracic wall
O: Anterior surfaces of ribs 3-5
I:Coracoid process of scapula
FOI Serratus anterior
F: Protracts scapula (pulls it forwards) and upwardly rotates it .
O: External surfaces of ribs 1-8/9
I - anterior surface of medial border of scapula
What is costochondral joint
Joins rib to costal cartilage
What is sternochondral joint
Sternum to Costal cartilage
What is the costal groove and what does it contain
At the bottom of the rib on inner surface
Contains (from superior to inferior):
Intercostal Vein
Intercostal artery
Intercostal nerve
How do ribs join to vertebrae?
1)Head of rib and vertebral body of vertebra (Costocorporeal joint)
2)Articular facets of rib tubercle and transverse process off thoracic vertebra
Interchondral joints?
Between costal cartilage of the ribs
Label this sternum
Label this rib
Label this vertebra
