Thoracic Wall Flashcards
What is the superior thoracic aperture?
Passage of structures between thorax and upper limb/neck
What are the boundaries of the superior thoracic aperture?
- Body T1
- 1st pair of ribs and costal cartilage
- superior border of manubrium
What is the inferior thoracic aperture?
allows passage of structures between thorax and abdomen
what are the boundaries of the inferior thoracic aperture
- body T12
- 11th/12th ribs
- costal cartilage ribs 7-10
- xiphisterna joint
How do true ribs connect to sternum (1-7)
connect via own cartilage
how to false ribs connect to the sternum (8-10)
connect indirectly via cartilage of ribs above
how do floating ribs connect to sternum (11-12)
no connection to thoracic cage
describe a the features of a typical rib
- 3rd - 9th rib
- wedge shaped head
- 2 articular facets separated by crest
- neck connects body and head at tubercle
- tubercle with articular and non articular parts
- thin, flat and curved body
describe features of the 1st rib (atypical)
- single facet on head
- only articulates with T1
- grooves for subclavian vessels on superior surface
- separated by scalene tubercle
describe features of the 2nd rib (atypical)
- rough area on upper surface
- tuberosity for serratus anterior muscle
describe the features of the 10th-12th ribs (atypical)
- single facet on head
- articulate with single vertebra
- 11th-12th are short with no neck or tubercle
what joints lie between IV discs
2nd degree cartilaginous joints
what joints lie between articular facets of vertebrae
synovial plane joints
what type of sternocostal joint is at the 1st rib
1st degree cartilaginous joint
what type of sternocostal joint is at ribs 2-7
synovial plane joints
describe the Interchondral joints of ribs 6-10
synovial plane between 6-9
fibrous between 9-10
what is the main muscle of respiration
diaphragm
what innervates the diaphragm
Phrenic nerve - anterior rami C3,4,5
what are the secondary muscles of respiration
- scalene
- serratus posterior muscles
what innervates the pectoralis major?
- medial pectoral nerve (ant. rami C8-T1)
- lateral pectoral nerve (ant rami C5-7)
what innervates the pectoralis minor
- medial pectoral nerve (ant. rami C8-T1)
what innervates the external oblique
- ant. rami T7-T12
what innervates the rectus abdominus
- ant. rami T7-12
what innervates the serratus anterior
- long thoracic nerve (ant. rami C5-7)
what innervates the anterior scalenes
- ant. rami C3-7
what innervates middle scalenes
- ant. rami C4-7
what innervates the posterior scalenes
- ant. rami C5-7
what innervates serratus posterior superior
- 2nd-5th intercostal nerves
what innervates the serratus posterior inferior
- ant. rami T9-12
describe the external intercostal muscles
- fibres pass downwards and forwards
- from tubercles of ribs to costochondral junction
what innervates the external intercostal muscles
- ant. rami T1-11
describe the internal intercostal muscles
- fibres pass down and back
- from sternum to angle of ribs
what innervates the internal intercostal muscles
intercostal nerves
describe the innermost intercostal muscles
- deepest layer
- fibres pass down and back
- very thin
- often incomplete
what innervates the innermost intercostal muscles
intercostal nerves
describe the subcostal muscles
- deep
- near angle of ribs
- spans 1-2 intercostal spaces
what innervates the subcostal muscles
intercostal nerves
describe the transversus thoracis
radiates from sides of sternum to costal cartilages 2-6
what innervates the transversus thoracis
intercostal nerves
where does the neurovascular plane lie
between internal and innermost intercostal muscles
what runs in the costal groove
- intercostal Vein
- intercostal Artery
- intercostal Nerve
(VAN)
Where does the 1st and 2nd posterior intercostal artery arise from
supreme intercostal artery (branch of costocervical trunk from subclavian artery)
where does the 3rd-11th (and subcostal 12th) posterior intercostal artery arise from
thoracic aorta
where does the 1st-6th anterior intercostal artery arise from
direct from internal thoracic artery
where does the 7-9th anterior intercostal artery arise from
musculophrenic artery
describe the venous drainage of the right hand side body wall
- 1st intercostal vein directly into right brachiocephalic vein
- rest drain directly into azygos vein
describe venous drainage of the left hand side body wall
- veins 1-4 drain into left brachiocephalic vein
- veins 5-8 drain directly to accessory hemiazygos vein
- veins 9-11 drain to hemiazygos vein
describe lymphatic drainage of the thoracic wall
- anterior and lateral body wall drains to anterior and pectoral lymph nodes
- posterior chest wall drains to axillary nodes
describe arterial supply to the breast
- lateral mammary branches from lateral thoracic artery
- medial mammary branches from internal thoracic artery
describe venous drainage of the breast
- venous drainage by medial and lateral mammary veins
describe the lymphatics of the breast
- 75% to axillary nodes
- rest to parasternal nodes
