Region 1 - Thorax Flashcards
What are the boundaries of the superior thoracic aperture?
Body of T1
1st pair of ribs and their cartilages
Superior border of manubrium
What is the function of the superior thoracic aperture?
Passage of structures between thorax and neck/upper limb
What are the boundaries of the inferior thoracic aperture?
Body of T12
11th and 12th pairs of ribs
Costal cartilages of ribs 7-10 (costal margin)
Xiphisternal joint
What is the function of the inferior thoracic aperture?
Passage of structures between thorax and abdomen
What are the name and type of joints between vertebral articulate processes?
Zygopophysial (facet) joints
Synovial plane
What do the heads of the typical ribs articulate with?
Body of own vertebra
Body of vertebra above
IV disc (via crest)
What do the tubercles of the typical ribs articulate with?
Articulate part with transverse process of own vertebra
What is the function of the non-articular part of a typical rib?
Costotransverse ligament attachment
What are the numbers of the typical ribs?
3-9
What separates the articulate facets on the head of a typical rib?
Crest
What defines a true rib? What numbers are the true ribs?
Connect directly to sternum via own cartilage
1-7
What defines a false rib? What numbers are these?
Connects to sternum indirectly via cartilage of ribs above
8-10
What defines a floating rib? What numbers are these?
Does not connect to sternum
11 and 12
What is the name for the most curved part of the body of a rib?
Costal angle
Where is the costal groove found on the rib?
Internal surface of the inferior border of the body of the rib
What is the function of the costal groove?
Protects intercostal NVB
What are the atypical features of rib 1?
Single facet in head for T1 (C7 has no articulate surface)
Grooves for subclavian vessels
- On superior surface
What is the function of the scalene tubercle?
Separates grooves for subclavian vessels on superior surface of rib 1
Attachment point for anterior scalene muscle
What is the function of the rough area on the superior surface of rib 2?
Tuberosity for serrated anterior
What ribs don’t have a neck or tubercle?
11th and 12th ribs
What type of cartilaginous joints are the IV discs and what is the other name for this type of joint?
Secondary
Symphysis
What type of joint does rib 1 have with the sternum?
Primary cartilaginous (synchondrosis)
What types of joints do ribs 2-7 have with the sternum?
Synovial plane
What types of joints are the interchondral joints?
Synovial plane (between 6+7, 7+8 and 8+9) Fibrous joint (between 9+10)
What is the axis of the upper ribs (1-6) and how does this affect their movement during respiration? What is the movement called?
More lateral
Ribs move up and out (anteriorly) - Pump handle movement
What is the axis of the lower ribs (7-12) and how does this affect their movement during respiration? What is the movement called?
More anteroposterior
Ribs flare out more laterally - bucket handle movement
What are the changes in dimension during respiratory movements and how are hose achieved?
Anteroposterior - Sternum moves anteriorly and superiorly
Lateral - Lower rib cage moves outwards
Vertical - Diaphragm descends
What are the secondary muscles of respiration?
Scalene muscles
Serrated posterior superior and inferior
What nerve(s) innervate the pectoralis major?
Medial pectoral (C8, T1) Lateral pectoral (C5-C7)
What nerve(s) innervate pectoralis minor?
Media pectoral nerve (C8, T1)
What nerves supply the external oblique and rectum abdominis?
Anterior rami of T7-T12
What supplies serratus anterior?
Long thoracic nerve (C5-C7)
What supplies serratus posterior superior?
2nd-5th intercostal nerves
What supplies the serratus posterior inferior?
Anterior rami T9-T12
What innervates the anterior scalene muscle?
Anterior rami C3-C7
What innervates the middle scalene muscle?
Anterior rami C4-C7
What innervates the posterior scalene muscle?
Anterior rami C5-C7
What direction do the external intercostal muscles move in?
Downwards and forwards (hands in pockets)
Where do the external intercostal muscles run from and to?
From tubercles of ribs to costochondral junction
What are the external intercostal muscles replaced by anteriorly?
External intercostal membrane
What function do the external intercostal muscles serve?
Raise the ribs on inspiration
What direction do the internal intercostal muscles move in?
Downards and backwards
Where do the internal intercostal muscles run from and to?
Sternum to angle of rib
What are the internal intercostal muscles replaced by posteriorly?
Internal intercostal membrane
What are the functions of the internal intercostal ribs?
Depress ribs (interosseous part) Raise ribs (interchondral part)
Where do the innermost intercostal muscles lie?
Deep to lateral part of internal intercostals
What direction do the innermost intercostal muscles run in?
Downwards and backwards
Where are the subcostal muscles found?
Near angle of ribs
How can the subcostal muscles be differentiated from intercostal muscles?
Span 1 or 2 intercostal spaces
What muscle radiates from the sides of the sternum to costal cartilages 2-6?
Transversus thoracis
What are the contents of an intercostal space?
Intercostal muscles Neurovascular bundle: - Intercostal vein (most superior) - Intercostal artery - Intercostal nerve (most inferior)
Where does the intercostal neurovascular plane run?
In the costal groove of the rib between the internal and innermost intercostal muscle layers
From what artery do the 1st and 2nd posterior intercostal arteries from? Where does this artery originate?
Supreme intercostal artery from costocervical trunk (branch of subclavian)
Where do posterior intercostal arteries 3-11 and the subcostal artery arise from?
Thoracic aorta
Where do the 1st-6th anterior intercostal arteries arise from?
Internal thoracic artery (branch of subclavian)
Where do the 7th-9th anterior intercostal arteries arise from?
Musculophrenic artery (from internal thoracic)
Where does the superior epigastric artery arise from?
Internal thoracic artery
Where do the anterior intercostal veins drain to?
Internal thoracic veins
Where do the posterior intercostal veins on the right side from the 2nd-4th spaces drain to?
Right superior intercostal vein (draining to azygos)
Where do the posterior intercostal veins on the right side from the 2nd and 3rd spaces drain to?
Left superior intercostal vein (draining to left brachiocephalic +/- accessory hemiazygos)
What veins drain the 1st intercostal spaces?
Supreme intercostal veins (drain to brachiocephalic veins)
Where does venous blood drain to from posterior intercostal spaces on the right side (5-11 and subcostal)?
Azygos vein
Where does venous blood drain to from posterior intercostal spaces on the left side (9-11 and subcostal)?
Hemiazygos vein
Where does venous blood drain to from posterior intercostal spaces on the left side (4-8)?
Accessory hemiazygos
Where do lateral mammary branches arise from?
Lateral thoracic artery (from axillary)
Where do medial mammary branches arise from?
Internal thoracic artery
Where does 75% of lymph from the breast drain to?
Axillary nodes
Where else can breast lymph drain to?
Parasternal nodes (Abdominal nodes)
What are the four parts of the parietal pleura?
Cervical
Costal
Diaphragmatic
Mediastinal