Throax Flashcards
X-ray colouring explained
White- dense so rays don’t pass through
Grey- some pass through, soft tissue
Black- all pass through, air/fat
Contrasting agents
Barium
Iodine
3 planes in imagery
Sagittal
Axial
Coronal
Difference between T1 and T2 MRI
T1 fluid is black
T2 fluid is white
Difference in CT and MRI
Fat is black in CT and white in MRI
Bone marrow is grey in CT
Cortical bone is white in CT and black in MRI
PET scan shows
Which tissues are metabolically active, useful for showing cancers
Describe rib formation with sternum
Rib 1 costal cartilage joins to manubrium
Rib 2 joins at sternal angle
Ribs 3-7 joins to the body With 7th on xiphoid-body joint
8-10 join costal cartilages above
Categories the ribs
Ribs 1-7 are true ribs
Ribs 8-10 are false ribs
Ribs 11 and 12 are floating ribs
What is located in thoracic inlet
Subclavian arteries and veins Internal jugular veins Common carotid arteries Oesophagus Trachea Apex of lungs
External intercostal formation and direction
Form inferiorly and laterally from lower border of rib above
Run inferiorly and anteriorly from rib above in oblique direction
Internal intercostal formation and direction
Formations begin at lower border of rib above to the rib below
Are at 90degrees to external intercostal
Run inferiorly and posteriorly in oblique direction
Innermost Intercostal
Deepest and extend in same direction as internal intercostal
Intercostal nerve origins
Originate from ventral ramus of spinal nerve giving formation of lateral and anterior cutaneous branches
Intercostal bundles
Vein- most superior
Artery
Nerve
Intercostal artery origin
Posteriorly anastomoses with aorta
Anteriorly anatomoses with thoracic artery
Anterior branching of intercostal arteries
Spaces 1-6 have direct branches off of internal thoracic artery
7-9 have branches off the end branches
10-11 have no anterior branches
Mediastinum
Area between the two lungs in the thorax
Parts of the pectoralis major
Sternoclavicular head- originates from sternum and first 7 costal cartilage
Clavicular head- originates from anterior surface of medial half of clavicle
Join to humerus
Subclavius
Passes laterally from where rib 1 meets costal cartilage to middle third of clavicle
Contracts clavicle medially to stabilise joint
Pectoralis Minor
Passes from anterior surface of ribs 3-5 to carotids process of scapula
Trachea levels
From C6 to T4/5
Lobes and fissures of each lung
Right has inferior, middle and superior lobes
Oblique fissure separates superior from muddle and inferior and horizontal fissure separates middle and inferior
Left has an oblique fissure which separates superior and inferior
Spaces in pleural cavity
Costodiaphragmatic recess- inferior
Costomediastinal recess- medial
Margin of diaphragm
Attaches to xiphoid proces
Costal cartilage
Floating ribs
Lumbar vertebrae and median arcuate ligament
Breathing mechanics
Ribs are thrusted forward and upwards like a bucket handle
Increases transverse diameter of thoracic cavity
Contraction of diaphragm increases vertical diameter of thoracic cavity
Overall reduces pleural pressure and causes entry of air
Superior Mediastinum Outline
From thoracic inlet to line from sternal angle to between t4/5
Division of mediastinum
Above sternal angle is the superior
Below is inferior which is divided into anterior, middle(pericardial sac) and inferior
Azygous vein function and divisions
Drains posterior wall of thorax and abdomen arching over right lung root to sac
Provides veins for intercostal space
Produces hemiazygous and accessory hemiazygous (superior to hemiazygous)
Shunts that change at birth
Ductus arteriosis to ligamentus arterosis
Foreamen ovale to ovale fossa
Right Vagus Pathway
Lies beside trachea
Posterior to brachiocephalic vein and anterior to arteries
Crosses posterior to root of lung
Right recurrent laryngeal goes around right subclavian
Breaks up into batches on oesophagus
Left Vagus Pathway
Between left common carotid and subclavian artery
Crosses left side of aortic arch with recurrent laryngeal going underneath
Passes posterity to root of lung
Phrenic nerve functions
Motor to diaphragm Sensory to tendon of diaphragm Mediastinal pleura Peritoneum of central diaphragm Pericardium