Thoracic wall, Mediastinum & Diaphragm Flashcards
three other minor muscles that help to move the ribs?
serratus posterior superior, serratus posterior inferior and levator costae
VAN occupies which groove?
costal groove
note: VAN is between internal intercostal and innermost intercostal muscles
whats the mediastinum?
central compartment of the thorax between the two pleural cavities
Structures at the transverse thoracic plane (T4/T5)? hint: 8
- Bifurcation of trachea,
- concavity of the aortic arch
- just above it the bifurcation of the pulmonary trunk
- the azygous enters the SVC,
- thoracic duct reaches left side of oesophagus
- ligamentum arteriosum with left recurrent laryngeal nerve recurving below it
- tracheobronchial lymph nodes,
- superficial and deep parts of cardiac plexus
structures found in superior mediastinum? hint: 9
- esophagus
- trachea
- thoracic duct
- brachiocephalic veins
- superior vena cava
- vagus nerve (L recurrent laryngeal n)
- phrenic nerves
- arch of aorta
- thymic remnants
2 portions of the diaphragm?
- peripheral- muscular part (sternal, costal, lumbar)
- central- aponeurotic- tendon
middle/anterior leaflet of central tendon is fused with the pericardium. T or F.
T
From its circumferential origin the fibres of the diaphragm arch upwards in a pair of domes and then descend into a central tendon which lies at what level?
lies at the level of the xiphisternal joint at T8 level
Domes can ascend in full expiration to 4th intercostal space (normal position of nipples) on right and 5th rib on left. T or F.
T- right is higher than the left
Tendinous fibres of each crus unite with one another in front of the aorta at the level of T12 vertebra to form the?
median arcuate ligament
medial arcuate ligament?
thickening of the psoas fascia
lateral arcuate ligament?
a thickening of anterior layer of lumbar fascia on quadratus lumborum muscle
what passes alongside the inferior vena cava through the opening of the vena cava in the diaphragm?
right phrenic nerve
what passes alongside the aorta through the aortic opening in the diaphragm?
azygous vein and thoracic duct
what passes alongside the oesophagus through the oesophageal opening in the diaphragm?
Vagal trunks, oesophageal branches of the left gastric artery, veins and lymphatics
the walls of which part of the bronchial tree contains no cartilage but instead smooth muscle?
terminal bronchioles
nerve supply of diaphragm?
motor nerve supply is solely from phrenic nerve (C3,4,5).
whats the major role of the diaphragm?
inspiration
note: also used in abdominal straining for defaecation, micturition etc.
outer layer of thoracic muscles?
- serratus posterior superior (elevate upper ribs for inspiration)
- serratus posterior inferior (depresses lower ribs for expiration)
- levator costae muscles
- external intercostals
middle layer of thoracic muscles?
- internal intercostal muscles
inner layer of thoracic muscles?
- innermost intercostal muscles
- subcostal muscles
- transverse thoracis
whats a pleural tap?
- Aspiration of pathological material from pleural cavity (serous fluid, fluid mixed with tumor cells, blood, pus, etc..) done through intercostal space.
- Usually, intercostal space 6, 7 or 8
- Needle or trocar inserted just above the rib forming lower boundary of the space to avoid main nerve and vessels
central tendon is connected to what?
pericardium
blood supply to the diaphragm?
- costal margin: lower 5 intercostals and subcostal arteries
- crura: right and left phrenic arteries of abdominal aorta
- small contributions: musculophrenic and pericardiophrenic branches of internal thoracic artery; superior phrenic arteries of thoracic aorta
