Thorax Anatomy Flashcards
What epithelium lines the oesophagus? How does this change in Barretts?
Stratified squamous non-keratanised epithelium
Metaplasia to columnar type intestinal epithelium
What part of the brachial plexus lies behind the subclavian artery behind the first rib?
Inferior trunk
What is subclavian steal syndrome?
Proximal blockage of subclavian artery causes retrograde blood flow down the ipsilateral vertebral artery causing brain ischaemia on arm exercise as there is vertebrobasilar insufficiency
Symptoms/signs: vertigo, blurred vision, syncope & hearing problems - vascular insufficiency or UL & BP difference
What are the contents of the posterior mediastinum?
HINT: DATES
Descending thoracic aorta & branches
Ayzgous veins
Thoracic duct
Esophagus
Sympathetic trunks
Bordered posteriorly by T4-T12, line to sternal angle anteriorly @ T4 with pericardium anteriorly then diaphragm inferiorly bounded laterally by mediastinal pleura
What are the openings in the diaphragm and their contents?
Caval opening (T8): IVC & R. Phrenic nerve
Oesophageal hiatus (T10): oesophagus, CNX & oesophageal branch of L. Gastric artery
Aortic hiatus (T12): descending aorta, thoracic duct & azygous vein
What is the function of chordae tendinae?
Prevent AV valve (tricuspid/mitral) prolapse during ventricular systole
What are the branches of the ascending aorta?
RCA
LCA
Arise @ aortic sinus opposite AV
What are the tributaries of the ayzygous vein?
HINT: Right Handed PM Loves Eating Burgers
Right superior intercostal
Hemiazygous & accessory hemiazygous
Pericardial
Mediastinal
Lower right posterior intercostal
Esophageal
Bronchial
What drains into the thoracic duct?
L/R lumbar & intestinal lymph trunks forming the cysterna chyli (below diaphragm) & L jugular trunk, subclavian trunk, bronchomediastinal trunk, mediastinal & thoracic
Lymph drained from the whole body except the upper right quadrant including UL, lung, breast & head/neck (this part drains directly into R brachiocephalic)
Drains into angle between left subclavian and IJV
What level does sympathetic chain cross and how does it connect to spinal nerves?
T1-L2
Connects via ganglion, white ramus communicans & grey ramus communicans
What is the difference between the right and left CNX?
Right: anterior to subclavian artery - posterior to oesophagus
Left: passes down between L. CCA & L. Subclavian artery - anterior to oesophagus
Both travel from jugular foramen, in carotid sheath behind root of lung to form plexus around oesophagus
What is the difference between RLN on right vs left?
Right: hooks underneath right subclavian
Left: hooks underneath arch of aorta
What are the branches of the carotid arteries?
External (Some Angry Lady Found Out PMS):
Superior thyroid
Ascending pharyngeal
Lingual
Facial
Occipital
Posterior auricular
Maxillary
Superficial temporal
Internal:
Artery of pterygoid canal
Opthalmic
Anterior choroidal
Post. communicating
ACA
MCA
What are the branches of the aortic arch?
From right to left:
Brachiocephalic (goes into R subclavian and R CCA)
L CCA
L Subclavian
What are the branches of the pulmonary trunk? What level does it divide at? How many pulmonary veins are there?
R & L pulmonary arteries (deoxygenated blood to lungs) at T5
4 pulmonary veins (carrying oxygenated blood back to left atrium)
What structures pass through hilum of lung?
Pulmonary artery/vein (anteriorly)
Right and left main bronchus (posterior)
Bronchial artery/vein
LNs
Autonomic nerves
What is the pulmonary ligament and where is it attached?
Pleural fold connecting mediastinal surface of lung to pericardium to allow expansion of pulmonary veins with increased blood flow
What level is the carina and hilum of the lung?
Carina @ T4
Then hilum @ T5-7
What are the attachments of the diaphragm? What passes through the central tendon?
3 attachments:
1. Lumbar vertebrae & arcuate ligaments (medial/median/lateral) -> right crus arises from L1-3 (surround oesophageal hiatus) & left crus from L1-2
2. Costal cartilages of ribs 7-10 then attaching directly to ribs 11-12
3. Xiphoid process of sternum
Muscle fibres combine to form central tendon which ascends to fuse with fibrous pericardium -> caval opening
What is the surface anatomy of the lungs, pleura and fissures?
Curved line from SC joint to 3cm above junction between medial and middle 1/3rd of clavicle (apex) then descends medially at SC joint to xiphisternal joint parasternally -> left lung deivates @ 4th CC to form cardiac notch and right deviates @ 6th CC -> 6th rib MCL -> 8th rib MAL -> 10th rib vertebral column with transverse processes of C7-T10 being the posterior border (parietal pleura is 2 levels below this at all times)
Horizontal (R): runs from 4th CC to oblique fissure when crossing 5th rib - separates ML and UL
Oblique fissure (B/L): line drawn obliquely and down from 2.5cm lateral to T3 spine, along 5th ICS and to 6th CC 4cm from midline (if you ask patient to raise hands above head medial scapula border corresponds to this fissure) - divides lung in to UL/LL
What is the course of DVT to cause a PE?
Popliteal
Femoral
EIA
CIA
IVC
RA
Tricuspid valve
RV
Pulmonary valve
Pulmonary arteries to lungs
What ligaments attaches liver to diaphragm?
Coronary ligament reflect off inferior surface of diaphragm demarcating bare area of liver
Triangular ligaments (lateral extensions of coronary) connecting diaphragm to R/L liver lobes
Falciform has a minor role attaching it to the diaphragm (mainly attaches it to anterior abdominal wall)
What are the first 2 organs damaged in knife wound to the epigastrium just under xiphoid?
Left lobe of liver
Diaphragm
(and stomach)
How many bronchopulmonary segments in each lung? What are they called?
10 in right and 9 in left
Right lung:
- Superior lobe: apical, posterior & anterior
- Middle lobe: lateral & medial
- Inferior lobe: superior & basal (median, anterior, lateral & posterior)
Left lung:
- Superior lobe: apicoposterior, anterior, superior lingular & inferior lingular
- Inferior lobe: superior & basal (medial, anterior & lateral) - missing posterior basal
Where do foreign bodies lodge in bronchi and why?
Right main bronchus into right lower and middle lobes because its more vertical, shorter and wider than the left
How can you count vertebral bodies posteriorly?
Use landmarks:
C7 is most prominent due to large spinous process
Spine of scapula is T3
Inferior angle of scapula is T7
What nerve lies anteriorly vs posteriorly of lungs?
Anterior: phrenic
Posterior: CNX & sympathetic chain
Where would you insert a chest drain? Where would you decompress a tension?
Triangle of safety for drain: 5th ICS, anterior border of lat dorsi/MAL and posterior border of pec major
Needle decompression: MAL 5th ICS
What are the branches of subclavian artery?
HINT: VIT C & D
Vertebral
Internal thoracic
Thyrocervical trunk
Costocervical
Dorsal scapular
What is difference between left and right phrenic nerve?
Right: descends to right of brachiocephalic vein, SVC, RA then IVC passing through diaphragm with it @ T8
Left: descends left of left subclavian artery, aortic arch, left ventricle & pierces diaphragm alone
