mediastinum Flashcards
what are the 3 parts of the thoracic cavity from l to r
plueral, mediastinum, pleural
what are the upper and lower boundaries of the mediastinum
sternum, diaphragm
why does the pericardial sac elongate
attached to diaphragm, stretches on inspiration
what is the transthoracic plane
angle of Louis thru T4/5
when supine, what does the transthoracic plane pass through
aortic arch, carina
which nerves innervate the diaphragm
C3,4,5 phrenic nerve
whst else does the phrenic nerve innervate and what sort of nerves are they
diaphragm - motor
pericardium - sensory
mediastinal pleura - sensroy
what is in the superior mediastinum
aortic arch
phrenic nerves
vagus nerve
recurrent laryngeal nerves
oesophagus
trachea
thoracic duct
what is in the posterior mediastinum
goose x 3
duck
(vagus, azygous, oesophagus, thoracic duct)
where do the thyrocervical arteries branch from
subclavian
what is supplied by the thyrocervical arteries (5)
Inferior part of the thyroid gland, parathyroid glands, larynx, pharynx, platysma, brachial plexus, deep cervical and shoulder muscles, skin of the neck and shoulders
where does the recurrent laryngeal nerve branch from
vagus
where do R and L recurrent laryngeal nerves go
L under aortic arch
R under subclavian
why is paralysis of phrenic nerve after surgery usually transient
peripheral nerves can regenerates
what are the vertebral levels of the trachea
C6-T4
where is the bifurcation of the trachea
T4/5
what does the aorta branch over
primary branch of L bronchus and L hilum
what are the vertebral levels of the oesophagus
C6 (same as trachea)-T10
(count letters of oesophagus)
what are the vertebral levels of the oesophagus
C6 (same as trachea)-T10
(count letters of oesophagus)
what is a feature of the oesophagus that aids digestion
indentations
where are the indentations in the oesophagus
pharyngoesophagal jct
arch of aorta
transverse diaphragm
what do azygous and hemi-azygous veins provide
venous drainage to thoracic area
what relative space should the heart occupy on an x-ray
1/3 R, 2/3 L, no more than 50% of thoracic space
which arteries supply C1and C2
Costocervical arteries, directly from subclavian
where do the posterior intercostal arteries get their blood from?
descending aorta
where do coronary arteries get their blood from
first dibs from aorta
how do coronary arteries get blood
after systole, blood falls back into aortic valve cusps and can trickle down into coronary arteries
what supplies the anterior intercostal arteries
internal thoracic artery
where does the internal thoracic artery originate
subclavian
what goes in the little groove at the bottom of each rib?
one vein, one artery, one nerve “neurovascular bundle”
where would you take a sample of pleural fluid?
T9/10
why would you take a sample of pleural fluid there and what should you be aware of
lungs don’t go all the way down. Not diaphragm, not liver
go in teh middle/towards the bottom of the space to avoid the neurovascular bundle
how would you reinflate a pneumothorax
needle in T9/10 space
what are the functions of the pericardium
fixes heart in place
prevents heart stretching too much
lubrication
protects heart from infection (eg muck brought into lungs)
what is a pericardial infusion called and what is it
tamponade, fluid/blood between visceral and parietal layers of pericardium
what’s the difference between acute and chronic tamponade
acute very bad: 150ml=death
chronic: pericardium can stretch and accommodate up to 1l without death
what are pulmonary crackles called
rales
what happens in acute tamponade
RV collapse
what is the thing between the atria and ventricles called and what is in it
atrioventricular sulcus - fat and coronary arteries
what is the thing between the ventricles called and what’s in it
interventricular sulcus - fat and more coronary arteries. overlies internetricular septum
where are auricles
inferior part of atria
how many pulmonary veins feed into the L atrium
4
what is the venous return of the coronary arteries
coronary sinus
what feeds into the r atrium
IVC SVC coronary sinus
what is the indentation in the atria
fossa ovale
what does the fossa ovale allow in foeti
blood to pass between atria
where is the SAN
jct between SVC and r atrium
what is the dense band of connective tissue between the Purkinje fibres and the intervemtricular septum called
moderator band
which is the smoothest chamber of the heart
LA
what is the LAD
left coronary artery
where do the majority of myocardial infarctions happen
LAD
what can be a consequence of RCA myocardial infarction
SAN damage -> heart block
what holds the heart together
fibrous skeleton; 2 figures of 8
which vlavled are open during diastole
AV
what happens in systole
papillary muscles contracted
chordae tendinae taut
A and P valves open
AV valves shut
when is first heart sound
start of systole
when is second heart sound
start of diastole
when is second heart sound
start of diastole
does the heart feel pain
no. only referred pain to relevant dermatomes and other sensory nerves
does the heart feel pain
no. only referred pain to relevant dermatomes and other sensory nerves
where do you get pain with posterior wall MI
epigastric T7,8,9
what is ischaemia
decreased blood flow & therefore O2 to heart muscle
what causes pain in MI
ischaemia and heart muscle damage
