Thorax Flashcards
boundaries of the superior thoracic aperture
3
body of T1
1st pair of ribs + costal cartilages
superior border of manubrium
boundaries of inferior thoracic aperture
4
body of T12
11th and 12th pairs of ribs
costal cartilages of ribs 7-10 (costal margin)
xiphisternal joint
which vertebral body/bodies do ribs articulates with
mostly with its named body, but also partly with the body above
eg T7 articulates with T7 and partly with T6
typical ribs
3-9
describe head of typical rib
wedge shaped
2 articular facets separated by crest
which part of the rib articulates with the IV disc
crest
separates the two articular facets on head of rib
what is the function of the neck of typical ribs
connects head and body at tubercle
what connects to the articular and non-articular parts of the tubercle of the rib
articular part = transverse process of own vertebra
non-articular = costotransverse ligament
what is the costal angle
the most curved part of the body
what is the purpose of the costal groove and where is it found
protection for intercostal neurovascular bundle
which ribs are classed as atypical
1st
2nd
10-12th
describe the first rib (what makes it atypical)
single facet on the head (articulates with T1 only)
grooves for subclavian vessels on superior surface (vein more medial)
grooves separated by scalene tubercle
what attaches as the scalene tubercle of the 1st rib
anterior scalene muscles
describe the 2nd rib (what makes it atypical)
rough area on upper surface (tuberosity for serrates anterior)
describe ribs 10-12
only articulate with own vertebra
11/12 have no neck or tubercle (very short)
what are the true ribs and what does this mean
1-7
attach to sternum directly via their own costal cartilage
what are the false ribs and what does this mean
8-10
indirectly attach to sternum via cartilage of ribs above (costal margin)
what are the floating ribs and what does this mean
11-12
no connection to sternum
what are the sections and joints of the sternum
manubrium, body and diploid process sternal angle (manubrium and body) xiphisternal joint (body and diploid process
where is the first costal notch
manubrium
where is the second costal notch
sternal angle
which costal notch is at the xiphisternal joint
7th
which bone articulates with the sternum immediately superior to the first costal notch
clavicle
at clavicular notch
the 1st sternocostal notch is which type of joint
primary cartilaginous (synchondrosis)
sternocostal joints 2-7 are which type of joint
synovial plane
what type of joints are interchondral joints
synovial plane joints between ribs 6-7, 7-8 and 8-9
fibrous between 9 and 10
what are the articular surface of the costotransverse joints
transverse process of vertebra of same number as rib
tubercle of rib
describe the movements of the upper ribs (1-6)
pump-handle movement
more up and down
axis of movement is lateral
describe the movement of the lower ribs (7-12)
bucket-handle movement
more outward flaring
axis of movement more posterior
how is the AP diameter of the thoracic cage increased during respiration
sternum moves anteriorly and superiorly
how is the lateral diameter of the thoracic cage increased during respiration
lower ribcage moves laterally
how does the vertical volume of the thoracic cage increase during respiration
diaphragm descends
nerve supply of pec major
medial pectoral nerve C8/T1
lateral pectoral C5-7
nerve supply of pec minor
medial pectoral nerve C8/T1
nerve supply of external oblique
anterior rami T7-12
nerve supply rectus abdominis
anterior rami T7-12
nerve supply of serratus anterior
long thoracic C5-7
nerve supply of serratus posterior superior
2-5 intercostal nerves
nerve supply of serratus posterior inferior
anterior rami T9-12
nerve supply of anterior scalene
anterior rami C3-7
nerve supply of middle scalene
anterior rami C4-7
nerve supply of posterior scalene
anterior rami C5-7
direction of fibres of external intercostal muscles
downwards and forwards
attachments of external intercostal muscles
start at levels of tubercles and stop at junction of costal cartilage
function of external intercostals
raise ribs on inspiration
direction of fibres of internal intercostals
downwards and backwards
attachments of internal intercostals
start at edge of sternum and reach angle of ribs
function of internal intercostals
interosseous parts depress the ribs
interchondral parts raise the ribs
direction of fibres of innermost intercostals
downwards and backwards
where are the subcostal muscles and transversus thoracis found
deep to the ribs
describe subcostal muscles
found near the angle of the ribs
spans 1 or 2 intercostal spaces
fibres blend with innermost intercostals
describe transversus thoracis
radiates from side of sternum to costal cartilages 2-6
which vessels are associated with anterior surface of transversus thoracis
internal thoracic artery
which structures are found int he intercostal space
intercostal muscles
neurovascular bundle
where is the neurovascular plane found
between internal and innermost intercostal muscles
order of neurovascular vessels in intercostal space
vein
artery
nerve
VAN
the neurovascular bundle runs above/below the rib
below
in costal groove on inferior surface of body of rib
internal thoracic artery supplies which aspect of the thoracic wall
anterior
where do posterior intercostal arteries mainly arise from
thoracic aorta
3-11 and subcostal (12)
where do the 1st and 2nd posterior intercostal arteries arise from
supreme intercostal artery
branch of costocervical trunk from subclavian artery
where do the first 6 anterior intercostal arteries arise from
internal thoracic artery
which artery supplies intercostal spaces 7-9
musculophrenic artery
branch of internal thoracic
the internal thoracic artery branches into which two arteries
musculophrenic artery
superior epigastric artery
where do intercostal veins drain
anterior = internal thoracic vein posterior = azygous system
where do the lateral mammary branches arise from to supply the breast
lateral thoracic artery
where do the medial mammary branches arise from to supply the breast
internal thoracic
3 main division of thoracic cavity
mediastinum
right hemithorax
left hemithorax
what are the sections of the parietal pleura
cervical
costal
diaphragmatic
mediastinal
in which area is there a loosening of the pleura and why
at the lung hilum the pleura hangs down to form the pulmonary ligament
to allow vessels entering the hilum to change diameter whiteout stretching or damaging the pleura
how is the parietal pleura attached to the thoracic wall
endothoracic fascia
what is the supra pleural membrane and what is its function
tough fibrous membrane that attaches the lung to the 1st rib and transverse process of C7
stop lung inflating beyond the thoracic inlet
what is the anterior surface marketing of the visceral pleura
midclavicular line 6th rib
what is the lateral surface marking o the visceral pleura
midaxillary line 8th rib
what is the posterior surface marking of the visceral pleura
scapular line 10th rib
what is the anterior surface marketing of the parietal pleura
miclavicular line 8th rib
what is the lateral surface marketing of the parietal pleura
midaxillary line 10th rib
what is the posterior surface marketing of the parietal pleura
scapular line 12th rib
what are the surfaces of the lungs
costal
diaphragmatic
mediastinal
how many lobes in each lung
3 in right
2 in left
describe the locations of the structures of the lung hilum
pulmonary veins inferiorly and anteriorly
pulmonary artery superiorly
bronchus posteriorly
which vascular structures are associated with each lung
right lung: arch of azygous and SVC
left lung: descending aorta and arch of aorta
the phrenic nerve runs ________ in relation to the hilum
anterior
the vagus nerve runs ________ in relation to the hilum
posterior
describe the course of the recurrent laryngeal nerve in the thorax
left: branches from left vagus and loops around arch of aorta
right: branches from right vagus and loops around subclavian artery
at which level does the trachea spilt
T4
left lung lobes/segments
2 lobes
5 segments each
right lung lobes/segments
3 lobes
3 segments upper
2 segments middle
5 segments lower
describe the course of lymph from the lungs
pulmonary nodes»_space;> bronchopulmonary (hilarity) nodes»_space;> inferior tracheobracheal (carinal) nodes»_space;> superior tracheobrachial nodes»_space;> paratracheal nodes
what separates the superior and inferior mediastinum
transverse thoracic plane
level of sternal angle
what are the borders of the anterior mediastinum
body of sternum
pericardium
transverse thoracic plane
diaphragm
what is contained in the anterior mediastinum
loose connective tissue
lymphatics
thymus in children
what are the content of the middle mediastinum
heart and serous pericardium lining the fibrous pericardium
structures adjacent to middle mediastinum
great vessels
phrenic nerves
lung root structures
which structures does the fibrous pericardium blend with superiorly and inferiorly
tunica adventitia of great vessels superiorly
central tendon of diaphragm inferiorly
describe the course and function of pericardiophrenic artery
arises from internal thoracic artery at level of lower margin of manubrium and runs with the phrenic nerve
supplies the phrenic nerve, pleura, pericardium and diaphragm (minimal contribution)
what is the pericardial cavity
between the parietal and visceral layers of serous pericardium
the visceral serous pericardium is also known as
epicardium
where is the transverse pericardial sinus found
between the inflow and outflow great vessels
where is the oblique pericardial sinus found
space behind the heart, extending where the pulmonary veins enter the left atrium
base of heart
left atrium (posteriorly)
right border of heart
right atrium
inferior border of heart
right ventricle
apex of heart
wall of left ventricle
left border of heart
left ventricle
superior border of heart
right and left atria and auricles
what is the ligament arteriosum
fibrous remnant of ductus arteriosus
what is the relation of the left recurrent laryngeal to the ligament arteriosum
left recurrent laryngeal nerve runs posterior to ligament arteriosum
where do cardiac veins drain
into coronary sinus
APART from anterior cardiac veins»_space;> directly into right atrium
what are the ridges in the right atrium called
musculae pectinatae
what is the crest terminalis
border between smooth part of wall and muscular ridged wall in right atrium
what is the sinus venarum
smooth venous area in right atrium
opening of IVC, SVC and coronary sinus
which valve separates the right atrium and ventricle
tricuspid
what are the ridges in the right ventricle called
trabecular carneae
which structure is unique to the right ventricle
moderator band
what is the moderator band
band of tissue running from the inter ventricular septum to the anterior wall
carries part of the conducting system
ensures papillary muscles contract at the same time as rest of heart muscle
which valve separates the left atrium and ventricle
bicuspid/mitral
semilunar valves are closed in high/low pressure
low
function of the semilunar valves
to prevent back flow of blood back into ventricles
cuspid valves are closed in high/low pressure
high
describe how cuspid valves work
ventricles contract»_space;> increased pressure»_space;> papillary muscles contract»_space;> creates tension in cordae tendineae»_space;> keeps leaflets closed
what is the function of the fibrous skeleton of the heart
support for the valves
electrical insulation between atria and ventricles
autonomic innervation of the heart
from cardiac plexus (SA node)
SA node depolarises»_space;> spreads through atria (contraction)»_space;> reaches AV node, causing depolarisation»_space;> passed down AV bundle»_space;> bundle of His»_space;> purkinje fibres
parasympathetic innervation of heart
vagus (CN X)
cardiac plexus to intrinsic ganglia
sympathetic innervation of heart
T1-5/6
cervical and superior thoracic paravertebral ganglia of (sympathetic chain)
what are the boundaries of the superior mediastinum
manubrium bodies of T1-4 vertebrae transverse thoracic plane thoracic inlet parietal pleura
what is the level of the transverse thoracic plane
sternal angle and T4/5 IV disc
what is contained in the superior mediastinum
thymus (in children) brachiocephalic veins and SVC arch of aorta trachea oesophagus phrenic and vagus nerve lymphatics
which structures are found only in the superior mediastinum (not in any part of the inferior mediastinum)
thymus
brachiocephalic veins
arch of aorta
trachea
branches of the arch of the aorta
brachiocephalic trunk
left common carotid
left subclavian
what are the branches of the brachiocephalic trunk
right subclavian and right common carotid
describe the course of the right vagus nerve in the superior mediastinum
anterior to right subclavian
gives off right recurrent laryngeal nerve that loops under right subclavian artery
where does the right recurrent laryngeal nerve run as it ascends the superior mediastinum
in space between trachea and oesophagus
describe the course of the left vagus nerve in the superior mediastinum
runs between left common carotid and left subclavian
gives off left recurrent laryngeal which loops under arch of the aorta (posterior to ligament arteriosum)
what does the vagus nerve innervate in the thorax
gives branches to cardiac plexus deep to arch of aorta
gives branches to right and left pulmonary plexus on right and left main bronchi
describe the oesophageal plexus
left and right vagus nerves combine to form an anterior and posterior oesophageal plexus
they then continue as anterior and posterior vagal trunks
which vagus nerve provides the majority of the fibres of the anterior and posterior vagal trunks
anterior = mostly left vagus nerve fibres posterior = mostly right vagus nerve fibres
nerve roots of phrenic nerve
C3,4,5
describe the course of the right phrenic nerve in the thorax
runs alongside the right brachiocephalic vein, SVC and pericardium over the right atrium
anterior to root of right lung
where does the right phrenic nerve pierce the diaphragm
near the caval opening
describe the course of the left phrenic nerve in the thorax
lies between left subclavian artery and vein, to the left of the arch of the aorta and anterior to vagus
anterior to root of left lung hilum onto surface of pericardium over left atrium and ventricle
where does the left phrenic nerve pierce the diaphragm
to the left of the pericardium
what type of innervation does the phrenic nerve provide
motor innervation to diaphragm
sensory innervation to fibrous pericardium
where does the trachea begin
C6/7
below larynx
where does the trachea bifurcate and what is the name of the bifurcation
T4/5
carina
describe the structure of the trachea and how this aids its function
C-shaped cartilages anteriorly with trachealis muscle posteriorly
cartilage keeps airway patent
muscle allows expansion of oesophagus which lies posteriorly
which lymph nodes are associated with the trachea
bronchopulmonary
carinal
where does the oesophagus begin
C6
continuation of pharynx
describe the course of the oesophagus through the thorax
initially lies to the right of the aorta
crosses anteriorly prior to piercing the diaphragm
where does the oesophagus pierce the diaphragm
T10
what causes the constrictions of the oesophagus visible on imaging studies
arch of aorta
left bronchus
diaphragm
what are the boundaries of the posterior mediastinum
transverse thoracic plane
bodies of T5-12
pericardium and diaphragm
parietal pleura
branches of thoracic aorta
oesophagus pericardium bronchi thoracic wall diaphragm
where is the azygous vein
runs to the right of the VC
which intercostal veins drain directly into the azygous vein
right T2-11 and subcostal
how do the left intercostal veins drain into the azygous system
1-4 drain straight into brachiocephalic vein
5-8 to accessory hemiazygous
9-11 and subcostal to hemiazygous
where does the thoracic duct lie
between the azygous vein and aorta
which vein does the thoracic duct arch over to connect to the left venous angle
internal jugular
which veins make up the venous angle
internal jugular and subclavian
which rami communicantes are associated with sympathetic inflow and outflow
inflow = grey outflow = white
sympathetic outflow occurs at which vertebral levels
T1-L2/3
which vertebral levels make up the greater splanchnic nerves
T5-9
which ganglia do the greater splanchnic nerves innervate
coeliac and superior mesenteric
which vertebral levels make up the lesser splanchnic nerves
T10-11
which ganglia do the lesser splanchnic nerves innervate
superior mesenteric and aorticorenal
which vertebral levels make up the least splanchnic nerves
T12
which ganglia do the least splanchnic nerves innervate
aorticorenal
what is the function of the thoracic splanchnic nerves
supply sympathetic innervation to the abdominal viscera
what level is the caval opening
T8 (VENA CAVA has 8 letters)
what passes through the caval opening of the diaphragm
IVC
what forms the caval opening of the diaphragm
opening in the central tendon
what level os the oesophageal hiatus
T10 (OESOPHAGUS has 10 letters)
what passes through the oesophageal hiatus
oesophagus and vagal trunks
what level is the aortic hiatus
T12
what forms the aortic hiatus
space posterior to the median arcuate ligament
what passes through the aortic hiatus
aorta, thoracic duct, azygous vein
which structures pass through the opening of the diaphragmatic crura
greater and lesser splanchnic nerves
which structures pass behind the medial arcuate ligament
least splanchnic nerve and sympathetic trunk
