anatomy of thorax and lungs Flashcards
what are the main anatomical features of the thorax?
thoracic outlet, thoracic inlet, heart, lungs, sternum and ribs
where does the thoracic inlet attach?
T1 posteriorly
1st rib bilaterally
costal cartilage of 1st rib and superior border of manubrium
where does the thoracic outlet attach?
T12 posteriorly
11th and 12th ribs laterally
costal cartilage of 7th-10th ribs and xiphisternal joint anterolaterally
what is the manubrium?
part of the sternum
what are the three classes of ribs?
true- 1st-7th because they’re directly connected to the sternum
false- 8th-10th because they’re indirectly connected to the sternum
floating- 11th-12th because they’re not connected to the sternum
describe superficial intercostal muscles
formed by external intercostal muscles and the fibres have an inferior direction
describe middle intercostal muscles
formed by internal intercostal muscles and fibre direction is inferiorposteriorly
in what order does the neuromuscular bundle above the intercostal muscles go?
vein-artery-nerve
where does VAN lie between?
internal ad innermost intercostal muscles
what do external intercostal muscles become (anteriorly)?
external intercostal membrane
what do internal intercostal muscles become (posteriorly)?
internal intercostal membrane
where do the innermost intercostal muscles exist in relation to the thoracic cage?
only in the middle part of the thoracic cage
how is blood supplied in the thoracic cage ?
by the posterior intercostal arteries, anterior intercostal arteries and branches of axillary arteries
where does venous drainage from the thoracic cavity drain to?
into the azygous system
where does the mediastinum extend to and from?
from the thoracic inlet to the diaphragm
where does the mediastinum divide into superior and inferior?
at the sternal angle
what does the inferior part of the mediastinum divide into?
middle- contains heart, vessels, oesophagus, thymus and lymph nodes
anterior and posterior- contains lungs and pleura
what is the posterior and middle parts or the inferior mediastinum deviated by?
pericardial sac
describe lymphatic drainage on the anterior chest wall and breast
left side of chest- thoracic duct into left subclavian vein
right side of chest- right lymphatic duct into right subclavian vein
breast- axillary lymph node, parasternal lymph node, abdominal lymph node
where do phrenic nerves pass through?
root of phylum, side of heart and innervates the diagram
where do phrenic nerves originate from?
C3-C5 and they are both sensory and motor
from what position do phrenic nerves pierce and innervate the diaphragm?
inferiorly
what supplies the central part of the diaphragm?
phrenic nerves
what happens if phrenic nerves are damaged?
the side on which the nerve is damaged will be paralysed
eg. if the right phrenic nerve is damage the right side of the diaphragm dome will be paralysed so it wouldn’t descend during inspiration
where does the costovertebral joint lie?
between ribs and vertebrae
in the 1st rib where do the anterior and posterior grooves lodge?
anterior- subclavian vein
posterior- subclavian artery and lowest trunk of the brachial plexus
in regards to the ribs what increases during forceful inspiration?
transverse diameter of rib and intercostal diameter of thoracic gate, this elevates sternum and ribs upwards
describe the right and left crus of the diaphragm
right crus- L1-3 vertebrae, prevents the reflux of gastric content back to the oesophagus
left crus- L1-2
what are the 3 openings (hiatuses) of the diaphragm?
T8- caval opening
T10- oesophageal opening
T12- aortic hiatus
what are the two parts of the respiratory tract and what do they contain?
upper respiratory tract- nose, pharynx, larynx
lower respiratory tract- trachea, bronchi, bronchioles
how many bronhiopulmonary segments does each lung have?
10
what surrounds the right lung mediastinal surface?
heart, superior/inferior vena cava, oesophagus, right subclavian vein and artery
what surrounds the left lung mediastinal surface?
heart, aortic arch, thoracic aorta, oesophagus, left subclavian vein and artery
where does the trachea start and where does it bifurcate?
starts at C6 (lower larynx) and splits at sternal angle to give rise to the right and left bronchus
what is the tracheobranchial tree?
branching structure of airways which consists of conducting and respiratory portions
conducting portion does not undergo gas exchange
respiratory portion undergoes gas exchange
what does the conducting portion of the tracheobronchial tree consist of?
trachea main bronchus lobar bronchus segmental bronchus conducting bronchiole terminal bronchiole
what does the respiratory portion of the tracheobronchial tree consist of?
respiratory bronchiole
alveolar duct
alveolar sac
alveolus
what are the 3 lobes, borders and surfaces of the lungs?
lobes- superior, inferior, middle(only in right lung)
borders- anterior, posterior, inferior
surfaces- costal, mediastinal(medial), diaphragmatic(inferior)
how many fissures are in the left and right lungs ?
right- 2 horizontal and oblique
left- 1 oblique
what is the lingula?
tongue like projection of the left lung under the cardiac notch
what is a lung root?
structures such as bronchus, artery, veins, lymphatics and nerves that enter or leave the hilum
what is the hilum?
area located on mediastinal surface
how can you identify the left hilum from the right hilum ?
right- bronchus dividing into 2 pulmonary arteries which enter inferiorly and 2 pulmonary veins
left- 2 pulmonary veins
why are the pulmonary veins in the hilum red?
because they carry oxygenated blood
what is the clinical advantage of bronhopulmonary segments?
in cases of cancer the cancer cause be surgically removed from one segment before it moves into another
what is the lung supplied and drained by?
supplied by bronchial arteries (thoracic aorta, posterior intercostal artery)
drained by bronchial veins (azygous)
how does pulmonary innervation around the hilum happen?
by the pulmonary plexus
what does the pulmonary plexus contain?
parasympathetic fibres- vagus nerve either motor to bronchial muscle (causes bronhoconstriction) or secretomotor ( secretes mucus and vasodilator) to mucus glands
sympathetic- T2-5 either inhibitory to bronchial muscle (bronchodilator) or motor to blood vessel muscle
how many intercostal spaces are between the lung and the pleura?
2
lung- midclavicular 6, midaxillary 8, paravertebral 10
pleura- midclavicular 8, midaxillary 10, paravertebral 12
what’s the pleura that’s attached to the lungs?
visceral
what’s the pleura that’s attached to the thoracic cage?
parietal
what nerve supply is associated with the visceral and parietal pleura?
visceral- autonomic
parietal- somatic
what’s the pleural sac?
serous fluid, flows movement of lung during inspiration and expiration
what’s plural recess and reflection ?
recess- loose pocket at the lower part of the pleural sac where fluid accumulates
reflection- place at which parietal pleura changes direction to become visceral pleura
