The tracheobronchial Tree and Larynx Flashcards
suprasternal notch
T2/3
sternal angle of Louis
T4/5(2nd rib ends)
inferior angle of scapula
T8
Xiphisternum
T9
lowest part of the costal margin
10th rib L3
pleural fluid
creates surface tension which keeps lung surface in contact with thoracic wall while still allowing sliding of surfaces
trachea
extends from the larynx at the level of C6 to T5
levels of the trachea
mucosa(pseudostratified ciliated columnar epithelium)
submucosa(areolar connective tissue with seromucous glands and ducts)
C-shaped ring of hyaline cartilage(completed posteriorly by the tracheal smooth muscle and connective tissue)
Adventitia(made of areolar connective tissue)
tracheal bifurcation
carina
level of sternal angle
secondary lobar bronchi
plates of hyaline cartilage
tertiary segmental bronchi
pseudo stratified ciliated
columnar epithelium
smaller bronchi
reduced or no plates of hyaline cartilage
bronchioles
simple ciliated columnar/cuboidal epithelium
no cartilage ,more smooth muscles
Terminal bronchioles
simple cuboidal epithelium
no goblet cells and underlying mucous glands
respiratory bronchioles
simple squamous epithelium
blood supply of the trachea
neck-inferior thyroid arteries
chest-branches from the bronchial arteries
blood supply of lung
each lung has a pulmonary artery
divers alongside the bronchial tree
carry low O2 ‘venous blood’ to lungs for oxygenation
venous supply of lungs
2 pulmonary veins
-superior and inferior
-right middle lobe to superior
carry oxygen rich ‘arterial blood’ to left heart
independent of bronchial tree and pulmonary arteries
except centrally visceral pleura and bronchial venous blood drain into pulmonary veins
bronchial arteries
supply blood for nutrition to the lungs, structures of the root of the lungs and visceral pleura
two left bronchial arteries
-directly from the thoracic aorta
single right bronchial artery
-may arise directly from the thoracic aorta or indirectly from one of the three posterior intercostal arteries or the left superior bronchial artery
parietal pleura supplied and drained by thoracic wall vessels
in exercise
-increased sympathetic activity
-relase of adrenaline and noradrenaline by the adrenal gland
-relaxation of the smooth muscles in the bronchiole
increase lung ventilation
histamine
parasympathetic activities
contract the bronchiolar smooth muscles
decrease lung ventilation
surface anatomy of trachea
midline
-from laryngeal prominence (C4-C5 vertebral level)
immediately posterior to suprasternal notch
bifurcates at sternal angle
tension pneumothorax
medical emergency
insert large bore cannula-mid clavicular line 2nd intercostal space
positive intrapleural pressure collapses lung and eventually causes mediastinal shift to the opposite side
as this happens it can cause kinking of the vena cava resulting in :
no venous returns heart=no cardiac output=risk of cardiac arrest
chest tube
incision is made in the 5th and 6th intercostal space in the midaxillary line
the tube may be directed superiorly toward the cervical pleura for removal of airier inferiorly toward the costodiaphragmatic recess for fluid drainage
larynx
suspended from the hyoid bone
C3-C6
laterally-thyroid gland
posteriorly oesophagus
thyroid
C4
laryngeal prominence
superior and inferior horns
thyrohyoid membrane attaches to hyoid
cricoid
ring
crocothyroid joints
change length of vocal folds
epiglottis
posterior to root of tongue
extrinsic laryngeal muscles
elevate or depress the larynx during swallowing
intrinsic laryngeal muscles
move the individual components of the larynx, for breathing and phonation
blood supply of the larynx
superior laryngeal artery-a branch of the superior thyroid artery
inferior laryngeal artery-a branch of the inferior thyroid artery
venous drainage of larynx
the superior laryngeal vein drains to the internal jugular vein via the superior thyroid
the inferior laryngeal vein drains to the left brachiocephalic vein via the inferior thyroid vein
nervous innervation of the larynx
vagus nerve
inferior laryngeal nerve-sensory to infra glottis and motor of internal muscles
superior laryngeal nerve-sensory to supra glottis and motor to cricothyroid
recurrent laryngeal nerve palsy
apical lung tumour thyroid cancer aortic aneurysm cervical lymphadenopathy iatrogenic (thyroid surgery) -leads to hoarseness of voice due to paralysis of the vocal fold.
unilateral rln palsy
- hoarseness
- increased risk of aspiration
bilateral rln palsy
- cords adducted
- breathing impaired (stridor, snoring)
- phonation cannot occur
left recurrent laryngeal nerve
- long course
- down into chest and loops under aortic arch up to larynx
right recurrent laryngeal nerve
shorter and loops around subclavian artery
cricoid pressure
- during intubation pressure can be applied to the cricoid cartilage of the larynx
- this occludes the oesophagus-preventing gastric regurgitation
