The tracheobronchial tree and larynx Flashcards
what level is the suprasternal notch?
T2/3
what level is the sternal angle?
T4/5
what level is the inferior angle of the scapula?
T8
what level is the xiphisternum?
T9
what level is the lowest part of the costal margin - 10th rib?
L3
how many ribs are there?
12
connections of the ribs
the first 7 are connected via costal cartilages to sternum
8-10 are articulated with the rib above
11 and 12 are free
what is the role of the thoracic cage?
protection of the thoracic and abdominal organs
resists negative intrathoracic pressure of lung recoil can change shape for respiration
attachment and movement of upper limbs
naming of intercostal spaces
named after the rib above the space
what is the role of pleural fluid?
creates surface tension which keeps lung surface in contact with thoracic wall while still allowing sliding of surfaces
what is the root of the lungs?
the structures that pass to or from the hilum
bronchus
bronchial arteries and veins
pulmonary artery and veins
trachea
11-12cm long and 2.5cm wide
fibrocartilagenous tube supported by cartilage rings
extends from the larynx at the level of C6 to T5 (sternal angle)
what are the layers of the trachea?
mucosa - pseudostratified ciliated columnar epithelium
submucosa - areolar connective tissue with seromucous glands and ducts
C shaped ring of hyaline cartilage - completed by trachealis smooth muscle and connective tissue
adventitia - made of areolar connective tissue
where does the trachea bifurcate?
carina
level of sternal angle
main bronchi
enter lungs at hilum
right is wider, shorter and more vertical and the left is inferior to the aortic arch and anterior to esophagus and descending thoracic aorta .
what is the largest subdivision of the bronchial tree?
bronchopulmonary segments
bronchopulmonary segments
largest subdivision of lung
pyramidal shape, apex at hilum
discrete anatomical and functional units separated by connective tissue.
surgically resectable
blood supply and drainage of bronchopulmonary segments
supplied by segmental bronchi, pulmonary and bronchial arteries centrally
venous and lymphatic drainage at edges
drain adjacent segments
how many bronchopulmonary segments are there in the left lung?
8-10, 4-5 per lobe
how many bronchopulmonary segments are there in the right lung?
10
3 superior
2 middle
5 inferior
what comes from secondary bronchi?
segmental bronchi / tertiary
segmental bronchi
divide into conducting bronchioles that end as terminal bronchioles
bronchioles
transport air, no alveoli
bronchioles lack cartilage
terminal bronchioles divide into respiratory bronchioles
respiratory bronchioles
outpouchings - alveoli
structural unit of gas exchange
involved in transport and gas exchange
divide into alveolar ducts (2-11)
alveolar ducts
give rise to alveolar sacs (5-6)
multiple alveoli clusters open
how many alveoli are there?
300 million
what is a bronchopulmonary segment?
part of lung supplied by a tertiary/ segmental bronchus and arteries
what is there within each bronchopulmonary segment?
lobules of the lung segmental bronchus segmental branches from pulmonary artery branches of bronchial artery pulmonary vein and lymphatics at margin
branches of bronchial tree
secondary/ lobar bronchi tertiary/ segmental bronchi smaller bronchi bronchioles terminal bronchioles respiratory bronchioles
secondary bronchioles
aka lobar
plates of hyaline cartilage
tertiary bronchi
aka segmental
pseudostratified ciliated columnar epithelium
smaller bronchi
reduced or no plates of hyaline cartilage
bronchioles
simple ciliated columnar/ cuboidal epithelium
no cartilage, more smooth muscles
terminal broncioles
simple cuboidal epithelium
no goblet cells and underlying mucous glands
respiratory bronchioles
simple squamous epithelium
blood supply to trachea
neck - inferior thyroid arteries
chest - branches from bronchial arteries
blood supply of lungs
each lung has a pulmonary artery and 2 pulmonary veins (superior and inferior)
pulmonary artery
divides alongside the bronchial tree
carry low O2 blood to lungs for oxygenation
pulmonary veins
right middle to superior lobe
carries oxygen rich blood to the left of heart
independent of bronchial tree and pulmonary arteries
bronchial arteries
supply blood for nutrition to the lungs, structures of the root of the lungs and visceral pleura
where do the left bronchial arteries come from?
2 from thoracic aorta
right bronchial artery
1 from thoracic aorta or from one of the 3 upper posterior intercostal arteries or left superior bronchial artery
blood supply to parietal pleura
supplied and drained by thoracic wall vessels
emphysema
lung tissue destruction and reduced airflow
chronic bronchitis
inflammation and scarring and narrowed airways
asthma attack
smooth muscle spasms occur at bronchiolar level of bronchial tree and closes off airways as there is no cartilage
what happens during exercise?
increased sympathetic activity
release of adrenaline and noradrenaline by the adrenal gland
relaxation of smooth muscles of bronchiole
bronchodilator
increase lung ventilation
what happens at rest/ in allergies
parasympathetic activity
allergic mediators released - histamine
contracts the bronchiolar smooth muscles - bronchoconstriction
decrease lung ventilation
where is laryngeal prominence
C4-5
trachea surface anatomy
midline from laryngeal prominence
immediately posterior to suprasternal notch
bifurcates at sternal angle
tracheal deviation
caused by tension pneumothorax
symptoms of tension pneumothorax
tracheal deviation chest pain shortness of breath rapid heart rate shallow breathing anxiety blue or ashen skin kinking of vena cava causing no venous return to heart, no cardiac output, risk of cardiac arrest
how does a tension pneumothorax form?
opening in pleura acts as 1 way valve so air comes in on inspiration but the valve closes on expiration and the air cannot escape
positive intrapleural pressure collapses the lung and eventually causes mediastinal shift to the opposite side
treatment for tension pneumothorax
medical emergency
insert large bore cannula to mid clavicular line 2nd intercostal space
chest tube
incision is made in the 5th and 6th intercostal space in the midaxillary line (nipple level)
directed superiorly to cervical pleura to remove air or inferiorly to remove fluid
Larynx
anterior neck
functions of larynx
phonation
cough reflex
protection of lower respiratory tract
structure of larynx
primarily cartilaginous skeleton - 9 cartilages
ligaments and membranes
laryngeal muscles move components of the larynx for phonation and breathing
anatomy of larynx
suspended from hyoid bone C3-6 below pharynx and above trachea behind infrahyoid muscles in front of oesophagus and medial to thyroid gland
subdivisions of larynx
internal cavity divided into 3
supraglottis
glottis
subglottis/ infraglottis
supraglottis
from inferior surface of epiglottis to vestibular folds
glottis
vocal apparatis
contains false and true vocal cords
laryngeal ventricle - lateral recess between vestibular and vocal folds
rima glittidis
opening between vocal cords, size altered by muscles of phonation
subglottis
from vocal folds to trachea
laryngeal cartilages
unpaired and paired
unpaired laryngeal cartilages
thyroid
cricoid
epiglottis
thyroid cartilage
laryngeal prominence
superior and inferior horns
thyrohyoid membrane attaches to hyoid
cricoid cartilage
ring cricothyroid joints changes length of vocal folds cricothyroid ligament cricotracheal ligament
epiglottis
posterior to root of tongue
paired laryngeal cartilage
arytenoid
corniculate
cuneiform
vocal folds
under control of muscles of phonation
vocal ligament
vocalis muscle
what is the space between the vocal folds called?
rima glottidis
vestibular folds
false vocal cords lie superiorly to the true vocal cords consist of vestibular ligament fixed folds provide protection to larynx
laryngeal muscles
extrinsic and intrinsic
extrinsic laryngeal muscles
elevate or depress the larynx during swallowing
larynx suspended from hyoid
infrahyoid muscles depress
suprahyoid muscles elevate
intrinsic laryngeal muscles
move the individual components of the larynx for breathing and phonation control shape of rima glottidis adductors abductors sphincters tensors relaxers vocalis muscles
innervation of intrinsic laryngeal muscles
inferior laryngeal nerve from recurrent laryngeal nerve
innervation of cricothyroid
superior laryngeal nerve
laryngeal ligaments
extrinsic
intrinsic
extrinsic laryngeal ligaments
attach larynx to external structures
intrinsic laryngeal ligaments
hold cartilages of the larynx together as one functional unit internally
cricothyroid and quadrangular membrane
appearance of false and true vocal cords
false/ vestibular folds = covered by mucous membrane, are pink
true vocal folds = avascular so appear white
blood supply of larynx
superior and inferior laryngeal artery
superior laryngeal artery
branch of superior thyroid artery
supplies internal surface
inferior laryngeal artery
branch of inferior thyroid artery
supplies mucous membranes and muscles of inferior larynx
venous drainage of larynx
superior and inferior laryngeal veins
superior laryngeal vein
drains to internal jugular vein
inferior laryngeal vein
drains to left brachiocephalic vein
lymphatic drainage of larynx
superior to vocal folds = superior deep cervical lymph nodes
inferior to vocal folds = pretracheal and paratracheal lymph nodes - inferior deep cervical lymph nodes
innervation of larynx
motor and sensory from vagus nerve, via superior and inferior laryngeal nerve
inferior laryngeal nerve
continuation of recurrent laryngeal nerve
sensory to infraglottis
motor to all internal muscles except cricothyroid
superior laryngeal nerve
sensory to supraglottis
motor to cricothyroid muscle
what causes a recurrent laryngeal nerve palsy?
apical lung tumour thyroid cancer aortic aneurysm cervical lymphadenopathy iatrogenic
symptoms of recurrent laryngeal nerve palsy
hoarse voice due to paralysis of vocal fold
weak voice
bovine cough
unilateral RLN palsy
hoarseness
increased risk of aspiration
bilateral RLN palsy
cords adducted
breathing impaired - stridor, snoring
phonation cannot occur
cricoid pressure
during intubation pressure can be applied to cricoid cartilage of larynx and occludes the oesophagus preventing gastric regurgitation
