The Tracheobronchial Tree and Larynx Flashcards
What is immediately posterior to the suprasternal notch?
Trachea
What is the sternal angle?
Where trachea ends and becomes right and left bronchus
What is the manubrium?
Massive, thickest and squarest of 3 main parts of sternum
What is the angle of louis?
Name given for sternal angle which is a palpable feature formed from manubriosternal junction
What are the symptoms of Tension Pneumothorax?
Chest pain + tightness Cough Blue or ashen skin (cyanosis) Rapid heart rate Fatigue Anxiety Shortness of breath Shallow breathing Seen respiratory distress Asymmetrical chest expansion Tracheal deviation on neck palpation
What causes tension pneumothorax?
Secondary to mechanical ventilation
Ongoing air leak
Can occur after penetrating or blunt chest trauma or potentially after failed subclavian or jugular venous catheter insertion attempts
Mechanism behind tension pneumothorax?
1) Opening in the pleura acts as 1 way valve so air in on inspiration but valve closes on expiration so can’t escape
2) Positive intrapleural pressure collapses lung
3) Eventually causes mediastinal shift to opposite side (tracheal shift)
4) This happening can cause kinking of vena cava resulting in decreased or no venous return to heart
5) Compresses the opposite lung
6) If no venous return can lead to no cardiac output = Risk of cardiac arrest
Management of Tension Pneumothorax (non-emergency)
Incision made in the 5th and 6th intercostal space in midaxillary line (approx nipple line)
Tube directed superiorly toward cervical pleura for removal of air or inferiorly toward costodiaphragmatic recess for fluid drainage
Management of Tension pneumothorax (emergency)
Cannula 2nd intercostal space in mid-clavicular line then chest drain
Trachea extends from which spinal levels?
From larynx at level of C6 to T5 (sternal angle)
What is the carina?
Where is it?
Ring of cartilage that has a hook underneath it that splits it into right and left bronchus
At level of sternal angle
What are the layers of the trachea?
Mucosa includes cilia, pseudo-stratified columnar epithelium, lamina propria
Submucosa
C-shaped ring of hyaline cartilage
Adventitia
What is the hilum?
Where the bronchi and pulmonary vessels enter the lung
Difference between left and right bronchi?
Right is wider, shorter and more vertical
What are the lobes in the lungs? How are they separated?
Left lung: Upper and lower love separated by oblique fissure
Right lung: Upper lobe, lower lobe and middle lobe
Upper and middle separated by horizontal fissure and all 3 separated by oblique fissure
Order of the bronchial tree?
Main bronchi (primary) Lobar bronchi (secondary) Segmental bronchi (tertiary) Terminal bronchioles Respiratory bronchioles Alveolar ducts Alveoli
What do the segmental bronchi (tertiary) supply?
bronchopulmonary segments
e.g upper, middle, lower lobes
What do bronchioles lack?
cartilage
Secondary (lobar) bronchi structural specialization
Plates of hyaline cartilage
Tertiary (segmental) bronchi structural specialization
Pseudostratified ciliated columnar epithelium
Terminal bronchioles structural specialization
Initially ciliated, then simple columnar epithelium
No cartilage, more smooth muscles
No goblet cells, no mucous
Respiratory bronchioles structural specialization
Simple squamous epithelium
Surfactant producing
Alveoli structural specialization
Single-cell layer of pneumocytes
Cause of acute asthma?
Allergen that causes sudden inflammation and contraction of bronchiole smooth muscle (bronchospasm), narrowing the airways
Symptoms of acute asthma
Difficulty breathing
Wheezing
What type of disease in terms of genes is cystic fibrosis?
Autosomal recessive
What is the pathophysiology of cystic fibrosis?
Deranged transport of chloride and other ions alters the viscocity of mucous
Makes patient more prone to infection, damaging bronchi resulting in bronchiectasis
Symptoms of COPD
Chronic bronchitis (mucus hypersecretion Emphysema (tissue destruction) Bronchiolitis (small airway inflammation and fibrosis)
Lead to resistance to airflow in airways
increased compliance in lungs
air trapping
Progressive airflow obstruction
What causes COPD?
Long term exposure to harmful particles and gases causing abnormal inflammatory response
Smoking major cause
Which arteries supply the lungs and visceral pleura?
Bronchial arteries
2 left bronchial arteries
single right bronchial artery
What vessels supply the parietal pleura?
Thoracic wall vessels
The lymphatic drainage steps for lungs
1) Bronchopulmonary nodes
2) Tracheobronchial nodes
3) Pratracheal nodes
4) Bronchomediastinal lymphatic trunks
5) Thoracic duct
Where is the larynx located?
In anterior neck
Functions of larynx ?
Phonation- production of vocal sound + speech
Cough reflex
Protection of the lower respiratory tract
How is the larynx interior surface lined?
Pseudostratified ciliated columnar epithelium except for vocal cord which stratified squamous epithelium
Larynx spinal root position
C3-C6
What is above and below the larynx
Superior pharynx
Inferiorly trachea
3 parts of the larynx
Supraglottis
Glottis- contains false and true vocal cords
Subglottis/infraglottis- vocal folds to trachea
Name 3 laryngeal cartilages (unpaired)
Epiglottis- flattens during swallowing
Thyroid (C4)
Cricoid (C6)- can be compressed during emergency intubation to stop regurgitation of stomach content
Name 3 paired laryngeal cartilages
Arytenoid
Corniculate
Cuneiform
What do vocal folds do?
produce speech
protect airway from choking from material in throat
regulate flow of air into lungs
What is Reinke’s space?
In true vocal cords. Watery layer. Due to fluidity, epithelium able to vibrate freely above it to create sound
What is Rima Glottidis?
Space between vocal cords
Difference between true and false vocal cords?
True: non-keratinized stratified squamous epithelium
False: vestibular ligament covered by mucous membrane
Similarities between true and false vocal cords?
Protection to larynx
What nerve innervates the larynx?
Vagus nerve (Motor and sensory)
What branch of the vagus nerve supplies the supraglottis?
Internal branch of superior laryngeal nerve
What branch provides innervation to infraglotttis?
Inferior laryngeal nerve (continuation of recurrent laryngeal nerve)
Which is more prone to palsy right or left recurrent laryngeal nerve?
Left as has a longer course- loops under aortic arch
Damage of RLN causes
Apical lung tumour
Thyroid cancer
etc.
Symptoms of Unilateral RLN palsy (recurrent laryngeal nerve)
Hoarseness
Increased risk of aspiration
Bovine cough
Symptoms of bilateral RLN palsy
Cords adducted
Breathing impaired (stridor, snoring)
Phonation cannot occur
What do the extrinsic laryngeal muscles do?
Elevate/superiorly or depress/inferiorly the larynx during swallowing
What do the intrinsic laryngeal muscles do?
Move individual components of larynx for breathing and phonation
What do the suprahyoid muscles do? (extrinsic)
Elevate the larynx
What do the infrahyoid muscles do?
Depress the larynx
How do the vocal cords produce sound?
Adduction of arytenoids and elongation of vocal folds closes the airway
What do extrinsic laryngeal ligaments do?
attach larynx to external structures?
What do intrinsic laryngeal ligaments do?
Hold cartilages of the larynx together as one functional unit
What is cricothyroidotomy
Emergency procedure that provides a temporary airway in situations where there is obstruction at or above the larynx
(facial trauma, oedema, foreign body)
How to do a cricothyroidotomy
1) Depression below thyroid cartilage can be palpated
2) Incision made here
3) ET tube inserted to secure airway
Vein drainage
Superior laryngeal vein draining to internal jugular vein and inferior laryngeal veins draining to left brachiocephalic vein
What lymph nodes are superior to vocal folds?
Superior deep cervical lymph nodes
What lymph nodes are inferior to vocal folds?
Pretracheal and paratracheal lymph nodes
Inferior deep cervical lymph nodes
What does the inferior laryngeal nerve innervate?
Sensory innervation to Infraglottis
Motor innervation to all internal muscles of larynx except cricothyroid
What does the superior laryngeal nerve innervate?
Sensory innervation to supraglottis
Motor innervation to cricothyroid
lung blood supply
1 pulmonary artery
2 pulmonary veins
2 left brachial arteries
1 right brachial artery
