Respiratory anatomy (including clinical scenarios) Flashcards
What are the boundaries of the anterior triangle of the neck?
superior boundary = inferior border of mandible
posterior boundary = anterior margin of sternocleidomastoid
anterior boundary = midline of neck
What is the function of the infrahyoid and suprahyoid muscles?
suprahyoid muscles = elevate hyoid/larynx
infrahyoid muscles = depress hyoid/larynx
Which cranial nerves do the laryngeal nerves branch from?
laryngeal nerves are branches of cranial nerve 10 (vagus nerve)
Which group of muscles does the recurrent laryngeal nerve innervate?
all of intrinsic muscles of the larynx (except for cricothyroid)
What are enclosed in the pretracheal fascia?
thyroid gland and trachea
How can the thyroid gland and trachea being enclosed in the pretracheal fascia cause a potential problem following a thyroidectomy?
fascia surrounds the thyroid gland, trachea and pharynx forming an enclosed space
if a vessel is damaged during a thyroidectomy, blood can fill this space, leading to an onset of asphyxiation and airway compromise
What are pleurae?
fluid-secreting membranes that line the internal thoracic wall, diaphragm, mediastinum and external surface of the lungs
What is the function of the parietal and visceral pleura?
produce serous fluid that allows the lungs to slide smoothly against the chest wall
surface tension of the pleural fluid provides the cohesion that keeps the lung surfaces in contact with the thoracic wall, resulting in the lungs expanding and filling with air when the thorax expands
What is the innervation of the parietal and visceral pleurae and why may this be clinically relevant?
parietal = somatic innervation
visceral = autonomic innervation (not very sensitive or specific to pain)
clinical relevance = a lesion/tumour affecting lung tissue (covered by visceral pleura) will not present as a sharp, localised pain
if it spreads and invades/comes into contact with the parietal pleura, the pain will become sharp and highly localised
What is the normal function of the costodiaphragmatic and costomediastinal recesses?
act as potential spaces for the lungs to expand into during forces inspiration
Why can the costodiaphragmatic and costomediastinal recesses be important clinically?
pleural effusions collect in the costodiaphragmatic recess when in the standing position
pleural taps often work in this space as there is a decreased risk of puncturing the lung
Which peripheral nerve (and nerve roots) innervate the diaphragm?
phrenic nerve (C3, C4, C5)
[3, 4, 5 keep the diaphragm alive)
Where might irritation of the diaphragm present referred pain to?
C3 and C4 also supply supraclavicular nerves, whilst C5 forms the upper root of the brachial plexus and receives sensation from the lateral arm and shoulder region
irritation of the diaphragmatic pleura or peritoneum can present as pain in the region above the clavicle and shoulder tip
What neurovascular structures lie in the groove between the attachments of the anterior and middle scalene muscles?
trunks of the brachial plexus
subclavian artery
What are the names of the 2 actions of rib movement?
pump handle action = intercostal muscles acting on upper ribs contract, rib cage expanded in antero-posterior plane
bucket handle action = lower ribs take a more oblique course from posterior to anterior, when the intercostal muscles pull on these ribs, they tend to swing out laterally
How do we cause air to move into the lungs?
increase intrathoracic volume
this drops the pressure below atmospheric pressure
air will move into the lungs in any way it can to equalise the pressure
Which muscles are involved in quiet respiration?
primarily the diaphragm
with assistance from the intercostals/scalene if needed
What are the accessory muscles of respiration?
sternocleidomastoid
pectoralis major
serratus anterior
latissimus dorsi (inspiration)
abdominal muscles (expiration)
What is a pneumothorax?
air in pleural cavity
What is a tension pneumothorax?
the opening in the pleura creates a flap that acts as a one-way valve
this allows air to enter the cavity during inspiration, but stops it from leaving during expiration
What is a haemothorax?
blood in the pleural cavity
What is a pleural effusion?
liquid in pleural cavity (commonly as a result of infection)
What is the difference between a primary and secondary spontaneous pneumothorax?
primary spontaneous pneumothorax = develops for no apparent reason in an otherwise healthy person, usually young adult
thought to be due to tiny tear of an outer part of the lung, commonly near the apex of the lung
secondary spontaneous pneumothorax = develops as a complication (a secondary event) of an existing lung disease