Respiratory Flashcards
Name the laryngeal cartilages
name the paranasal sinuses
- green: frontal sinuses
- red: sphenoid sinuses
- blue: maxillary sinuses
- purple: ethmoid sinuses
Muscle that tensions vocal cords
vocalis
histology
- larynx
- contains several plates of hyaline cartilage and a complex arrangment of striated muscles embedded in fibrous connective tissue
- Trachea is respiratory epithelium
- Vocal folds are stratified squamous
nerve supply to frontal sinuses
opthalmic branch of CN V
what is the hiatus semilunaris
this is the hole through which all sinuses except the sphenoid open into the middle meatus
what structures is the sphenoid sinus close to?
- carotid artery
- Cranial nerves
- 3
- 4
- 5
- 6
- NB it is medial to the cavernois sinus
what is the nerve supply to the sphenoid sinus
the opthalmic nerve
9 cartilages of the larynx
- Three single
- Epiglottis – barrier that blocks laryngeal opening while swallowing
- Thyroid
- Cricoid
- Six are paired
- Arytenoid (look like little As at the back that are intimately related to the vocal chords)
- Cuneiform
- Corniculate (on the very top of the arytenoid)
where would an emergency tracheostomy be done
through the crico-thyroid membrane between cricoid and thyroid cartilages
- lines the conducting airways where no gas exchange happens
- simple or pseudo-stratified columnar ciliated epithelium with non-cilliated goblet cells
- found in the
- nose
- nasopharynx
- larynx
- trachea
- bronchi
- bronchioles
innervation of larynx - can you draw the diagram
where do the left and right laryngeal nerves loop around?
- Left: loops under the arch of the aorta and ascends between the trachea and the oesophagus
- Right: loops under the right subclavian
why might a lung tumour cause a horse voice
it could cause a recurrent laryngeal nerve palsy
what is the division between the upper and lower airways?
the larynx
to which rib does the sternal angle attach?
2nd
what surface area of gas exchange is there per lung
20m2
what is the amount of air in and out of the lungs in one minute
5L
what is the bifurcation of the trachea called?
carina
what level is the carina
T4/5
what epithelia is the trachea lined with
respiratory epithelium
pseudostratefied, ciliated columnar epithelium with goblet cells
how many lobes does each lung have? describe the fissures that seperate them
- Right Lung:
- Upper lobe
- Middle lobe
- Lower lobe
- Left lung
- Upper lobe (and lingula)
- Lower lobe
what is a terminal bronchiole?
it is the last conducting airway before respiratory bronchioles
what is the functional unit of the lungs - briefly describe it.
- The acinus
- It contains:
- respiratiry bronchiole
- alveolar ducts
- alveoli
what are the interconnections between alveoli called
pores of kohn
these ensure equal inflation
describe thickness of alveolar walls
- 70% of the surface area of the alveolar sacs is less than 1 micrometre thick (between air sac and capillary lumen) allowing rapid diffusion of gases across this air blood barrier (see later).
- Elsewhere cell nuclei and connective tissue elements add to the thickness of the walls of the aveoli
how many alveoli are there per lung?
about 300,000,000
Pleura
- Of mesodermal origin
- 2 layers
- Visceral – lung surface
- Parietal – internal chest wall
- Each layer is a single cell thick
- Continuous with each other at the hilum
- Parietal pleura has pain sensation
- Visceral pleura has only autonomic innervation
7 layers of gas exchange
- surfactant
- aveolar epithelium
- basement membrane
- tissue interstitium
- capillary endothelium
- red cell membrane
- Hb binding
What is the purpose of surfactant
- reduces surface tension of water that lines the lung
- this increases compliance
- this reduces energy needed to expand the lung
- it also prevents collapse
- It is produced by type II pneumocytes from 24 weeks
- very prem babies can go into respiratory distress if they haven’t begun producing surfactant
- breathing is too exhausting
describe pump handle rib movements
- ribs move up anteriorly, articulating at the vertebral column
describe bucket handle rib movements
- lateral side of ribs move up, articulating with the sternum and vertebral column
which nerve innervates the diaphragm
phrenic: C3,4 and 5
what is dead space and how is it split up?
this is the volume of air that does not contribute to ventilation
- anatomic: 150mls
- stays in conducting airways
- alveolar: 25ml
- Physiologica: 175ml
- alveolar and anatomical combined
what does lung capillary perfusion depend on?
- Pulmonary artery pressure
- Pulmonary venous pressure
- Alveolar pressure
- How low in the lung they are (lower ones preferentially perfused)
hypoxia in the lungs
- Hypoxic pulmonary vasoconstriction
- Diverts blood away from the least well oxygenated areas
- This is the opposite of what happens in the body where they
what is VA
Alveolar ventilation
what is VCO2
CO2 Production
3 ways CO2 is carried in the blood
(i) Bound to Haemoglobin (protein chain) 23% approximately
(ii) Plasma dissolved CO2
(iii) As HCO3-
innervation of maxillary sinus
maxillary branch of trigeminal (V2)
innervation of the ethmoidal sinus
opthalmic and maxillary branches of the trigeminal nerve
(V1 and V2)
innervation of the sphenoid sinus and where it drians into
drains through the sphenoethmoidal recess into the superior meatus
Innervated by opthalmic branch of the trigeminal V1
what is the inferior border of the oropharynx?
the epiglottis
what is the inferior border of the laryngopharynx
the cricoid cartilage
what are the two muscle layers of the pharynx
name the muscles in the layers
what are they innervated by
- Inner longitudinal
- stylopharyngeus
- salpingopharyngeus
- palatopharyngeus
- Outer circular
- superior constrictor
- middle constrictor
- inferior constrictor
- ALL muscle of pharynx are innervated by the vagus except for stylopharyngeus which is innervated by the glossopharyngeal
at what vertebral level is the thyroid gland?
C5-T1
Label this diagram
what vertebral levels does the trachea span?
what innervates it?
C6-T4
innervated by the recurrant laryngeal (CN X)
difference in the cartilage between the trachea and the bronchi
Trachea cartilage is C shaped and deficient posteriorly
Bronchi cartilage is a complete ring
Trachiobronchial tree
cells in the alveoli
- Type I pneumocytes
- less common but cover most surface area
- thin squamous epithelieal cells
- gas exchange
- Type II pneumocytes
- more common but cover less surface area
- lots of cytoplasm and organelles
- produce surfactant
- Alveolar macrophages
- present in the lumen of alveoli and alveolar ducts
Inspiration
- phrenic stimulates diaphragm to flatten
- volume of thoracic cavity increases
- chest wall moves away from the lung surface meaning parietal pleura moves away from visceral pleura
- intrapleural pressure drops
- transpulmonary pressure increases
- TP pressure is enough to overcome the intrinsic elastic nature of the lungs
- lungs expand
- alveolar pressure drops below that of the atmosphere
- this draws air into the lungs through the conducting airways