1. Anatomy of the respiratory system Flashcards
describe the development of the respiratory system
develops as a diverticulum from the pharynx
what are the adaptations of the lateral nasal cavity to maximise warming and moistening inspired air?
Inferior middle and superior conchae increase the surface area of the nasal cavity – this increases the amount of inspired air that can come into contact with the cavity walls. They also disrupt the fast, laminar flow of the air, making it slow and turbulent. The air spends longer in the nasal cavity, so that it can be humidified.
what is the function of the nasal cavity?
induce turbulent flow warm and moisten inspired air recover water from expired air speech production (phonation) olfaction
what are the paranasal sinuses?
The paranasal sinuses are air-filled extensions of the nasal cavity.
what is the function of the paranasal sinuses?
Lightening the weight of the head
Supporting immune defence of the nasal cavity
Humidifying inspired air
Increasing resonance of the voice
why are the cartilages of the trachea incomplete?
as the oesophagus runs posterior to the trachea and needs space to expand when swallowing a food bolus.
what form the conducting airways?
trachea primary bronchi secondary (lobar) bronchi tertiary (segmental) bronchi bronchioles terminal bronchioles
what is meant by the conducting airway?
sections of the respiratory tract which do not directly participate in gas exchange and instead simply allow bulk flow of air to areas which are responsible for gas exchange.
how many true ribs do we have?
12
how many false ribs do we have?
5 pairs
what are the boundaries of the thoracic cavity?
walls = sternum, ribs and vertebrae roof = superior thoracic aperture floor = diaphragm, inferior thoracic aperture
where do the ribs articulate on the vertebrae?
on the demifacets. each rib articulates with 2 vertebrae
what is the mediastinum?
The mediastinum is a division of the thoracic cavity; it contains the heart, thymus gland, portions of the esophagus and trachea, and other structures. It is the septum between the pleural cavities
how does the chest wall move on inspiration?
increase in the lateral dimension of the chest as ribs ascend
sternum moves up and outwards to increase the anteroom posterior dimension of the thorax
what pressure change occurs to allow inspiration?
the volume of the thoracic cavity increases, dropping intrapleural pressure
alveolar pressure must be lower than atmospheric pressure for air to enter the alveoli
describe the structure of intercostal muscles?
3 layers. external intercostals, internal intercostal and innermost intercostal
what vessels are associated with the ribs?
below the ribs = intercostal artery, vein and nerve
above the ribs = collateral branches
what innervates the diaphragm?
phrenic nerve - c3 c4 c5
what are the 3 major openings of the diaphragm?
vena cava T8
oesophagus T10
aortic hiatus T12
what muscles are accessory muscles of ventilation?
pectoral muscles
SCM
intercostal arteries have a dual blood supply, what are they?
aorta
internal thoracic artery
where are chest drains inserted?
above the ribs
what drains into the azygous vein?
thoracic cage - drains blood from the level of the heart so that it doesn’t go straight into the right atrium
describe the variation in the structure of the left and right lobes?
the left lung has 2 lobes separated by the oblique fissure. It is indented by the heart
the right lung has 3 lobes. the superior and middle lobe are separated by the transverse fissure. the middle and the inferior lobe of the right lung are separated by the right oblique fissure
why is it more common to inhale objects into the right bronchus than the left?
as the right bronchus sits at a straighter angle than the left bronchus
what is the hilum of the lung?
the hilum is on the medial surface of the lung and is the area where vessels run in and out . Contains bronchi, pulmonary arteries and veins
at what level is the hilum of the lung?
T3/T5
what are the divisions of the mediastinum?
the anterior
the superior
the middle
the posterior
what is the difference between the visceral and parietal pleura?
visceral pleura is adhered to the organ, parietal is in contact with the thoracic wall.
parietal = rich innervation, somatic pain
visceral = no somatic innervation, do not feel pain as sharply, more of an ache.
what is the pleural cavity?
a potential space between the visceral and parietal serous membranes. Contains a small amount of serous fluid
what is the costophrenic recess
A potential space around the lung inside the pleural cavity. Is in the lower most part of the pleura, and from the angle between the ribs and the diaphragm.
what is the blood supply to the lungs
pulmonary arteries
bronchial arteries
why is the right hemidiaphragm higher than the left?
as the liver pushes it higher
