Lungs And Airways Flashcards
Define ventilation
The action of mobilizing the body to create breathing action
What is respiration ?
It’s a cellular phenomenon
It’s both external and internal
External respiration happens when gaz are exchanged between capillaries and cells in tissues
Internal respiration happens when mitochondria use oxygenated blood to create ATP
What is the ventilation rate in healthy adults ?
10 cycles of inhale/ exhale (movement) per minute
What is the average heart frequency in healthy adults (at rest)
70 beats/ minute
Which nervous structures control the breath ?
- primarily involves neurons in the reticular formation of the medulla and pons
- medulla sets the breathing rhythm
- pons influences and modifies the activity of medullary neurons
Describe the aerobic respiration
Takes place in the mitochondria
It requires oxygen and glucose and produces carbon dioxyde, water and ATP
Which structures compose the upper thoracic tract ?
—> extra thoracic structures : Mouth External nose Nasal cavity Nasopharynx and oropharynx and laryngopharynx composing the pharynx Larynx
Regarding upper and lower thoracic tracts, how does their proportions evolve through life ?
50/50 in newborn, who are therefore much more exposed to virus and risk of respiratory disease
The proportion of low thoracic tract grows with age as well as the surface area of the alevoli
What are the functions of the external nose ?
Sole olfactory AND respiratory organ
Resonator of voice
Define the mucous membrane of the external nose
Specialize epithelial cells called goblet cells
Filter particulate matter
Adjust temperature and humidity of inspired air
What specific structures form the nasal cavities
The superior, middle and inferior concha
Where is located the olfactory region
In the nasal cavity
At the level of the superior concha
What is the technique to properly remove the secretions stagnating in the nasal mucosa ?
Sniff and spit
What is the specific role of goblet cells ?
Goblet cells form the membrane of the mucosa / the nasal epithelium. They extend into cilia which swap the secretions from the lungs to the periphery (approx 100 mL per day)
What are the anatomical zones of the pharynx
- nasopharynx
- oropharynx
- laryngopharynx
What is the cervical level of the larynx in adults ? In children ?
Adults : C4
In children it’s located higher : C3
What happens to trachea when we swallow ?
Epiglottis blocks the way to trachea
Where is the larynx located ?
Between the pharynx and the trachea from C3 to C6
What is the role of the larynx ?
Voicebox + air guidance
What is the structure of the larynx
Respiratory mucosa
Ligaments + 9 cartilage structures :
Unpaired : epiglottis, thyroid, cricoid
Paired : cuneiform, corniculate, arytenoid
Define the thoracic airways
Complex series of branching tubes that culminate in the gaz exchange area Composed of the tracheobronchial tree : - trachea - 2 main bronchi - lobar bronchi - segmental bronchi - bronchiole (respiratory bronchi + alveolar duct) - alveoli
What is the specificity of bronchioles
They are composed of respiratory bronchi and alveolar duct
As some alveoli are attached to the respiratory bronchi, some gaz exchanges happen at this level too
What are the 2 zones of the intrathoracic airways ?
Conducting zone
Respiratory zone
Limit between both : bronchioles
What can you tell about the angle formed by the tracheal and the main bronchi ? Why ?
Angle formed by the right main bronchi and trachea is bigger than the one formed by the left main bronchi and trachea. This is caused by the presence of the heart.
What is the name of the junction between the two main bronchi ?
The carina
Any bifurcation can be called a carina
What is the shape of the tracheal cartilage ? Why ?
C shaped
Posteriorly related to the esophagus
What happens to intra thoracic airways structures when you go deep ?
From cartilage it becomes smooth muscles in the bronchiole
What is the structure of wall and type of cells present in the trachea
Structure of wall : hyaline cartilage, smooth muscles and elastic fibers
Type of cells : goblet and ciliated cells
Define ciliated cell
A cell that is covered in microscopic projections that look like tiny hairs. Ciliated cells use a sweeping motion to remove toxins from the lungs
What is the structure of wall and type of cells in the main bronchi ?
Wall structure : hyaline cartilage, smooth muscles and elastic fibers
Type of cell : globet and ciliated
Define goblet cell
A column-shaped cell found in the respiratory and intestinal tract which secrete the main components of mucus
What is the composition of the wall and type of cells of the lobar bronchi
Walls : hyaline cartilage, smooth muscles and elastic fibers
Cells : goblet, ciliated and Clara cells
Define Clara cells
Also know as club cells, they are dome shamed with short microvili. Their main function is to protect the bronchiolar epithelium by producing pulmonary surfactant. As such Clara cells are responsible for detoxifying harmful substances inhaled into the lungs.
What is the structure of the walls and type of cells present in the segmental bronchi ?
Wall : smooth muscles and elastic fibers
Cells : Clara and cilliated
What is the structure of the wall and type of cell present in the bronchioles ?
Wall : smooth muscles and elastic fibers
Cells : Clara and cilliated
What is the type of wall and cells present in the alveoli ?
Wall : elastic fiber
Cells : cells responsible of respiration (epithelial cells)
What is the mucociliary escalator ?
Defines the specificity of the respiratory epithelium composed of goblet cells producing mucus which destroys bacteria and viruses/ captures dusts and chemicals and of cilia which organises the transport from lungs to periphery into the pharynx and stomach.
How do we call the level of oxygenation in the blood ?
Oxemya
Hypo-oxemya exists whereas hyper-oxemya deosn’t
How many lobar bronchi do we have ?
On the right side : 3
- right superior lobar bronchi
- right middle lobar bronchi
- right inferior lobar bronchi
On the left : 2
- left superior bronchi
- left inferior bronchi
What are the different anatomical subdivisions of the bronchiole ?
- terminal bronchiole
- respiratory bronchiole
- alveoli
What is the specificity of the respiratory bronchiole ?
It’s made up of alveolar duct and sacs and culminate into alveoli
Which part of the respiratory tract is used for gaz exchange ?
Respiratory bronchioles + alveoli
What is the structural composition of the blood-air barrier ?
Alveoli
Central arterial vessel conveying deoxygenated blood
Peripheral veinous vessel conveying oxygenated blood
Where is surfactant created ?
In the alveoli under the form of pneumocytes 2
Describe the gaz exchange along the blood air barrier
- O2 lieaves the alveoli to enter the blood flow and bind to hemoglobin
- CO2 lives leaves the blood flow and enter the alveoli
What is the pressure of O2 at the level of the see
Pressure : 760 mmHg
O2 : 21%
So O2 pressure = 159 mmHg (we take 160 mmHg into consideration)
How much pressure of O2 do we lose in the intrathoracic airways ?
60 mmHg of O2
How much pressure of O2 reaches the alveoli ?
We lose 60 mmHg of O2 in the airways so 100 mmHg of O2 reaches the alveoli
What happens if after inspiration the pressure of O2 is lower than 80 mmHg in the alveoli
Hypoxemia
At the top of the Everest, what changes regarding O2 ?
The proportion of O2 is still 21% of air but the pressure is different : 256 mmHg so the pressure of O2 equals to 53 mmHg which causes sever hypoxemia
How many lobes do the lungs have ?
Right lung : 3 lobes
Left lung : 2 lobes
What is the relation between intrapulmonary pressure and intrapleural pressure ?
- inter pulmonary = 760 mmHg
- intra pleura = 754 mmHg so negative pressure of -4mmHg but it’s a gradient because due to gravity the difference varies from -10 (on top) to -2 (at the bottom)
What happens in a pneumo thorax ?
The pleura is pierced
The atmospheric pressure = the intra pulmonary pressure
and the lung collapses
What are the anatomical sections of the lungs
Apex
Base
Root
Hilium
What is the hilium of the lung
Orifice through which main bronchi pulmonary arteries and veins enter the lungs
Where are the hiliums of the lungs located
On the center of the mediastinal surface of lung and behind the impression of the cardiac impression
It’s the meeting point of visceral and parietal pleura
Describe the arterial supply of the lungs on the right side
- right pulmonary artery
- right bronchial artery
Describe the arterial supply on the left side
- left pulmonary artery
- left superior bronchial artery
- left inferior bronchial artery
Describe the venous drainage of the lungs
- right brachiocephalic vein
- left brachiocephalic vein
- superior vena cava
Describe the pulmonary ligament
Not a musculoskeletal ligament but a fusion between the visceral pleura and mediastinal pleura.
Name the different surface of the lungs
Mediastinal surface (+ hilium)
Costal surface
Diaphragmatic surface
How is positioned the medial lobe on the right lung ?
It’s anterior so you cannot see it from a posterior view of the right lung
Name the fissures present between lung lobes
Right lung :
- horizontal fissure
- oblique fissure
Left lung :
- oblique fissure
Why are there 3 lobes on the right lung on only 2 on the left lung ?
It’s associated with the subdivision of the airways more specifically :
On right side : superior lobar bronchi, middle lobar bronchi, inferior lobar bronchi
On the left side : superior and inferior lobar bronchi
What are the right main bronchus divisions ?
Superior right lobar bronchi :
- apical segmental bronchi
- posterior segmental bronchi
- anterior segmental bronchi
Middle right lobar bronchi :
- lateral segmental bronchi
- medial segmental bronchi
Inferior right lobar bronchi :
- superior segmental bronchi
- medial, anterior, lateral, posterior basal segmental bronchi
Describe the left bronchus main divisions
Superior left lobar bronchi :
- apicoposterior segmental bronchus
- anterior segmental bronchus
- superior lingular segmental bronchus
- inferior lingular segmental bronchus
Inferior left lobar bronchi :
- superior segmental bronchus
- medial basal segmental
- anterior basal segmental
- lateral basal segmental
- posterior basal segmental
