Lung Structure And Function Flashcards
How many lobes does the right lung have and what are they called?
3 (upper, middle and lower)
How many lobes does the left lung have and what are the called?
2 (upper and lower)
Why is the right lung larger than the left lung?
Right is larger than left because it doesn’t have to accommodate to make space for the heart
What do oblique fissures do?
Separate the upper and lower lobes of the left lung and separate the middle and lower lobes on the right lung
What do horizontal fissures do?
Separate the upper and middle lobes in the right lung
What are the segments of the lungs called?
Bronchopulmonary segments
How many bronchopulmonary segments does the right lobe have?
10
How many bronchopulmonary segments does the left lobe have?
8
What are the lungs surrounded by?
Pleura (visceral and parietal)
Describe the anatomical location of the lungs
2.5cm above midpoint of the medial 1/3 of the clavicle
6th costal cartilage 7cm from midline anteriorly
Rib 8 laterally
T2->T10 posteriorly
Name the 6 functions of the lungs
Gaseous exchange
Surfactant production
Reservoir for blood
Filter
Part of the immune system
PH balance
What is the upper respiratory tract made up of?
Nose
Mouth
Pharynx
Larynx
What is the lower respiratory tract made up of?
Trachea
Primary bronchi
Secondary bronchi
Tertiary bronchi
Bronchioles
Terminal bronchioles
respiratory bronchioles
Aveolar ducts
Alveolar sacs
Where does the trachea begin?
Immediately below the larynx (C6)
What are the potential pathologies of the trachea?
Floppy i.e. no cartilage, obstruction
What are the primary bronchi separated by?
Carina
What is the difference between the right and left primary bronchi?
Right is larger in diameter than left and descends at a steeper angle
What is the potential pathology of the primary bronchi?
Obstruction
How many secondary bronchi does the right lung have?
3 serving the upper, middle and lower lobes
How many secondary bronchi does the left lobe have?
3 serving the upper and lower lobes
Which structures of the lower respiratory tract have cartilaginous plates?
Secondary bronchi and tertiary bronchi
Which structures of the lower respiratory tract have C-shaped cartilaginous rings?
Trachea and primary bronchi
What potential pathology do secondary bronchi have?
Lobar pneumonia
What does each tertiary bronchi supply air to?
A single bronchopulmonary segment
What effect does the decrease in cartilaginous support have in tertiary bronchi?
With less cartilaginous support, the amount of tension in those smooth muscles has a greater effect on the bronchial diameter and resistance to airflow
What are the potential pathologies of tertiary bronchi?
Infection (bronchitis)
What are the potential pathologies of the bronchioles?
COPD and fibrosing alveoli this
What are the terminal bronchioles made up of?
Smooth muscle
What regulates the terminal bronchi?
Autonomic system
What are the potential pathologies of terminal bronchioles ?
Asthma and fibrosis
What does each terminal bronchiole branch to server ACL of?
Respiratory bronchioles
What is the structure of respiratory bronchioles?
Thin and delicate with no cilia
What are the purpose of respiratory bronchioles?
Deliver air to gas exchange surfaces of the lung
What are alveolar ducts affected by?
CF or pneumonia
What is the name of the joint between respiratory bronchioles and alveoli?
Alveolar ducts
Where does gas exchange occur in the lungs?
At the alveolar sacs
What are alveolar sacs affected by?
CF or pneumonia
Where is the conducting zone of the lower respiratory tract?
Trachea to terminal bronchioles
What is the conducting zone of the lower respiratory tract?
It is where no gas exchange takes place
Gas is transported by convection
It is the location of anatomical dead space
Where is the respiratory zone of the lower respiratory tract?
Respiratory bronchioles to alveoli
How is gas transported in the respiratory zone of the lower respiratory tract?
By diffusion
What are the two types of alveoli cell?
Pneumocyte type I cell
Pneumocyte type II cell
What is a pneumocyte type I cell responsible for?
Gas exchange
It is there to help gasses transfer across its membrane
What is the function of a pneumocyte type II cell?
They are there to produce surfactant
If there is damaged to the type I cells they can make and replicate into type I to replace the damaged ones
What is collateral ventilation?
A network of interconnections between respiratory bronchioles and alveoli
What is an inter bronchiolar channel of Martin?
A channel from one respiratory bronchiole to another
What is a Bronchiole-alveolar channel of Lambert?
A channel from a respiratory bronchiole to alveoli
What is an inter alveolar pore of Kohn?
It is between two alveoli or more
Name the major muscle of respiration
Diaphragm
Describe the shape I of the diaphragm
Large domed shape muscle
What does the diaphragm do on contraction?
Flattens
What does the diaphragm do on relaxation?
Domes
What does the movement of the diaphragm alter?
The pressures within the lungs
What is the diaphragm sometimes referred to (referred to as two sides)?
Hemidiaphragms
What are the 2 circulatory systems of the lung?
Pulmonary and bronchial
What is the pulmonary circulatory system of the lungs involved in?
Gas exchange -> taking in oxygen a new getting rid of carbon dioxide via the blood
Which circulatory system of the lungs is at a higher pressure?
Bronchial
Is the Bronchial circulatory system involved in gas exchange?
No
What does the bronchial circulation supply?
Airways
What is compliance (in the lungs)?
The expandability of the lungs
What is the equation for compliance?
Change in volume/change in pressure
What does Boyle’s Law say (in relation to compliance)?
When you increase the pressure the volume decreases. When you increase the volume the pressure decreases
Name 6 causes of reduced compliance
Atelectasis
Fibrosis
Pneumothorax
Obesity
Pulmonary vascular engorgement
pleural effusion
What is resistance (in relation to the respiratory system)?
Resistance to flow is present where air flows through a vessel. It is composed of airway resistance and tissue resistance
What is 80% of airway resistance produced by?
Medium sized bronchi
What is 20% of air way resistance produced by?
Small airways with a diameter <2mm
Name the factors determining airway resistance
Lung volume
State of contraction of bronchial smooth muscle
Airway obstruction
Tissue resistance
Type of airflow
What are the three patterns of air flow?
Laminar flow pattern
Turbulent flow pattern
Transitional flow pattern
What is laminar flow pattern?
It is when air flow is more organised and will travel in straight lines
When is laminar flow pattern seen mainly?
In very small airways
When is turbulent flow pattern seen?
In the trachea and larger airways, especially with higher velocit
How does turbulent flow pattern travel?
In a disorganised nature
What is transitional flow pattern?
A combination of laminar and turbulent
When is transitional flow pattern seen?
It is seen in most medium-sized airways especially at branch points
What is elastic resistance/ elastance?
A measure of the work that has to be exerted by the muscles of inspiration to expand the lungs
What is elastic recoil?
The ability of the lungs to rebound having stretched during inhalation
What is work of breathing?
The physical work that has to be carried out by the muscles of respiration to overcome the eleastic resistance and the non-elastic resistance of the airways
Why do alveoli stay open?
They stay open due to surfactant and collateral channels
What is the normal breathing rate?
12-18bpm
What is the normal breathing ratio?
1:2
