Lungs Flashcards
Lungs Structure- Key points.
- 3 lobes right - upper middle and lower
- 2 lobes left - upper and lower
- Horizontal and oblique fissures
- Bronchopulmonary segments - Right =10 and left =8
- Surrounded by the pleura ( visceral outer and parietal inner)
lung function - Key points.
- Gas exchange
- Surfactant production
- Reservoir for blood
- Filter
- Part of the immune system
- pH balance
Structure of the Trachea- Key points
- C shaped cartilage rings
- Two branches at the carina.
- Flexible for swallowing
- Pathologies- Floppy, cartilage and obstruction
Structure of Primary Bronchi - Right and left.
- C shaped cartilaginous rings
- Access the lungs via the hilum
- Pathology - Obstruction
- Rt is larger in diameter and descends at a deeper angle.
Structure of Secondary Bronchi-
- Rt have 3
- Lt has 2
- Cartilaginous plates
- Pneumonia
Structure of Tertiary Bronchi-
- Rt- 10
- Lt - 8-9
- Cartilaginous plates
- Increased amount of smooth muscle
Structure of Bronchioles-
- More smooth muscle than cartilage
- COPD
Structure of terminal bronchioles-
- Smooth muscle
- Asthma and fibrosis
- Autonomic system regulates
Structure of respiratory Bronchioles-
- Thin and delicate with no cilia
- Deliver air to gas exchange of the lung .
Structure of Alveolar ducts -
- Connect respiratory bronchioles to alveoli
- affected by CF or pneumonia
Structure of Alveolar sacs-
- site of gas exchange
- Surfactant
- Affected by CF or pneumonia.
Outline the Conducting zone in the lungs-
- Trachea to terminal bronchioles
- no gas exchange
- gas transport
- by convection
- location of anatomical dead space
Outline the respiratory zone in the lungs-
- Respiratory bronchioles to alveoli
- Gas exchange at alveolar//capillary membrane
- Gas transport by diffusion
- large surface area
Give the types of Alveoli and their function-
Pneumocyte type 1 - Gas exchange
Pneumocyte type 2 - Surfactant
Pneumocyte can replicate themselves into type 1 if damaged
Give the 3 collateral channels -
Martin - one respiratory bronchiole to another
Lambert - Respiratpry bronchiole to alveloi
Kohn - between alveoli
Give the structure of the Diaphragm-
- Large dome shaped muscle
- Flattens on contraction and domes on relaxation
- its movement will alter the pressure within the lungs
- sometimes refered to as 2 sides - Hemidiaphrapgms
State the blood supply of the lungs-
- Pulmonary artery recieves all of the output from the right heart
- Pulmonary system - low pressure system
- Bronchial circulation supplies airways
Give a brief overview of Compliance.
Compliance=Expandability of the lungs. -
Boyles law = When you increase the pressure the volume decreases , when you increase the volume the pressure decreases
- Causes of reduced compliance - Fibrosis , Pneumothorax , obesity, pleural effusion
Give a brief overview of resistance-
Resistance = resistance to flow is present where air flows through a vessel
- R to air flow is composed of airways resistance and tissue resistance
- 80% of airway resistance ( AWR) is produced by medium sized bronchi, 20% of AWR is produced by small airways with a diameter <2mm
- Factors determining airway resistance - Lung volume , state of contraction of bronchial smooth muscle ,Airway obstruction ,tissue ,resistance ,type of airflow
Give a brief overview of elastic resistance-
- Elastic resistance or elastance = is a measure of the work that has to be exerted by the muscles of inspiration to expand the lungs
- Elastic recoil= Is the ability of the lungs to rebound having been strecthed during inhalation
Give a brief overview of WOB-
- Work of breathing - is the physical work that has to be carried out by the muscles of respiration to overcome the elastic resistance and non-elastic resistance of the airways
- WOB increases = Poor compliance , increased resistance , decrease in respirapty capacity , More elastic resistance
Give the 3 Types of airflow pattern-
laminar = Seen in very small airways
Turbulent = Seen in trachae and larger airways , especially with higher velocity
Transitional = Combination of both - seen in medium sized airways especially at branch points
Opening and closing pressures of alveoli-
- High pressures needed for opening collapsed alveoli
- At critical opening pressure , a maintained inspiratory effort will inflate most of the lung tissue
- On deflation , alveoli tend to remain open , and empty at lower pressures
- Stay open due to surfactant and collateral channels
