Overview of Respiratory Pathologies: Part 1 Flashcards
the respiratory system
what is the respiratory system divided into structurally and functionally?
divided into conducting airways and respiratory airways
the respiratory system
what 6 things do the conducting airways portion of the respiratory tract comprise?
- nose
- pharynx
- larynx
- trachea
- bronchi
- bronchioles (main –> Terminal)
the respiratory system
what 4 things does the respiratory airway portion of the respiratory tract comprise of?
comprise of:
- respiratory bronchioles
- alveolar duct
- alveolar sacs
- alveoli
histology of repiratory wall
what 3 things make up the respiratory epithelium in the respiratory wall from the nasopharynx to the bronchi
- psuedostratified columnar epithelium (in contact with basement membrane)
- Cilia
- Goblet cells
what happens to the epithelium as the respiratory tract gets smaller, to the main bronchioles?
it transistions from psuedostratified columnar respiratory epithelium to JUST simple columnar epithelium
what happens to the epithelium as the respiratory tract gets to the smaller bronchioles, terminal bronchioles, respiratory bronchioles and the alveolar ducts?
goes from simple columnar epithelium to simple cuboidal epithelium
what happens to the epithelium as the respiratory tract goes from the alveolar ducts to the alveolar sacs and alveoli?
goes from simple cuboidal epithelium to simple squamous epithelium
why is the simple squamous epithelium ideal in the alveoli?
because it enhances/facilitates gaseous exchange
divisions of the bronchial tree
how long is the trachea in the average adult and what shape and type is its cartilage
- 12cm
- c shaped, hyaline cartilage
what is a difference between the right and left bronchus in terms of size and length and what does this increase likelihood of?
- right bronchus is shorter and wider than left bronchus
- this means aspirated foreign materials are more likely to enter right bronchus
what does each respiratory bronchiole branch into and what type of epithelium do they retain
branches into 2-11 alveolar ducts that retain cuboidal epithelium
what are found along the walls of alveolar ducts
- alveolar sacs that comprise 2-4 alveoli
- single alveoli by themselves
what is the space at the entrance from the alveolar duct to an alveolar sac referred to as?
the atrium
Not to be confused with atrium of the heart
what happens to cartilage as you go down the respiratory tract, towards the respiratory bronchioles etc?
the cartilage disappears and is replaced by smooth muscle
what 2 things does the absence of cartilage in the bronchioles allow for?
allows for:
- bronchioles to be more collapsible and responsive to changes in smooth muscle tone
- allows for fine control of airflow
histology of alveoli
what are 2 features of type I pneumocytes, what type of epithelial cells are they in the alveoli, and what do these features allow for
features:
- thin
- flat
type of epithelium:
- simple squamous
these 3 features allow for rapid diffusion for gas exchange across alveolar membrane
what type of epithelial cells are type II pneumocytes, what do they secrete and what does this prevent and how
- cuboidal epithelial cells
- secrete pulmonary surfactant
- prevents collapse of alveoli during exhalation by reducing surface tension of alveoli membrane
what do alveoli macrophages do
- clean and sterilize alveoli spaces by engulfing and digesting inhaled microbes and pathogens
disorders of airway and gas exchange
what 2 diseases come under COPD
- bronchitis
- emphysema
define an obstructive respiratory disease
limitation of airflow due to obstruction of airways, causing increased airway resistance
what are 3 ways an obstructive disease can occur and give an example of a disease with each one
- airway narrowing (asthma)
- loss of elasticity (emphysema)
- increased secretions (bronchitis/asthma)
what disease encompasses both emphysema and chronic bronchitis
COPD
define a restrictive respiratory disease
restriction of normal lung movement during respiration
what is 1 way restrictive respiratory disease can occur and state what this means for the lung in terms of capacity
- reduced expansion of lung parenchyma
- this leads to decreased total lung capacity
