Histology of the Respiratory System Flashcards
Describe the physical process required for respiration.
Ventilation which involves inspiratory and expiratory movement of the chest wall/
Describe the chemical process required for respiration.
Exchange of gas takes place between air and blood takes places at a cellular level.
List the components of the upper respiratory system (for practice).
Nose, pharynx and larynx
List the components of the lower system (for practice).
Trachea, bronchi, bronchioles and alveoli.
Name the two functional parts of the respiratory system.
Conducting and respiratory portions
What happens in the conducting portion of the respiratory system?
No gaseous exchange takes place here with the bloodstream
Which components make up the conducting portion of the respiratory system?
Nose, pharynx, larynx, trachea, bronchi, bronchioles
What happens in the respiratory portion of the respiratory system?
Gaseous exchange takes place within the bloodstream.
Which components make up the respiratory portion of the respiratory system?
Respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli
What are the parasympathetic innervations of the respiratory system?
: Bronchoconstriction, mucous secretion, vasodilatation
What is the sympathetic innervation of the respiratory system?
Bronchodilation
What gas goes into the alveoli and which gas is released?
CO2 in
Oxygen released
What type of cell covers in the inner lining of the alveoli?
Type 1 pneumocytes
What the thickness of the alveoli to allow gas exchange to take place?
0.2 microns
What happens if there is fluid in the alveoli?
Fluid increases the thickness of the alveoli and gas cannot diffuse properly, causing breathlessness.
Name the four main layers of the respiratory system.
- Mucosa (epithelium and supporting lamina propria)
- Submucosa
- Cartilage and/or Muscle layer
- Adventitia
Name the glands found in the submucosa layer.
Seromucous glands
What happens to the number and quantity of cartilage as it gets further down the respiratory tract?
It decreases
What type of layer is there between the mucosa and submucosa layers?
Smooth muscle
In the trachea, what is the muscle layer replaced by?
Elastic tissue
Describe the structure of the trachea.
Wide, flexible tube composed of 20 C-shaped tracheal cartilages.
What is the length and diameter of the trachea?
15-20cm long
2-3cm diameter
Where is the trachea situated?
Between the larynx and a cartilage called carina.
What type of cartilage are the C shaped tracheal cartilages made of?
Hyaline cartilage
What are the gaps between the rings of cartilage filled with?
Trachealis muscle and fibroelastic tissue.
What is the function of the mucosa and submucosa?
Warm and moisten the air, and to trap foreign particles in mucous.
What do the cartilage in the trachea do regarding the lumen?
Keeps the lumen patent
Describe the function of the lumen
Thick mucous layer in the lumen which traps foreign partilces.
Describe the tissue of the mucosa.
Pseudostratified ciliated columnar epithelium.
What are basal cells?
Stem cells which can regenerate the columnar cells if these are damaged or renewal is needed.
Where are basal cells found?
Base of the respiratory epithelium.
What does the lamina propria contain?
Areolar connective tissue
What is found in areolar connective tissue?
Elastin and blood vessels.
Potentially macrophages and other immune cells.
What lines the tracheobronchial tree?
Respiratory epithelium.
What do goblet cells do in the respiratory system?
They secrete mucin and create a protective mucus layer.
Where is lamina propria?
Under the epithelium.
Which type of gland is in the submucosa?
Mixed sero-mucous glands
In which direction are any particles trapped by the mucous in the submucosa transported?
Upwards towards the pharynx by cilia on the epithelium.
What is the function of Adventitia?
Connects and supports trachea to surrounding tissue, eg. thyroid and oesophagus.
What does Adventitia contain?
Contains nerves, vessels and adipose tissue.
What type of tissue is laminar propria?
Loose connective tissue
RECAP- Describe the division of the trachea to the rest of the respiratory system.
Trachea branches into two principle bronchi- one right and left
Principle bronchi divide into secondary and then tertiary bronchi
RECAP- how many lobes does the right lung have?
3
RECAP-how many lobes does the left lung have?
2
Which bronchi is the primary bronchi?
Primary/principle bronchi
Describe the cartilage of the intrapulmonary bronchi
Less cartilage and does not fully surround the lumen
What are the gaps in the cartilage of intrapulmonary bronchi known as?
Cartilage plates
Which bronchi has layers of smooth muscle between the mucosa and submucosa?
Intrapulmonary bronchi
What is the diameter of a brocnhiole?
1mm or less
What tissue are bronchioles covered with?
Ciliated columnar epithelium
Which bronchioles have non-ciliated columnar epitherlium?
Smaller bronchioles like tertiary bronchioles.
Do bronchioles have more or less smooth muscles than the bronchi?
More
What do Clara cells in bronchioles do?
Secrete surfacant
Which cells/glands etc are seen in bronchus but not bronchioles?
Goblet cells (a few goblet cell may be found in the initial part)
Ciliated cells
Submucosal Glands
Cartilage
What tissue is the respiratory bronchioles made of?
Simple cuboidal epithelium
if you look at powerpoint and are confused, Dr Shahana said there was a typo xo
What are alveolar ducts surrounded by?
Smooth muscles, elastin and collagen
What are the alveolar sacs surrounded by?
Blood vessels/pulmonary capillaries.
What are alveoli surrounded by?
Blood vessels/pulmonary capillaries.
RECAP-where does gas exchange between blood and air take place?
Alveoli
What are elastic fibres important for?
The recoil function of the lung during inspiration and expiration.
Which part of the airway has no cartilage?
Bronchiole
Is the smooth muscle layer of the bronchioles thicker or thinner than that of the bronchi?
Thicker
Describe the epithelium of bronchioles.
Simple columnar with few cilia.
Are there glands in the laminar propria of bronchioles?
No
What are the two main cells of the epithelium of the alveoli?
Type 1 pneumocytes
Type 2 pneumoncytes
What epithelium are type one pneumocytes made of?
Simple squamous epithelium
What do type 2 pneumocytes do?
Secrete ‘surfactant’ which decreases alveolar surface tension and stops alveoli collapsing when we breathe out.
What type of cell helps to trap dust in the alveoli?
Macrophages
Where does gas exchange in the alveoli take place through?
Takes place through the endothelial cell of the capillary, basement membrane and type I pneumocyte.
REVISION TASK-optional don’t hate me pls
Look at Term 2, week 2 anatomy lectured part three, 10 mins in at the diagram on the left. May help to remember which cells are in which compartment :)
Also 12 mins in is a table which you could copy out to help memory?
What do club cells do?
Club cell=clara cell!
Protect airways
Regenerate bronchiolar epithelium
Produce surfactant
List four things which the conducting part of the respiratory system is characterised by.
- pseudostratified columnar epithelium with cilia
-goblet cells
-gland tissue
-hyaline cartilage.
List three things which the respiratory part of the respiratory system is characterised by.
-epithelium gradual transition from cuboidal to simple squamous.
-cartilage ends
-abundant smooth muscle, elastic fibres, reticular fibres
FINALLY
There are questions at the end of the powerpoint slides for these lectures if you want some anatomy questions :) warning idk how easy they are but ig that’s good practice
oops nm what level is the carina at?
Around the fourth thoracic vertebrae and also around the level of the sternal angle anteriorly.
