lecture 15 Flashcards
Components of the LRT?
Larynx Trachea Bronchi Bronchioles Alveoli
Functions of LRT?
Conducts air to/from site of gas exchange
Completes cleaning, warming and humidifying of air
barrier between air and blood with large surface area
What is the the larynx a passage for?
Air only
What is the function of cartilage in the larynx?
protect and maintain open airway
what is the purpose of the epiglottis?
closing over the airway when swallowing
What is the larynx anterior to?
Oesophagus
What are the most important cartilages in the larynx?
Cricoid cartilages
Thyroid cartilages
Laryngeal Prominence (Adams apple)
epiglottis
What is the glottis?
Voicebox
What are the vocal folds?
true vocal folds
How are sound waves made?
passing air causes vibrations
Why do men have deeper voices?
Testosterone affects cartilage and muscle, making longer, thicker folds
what are vestibular folds?
false vocal cords
Where are the vestibular folds?
superior to the vocal folds
What is the function of the vestibular folds?
prevent foreign object entry to glottis
Where is the trachea?
anterior to oesophagus, between larynx and primary bronchi
What is the function of the trachea?
maintain a patent airway
clean, warm and humidify air
How does the trachea maintain a patent airway?
C-shaped cartilage rings connected by smooth muscle
What is the trachealis?
Smooth muscle which contracts when coughing and connects c-shaped cartilage
What and where is the mucociliary escalator?
In the trachea and it is there to remove debris to the pharynx
How does the mucociliary escalator work?
mucus is produced by goblet cells which traps debris and cilia beats the mucus up towards the pharynx
Why is the trachea C-shaped?
to prevent pushing into the oesophagus
What muscle is important to eject food if it does get down the airway?
trachialis muscle
What provides movement when coughing?
elastin fibres in mucosa and submucosa
Which side of the lungs has 2 lobes?
the left because of the heart
how many lobes do the right lungs have?
3 lobes right
What is the hilum?
Where bronchi and blood vessels enter lungs
Where is the apex of the lung?
On the superior region of the lung
What is the costal surface?
The outer surface against the ribs
Where is the base of the lungs?
the inferior aspect that sits on the diaphragm
What is apart of the bronchial tree?
Trachea 1 bronchi 2 bronchi (lobar) 3 bronchi (segmental) Bronchioles terminal bronchioles
What is the primary (1) bronchi lined with?
Respiratory epithelium
cartilage and smooth muscle rings
What happens to respiratory epithelium in the 2nd and 3rd bronchi?
respiratory epithelium starts to decrease in height and goblet cell numbers reduce
What epithelium lines the bronchioles?
Cuboidal epithelium
What is the purpose of thick smooth muscle in the bronchioles?
Thick smooth muscle for bronchoconstrion/dilation
What do the terminal bronchioles supply?
pulmonary lobule
What are air sacs?
Pulmonary lobules made of many alveoli arranged like a bunch of grapes
how many alveoli are there per lung?
~150 million per lung
what lines the alveolar walls?
simple squamous epithelium on a thin basement membrane
what covers the external surface of alveoli?
a fine network of pulmonary capillaries
alveolus are similar to what structure?
A pocket, one opening
alveolus are covered by?
dense capillary network
what forms the respiratory membrane/blood-air barrier?
Type 1 squamous with capillary wall and shared basement membrane
what is the purpose of type II cuboidal epithelium in the blood-air barrier?
Secrete surfactant
What is surfactant?
a complex lipoprotein that reduces the surface tension of alveolar fluid
What structures form the respiratory membrane?
alveolus wall, fused basement membrane, capillary wall
what is the structure of the alveoli?
type I pneumocystis form wall of alveoli and type II pneumocystis secrete surfactant
Which cells remove debris from the alveoli?
macrophages
