Lecture 15 Flashcards
What are the components of the lower respiratory tract?
Larynx Trachea Bronchi Bronchioles Alveoli
What are the functions of the LRT?
Conduct air to and from gas exchange
Complete cleaning, warming and humidifying
Provide a barrier between the air and blood and a large surface area for gas exchange
Location and structure of the Larynx?
Anterior to the esophagus, from hyoid bone to trachea
Thyroid cartilage gives structure.
Functions of the Larynx?
Passage for air only
Respiratory cleaning, warming etc
- Cartilages protect and maintain. open airway
- Epiglottis closes over airway when swallowing
What is the glottis?
voicebox
The membranes that vibrate as air passes over.
Location of vocal cords
Features of vocal folds?
- “true” Vocal cords
- passing air causes vibrations = sound waves
- Normal phonation
- Testosterone affects cartilage and muscle, resulting in longer thicker folds = deeper voice
Features of vestibular folds?
- “false” vocal cords
- Superior to folds
prevent foreign object entry to glottis - can produce very deep sounds
Location of the trachea?
Anterior to the esophagus, between larynx and primary bronchi
Function of trachea?
Maintain patent airway.
Trachealis contracts for coughing.
Clean, warm, humidify air
Structure of the trachea?
C-shaped cartilage rings.
Ends connected by band of smooth muscle: trachealis.
Many elastin fibres in lamina propria/submucosa layers
Role of the Mucociliary escalator?
Removes debris to the pharynx, to be swallowed and digested.
- Mucus from goblet cells and mucous gland coat surface of epithelium.
- Debris becomes trapped.
- Cilia moves mucus to pharynx
How many lobes do the lungs have?
lobes on the right and 2 lobes on the left
What is a Hilum?
connects lungs to their supporting structures and where pulmonary vessels enter and exit .
Where is the apex located
superior region of the lung
What is the costal surface?
Outer surface against ribs
Where is the base located
Inferior, sits on diaphragm
Structure of the Bronchial tree?
Trachea branch into primary bronchi, branch into secondary (lobar) bronchi, branch into tertiary (segmental) bronchi, then into bronchioles, keeps branching getting deeper into lungs until reaches terminal bronchioles.
What type of epithelium is found in the trachea, and bronchi?
Respiratory
What type of epithelium is found in the bronchioles?
Cuboidal
Structure of the Respiratory Zone?
respiratory zone is found deep inside the lungs and is made up of the respiratory bronchioles, alveolar ducts, and alveoli. These thin-walled structures allow inhaled oxygen (O2) to diffuse into the lung capillaries in exchange for carbon dioxide (CO2).
Features of Alveoli>
Alveolar walls are very thing: simple squamous epithelium on a thin basement membrane.
Large surface area.
External surface of alveoli covered in fine network of pulmonary capillaries.
Structure of Alveolus?
Each alveolus is cup-shaped with very thin walls. It’s surrounded by networks of blood vessels called capillaries that also have thin walls. The oxygen you breathe in diffuses through the alveoli and the capillaries into the blood.
What is the role of type 1 pneumocytes?
SQUAMOUS
gas exchange.
forms the wall of alveoli
What is the role of type 2 pneumocytes?
CUBOIDAL
Scattered amongst type 1.
Secrete surfactant, a complex lipoprotein that reduces the surface tension of alveolar fluid.
Role of roaming macrophage?
Remove debris that makes it to alveoli
Role of respiratory membrane?
Capillary
Connection to neighbouring alveoli
Why are alveoli connected?
So gas can flow through
Structure of the Respiratory Membrane?
(Blood air barrier)
- Alveolar cell layer
- fused basement membrane of alveolar, epithelium and capillary endothelium.
What causes the larynx to become narrower?>
Less cartilage support, more smooth muscle and flattening of epithelia
