HUBS192 Lecture 15 - Respiratory System II: The Lower Respiratory Tract Flashcards
what is the respiratory membrane?
type 1 pneumocytes that can also be described as simple squamous epithelial cells attached via a fused basement membrane to the capillary endothelium
what are the 5 components of the LRT?
1) larynx
2) trachea
3) bronchi
4) bronchioles (tiny bronchi)
5) alveoli
what are the 4 functions of the LRT?
1) conducts air to/from site of gas exchange
2) completes cleaning, warming and humidifying (moistening) of air
3) provides a barrier between the air and blood
4) a large surface area for gas exchange
what is the beginning of the LRT?
the larynx
what is the larynx?
a passage for air only that is anterior to the oesophagus
where is the larynx located?
located from the hyoid bone down to the trachea
what is the structure used to keep the airway patent down the LRT?
cartilage protects and maintains open airways
what is the largest part of cartilage around the larynx?
thyroid cartilage
what is the enlarged area of cartilage that sticks out anteriorly of the larynx?
the laryngeal prominence
-also known as the Adams apple in males
what is the cricoid cartilage of the larynx ?
a complete ring of cartilage, completely encapsulates the whole of the larynx
what is the epiglottis?
piece of cartilage that is pushed back by the tongue to prevent food from being swallowed down the trachea by pushing it down the esophagus
what is the function of the epiglottis?
cartilaginous structure that prevents food from entering into the airway by flopping down and covering the larynx ensuring food only travels down to the oesophagus
what happens when you swallow?
the tongue pushes backwards onto the epiglottis and the larynx itself lifts upwards
what does the word glottis mean?
voice box
what is the glottis used for?
used to produce sound
what is the glottis composed of?
within the glottis, there are folds of tissue that are attached to cartilages that provide movement and vibrations (sound)
what are the 2 sets of folds in the glottis?
1) vocal folds
2) vestibular folds (above the vocal folds)
what are the vocal folds within the glottis?
‘true’ vocal cords (inferior to the vestibular folds)
how does testosterone affect the vocal folds (cords)?
testosterone affects cartilage and muscle, resulting in longer, thicker folds = deeper voice
what are the vestibular folds within the glottis?
-‘false’ vocal cords (superior to the vocal folds)
what is the trachea?
pathway down to the lungs that is anterior to the oesophagus
where is the trachea located?
between the larynx and the primary bronchi
what are the 2 functions of the trachea?
1) maintains patent airway
2) continues to clean, warm and moisten air by respiratory epithelium
what structures allow the trachea to maintain a patent airway?
by C-shaped cartilage rings where the ends are connected by bands of smooth muscle called trachealis
-many elastin fibres in lamina propria/submucosa layers
what structure is used to move mucus up the trachea against gravity?
the mucociliary escalator
what is the function of the mucociliary escalator?
removes debris to be swallowed and digested
why is the cartilage of the trachea C-shaped?
to provide protection by keeping the airway open, but allow room for the oesophagus (posterior) and the trachealis muscle to contract for coughing to clear obstructions
which structure prevents food from entering the larynx?
the epiglottis
how many lobes are in the right lung?
3 lobes