Lecture 19&20 Flashcards
Final exam content
How wide is the trachea? How long?
10-13 cm long
The width of the thumb
How much of the trachea is extra-thoracic?
4 cm (accessible by the neck). The rest is intrathoracic
About how many cartilaginous rings are in the adult trachea? What connects each ring?
20 cartilaginous rings. Annular ligaments connect each ring.
Are the tracheal rings continuous (circles)? Why is this significant?
No the posterior part of the rings is open. This gives room for the adjacent esophagus to swallow food boluses. The cartilage that connects the ends of the rings also has infoldings that helps us generate enough pressure to cough up secretions (with the help of villi).
How many bronchopulmonary segments in the right lung? The left lung?
Right: 10 bronchopulmonary segments
Left: 8 bronchopulmonary segments
What are some key differences between the two mainstem bronchi?
Left mainstem is longer (4-6cm) and more narrow,
Right mainstem is wider, shorter and more vertical
What is the angle from the vertical axis of the right mainstem? the left mainstem? the total angle of bifurcation?
Right: 25 degrees
Left: 45 degrees
Total: 70 degrees
the bifurcation point (v-shaped cartilage just before the two mainstem bronchi split) is also called…
the carina
What do you need to consider if you are ventilating a patient with a tracheotomy?
Need to provide humidification
When you place the patient in a sniffing position (head tilt) what happens to the trachea?
This allows for better visualization, but makes the trachea longer and more narrow.
What is the narrowest point on a child 10 years and younger? In an adult?
Children: cricoid cartilage
Adult: transglottic space (between the vocal cords)
Where should you be able to feel the ETT pressure cuff inflate?
in the sternal notch or sternal angle
What happens when you contract the cricothyroid muscle?
this pulls the front of the larynx down, which stretches the vocal cords (tightens them)
What are the 6 laryngeal muscle sets?
- cricothyroid muscle
- vocalis muscle
- thyroarytenoid muscle (axis)
- transverse arytenoid muscle
- posterior cricoarytenoid muscle
- lateral cricoarytenoid muscle
What is significant about the cricothyroid muscle?
The only muscle that is outside the larynx. It tightens the cords.
Which muscle set runs parallel to the vocal cords?
vocalis muscles
Which laryngeal muscle opens the vocal cords?
posterior cricoarytenoid muscle
Which laryngeal muscles rely on there being an axis to swivel on or bend?
thyroarytenoid, transverse arytenoid, posterior arytenoid
What is maybe one reason why we can still speak if one of our laryngeal nerves is damaged?
there are so many muscles that adduct the cords so these might be able to still work together to close the cords enough to phonate
What is a short-term compensation the body makes at high altitude? A long-term compensation?
Short-term: hyperventilate
Long-term: low PO2 in blood, kidney O2 sensors deep in the medulla sense low O2 and increase epo levels to expand Hct
If you are born at high altitude and grow up at a higher altitude, what is different about your respiratory system?
You’d have more alveoli and greater surface area in the lungs
What is superoxide?
oxygen with an extra electron, very reactive!
If we have too much nitric oxide (NO), how can it be toxic?
If we have too much NO it can interact with superoxide and make peroxynitrite, which can destroy DNA and cause cancer
Where is hydrogen peroxide normally located in limited amounts and useful?
macrophages or in immune killer cells
What enzymes and compounds are useful in cleaning up ROS (reactive oxygen species)?
superoxide dismutase, peroxidases, catalase, and acetylcysteines
