The trachea is made of 20 C shaped cartlaginous rings (hyaline) . The posterior open ends are connected by what?
Smooth Muscle and dense fibroelastic ligament
What is posteior to the trachea?
Why do we have the fibroelastic ligament?
covers the open ends of the C shaped cartilage rings of our trachea and they prevent distention of the lumen
so if we swallow a bolus of food and it expands the esophagus, this ligament allows us to accomodate this big bolus of food.
3 layers of the trachea?
1) Mucosa (pseudostat. with goblet cells)
2) Submucosa (has seromucous glands)
3) Adventitia (fibroelastic CT)
As we go down the bronchiole tree..... from the trachea to the primary bronchus > secondary bronchus > bronchiole > terminal bronchiole > respiratory bronchiole >alveolar duct >alveolar sac what trend do we see histologically?
Smaller size progressively
Decrease in the amount of cartilage
Decrease in # of glands
Decrease in # goblet cells
Decrease in height of epithelium
Increase in amount of smooth muscle & elastic tissue.
The trachea divides into two primary bronchi which enter the lung at the ?
How many secondary bronchi do you have in your right lung vs left lung?
right lung we have 3 primary bronchi
left lung we have 2 primary bronchi
Extrapulmonary bronchi look similar to what histologically?
Intrapulmonary bronchi (lobar) bronci have?
have irregular plates of hyaline cartilage (instead of c rings)
Think I = Intrapulmonary = Irregular plates of hyaline!
When do primary bronchi become intrapulmonary bronchi?
When they enter the lungs
Secondary bronchus are also know as?
Does a bronchiole have any cartilage?
NO! When the cartilage plates disappear is where the bronchioles begin.
At the point when the bronchus enters the lung (through the hilum) the cartilage rings become what?
cartilage plates that are discontinuous
When the cartilage plates of the bronchus disappear and the size of the bronchus is around 1mm what part of the lung are we in?
Sympathetic stimulation of the bronchus results in?
relaxation of the smooth muscle
Parasympathetic, vagal stimulation of the smooth muscle of the bronchus results in?
constriction of the smooth muscle of the bronchus
No cartilage in this respiratory structure. What am I?
Bronchioles are defined as?
distal airways between the cartilage walled bronchus and the site where cilliated epithelium ceases.
Do bronchioles have cartilaginous support?
they are between the cartilage walled bronchus and where the ciliated epithelium ceases.
What is the sequence from lobar (secondary) bronchus on?