Bronchioles Flashcards
Each tertiary bronchus branches into multiple
bronchioles
Bronchioles branch into
terminal bronchioles
One tertiary bronchus forms about ____terminal
bronchioles
6500
Bronchioles
* Have no ____
* Are dominated by ___
- cartilage
-smooth muscle
- Autonomic Control
- Regulates _____
- Controls diameter of _______
- Controls airflow and resistance in ______
smooth muscle
bronchioles
lungs
Bronchodilation
- Dilation of bronchial airways
- Caused by sympathetic ANS activation
- Reduces resistance
Bronchoconstriction
- Constricts bronchi
- Caused by:
- Parasympathetic ANS activation
- Histamine release (allergic reactions
- Constricts bronchi
- Caused by:
- Parasympathetic ANS activation
- Histamine release (allergic reactions
- Asthma occurs when there is and this can cayse
- Excessive stimulation and bronchoconstriction
- Stimulation severely restricts airflow
- Trabeculae
Fibrous connective tissue partitions from root of
lung
* Contain supportive tissues and lymphatic vessels
* Branch repeatedly
* Divide lobes into increasingly smaller
compartment
- Pulmonary lobules are divided by the smallest
trabecular partitions (interlobular septa)
- Each terminal bronchiole delivers air to a single
pulmonary lobule
Each pulmonary lobule is supplied by pulmonary
arteries and veins
- Each terminal bronchiole branches to form several
respiratory bronchioles, where
gas exchange takes place
Respiratory bronchioles are connected to alveoli
along
alveolar duct
Alveolar ducts end at
t alveolar sacs
* Common chambers connected to many individual
alveoli
Each alveolus has an extensive network of
capillaries
* Surrounded
by elastic fiber
Alveolar Epithelium
* Consists of simple squamous epithelium
* Consists of thin, delicate———–controlld by——
type I pneumocytes
patrolled by alveolar macrophages (dust cells)
* Contains type II pneumocytes (septal cells) that produce sufectant
Surfactant
Is an oily secretion
* Contains phospholipids and proteins
* Coats alveolar surfaces and reduces surface
tensio
Gas Pressure and Volume
* Boyle’s Law
* Defines the relationship between gas pressure and
volume
P = 1/V
- In a contained gas:
- External pressure forces molecules closer together
- Movement of gas molecules exerts pressure on
containe