Bronchioles Quiz and Flashcards for Respiratory System

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Questions and Answers

What type of epithelial lining is present in larger bronchioles?

Simple cuboidal

Ciliated pseudostratified columnar

Simple columnar

Ciliated simple columnar with occasional goblet cells (correct)

What type of cells are found in bronchioles and are believed to protect the bronchiolar epithelium?

Goblet cells

Basal cells

Clara cells (correct)

Ciliated columnar cells

What is a key difference in the muscle layers between bronchi and bronchioles?

Bronchi have a spirally arranged smooth muscle layer (correct)

Bronchioles have a thick smooth muscle layer

Bronchi have no smooth muscle layer

Bronchioles have more layers of smooth muscle

What is true about the cartilage in bronchioles?

It is absent in bronchioles Signup and view all the answers

What is the function of Clara cells in bronchioles?

To produce a surfactant-like material Signup and view all the answers

What is the characteristic of the trachealis muscle in the trachea?

It connects the open ends of the C-rings posteriorly Signup and view all the answers

What is the result of metaplasia in the respiratory epithelium?

An increase in the number of goblet cells relative to ciliated cells Signup and view all the answers

What is the main difference between the walls of the trachea and the primary bronchi?

The walls of the primary bronchi are thinner than the trachea Signup and view all the answers

What is the characteristic of the right bronchus compared to the left bronchus?

The right bronchus is straighter than the left bronchus Signup and view all the answers

What is the characteristic of the intrapulmonary bronchi?

They have irregular hyaline cartilage plates Signup and view all the answers

What is the main function of the epithelium in the trachea?

To provide a barrier against infection Signup and view all the answers

Which type of cells are responsible for producing mucinogen in the trachea?

Goblet cells Signup and view all the answers

What is the main difference between the epithelial lining of the trachea and that of the bronchioles?

The presence of a pseudostratified columnar epithelial lining in the trachea but not in the bronchioles Signup and view all the answers

What is the function of the elastic fibers in the trachea?

To maintain the shape of the trachea during respiration Signup and view all the answers

What is the main function of the basal cells in the trachea?

To maintain the integrity of the epithelial lining Signup and view all the answers

Study Notes

Bronchioles

Bronchioles are the 10th to 15th generation of dichotomous branching of the bronchial tree
Less than 1 mm in diameter
Supplies air to a pulmonary lobule
Bronchioles possess no cartilage
The epithelial lining of bronchioles ranges from ciliated simple columnar with occasional goblet cells in larger bronchioles to simple cuboidal (many with cilia) with occasional Clara cells and no goblet cells in smaller bronchioles
The lamina propria of bronchioles has no glands; it is surrounded by a loose meshwork of helically oriented smooth muscle layers

Clara Cells

Clara cells are believed to protect the bronchiolar epithelium by lining it with their secretory product
Produce a surfactant-like material that reduces the surface tension of bronchioles and facilitates the maintenance of their patency
Clara cells divide to regenerate the bronchiolar epithelium

Trachea

The trachea is rounded anteriorly but flattened posteriorly
10 to 12 horse-shoe-shaped hyaline cartilage rings (C-rings) that are connected to each other by smooth muscle
The perichondrium of each C-ring is connected to those of other rings
Provides flexibility and permits elongation during inspiration

Respiratory Epithelium

The respiratory epithelium undergoes reversible alterations (metaplasia) due to chronic exposure to irritants (e.g., cigarette smoke and coal dust)
Increase in the number of goblet cells relative to ciliated cells, producing a thicker layer of mucus to remove irritants
Reduced number of cilia retards the rate of mucus elimination, resulting in congestion

Bronchi

Begins at the bifurcation of the trachea
Composed of airways located outside and inside the lung
Outside: 1° bronchi, extrapulmonary bronchi
Inside: intrapulmonary bronchi, bronchioles, respiratory bronchioles

Cartilages

Elastic cartilages (unpaired epiglottis, paired corniculate and cuneiform cartilages, and superior aspect of the arytenoids) connected to one another by ligaments
Their movements are controlled by intrinsic and extrinsic skeletal muscles

Epiglottis

Flexible flap of tissue, consisting of central elastic cartilage, covered by mucosa on both sides
During swallowing, positioned horizontally, closing off the upper entrance to the larynx
During respiration, stands straight up in the vertical position, permitting the flow of air