Respiratory System: Alveolar Cells and Blood-Air Barrier

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What is the function of pneumocyte type I cells in the alveoli?

Secreting surfactant

Involved in gas exchange (correct)

Acting as phagocytes

Producing mucus

What can be identified by examining the alveolar walls under high dry (40x) lens?

Elastic fibers (correct)

Absence of Clara cells

Presence of basal bodies

High density of goblet cells

Which type of epithelium lines the bronchioles where cilia become fewer?

Stratified squamous keratinized epithelium

Stratified squamous non-keratinized epithelium

Simple squamous epithelium

Simple columnar epithelium (correct)

What is the function of Clara cells in the respiratory tract?

Secreting surfactant to reduce surface tension Signup and view all the answers

Which type of epithelial lining forms the large air spaces in the lung?

Simple squamous epithelium Signup and view all the answers

What happens to the number of goblet cells as the epithelium transitions to bronchioles?

Goblet cells decrease and eventually disappear Signup and view all the answers

What is the main characteristic that distinguishes stratified squamous non-keratinized epithelium from stratified squamous keratinized epithelium?

Tough waterproof outer layer of dead flat cells Signup and view all the answers

What is the function of pneumocyte type II cells in the alveoli?

Production of surfactant Signup and view all the answers

Which epithelium is typically found on surfaces subjected to wear-and-tear?

Stratified squamous keratinized epithelium Signup and view all the answers

What makes up the blood-air barrier in the alveoli?

Pneumocyte type I cells Signup and view all the answers

Why do stratified squamous non-keratinized epithelia have many cell layers?

To resist mechanical stresses Signup and view all the answers

What is the primary function of elastic fibers in the alveolar wall?

Provide structural support and elasticity Signup and view all the answers

What type of epithelium lines the trachea according to the text?

Pseudostratified columnar epithelium Signup and view all the answers

In which part of the gastrointestinal tract can we find simple columnar epithelium?

Jejunum Signup and view all the answers

Where are the terminal bars located in the jejunum?

Deep to the brush border Signup and view all the answers

Which structure in the jejunum is composed of closely packed microvilli?

Brush border Signup and view all the answers

Which part of the body contains simple cuboidal epithelium in small ducts that are difficult to find without practice at microscopy?

Gall bladder Signup and view all the answers

What type of epithelium lines the finger-like projections (villi) at the luminal surface of the jejunum?

Simple columnar epithelium Signup and view all the answers