Histology of tracheobronchial & the lung Flashcards
MCqs
What is the primary function of Type I alveolar cells?
a) Secretion of surfactant
b) Phagocytosis of foreign particles
c) Formation of the blood-air barrier
d) Production of mucus
c) Formation of the blood-air barrier
What percentage of the alveolar surface do Type I alveolar cells cover?
a) 50-60%
b) 70-80%
c) 90-97%
d) 30-40%
c) 90-97%
the rest is by Type 2 pneumocytes
How are Type I alveolar cells connected to each other?
a) Tight junctions
b) Gap junctions
c) Desmosomes
d) Hemidesmosomes
a) Tight junctions
What structures are present in the alveolar septum to facilitate air passage between adjacent alveoli, thereby equalizing pressure?
a) Collagen fibers
b) Alveolar pores of Kohn
c) Smooth muscle fibers
d) Adipose tissue
b) Alveolar pores of Kohn
Which fibers enable the alveoli to expand during inspiration and contract passively during expiration?
a) Elastic fibers
b) Reticular fibers
c) Collagen fibers
d) Adipose fibers
a) Elastic fibers
recoils like an elastic band
What is the primary function of reticular fibers in the alveoli?
a) Facilitate air passage between alveoli
b) Equalize pressure in the alveoli
c) Support and prevent overdistention
d) Enable expansion during inspiration
c) Support and prevent overdistention
What is the function of alveolar pores in the alveolar wall?
a) Secretion of mucus
b) Absorption of oxygen
c) Equalization of air pressure in alveoli
d) Production of surfactant
c) Equalization of air pressure in alveoli
How do alveolar pores promote the collateral circulation of air?
a) By increasing surface tension in alveoli
b) By reducing the elasticity of alveolar walls
c) By inhibiting gas exchange
d) By allowing air passage when a bronchiole is obstructed
d) By allowing air passage when a bronchiole is obstructed
Where are alveolar pores located?
a) Alveolar septum
b) Alveolar wall
c) Alveolar ducts
d) Alveolar sacs
b) Alveolar wall
What is the primary function of Type II alveolar cells?
a) Gas exchange
b) Production of pulmonary surfactant
c) Phagocytosis of pathogens
d) Regulation of blood pressure
b) Production of pulmonary surfactant
Which term is also used to refer to Type II alveolar cells?
a) Septal cells
b) Squamous epithelial cells
c) Great alveolar cells
d) Stem cells
a) Septal cells
Where are Type II alveolar cells often located within the alveoli?
a) Alveolar septum
b) Alveolar pores
c) Points where alveolar walls unite
d) Alveolar sacs
c) Points where alveolar walls unite
What are the secretory granules in Type II alveolar cells called?
a) Golgi bodies
b) Multilamellar bodies
c) Lysosomes
d) Peroxisomes
b) Multilamellar bodies
How is pulmonary surfactant released from Type II alveolar cells?
a) Diffusion through cell membrane
b) Active transport
c) Exocytosis
d) Passive transport
c) Exocytosis
In the provided image, what structures are indicated by arrows containing newly synthesized pulmonary surfactant?
a) Type I alveolar cells
b) Lamellar bodies
c) Junctional complexes
b) Lamellar bodies
What is the function of the microvilli observed in the image?
a) Gas exchange
b) Phagocytosis
c) Increase surface area for absorption
d) Facilitate cell movement
c) Increase surface area for absorption
What do the junctional complexes (JC) shown in the image represent?
a) Tight junctions
b) Gap junctions
c) Desmosomes
d) Hemidesmosomes
a) Tight junctions
remember we’re talking abt alveolar cells
Which type of alveolar cell protrudes into the alveolar lumen?
a) Type I alveolar cell
b) Type II alveolar cell
c) Squamous epithelial cell
d) Great alveolar cell
b) Type II alveolar cell
What are alveolar macrophages commonly referred to as?
a) Squamous cells
b) Type III pneumocytes and squamous cells
c) Great alveolar cells and dust cells
d) Type III pneumocytes and Dust cells
d) Type III pneumocytes and Dust cells
What is the role of alveolar macrophages in relation to surfactant?
a) Production of surfactant
b) Assisting Type II cells to uptake surfactant
c) Phagocytosis of surfactant
d) Inhibition of surfactant production
b) Assisting Type II cells to uptake surfactant
What is one of the primary functions of alveolar macrophages?
a) Secretion of mucus
b) Regulation of blood pressure
c) Phagocytosis of air-borne particles and erythrocytes
d) Formation of the blood-air barrier
c) Phagocytosis of air-borne particles and erythrocytes
What is the Blood Gas Barrier (BGB)?
a) A thick region of the interalveolar septum
b) The thinnest region of the interalveolar septum where gases can be exchanged
c) A network of alveolar macrophages
d) A layer of mucus lining the alveoli
b) The thinnest region of the interalveolar septum where gases can be exchanged
What components make up the Blood Gas Barrier?
a) Type II alveolar cells and surfactant
b) Collagen fibers and reticular fibers
c) Type I alveolar cells, surfactant, common basal lamina, and endothelial cells
d) Elastic fibers and smooth muscle cells
c) Type I alveolar cells, surfactant, common basal lamina, and endothelial cells
Which cells contribute to the formation of the common basal lamina in the Blood Gas Barrier?
a) Type II alveolar cells
b) Alveolar macrophages
c) Type I alveolar cells and endothelial cells
d) Squamous epithelial cells
c) Type I alveolar cells and endothelial cells
What does oxygen traverse to reach the erythrocyte?
a) Alveolar macrophages
b) Surface lining of the alveolar epithelium, cytoplasm, fused basal laminae, and capillary endothelium
c) Type II alveolar cells
d) Reticular fibers
b) Surface lining of the alveolar epithelium, cytoplasm, fused basal laminae, and capillary endothelium
