Histology of Upper Respiratory Tract

Question 1

What are the two functional zones of the Respiratory system?

Answer 1

Conducting and Respiratory

Question 2

What are the functions of the conducting zone?

Answer 2

1. Move air into lungs
2. Warm and humidify air
3. Purify incoming air

Question 3

Why is there no gas exchange with blood in the conducting zone?

Answer 3

Distance b/t air and blood is too large

Question 4

How does the conducting zone purify the air?

Answer 4

Mucous;
Superficial layer: more viscous layer in which particulate matter is trapped
Mucociliary escalator: superficial layer “glides” over deep layer. Contains antimicrobial factors – IgA, lysozymes, lactoferrin

Deep layer: less viscous layer in which cilia are embedded

Question 5

How does the anatomy of the nasal cavity help with air conduction?

Answer 5

Vibrissae (hairs) w/in nasal vestibule filter out particulate matter
Turbinates (conchae) inc mucosal surface area & generate turbulence
Cilia: on epithelial cells expel particles trapped in mucous

Question 6

What are the two regions of the nasal cavity?

Answer 6

Olfactory and Respiratory

Question 7

Where is the olfactory region of the nasal cavity?

Answer 7

Roof of nasal cavity, superior concha, and upper septum

Question 8

Discuss the components epithelium of the olfactory region

Answer 8

1. Pseudostratified columnar epihelium
2. Olfactory cells (bipolar neurons that join CN1)
3. Basal cells
4. Brush cells (sensory for CN5)

Question 9

Describe the layout of an olfactory cell

Answer 9

bipolar neurons w/ apical vesicles, non-motile cilia w/ odorant-binding proteins/receptors, & basal axons which join CN I

Question 10

Discuss the components lamina propria of the olfactory region

Answer 10

1. Bowman’s glands; Provide solvent for odor molecules

2. Olfactory nerves

Question 11

Does the olfactory region rest on bone or cartilage?

Answer 11

BONE only

Question 12

What is unique about the olfactory epithelium?

Answer 12

1. More nuclei close to apical surface
2. No goblet cells
3. Sparsely ciliated

Question 13

Discuss the components of the Respiratory epithelium

Answer 13

1. Ciliated columnar cells
2. Goblet cells
3. Basal cells
4. Brush cells
5. Small-granule cells (neuroendocrine cells)

Question 14

Differentiate basal cells in respiratory epithelium from those in olfactory epithelium

Answer 14

These stem cells are near the basement membrane; THEY DO NOT EXTEND TO SURFACE

Question 15

Discuss the lamina propria of the respiratory epithelium

Answer 15

1. Highly vascular

2. Lymphoid cells

Question 16

Does the respiratory epithelium rest on bone or cartilage?

Answer 16

CAN REST ON EITHER ONE

Question 17

What type of epithelium is in the paranasal sinuses

Answer 17

Respiratory