Lecture 21

Question 1

Describe the epithelium that lines the nares and include specialized structures that can be found in this epithelium.

Answer 1

Stratified squamous epithelium that is continuous with the epidermis.

This epithelium contains sebaceous glands, sudoriferous glands, and hair follicles

Question 2

Characterize the respiratory epithelium and include it’s features (2 of them)

Answer 2

Pseudostratified ciliated columnar epithelium

Features a lamina propria (thin layer of loose CT) and Submucosa (Dense irregular CT)

Question 3

In terms of their functions in the olfactory epithelium, explain Sustentacular cells, Basal cells, Olfactory cells, and Glands of Bowman

Answer 3

Sustentacular cells: support cells with pigment granules

Basal cells: are stems cells (give rise to olfactory cells) that feature pigment granules

Olfactory cells: bipolar neurons that feature an apical end that projects into the nasal cavity as a “knoblike” ending with nonmotile cilia

Olfactory cells senesce and are replaced from the basal cells

Glands of Bowman: glands located in the lamina propria that feature an odor-binding protein that binds to odorant molecules in the nasal cavity
Secrete odorant-binding protein

Question 4

Explain how exactly Olfactory cells detect odors with their cilia that extend into the nasal cavity

Answer 4

These cilia possess G-protein-linked odor-specific receptors

The basal end of the cell extends as an unmyelinated axon, bundled with other similar axons, through the ethmoid plate to mitral cells located in the olfactory bulb

Question 5

List the 3 main structures considered to be part of the larynx and specify the type of epithelium that covers the larynx itself.

Answer 5

Epiglottis

False vocal cords

True vocal cords

The larynx itself is covered with pseudostratified ciliated epithelium

Question 6

Describe the epiglottis in terms of it’s 2 surfaces, and the composition of it’s core

Answer 6

Epiglottis has a lingual surface, pharyngeal surface, and the core of epiglottis elastic cartilage

Lingual surface: stratified squamous epithelium and a lamina propria with loose CT and elastic fibers

Pharyngeal surface: covered with pseudostratified ciliated epithelium and have a lamina propria with tubuloacinar seromucous glands

Core of the epiglottis: elastic cartilage

Question 7

Compare the true and false vocal cords in terms of the tissue type they are covered in and any glands/lamina they may feature

Answer 7

False vocal cords (vestibular folds): covered with pseudostratified ciliated epithelium and a lamina with seromucous glands

PART of the false vocal cords also features stratified squamous epithelium (this part may encounter some surface abrasions)

True vocal cords: covered with stratified squamous epithelium and LACK seromucous glands in their lamina propria

Question 8

State and describe the 3 layers of the trachea and any glands/lamina/features they have.

Answer 8

Mucosa: respiratory epithelium with thick basement membrane and a lamina propria with a delicate FECT and lymphatic tissue

Submucosa: features many sero-mucous glands

Adventitia: are 16-20 horshoe-shaped cartilages that are connected by FECT

The opening between the arms of the horseshoe-shaped cartilages closed by (FECT, mucous membrane, and smooth muscles (trachealis muscles))

Has mixed glands and capillaries

Question 9

beginning with the bronchi and ending with the alveolar duct, list the order that air flows through respiratory passages

Answer 9

Bronchi –>

secondary bronchi –>

terminal bronchiole –>

respiratory bronchiole –>

alveolar duct

Question 10

As the bronchi become smaller, there is a _____ in the height of the epithelium, a ______ in the cartilage and glands, and an ______ in the proportion of elastic fibers and smooth muscles

Answer 10

decrease

decrease

increase

Question 11

Compare type I alveolar cells and type II alveolar cells (function and location)

Answer 11

Type I alveolar type: Less numerous than type II pneumocytes and they cover the largest surface area
Found in the walls of the alveoli and septa

Type II alveolar type: cuboidal or rounded and serve as stem cells for type I and type II pneumocytes
Found in the walls of the alveoli and septa

Question 12

What is the following describing?

have a basal lamina that may be fused with the basal lamina of nearby capillaries, and they are held to other type I pneumocytes via tight junctions

These cover about 95% of the alveolar surface and have very thin cytoplasm

Answer 12

Type I pneumocytes

Question 13

What is the following describing?

rounded cells that bulge into the alveolar lumen and cover about 5% of the alveolar surface
They can divide to replace type I pneumocytes and produce a phospholipid-protein surfactant that coats the alveolar walls

Answer 13

Type II pneumocytes

Question 14

True or False: Type I pneumocytes and Type I alveolar cells are synonyms for the same term. explain

Answer 14

True

Question 15

What are the walls of the alveoli and septa composed of?

Answer 15

Type I alveolar cells (type I pneumocytes) , type II alveolar cells (type II pneumocytes) and macrophages (called dust cells in the lungs)

Question 16

Describe neuroendocrine cells in terms of what they contain, their function, and what they may be associated with

Answer 16

Neuroendocrine Cells: small granule cells the release catecholamines

May be associated with sensory reception and are more prevalent in infants

Question 17

Describe dust cells origin and their function

Answer 17

Dust cells: macrophages (called dust cells when found in the lungs) that are derived from monocytes
Dust cells phagocytize particles such as pollutants, bacteria, and surfactant that are not trapped in the mucous and expectorated

Question 18

Dust cells can play a major role in diagnosing a serious condition. State the condition and how dust cells are used to diagnose it.

Answer 18

Dust cells are related to CHF (congestive heart failure): in CHF, fluid containing the breakdown products of hemoglobin (iron-copntaining hemosiderin) leaks into the alveolar spaces and are phagocytized by the dust cells

These iron-containing dust cells are referred to as “heart failure cells”

Question 19

Define pore of Kohn

Answer 19

Openings between adjacent alveoli

Question 20

The blood-air barrier serves what protective function?

Answer 20

The blood-air barrier does not allow fluids or cells to enter the alveoli (normally)

Question 21

State the 2 components of the blood-air barrier

Answer 21

Thin capillary endothelium (continuous endothelium)

Thin epithelium of pneumocyte

Intervening basal lamina produced by both cell types