Respiratory Histology

Question 1

What structures comprise the conducting portion of the respiratory tract?

Answer 1

• nasal cavity, paranasal sinuses, nasopharynx
• trachea
• primary, secondary, tertiary bronchi
• conducting and terminal bronchioles

Question 2

What is the function of the conducting portion of the respiratory tract?

Answer 2

• warm, filter, and humidify air
• transmit air to the respiratory portion
• no gas exchange

Question 3

What structures comprise the respiratory portion of the respiratory tract?

Answer 3

• respiratory bronchioles

- alveolar ducts and sacs

Question 4

What is the function of the respiratory portion of the respiratory tract?

Answer 4

-pass air to alveoli for gas exchange

Question 5

What is the larynx?

Answer 5

-short passage for air b/w the pharynx and the trachea

Question 6

What substance reinforces the walls of the larynx?

Answer 6

• hyaline cartilage

- smaller elastic cartilages

Question 7

What type of cells are found in the true vocal cords?

Answer 7

• nonkeratinized stratified squamous

- -protects mucosa from abrasions

Question 8

What is found deep to the true vocal cords?

Answer 8

• vocalis m.

- -allows movement of the vocal folds

Question 9

What is the trachea?

Answer 9

• short, flexible tube that serves as a conduit for air

- connects larynx to main bronchi

Question 10

What structure keeps the lumen of the trachea open?

Answer 10

-C-shaped ring of hyaline cartilage

Question 11

What cell type is found in the trachea?

Answer 11

-pseudostratified ciliated columnar

Question 12

True or False: the trachea has many submucosal glands

Answer 12

True

Question 13

What type of cells are goblet cells?

Answer 13

-modified columnar epithelial cells

Question 14

What is the role of goblet cells?

Answer 14

-synthesize and secrete mucous

Question 15

What is a histological characteristic of a goblet cell?

Answer 15

-apical cytoplasm contains mucigen granules

Question 16

Does the trachea have goblet cells?

Answer 16

Yes, numerous!

Question 17

What cell type is found in the bronchi?

Answer 17

-pseudostratified ciliated columnar

Question 18

What are histological characteristics of cells in the bronchi?

Answer 18

• shorter cells
• fewer goblet cells
• few submucosal glands

Question 19

Describe the cartilaginous rings in the bronchi?

Answer 19

• full cartilage rings instead of C-shape in trachea

- transition to irregular cartilage plates

Question 20

What is the size of the bronchi?

Answer 20

> 1 mm diameter

Question 21

What is the size of the bronchioles?

Answer 21

< 1 mm diameter

Question 22

What cell type is found in the conducting bronchioles?

Answer 22

• large: simple ciliated columnar

- small: simple cuboidal

Question 23

Do bronchioles have cartilage?

Answer 23

No

Question 24

What are histological characteristics of conducting bronchioles?

Answer 24

• few goblet cells (club cells instead)
• increased elastic fibers
• prominent smooth muscle

Question 25

What cell type are found in the terminal bronchioles?

Answer 25

- simple cuboidal | - club cells

Question 26

What are club cells?

Answer 26

- non-ciliated, dome-shaped - secrete a lipoprotein - prevents luminal adhesion w/airway collapse - detoxification by antimicrobial peptides

Question 27

What type of cells are found in the respiratory bronchioles?

Answer 27

- simple cuboidal | - club cells

Question 28

What is a histological characteristic of respiratory bronchioles?

Answer 28

- mucosa contain openings to alveoli | - moving distally, alveoli become more numerous and group together

Question 29

What are alveolar sacs?

Answer 29

-clusters of 2+ alveoli

Question 30

What are alveolar rings?

Answer 30

-aggregates of smooth muscle, collagen, and elastic fibers that form rings around alveolar ducts

Question 31

What type of cells are found at the alveolar level?

Answer 31

-simple squamous --most efficient for oxygen absorption

Question 32

What are histological characteristics at the alveolar level?

Answer 32

- lots of capillaries | - Type I and Type II pneumocytes

Question 33

What are alveoli?

Answer 33

-blind-ended sacs lined with pneumocytes

Question 34

What are alveolar pores?

Answer 34

-small openings that permit movement of air b/w alveoli

Question 35

What type of cells are Type I pneumocytes?

Answer 35

-squamous

Question 36

Where are Type I pneumocytes found?

Answer 36

- lining almost the entire alveolar surface | - closely associated w/ capillaries

Question 37

What is the role of Type I pneumocytes?

Answer 37

-create a surface for gas exchange

Question 38

What type of cells are Type II pneumocytes?

Answer 38

-cuboidal/rounded

Question 39

What is the role of Type II pneumocytes?

Answer 39

- secrete surfactant via exocytosis | - precursor for Type I and Type II pneumocytes

Question 40

What are the components of the Blood-Air Barrier?

Answer 40

- Type 1 pneumocytes - fused basal lamina - capillary endothelial cells

Question 41

Pathology: Asthma

Answer 41

- chronic inflammatory disease - bronchospasms -infiltration of bronchiolar wall by eosinophils, lymphocytes, and mast cells

Question 42

What are histological changes as a result of chronic asthma?

Answer 42

- thick bronchiolar epithelium - increased goblet cells - thick basement membrane - hyperplastic smooth muscle

Question 43

What are symptoms of asthma?

Answer 43

- wheezing - dyspnea - productive cough

Question 44

Pathology: Emphysema

Answer 44

-permanent enlargement of air spaces distal to terminal bronchiole - destruction of alveolar walls - significant loss of gas exchange

Question 45

What are histological characteristics of emphysema?

Answer 45

- loss of elastic fibers in bronchioles | - - narrower bronchioles

Question 46

What are the causes of emphysema?

Answer 46

- smoking - chronic inhalation of particulates - autoimmune

Question 47

What are the symptoms of emphysema?

Answer 47

-dyspnea, cough, weight loss

Question 48

Pathology: Pneumonia

Answer 48

- inflammation of lung tissue | - air spaces filled with fluid exudate containing WBC, RBC, and fibrin

Question 49

What are histological characteristics of pneumonia?

Answer 49

- red hepatization stage, looks like liver | - enlarged capillaries congested with RBC

Question 50

What does a lung with pneumonia look like on gross examination?

Answer 50

- red - firm - heavy

Question 51

What are symptoms of pneumonia?

Answer 51

- fever and chills - productive cough - decreased breath sounds - crackles