Histology Respiratory Lecture

Front 1

What are the components of the conducting portion?

Back 1

Trachea, primary bronchus, secondary bronchus, bronchiole, terminal bronchiole

Front 2

What are the components of the respiratory portion?

Back 2

Respiratory bronchiole, Alveolar duct, Alveolar sac, Alveoli

Front 3

What are vibrissae?

Back 3

Thick short hairs that filter out large particles in the nasal vestibule

Front 4

What are the 3 cell types in olfactory epithelium?

Back 4

Olfactory, supporting, basal

Front 5

What are the 3 major components of the true vocal cords?

Back 5

Skeletal muscle (vocalis), vocal ligament, and covering of stratified squamous nonkeratinized epithelium

Front 6

How are the vestibular fold (false vocal cords) different structurally from the true vocal cords

Back 6

Respiratory epithelium (ciliated pseudostratified columnar with goblet cells), loose connective tissue with glands and lymphoid aggregates - lies superior to true vocal cords

Front 7

What is a small mucous granule cell?

Back 7

It is a "brush" mucous cell, due to the presence of microvilli. It contains a variable amount of mucous granules and actively divides

Front 8

Where does smooth muscle get introduced into the respiratory system?

Back 8

Secondary bronchioles - separates lamina propria from submucosal layer

Front 9

Where does cartilage disappear in the respiratory system?

Back 9

Bronchioles - replaced by smooth muscle

Front 10

What is the type of epithelium present in bronchioles?

Back 10

Varies from ciliated, simple cuboidal cells with secretory Clara cells (terminal/respiratory bronchioles) to ciliated simple columnar epithelium with goblet cells (primary bronchioles)

Front 11

At which point in the respiratory system do glands disappear?

Back 11

Starting in the bronchioles

Front 12

Where does gaseous exchange first begin to occur?

Back 12

Starting at the respiratory broncioles - beginning of respiratory portion

Front 13

What is the most distal portion of the respiratory system to contain smooth muscle?

Back 13

Alveolar duct

Front 14

What are the pores of Kohn?

Back 14

Communication pores between adjacent alveoli

Front 15

What are the 3 cell types present in alveoloar epithelium?

Back 15

Type I & II pneumocytes and alveolar macrophages

Front 16

What are key characteristics of Type I pneumocytes?

Back 16

Part of blood-gas barrier
Very thin cytoplasm
Covers 95% of alveolar surface
Forms tight junctions with adjacent cells
Nucleus stains darkly - clear cytoplasm

Front 17

What are key characteristics of Type II pneumocytes?

Back 17

Stores and releases surfactant, which is stored in lamellar bodies (cytoplasm)
Can divide and regenerate both types of pneumocytes
Often near septal intersections
Cytoplasm contains clear lipid droplets - surfactant

Front 18

Describe the action of Alveolar macrophages

Back 18

Removes dust, bacteria and other particulate matter. When full of debris, it migrates to the bronchioles and is carried via ciliary action to the upper airways and pharynx, where it is swallowed. Or, it can migrate to the interstitium and leave via lymph

Front 19

What are the layers of the thin portion of the blood-gas barrier in the lungs?

Back 19

Surface lining (surfactant) - Epithelium (Type I pneumocyte) - Fused basal lamina - Continuous capillary endothelium - erythrocyte

Front 20

Describe the relationship between bronchiole size and elastic fiber content

Back 20

The smaller the bronchiole, the greater the amount of elastic fiber

Front 21

What is clinically important about alveolar pores?

Back 21

They allow for the spread of infection to other alveoli

Front 22

Olfactory epithelium is of what cell type?

Back 22

Pseudostratified columnar

Front 23

What type of epithelium is present on the epiglottis?

Back 23

Stratified squamous on the lingual surface (top). Pseudostratified ciliated on the pharyngeal surface

Front 24

What is the arrangement of hyaline cartilage like in the trachea/primary bronchi?

Back 24

C-shaped, opening posteriorly connected by smooth muscle at the open ends

Front 25

What is the arrangement of glands in the respiratory system like?

Back 25

Goes from seromucous & mucous glands (trachea to primary bronchus) to seromucous (secondary bronchus) to none (bronchioles and beyond)

Front 26

What are features of Secondary Bronchi?

Back 26

2 helically oriented ribbons of smooth muscle

Front 27

What are features of Bronchioles?

Back 27

Clara Cells

Front 28

What are features of Terminal Bronchioles?

Back 28

Clara Cells

Front 29

What are features of Respiratory Bronchioles?

Back 29

Alveolar outpocketings

Front 30

What are features of Alveolar ducts?

Back 30

Type I and II Pneumocytes, outpocketings of alveoli

Front 31

Why is Alpha-1-Antitrypsin (AAT) important?

Back 31

It neutralizes elastase, an enzyme released by neutrophils and macrophages responsible for destroying microorganisms, but also digests the interstitium elastic fibers
It is inactivated by free radicals present in cigarettes

Front 32

What occurs in a smokers lung?

Back 32

Elastase destroys elastic fibers of alveoli, causing reduced recoil of the lung (prolonged expiration), leading to the destruction & dilation of airways - hyperinflated lungs (depressed diaphragm). Leads to emphysema

Front 33

What is Kartagener's Syndrome?

Back 33

genetic mutation in a gene coding for ciliary proteins (tubulin, dynein) that causes situs inversus. There is resulting recurrent sinus & pulmonary infections (inability to move mucus), and sterility in males (retarded sperm movement)

Front 34

What occurs to cause Asthma?

Back 34

Widespread constriction of smooth muscles in bronchioles, which is associated with difficult expiration, mucus accumulation and inflammatory cell infiltration.

Front 35

What is the treatment for Asthma?

Back 35

Albuterol (relaxes smooth muscles, dilates passageways) or corticosteroids (anti-inflammatory)

Front 36

What are the 2 types of lung cancer?

Back 36

Squamous cell and small cell (oat cell)

Front 37

Describe Squamous cell carcinoma

Back 37

Respiratory epithelium changed to stratified squamous . Initial metaplasia leads to dysplasia, then to carcinoma