Respiratory Histology & Bio of Airways

Question 1

What layers make up the mucosa?

Answer 1

epithelium, basement membrane, lamina propria and muscularis mucosa

Question 2

What layers are underneath the mucosa?

Answer 2

submucosa, adventitia- muscularis externa and hyaline cartilage

Question 3

What is secreted to moisten the air in the nasal passages?

Answer 3

serous secretion and mucous secretion

Question 4

What are the main functions of the respiratory system?

Answer 4

air conduction, filtration, gas exchange/respiration, carries stimuli for sense of smell, air passing through the larynx is used to produce sound/speech, involved in immune response against antigens in inhaled air, also endocrine

Question 5

What is the cellular make-up of the vestibule?

Answer 5

stratified squamous, keratinized, and lamina propria

Question 6

What is the defining characteristics of the respiratory epithelium in the nasal cavity and paranasal sinuses?

Answer 6

muco-cilliary escalator (airway defense mechanism), pseudostratified ciliated columnar cells (PSCC)- provides coordinated weeping motion of mucus, goblet cells- synthesize and secrete mucus, basal cells- stem cells give rise to other cells, enteroendocrine cells- small granule cells (Kulchitsky), and sensory receptor (brush cells)

Question 7

Describe the make-up of the lamina propria?

Answer 7

mucous and serous glands, immune cells, and vascular network

Question 8

What are the components of the muco-ciliary escalator?

Answer 8

serous and mucus secretion make a gel through action of the cilia, it traps particles and moves them up to be spit or swallowed

Question 9

What are the components of olfactory receptor cells?

Answer 9

bipolar neurons, enlarged dendritic vesicle

Question 10

What cells are in the olfactory mucosa?

Answer 10

olfactory receptor cells, sustentacular cells, basal cells, and serous glands

Question 11

What is the make up of the soft palate in the nasopharynx?

Answer 11

Epithelium is PSCC on the nasal side and stratified squamous, non-keratinized on the oral side; Lamina Propria- MALT- Waldeyer’s Ring: palatine, lingual and pharyngeal (adenoid) tonsils

Question 12

Describe the tissue makeup of the epiglottis.

Answer 12

lingual-stratified squamous, laryngeal- PSCC, Lamina propria- mixed mucous & serous glands, and elastic cartilage

Question 13

Describe the tissue makeup of the larynx.

Answer 13

exposed cords- stratified squamous, protected areas (ventricle)- PSCC, lamina propria-seromucous glands and elastic fibers, intrinsic muscles- skeletal, hyaline cartilage (thyroid, cricoid & arytenoids)

Question 14

Describe the tissue makeup of the trachea and Primary Bronchi.

Answer 14

epithelium-PSCC, goblet cells, and basal cells, enteroendocrine cells, receptor cells (brush cells), intermediate cells; basement membrane, lamina propria- loose CT with elastic fibers, lymphatic nodules, seromucous glands with myoepithelial cells; submucosa- mucous and seromucous glands- composed of mucus secreting acini with serous demilunes, rich blood, lymph supply, and nerves; adventitia- hyaline cartilage with smooth muscle trachealis

Question 15

What are the components of the airway defense mechanisms? The function? Complications?

Answer 15

muco-ciliary escalator: goblet cells (gel), submucosal glands (sol & gel), ciliary cells; lines nasal cavities, sinuses & airways, balance between sol & gel, sol allows cilia to beat freely, gel floats above sol layer, moved up; complications: kartagener’s syndrome (dynein)- immotile, excess serous secretion (sol)- top, excess mucus production (gel)- bottom

Question 16

Where does the cartilage stop in the lung tissue?

Answer 16

just before the terminal bronchioles

Question 17

What is the makeup of the intrapulmonary bronchi?

Answer 17

Mucosa- PSCC epithelium with goblet cells, basal brush and small granule cells, lamina propria, muscularis mucosa: SM spirally encircles lumen, long elastic fibers, submucosa- seromucous glands, and adventitia with irregular cartilage plates, dichotomous branching, and elastic fibers

Question 18

What is the makeup of bronchioles?

Answer 18

mucosa- simple ciliated columnar to cuboidal, no goblet cells, clara cells- nonciliated secretory cells, dome shaped, serous material to protect lining-Cl transport, stem cells, secrete surface active agent that prevents luminal adhesion, clara secretory protein (CC16), Lamina propria with thick muscularis mucosa, no glands, adventitia- no cartilage

Question 19

What is the makeup of the alveoli?

Answer 19

Pores of Kohn-openings between adjoining acini; sacs- rotunda like space; ducts: opening channels from respiratory bronchioles, discontinuous wall of simple squamous or cuboidal, few smooth muscles, some elastic & collagen fibers; alveoli lines by capillaries for gas exchange

Question 20

What is the makeup of the alveolar wall?

Answer 20

Type I pneumocytes, Type II pneumocytes, Alveolar macrophage (dust cell), Capillary Endothelial Cell, Interstitial cells: fibroblasts, mast cells, macrophages

Question 21

What is the characteristic of type I pneumocytes?

Answer 21

squamous cell, lining of alveolus (97%), connected by occluding junctions & desmosomes

Question 22

What is the characteristic of type II pneumocytes?

Answer 22

secretory cell, 3% of lining, connected by occluding junctions & desmosomes, lamellar bodies- make and secrete pulmonary surfactant

Question 23

What is the function of the alveolar macrophage or dust cell?

Answer 23

capture and destroy particulates

Question 24

What makes up the air-blood barrier?

Answer 24

surfactant lining, type I pneumocytes, epithelium basement membrane, interstitial space, endothelium BM, endothelial cell

Question 25

What happens with asthma that causes problems?

Answer 25

bronchoconstriction and excess mucus

Question 26

What happens with chronic bronchitis that causes problems?

Answer 26

thickened bronchial walls & mucus

Question 27

What happens with emphysema that causes problems?

Answer 27

destruction of alveolar wall & dilation

Question 28

What happens with pulmonary edema that causes problems?

Answer 28

increased hydrostatic pressure

Question 29

What happens with cystic fibrosis that causes problems?

Answer 29

thick mucus, defect in Cl-

Question 30

What happens with ARDS that causes problems?

Answer 30

endotoxin damage endothelium