5. Respiratory Histology

Question 1

what is the fxn of the conducting portion of lungs

Answer 1

warm, filter & humidify air

transmit to resp portion

=anatomical dead space bc no gas exchange

Question 2

what parts are included in the conducting portion

Answer 2

nasal cavity, pranasal sinuses, nasopharynx, trachea

bronchi (1, 2 & 3), bronchioles & terminal bronchioles

Question 3

what is the fxn of the respiratory portion of the lungs

Answer 3

pass air to alveoli for gas exchange

includes resp bronchioles, alveolar ducts and alveolar sacs

Question 4

what is the larynx

Answer 4

short passage for air btn pharynx & trachea

Question 5

what are the walls of the larnyx reinforced by

Answer 5

hyaline cartilage (thyroid & cricoid)

elastic cartilages

Question 6

what are the components of the larynx

Answer 6

• true vocal folds/cords (nonkeratinized stratified squamous epi) - protect mucosa from abrasion
• vocal ligaments: support free edges of vocal fold
• vocalis m. allow movement of vocal folds

Question 7

Answer 7

larynx

Question 8

what is respiratory epithelium

Answer 8

pseudostratified ciliated columnar epi

fxn: use mucus to protect airway & transport mucus up and out of resp tract via cilia

Question 9

what is present in respiratory epithelium

Answer 9

ciliated cells

goblet cells

basal cells (mitotically active, replace dead cells)

lamina propria w/ rich vascular network & capillary loops

Question 10

Answer 10

respiratory epithelium

cilia, goblet cells & basal cells

Question 11

what are goblet cells

Answer 11

modified columnar epi cells

synthesize and secrete mucus

base occupied by basal nuclei and crammed w/ organelles

Question 12

how doe goblet cells make mucous

Answer 12

mucigen granules on apical cytoplasm - exocytose into lumen - combine w/ water = mucous

Question 13

what is the trachea

Answer 13

short, flexible tube = conduit for air

connect larynx to main bronchi

contain cartilaginous rings to keep lumen open

Question 14

what are the four layers of the trachea

Answer 14

1. MUCOSA: resp epi (pseudostratified ciliated columnar epi) w/ elastic, fiber rich lamina propria
2. SUBMUCOSA: denser CT than lamina propria
3. CARTILANGINOUS LAYER: C shaped hyaline cartilage rings (bc esophagus behind it)
4. ADVENTITIA: trachealis M; CT that binds trachea to adjust structure

Question 15

Answer 15

trachea

mucosa, submucosa, cartilage, cartilage, marrow

Question 16

Answer 16

trachea

Question 17

what do the mucosa of the trachea contain

Answer 17

pseudostratified ciliated columnar epi

goblet cells

elastic, fiber rich lamina propria

bronchi associated lymphiod tissue

Question 18

what does the epithelia of the bronchi contain

Answer 18

pseudostratified ciliated columnar epi (cells shorter in height)

less goblet cells than trachea

increased elastic fibers in lamina propria

Question 19

what does the submucosa of the bronchi contain

Answer 19

loose/areolar CT

few submucosal glands

irregular cartilage plates

Question 20

Answer 20

bronchi

Question 21

Answer 21

walls of bronchi

Question 22

what does the epithelia of the bronchioles contain

Answer 22

large = simple ciliated columnar

small = simple cuboidal

*club cells

increased elastic fibers & Sm. M

(few goblet cells)

Question 23

what is unique about bronchioles

Answer 23

no cartilage plates

Question 24

Answer 24

bronchioles

Question 25

what are terminal bronchioles

Answer 25

final part of conducting portion cotnain club cells simple cuboidal epi

Question 26

what are club cells

Answer 26

non ciliated, dome shaped secrete lipoprotein to prevent luminal adhesion w airway collpse (expiration) detoxify inhaled material secrete antimicrobial peptides

Question 27

Answer 27

terminal bronchioles

Question 28

what are respiratory bronchioles

Answer 28

first part of resp portion mucosa w/ opening to alveoli - some gas exchange simple cuboidal epi w/ club cells

Question 29

Answer 29

1. respiratory bronchioles 2. alveolar ducts 3. alveolar sacs

Question 30

what are alveolar ducts/sacs

Answer 30

simple squamous epi increase SA via intricate organization to increase areas of gas exchange

Question 31

what are alveolar rings

Answer 31

groups of smooth M, collagen & elastic fibers that form ring around alveolar ducts

Question 32

what type of cells are the sacs of alveoli lined by

Answer 32

pneumocytes (type I & II)

Question 33

Answer 33

alveoli simple squamous epi

Question 34

what are type I pneumocytes

Answer 34

squamous (flat) line almost entire alveolar surface -make surface for gas exchange (closely associated with capillaries)

Question 35

What secretes surfactant & what does surfactant do

Answer 35

type II pneumocytes (cuboidal, rounded) reduce surface tension w/i alveoli to prevent collapse during respiration

Question 36

Answer 36

pleura covered in flattened mesothelium

Question 37

what are the 3 components of the blood-air barrier

Answer 37

1. type I pneumocytes 2. fused basal laminae 3. capillary endothelial cells air in alveoli and blood in capillaries are seperated by these

Question 38

what occurs in asthma

Answer 38

sudden constriction of smooth m in bronchioles (no cartilage to keep it open) = bronchospasm infiltration by eosinophils, lymphocytes & mast cells thick bronchiolar epi w/ increased goblet cells, thick basement mem & hyperplastic smooth M cells

Question 39

pt presents with dyspnea, wheezing & a productive cough what does this pt likely have

Answer 39

asthma

Question 40

premanent enlargement of air space after the terminal bronchioles & destruction of alveolar walls will lead to----

Answer 40

emphysema =sig loss of gas exchange bc decreased SA

Question 41

what causes emphysema & what are the symptoms

Answer 41

smoking, chronic inhalation of particulate material, genetic predisposition dyspnea, cough, weight loss

Question 42

what is "red hepatization stage"

Answer 42

occurs in pneumonia where lungs begin to look like liver bc - firm/heavy - due to fluid build up - red - due to increased RBCs in enlarged capillaries & air spaces (air spaces can also have WBCs & fibrin)

Question 43

what are the symptoms of pneumonia

Answer 43

fever/chills productive cough decreased breathing sounds crackles in lungs