Respiratory System

Question 1

respiratory portion

Answer 1

respiratory bronchioles
aveolar ducts
aveolar scas
alveoli
Exchange of gases bet air and blood
Maximize surface area

Question 2

conducting airways

Answer 2

nasal cavities
paranasal sinuses
pharynx
larynx
trachea
bronchi

Question 3

structure of conducting portion

Answer 3

1) Mucosa - epithelium
2) Lamina propria - underlying CT = loose fibro-elastic CT, may contain lymph
3) Submucosa - fibro-elastic CT
4) Support elements - bone/cartilage/smooth mm
5) Adventitia - CT merging w/ surrounding tissues (when not resting on bone)

Question 4

Respiratory epithelium

Answer 4

pseudostratified columnar
ciliated cells
goblet cells

Question 5

Olfactory epithelium

Answer 5

pseudostratified columnar
olfactory receptor cells
basal cells
(lacks goblet cells)
thicker than resp epithelium

Question 6

Bronchiolar epithelium

Answer 6

simple cuboidal -> columnar

Clara cells

Question 7

Alveolar epithelium

Answer 7

simple epithelium
Type I cells (squamous)
Type II cells (rounded to cuboidal)

Question 8

Nasal epithelium

Answer 8

minimally keratinized simple squamous epithelium

Question 9

Respiratory epithelial cell types

Answer 9

5 cell types:

1. columnar ciliated cells
2. goblet
3. brush
4. small granule

Question 10

columnar ciliated cells

Answer 10

type of resp epi

regular motile cilia move mucus

Question 11

goblet cells

Answer 11

type of resp epi
make and secrete mucus
features; rER, golgi, apical secretory vesicles
Mucus = hydrated mix of glycoproteins and proteoglycans

Question 12

brush cells

Answer 12

columnar cells with short blunt microvilli
general sensation
innervated by CN V

Question 13

small granule cells

Answer 13

Bronchial cell of Kulchitsky
diffuse neuroendocrine sys (DNES)
- amine precursor uptake & decarboxylation
Stain w/ silver salts

Question 14

extrapulmonary bronchi

Answer 14

c-shaped rings of cartilage
same structure as trachea just smaller
smooth mm restricted to cartilage-free border at first
ciliated pseudostrat columnar epi w/goblet cells

Question 15

intrapulmonary bronchi

Answer 15

complete but broken ring of cartilage

surrounded by lung parenchyma

Question 16

trachea

Answer 16

Mucosa - cil pseudostrat col epi w/ thick basement membrane (ciliated, goblet, and basal cells)
1) Lamina propria - loose fibro-elastic CT, also contains lymphoid aggregations
2) boundary w/ Submucosa marked by elastic lamina
Submucosa - mixed seromucous glands, blood vessels, larger lymph, ANS ganglia

Cartilaginous/ Smooth mm layer/Fibro-elastic CT

Adventitia - lots of fat, nerve cells, and blood vessels

Question 17

Primary bronchi divide into

Answer 17

lobar (secondary) bronchi

tertiary (segmental) bronchi

Question 18

lobar (secondary) bronchi divide into

Answer 18

tertiary (segmental) bronchi

Question 19

bronchopulmonary segment

Answer 19

supplied by a tertiary bronchus
largest subdivision of a lobe
separated by CT septa
surgically resectable portion - has own conduction system and vascular supply

Question 20

bronchial mucosa

Answer 20

similar to trachea but smaller lamina propria
spirals of smooth mm (muscularis mucosae) replace elastic fiber layer of trachea - sep mucosa from submucosa
Submucousa - serous and mucous glands become fewer the farther down, ANS ganglia, br of bronchial artery & vein, lymph
Adventia - irregular plates of cartilage

Question 21

bronchial glands

Answer 21

seromucous

Question 22

bronchioles

Answer 22

smallest conducting passages
lack cartilage
lack glands
goblet cells only in larger bronchioles
smooth mm major component of wall
attach to surrounding tissue via elastic fibers

Question 23

Clara Cells

Answer 23

Bronchiolar (clara) cells
inc as # of ciliated cells decrease
dome-shaped apical end projects into lumen
secrete some protein comp of surfactant
degrade toxins
stem cells for bronchiolar epithelium

Question 24

terminal bronchioles

Answer 24

ciliated cuboidal epithelium
clara cells
NO goblet cells in healthy lungs
last part purely conducting
must see a resp bronchiole branching from it to say it is truly terminal

Question 25

respiratory bronchiols

Answer 25

junction between conducting & exchange portion cuboidal epithelium interrupted by alveoli clara cell dominate br 3-8 times, ea br ends in an alveolar duct

Question 26

alveolar duct

Answer 26

linear arrangement of alveoli interalveolar septa smooth mm and collegen III regulate opening into ea alveolus lining the duct

Question 27

alveolar sac

Answer 27

small clusters of alveoli that open from a common space

Question 28

alveolus

Answer 28

small outpouching w/ thin-walls that permid gas exchange | alveolar pores - allow airflow between adjacent alveoli keeping pressures equalized

Question 29

alveolar wall (septum)

Answer 29

thin epi and CT layers CT - delicate reticular & elastic fibers in Interstitial tissue bet alveoli Capillary endothelium - simple squa, non-fenestrated type Alveolar type I and II cells at air surface (epithelial cells)

Question 30

alveolar type I cells

Answer 30

``` squamous pulmonary epithelial cell small alveolar cell pneumocyte type 1 cover 95% of alveolar surface provide intact surface of min thickness permeable to gases ```

Question 31

alveolar type II

Answer 31

cuboidal located at septal junctions numerous as type 1 but only cover 2-5% of alveolar surface lamellar bodies release pulmonary surfactant (via exocytosis)

Question 32

pulmonary surfactant

Answer 32

release by lamellar bodies of type II alveolar cells | decreases surface tension and prevents collapse of alveoli

Question 33

brush cells

Answer 33

found infrequently in alveolar epithelium | thought to be sensory receptor cells

Question 34

alveolar pores (pores of Kohn)

Answer 34

permit airflow bet adjacent alveoli, keeping pressures equalized imp in obstructive disease prevents normal passage of air to some alveoli also used by macrophhages, pathogens etc

Question 35

alveolar macrophage

Answer 35

``` alveolar phagocyte/dust cell derived from monocytes enter lung via bloodstream in CT and on alveolar surface phagocytose RBCs - yellow ```

Question 36

alveolar wall (inter-alveolar septum)

Answer 36

Thin region - basal lamina of cap and alveolar epi merge - minimal blood-air interface Thick region - epi retain own basal lamina, CT also contains some elastic and reticular fibers elastic fibers important for collapse of alveolus during exhalation major site of fluid accum in pulmonary edema

Question 37

bronchial arterial system

Answer 37

systemic circ, br of aorta supplies oxy blood to tissues of airway walls and pleura extend as fara as terminal bronchioles then anastomose w/ pulmonary arteries

Question 38

bronchial veins

Answer 38

only drain the CT of the hilar region of the lungs (hilar = hilum = root)

Question 39

lung pleura

Answer 39

two layers: Visceral - covers lung Parietal - covers chest wall and diaphragm meet at hilar root Pleural mesothelium rest on thin layer of collagen and elastic CT, cuboidal -> columnar

Question 40

parietal pleural lymphatics

Answer 40

major exit rout of liquid from the pleural space - stomas -> collecting lymphatics -> infracostal lymphatics -> parasternal and periaortic nodes -> thoracic duct -> systemic venous system

Question 41

innvervation of pleura

Answer 41

visceral portion not innervated | pain is from parietal pleura