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Flashcards in Respiratory System Deck (57)
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what are the functions of the respiratory system

1. oxygen and carbondioxide exchange
2. olfaction
3. phonation
4. provide defense
5. condition air - conducting portion (2-5)


describe the filtration system

1. large particle filters - ex, bugs
2. medium particle filters - ex, dust, pollen
3. small particle filters - ex. bacteria and viruses


what does the conducting portion of the respiratory system do

transports air to the respiratory portion


describe the vestibule of the nasal cavity

1. surface epithelium - keratinized stratified squamous
2. glands in CT - sebaceous and sweat
3. support - hyaline cartilage


what is the respiratory region of the nasal cavity

between limen nasi and superior and middle concha


functions of the respiratory region of the nasal cavity

1. warm air
2. clean air
3. humidify air
4. provide defense


describe the structure of the respiratory region of the nasal cavity

~surface epithelium - respiratory (ciliated pseudostratified columnar)
~mucociliary apparatus - medium sized filter
~Seromucus glands found in lamina propria


what are the mucus in seromucus glands for

1. mucociliary clearance
2. air humidity


what serous products are produced

1. lysozome - antibacterial
2. interferons - antiviral
3. cytokines - stimulates defensive cells
4. air humidity - small particle filter


where is the cavernous plexus found

lamina priopria


functions of the cavernous plexus

1. warm air
2. humidify air
3. provide defense


what are the effects of increased blood flow

~ venules enlarge and LP increases in size resulting in decrease in lumen size causing "stuffy nose"
~ oxygen increase will stimulate seromucus gland secretion causing "runny nose"


describe the structure of the olfactory region

1. surface epithelium - olfactory epithelium with supporting and basal cells and olfactory neurons
2. olfactory neurons are bipolar neurons with olfactory cilia extending onto the epithelial surface. basal axon is unmyelinated with a sheath of Schwann cells. basal cells are small pyramidal shaped cells that can divide and replace the other two cell typs
3. olfactory (bowman's) glands produces serous product to cleanse olfactory cilia
4. support - bone


describe paranasal sinuses

~found in ethmoid, sphenoid, frontal and maxilla bones, connect to nasal cavity thru small nasal ostia
~ epithelium - respiratory epithelium
~lamina propria - thin but has seromucuc glands and is quite vascular
~Small ostia - if LP swells ostia become blocked and sinus infection can thrive


what are the subdivisions of the pharynx

~ nasopharynx - superior
~ oropharynx - middle
~ laryngopharynx - inferior


describe the surface epithelium of the mucosas

1. nasopharynx - respiratory with mucociliary clearance
2. oropharynx - stratified squamous
3. laryngopharnx - stratified squamous


describe the LP of pharynx

nasopharynx - pharyngeal tonsils
oropharynx - palatine and lingual tonsils
laryngopharynx - no tonsils


does the pharynx have a muscular mucosa



describe the submucosa of the pharynx

~ pharyngobasilar fascia - collagen in periosteum of basilar portion of occiput blends into the wall of pharynx for added support


Describe the mascularis externa

~ all skeletal muscles
~ reversed pattern - a. inner longitudinal muscles
b. outer circular muscles
(also occurs in th ureters)


Describe the adventitia

~ epimysium of buccinator muscle blends into the adventitia of the pharynx
~adventitia is CT
~function - to hold in place


where does the larynx lie

between the pharynx and trachea


describe the specilized luminal wall structure

~surface epithelium - upper surface is stratified squamous, parts will transition to respiratory
~lamina propria - loose CT with seromucus glands
~cartilages with the wall of the larynx


functions of the cartilages with the laryngeal walls

a. maintain an open airway
b. along with skeletal muscle aid in sound production


types of cartilage within the larynx

~hyaline - thyroid, cricoid, and inferior arytenoid
~elastic - epiglottis, cuneiform, corniculate, and superior arytenoid


what is the function of the epiglottis

- keep food and liquid out of larynx


describe the vestibular folds

immovable folds of tissue
surface epithelium - respiratory epithelium
lamina propria - loose CT with seromucus glands and possible lymph nodes


describe the laryngeal ventricle

surface epithelium - mucosa is primarily stratified squamous


describe the vocal folds

-surface epithelium is stratified squamous
function to protect from abrasion and to some degree drying due to rapid air movement
-lamina propria has dense regular bundles of elastic CT which functions to support vocal fold


describe vocalis muscle

-located deep to the mucosa
-striated muscle which will adduct to narrow the rima glottidis
-sound created when air vibrates the vocal folds


describe the mucosa of trachea

a. surface epithelimum - respiratory
b. lamina propria - loose CT with seromucus glands that is quite vascular
c. no muscularis mucosa


what are the cell types in the surface epithelium of mucosa of the trachea

goblet - ~30%
ciliated columnar - ~ 30%
basal cells - ~ 30%
brusch cells - ~ 3% function maybe chemosensory
serous cells ~ 3% -secretes unknown product to lumen
DNES (small granule) Cells (Kulchitsky Cells) 3-4% - secretes in LP likely to influence respiratory epithelium


what does the submucosa of the trachea contain

hyaline cartilage c-ring and blends with LP


describe the muscularis externa of trachea

individual trachealis muscles - smooth


describe the adventitia of trachea



what are the structural trends in the bronchi

~decreases in:
amount of cartilage
number of glands (seromucus)
number of goblet cells
~increases in:
smooth muscle
elastic CT


what does the intrapulmonary bronchi include

secondary and tertiary bronchi


what are the characteristics of bronchioles

1. less than 1 mm
2. no cartilage
3. no seromucus glands
4. complete smooth muscle layer
5. epithelium type is simple columnar/cuboidal with some goblets and clara cells, but can vary some along the length
6. clara cells -- have short microvilli
7. other cells include chemosensory brush cells


what do secretory cells in the surface epithelium of bronchioles do

-secrete product to protect epithelium
-produce enzymes which degrades toxins
-regenerate bronchilar epithelium
-secrete lysozome
-produce surfactant type material


describe the terminal bronchioles

last part of the conducting portion of the respiratory system
epithelium - simple columnar/cuboidal with clara cells
LP - fibroelastic CT
1-2 layers of smooth muscle


Describe respiratory bronchioles

First region of respiratory portion
-simple cuboidal epithelium with clara and some cilia
-similar to terminal bronchioles but with some simple squamous epithelium therefore gas exchange is possible


what is the function of alveolar ducts and sacs

gas exchange ( same structure as alveoli)


Describe alveolar type I cells

type I pneumocyte (flat cells)
95% of alveolar surface
squamous type cells with zonula occludens between cells
general function is gas exchange


describe alveolar type II cells

type II pneumocyte
5% of alveolar surface but as numerous as type I
most to sides of alveoli - cuboidal cells
functions as stem cell for type I and type II
produce pulmonary surfactant and lysozome


describe alveolar macrophage

dust cells
develop from monocytes
function to clean septal walls using phagocytosis
produces lysozyme


what is an interalveolar septum

region between two alveoli
parts include type I and type II cells and continous capillaries, fibroblasts, basal lamina, small amounts of CT with many elastic fibers, myofibroblasts and mast cells


what is the blood gas barrier

region where oxygen and carbondioxide pass between the air and blood
this is the minimum diffusion distance/barrier that allows for the most efficient gas exchange


parts of the blood gas barrier

air to blood:
-pulmonary surfactant coating the internal aspect of alveoli
-alveolar type I - each cell has its own basement membrane
-fused basal lamina-shared bet alv type I and endohelial
cell of capillary
-endothelial cells of capillary - squamous


what results in bronchodilation

thoracic sympathetic chain ganglia provide fibers which will relax the bronchial smooth muscle


what causes the paradoxical response of constricting the pulmonary blood vessels

sympathetic fibers stimulate smooth muscle in the tunica media


when does broncho constriction occur

when the vagus is stimulated causing parasympathetic fibers to constrict bronchial smooth muscle


what happens when there is chronic exposure to irritants and metaplasia in the upper respiratory tract

-goblet cell numbers increase - increase mucus
-ciliated columnar cells decrease causes congestion
-seromucus glands increase in size causes more fluid
-much coughing develop patches of stratified squamous metaplasia instead of respiratory epithelium


what is RDS

Respiratory distress Syndrome in newborns- too few mature alveolar type II cells, therefore less surfactant


how is RDS treated

1. artificial surfactant and CPAP-only few treatments needed
2. glucocorticoids given before birth will induce surfactant production


what is emphysema

decrease in elastin so decrease in alveolar elasticity
reduced surface for gas exchange
inflammation attracts macrophages and neutrophils which secrete elastase


what are the causes of emphysema

1. inflammation - from infection irritatants, smoking
2. genetic - hepatocytes produce alpha 1-AT but can not release it therefore levels are too low


what is Alpha 1-AT

a protein that protects elastic fibers