Respiratory System Flashcards
what are the functions of the respiratory system
- oxygen and carbondioxide exchange
- olfaction
- phonation
- provide defense
- condition air - conducting portion (2-5)
describe the filtration system
- large particle filters - ex, bugs
- medium particle filters - ex, dust, pollen
- 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
- surface epithelium - keratinized stratified squamous
- glands in CT - sebaceous and sweat
- 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
- warm air
- clean air
- humidify air
- 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
- mucociliary clearance
2. air humidity
what serous products are produced
- lysozome - antibacterial
- interferons - antiviral
- cytokines - stimulates defensive cells
- air humidity - small particle filter
where is the cavernous plexus found
lamina priopria
functions of the cavernous plexus
- warm air
- humidify air
- 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
- surface epithelium - olfactory epithelium with supporting and basal cells and olfactory neurons
- 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
- olfactory (bowman’s) glands produces serous product to cleanse olfactory cilia
- 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
- nasopharynx - respiratory with mucociliary clearance
- oropharynx - stratified squamous
- 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
none
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
CT
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
- less than 1 mm
- no cartilage
- no seromucus glands
- complete smooth muscle layer
- epithelium type is simple columnar/cuboidal with some goblets and clara cells, but can vary some along the length
- clara cells – have short microvilli
- 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
- 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
irreversible
inflammation attracts macrophages and neutrophils which secrete elastase
what are the causes of emphysema
- 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
