respiration 1 Flashcards
Function of respiratory system
O2 Eleimate Co2 Regulat Ph Speech Microbial defecence Activate/inactivate chem messengers in blood defend against blood clots
what is the most critical function of the respiratory system
deliver O2
what is the problem with lots of CO2 in the blood
acidic waste product
how does the respiratory system provide microbial defense
Epithelial secretion
Lymphoid tissue in tract
Coughing and sneezing reflexes
how does the respiratory system defend against blood clots
Small blood clots get trapped in narrow vessels in lungs and are dissolved
what are the series of tubes needed to exchange air betwen lungs and environment
Airways
what makes up the upper airway
Structures outside the thoracic cavity
- mouth/nose
- pharynx
- larynx
- top of trachea
what makes up the conducting zone
thoracic cavity, but no gas exchange occurs
- trachea
- primary bronchi
- sec bronchi
- tertiary bronchioles
- bronchioles
- terminal bronchioles
what makes up the trachea and bronchi
cartilaginous rings
mucous glands
what makes up the bronchioles
Lose cartilage, glands, smooth muscle
what makes up the respiratory zone
Structures where gas exchange occurs
- respiratory bronchioles
- alveolar ducts
- alveolar sacs
functions of the conducting zone
Branching
Air is warmed and moistening
protection against microbes
what is the amount of branching in the conducting zone
1->8 mill tubes
what is responsibly for warming and moistening the air in the conducting zone
Heat and water vapor are exchanged with blood in airway walls
what does the trachea do to protect against microbes
Goblet cells secrete mucus that traps airborne particles and pathogens
what does the eipithelial layer have to protect aginst pathogens
Epithelial cells move mucs up to pharynx to be swallowed or expelled
what does the mutation in cystic fibrosis change
Cl- channel changes the amount of Na and Cl secreted across the epithelium into mucus
= less water in mucus, so mucus dry and thick
how does cystic fibrosis lead to disease
infectious agents trapped not expelled and airways are obstructed
what regulates the airflow in the lungs
Bronchiolar Smooth muscle
why are the alveoli well suited for optimizing gas exchange
High surface area
high vascularized
Respiratory surface very thin
low rate of bloodflow provides time for exchnage
what provides microbial defense in the respiratory zone
Pulmonary macrophages
what are the cells of the alveoli
Type I
Type II
macrophages
what is the roll of type I alveoli cels
Epithelium for gas exchange surface
what is the roll of type II alveoli cells
Secrete surfactant
what is the diameter of the alveolar sacs
.5 micrometers in diameter
what is the distance between alveolus and capillary
.2 micrometers
polarity of respiratory gases diffuse
small and non-polar
solubility of O2 and CO2
CO2=77 mmol/L
O2=2.2mmol/L
what must a gas cross to get into blood from the lungs
across apical membrane of type I cell Through cytoplasm across basal membrane of Type I cell Across basal almina and underlying connective tissue acoss basal membrande of endo cell through cytoplasm across apical membrane of endo cell plasma
what must a gas cross to get from blood to the tissue
reverse of how air goes from lungs to blood
what surrounds earch lung
a pleural sac made of two layers
what adheres to the underside of the thoracic wall and the top of the diaphram
parietal pleua
what covers the outer surface of the lung
Visceral pleura
what is the pleural sacq
the space between the parietal and visceral pleura
how thick is the intrapleural fluid
10-20 micrometers thick
what is the physics of ventilation of the lungs
relies on pressure difference
what is th flow equation
Flow= difference in Pressure from atm to lung/Resistance
what are the relative pressure for inspiration
pressure of alveolus is less than atmosphere
what is the relative pressure for expiration
pressure of the alveolus is greater than the atmosphere
what causes alveolar pressure to change
response to chnaging volume of the lungs (BOYLE’S law)
what are the important pressures used in ventilation
alveolar pressure
intrapleural pressure
transpulmonary pressure
what is intrapleural pressure
the pressure in the fluid of the intrapleural space
what is transpulmonary pressure
the difference in pressure between the intrapleural space and the alvelar pressure
what muscles are used in inspiration
Contraction of diaphram
external intercostal contraction
what muscles are used in expiration
relaxation of diaphram
external intercostals relax
internal intercostal contract
what is the alveolar pressure, atmospheric and intrapleural pressure at rest
alvolar and atm equal
intrapleural below atm
why is intrapleural pressue always subatmospheric
Lungs recoil inward
chest wall recoils outward
how does intrapleural pressure, transpulmonary and alveolar and atmospheric pressure change during inspiration
Intrapleural becomes more negative
transpleural increrases
air flows in until alveolar pressure equal atmospheric pressure
how does intrapleural pressure, transpulmonary and alveolar and atmospheric pressure change during expiration
intrapleural becomes less negative
transpleural decreases
air flows out until alveolar and atmospheric pressure are equal
what causes a pneumothorax occur
lung or pleural sac is punctured
does a pneumothroax happen to one or two lungs
just one lung
what causes the pneumothorax to colapse a lung
different pressures no longer exist so lung colapses and chest wall expands
