respiratory system Flashcards
what are the functions of the respiratory system
- gas exhange (supplies O2 and eliminates CO2)
- aids in regulation of pH and CO2
- produces sounds and speech + contains receptors for smell
- eliminates water and heat
- modifies substances (ie. angiotensin)
what are the 3 processes involves in respiration
- pulmonary ventilation
- external respiration
- internal respiration
what is pulmonary ventilation
- breathing
- the inhalation (inflow) and exhalation (outflow) of air
- exchange of air between the atmopshere and the alveoli
what do inhalation and exhalation permit?
- inhalation: permits O2 to enter the lungs
- exhalation: permits CO2 to leave lungs
what is external respiration
- aka pulmonary respiration
- exchange of gases between alveoli and blood in capillaries across respiratory membrane
- lungs exchange O2 and CO2
what is internal respiration
- known as tissue respiration
- exchange of gases between blood in systemic capillaries and tissue cells
- tissue exchange between O2 and CO2
what is cellular respiration
the metabolic reaction that consumes O2 and gives off CO2
what is the chemical reaction of cellular respiration
C6H1206 + 6 O2 –> 6 CO2 + 6 H2O + 34 ATP
how are the parts of the respiratory system organized
according to structure or function
how is the respiratory organized according to structure?
- upper respiratory tract (nose, nasal cavity, pharynx)
- lower respiratory tract (laeynx, trachea, bronchi, lungs)
how is the respiratory organized according to function
- conducting zone
- respiratory zone
what is a brief function of the conducting zone
interconnecting tubes and cavities that filter, warm and moisten air while conducting it to the lungs
what structures are in the conducting zone
- nose
- nasal cavity
- pharynx
- larynx
- trachea
- bronchi
- bronchioles
- terminal bronchioles
what is a brief function/summary of the respiratory system
tubes and tissues within lungs where gas exchange occurs
what structures are in the respiratory zone
- respiratory bronchioles
- alveolar ducts
- alveolar sacs
- alveoli
what is the function of the nasal cavity
- creates turbulence
- resonating chamber for sound production
what is the function of nares
- hairs
- create turbulence
- catch large particles
what is the function of conchae
- ridges
- create turbulence
- traps large particles
what is the function of pharynx
passageway for food and air
what is the function of glottis
opening to pharynx
what is the function of epiglottis
- flap that opens and closes
- prevents food from entering into the larynx
larynx
voice box
what is the function of the mucosial ciliary system
cleanses air
what is the mucosial ciliary system made out of
ciliated pseudostratified columnar cells with cilia and goblet cells
what is the function of cilia and goblet cells
cilia: moves microbes and debris up and out of airways
goblet cells: secrets mucous that traps particles and pathogens
besides cilia and goblet cells, how else does the mucosal ciliary system protect the respiratory system pathways from pathogens
in mucous:
- defensin: antibacterial compound
- lysozyme: antibacterial enzyme
what are the specialized structures in the conducting zone
and describe their functions
- c-shaped cartilage rings: keep passageways open
- conchae of nasal passage: create turbulence
- smooth muscles of bronchioles: regulate air flow
- blood vessels: run along tubes and warms air
How do the structures of the respiratory tract change from conducting zone to the respiratory zone?
- tube diameter decreases
- cartilage rings become irregular and then disappear
- columnar cells become cuboidal and then simple squamous
- loss of cilia + goblet cells
- increase in smooth muscles (good for air regulation in bronchiole)
describe the alveoli structure
- made of simple squamous
- pores connect each individual alveolus
- cuboidel cells secrete surfactant
- contains elastic fibers
- capillaries for ga exchange
- macrophages which provide immune defenses
what is the function of surfactant
- lower surface tension, which prevents alveolar from collapsing at end expiration
- interacts and kills pathogens
- modulates immune responses
is the respiratory membrane thin or thick and why
thin for diffusion
describe the components of the respiratory membrane
- 2 Cells thick
- simple squamous epithelial of alveolar wall
- simple squamous epithelial of capillary wall
- basement membrane anchors the 2 layers together
what compartments are involved in ventilation (breathing)
- thoracic cavity
- pleural cavity
- intrapulmonary cavity
what is the thoracic cavity
compartment containig the lungs
what is the pleural cavity
slit like space found between the parietal pleura and visceral pleura
contains liquid
whats the pressure like in the pleural cavity
always negative and becomes more negative with breathing
what is the intrapulmonary cavity
- space inside of lungs (the air filled alveoli)
- pressure fluctuates
what does the pleura do
attaches lungs to thoracic cavity
what kind of membrane in the pleura
double
what are the 2 membranes of the pleura and their functions
- parietal attaches to thoracic wall
- visceral attaches to the lungs
whats the role of the interpleural cavity
contains fluid that adheres the 2 layers together and adheres the lungs to the thoracic wall
what is the role of the elastic fibers
ensure expansion and recoil of lungs
what is compliance?
the measure of elasticity of the lungs
- lower compliance = greater force needed to expland of empty lungs
what factors affect compliance
- elastic fibers
- level of surfactant production
- mobility of thoracic cavity
normal inspiration requires the use of which muscles
contraction —- thoracic cavity volume
- diaphragm
- external intercostals
increases
normal expiration requires the use of which muscles
relaxation of muscles — thoracic cavity volume
- diaphragm
- external intercostals
decreases
forced inspiration requires the use of which muscles
- diaphragm
- external intercostals
- neck
- chest
- back
why does forced inspiration require the use of the neck chest and back
to help increase the volume
forced expiration requires the use of which muscles
- abdominal wall
- internal intercostals
the pressure gradient occurs between what?
the inside of the lungs and the atmopshere outside
what are the steps of inhalation
- respiratory myscles of normal breathing contract
- thoracic cavity volume inc which makes the intrapulmonary volume inc too
- the intrapulmonary pressure dec to 758 mmHg, which creates a pressure gradient
- air flows in, down the pressure gradient
- Pout (760) > Pin (758)
what are the steps of exhalation
- respiratory muscles relax
- thoracic cavity volume decreases which decreases the intrapulmonary volume
- the intrapulmonary pressure inc to 762 mmHg, which creates a pressure gradient
- air flows out
- Pin (762) > Pout (760)
the contraction of respiratory muscles causes..?
an increase in thoracic cavity volume which causes an inc in intrapulmonary volume
the contraction of intercostal muscles causes
the rib cage to raise
the contraction of the diaphragm causes
causes the diaphragm to flatten which increases the volume of the thoracic volume
why do changes in thoracic cavity volume cause a change in the intrapulmonary volume?
because the lungs are directly attached to the thoracic wall
what are the 5 respiratory volumes
- tidal volumes
- inspiratory volume
- expiratory volume
- residual volume
- dead space
what is tidal volume
- the normal breathing volume
- tv
what is the inspiratory reserve
- air inhaled beyond the tv
- irv
what is expiratory reserve
- erv
- the air evacuated after tidal volume
what is residual volume
- rv
- the amount of air left in the lungs after exhaling
what is dead space
volume of ingaled air in a breath that stays in the conducting zone
whats the difference between dead space and residual volume
dead space
- volume of inhaled air that stays in the conducting zone
- not part of gas exchange as the air stays in the trachea, bronchi and bronchioles
- 1/3 of every breath or 150 mls
- part of rv
rv
- amount of air left in the lungs after exhaling completely
- about 1.2 litres
- cant be exhaled
- participates in gas exchange –> mixes with gas exchange
- cant be removed only replaced
what is a respiratory capacity
sums of volumes
what is the inspiratory volume
tv + irv
what is the functional residual capacity
rv + erv
what is vital capacity
- total exchange of air
- tv + irv + erv
what is the total lung capacity
sum of all volumes
`
what are examples of restrictive pathologies and what do they do
- fibrosis and obesity
- cause stiff lungs which makes it difficult to inhale
- causes a dec in total lung capacity
what are examples of obstructive pathologies and what do they do
- asthma and bronchitis
- narrowing of passageways which make it difficutl to exhale
- causes an increase in residiual volume
what does pP mean
- partial pressure
- pressure exerted by the individual gas in a gaseous mixture
describe external respiration
- O2 diffuses from alveolus into blood
- CO2 diffuses from blood into alveolus
what factors affect external respiration
- large surface area + thin respiratory membrane
- favorable concentration gradients
- ventilation-perfusing coupling (optimal air flow to blow)
describe interal respiration
- O2 diffuses from alveolus into blood
- CO2 diffuses from blood into alveolus
what factors affect internal respiration
- available surface area (depends on capillary sphincters)
- pressure gradient alters with tissues activity
- blood flow (are arterioles constricted or dilated)
- air flow (are bronchioles constricted or dilated)
how is O2 transported
- by hemoglobin
how does hemoglobin transportation work
- picks up O2 at lungs (loading)
- drops off O2 at tissue (unloading)
- O2 reversibly binds to hemoglobin
what is saturation
- the binding of oxygen to hemoglobin
what are the percentages of saturation per molecules of O2
