Outcome 10 - Respiratory System Flashcards
what makes up the respiratory system?
nose, pharynx, larynx, trachea, bronchi and lungs
structurally the resp system is broken down into two components. What are they?
- upper resp system
- lower resp system
what makes up the upper resp system then?
nose, nostrils, nasal cavity, and pharynx
what are the 3 divisions of the pharynx?
- nasopharynx
- oropharynx
- laryngopharynx
what makes up the lower resp tract?
larynx, trachea, bronchi, and lungs
functionally, the resp system is broken down into two part as well. What are the two parts called?
- conducting zone - moistening, filtering air into lungs
- respiratory zone - site of gas exchange
what makes up the conducting zone?
nose, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles
what makes up the respiratory zone?
- resp bronicholes, alveolar ducts, alveolar sacs and alveoli
what are the functions of the nose?
- to warm, moisten and filter air
- detection of olfactory stimuli
- to modify speech vibrations
- mucus production
what is the job of the nasopharynx?
- starts at the posterior internal cares
- it receives the air and dust laden mucus, has cilia to move the mucus down to the oropharynx
- equalizes pressures by exchanging air with the auditory tubes
what is the job of the oropharynx?
- passage of food, air and drinks
*one opening to the oral cavity
what are the two parts of the laryngopharynx?
- opening to esophagus
- opening to larynx
what is the function of the pharynx?
- passageway for air, food and provides that resonating chambers for speech
- holds tonsils which react with immune response to pathogens
what is the larynx?
“structure” - voice box
- short structure that connects the laryngopharynx to the trachea; anterior to esophagus
what is the makeup of the larynx?
9 pieces of cartilage + two folds of tissue
_____ fold = _____ vocal cord
_____ fold = _____ vocal cord
vestibular fold = false vc
vocal fold = true vc
what is the makeup of a trachea? why is it like that?
16-20 anterior, hyaline cartilage c-shaped rings
the c-shape allows for structural support and where the c is, it allows for the expansion of the esophagus
trachea is ____ to the esophagus and divides at _____ into the r/l _____
anterior to the esophagus
divides at t5
r/l bronchi
what is the function of the trachea?
- passage of air
- production of some mucus to catch more dust
- ciliated cells to move dusty mucus up away from lungs to pharynx to be swallowed/expelled
what’s the difference between the right and left bronchi?
right is shorter, wider and more vertical
what is the branching of the bronchial tree?
trachea –> 2 primary bronchi –> 3 R, 2L secondary bronchi (lobar) –> 10 tertiary bronchi (segmental) –> bronchioles –> terminal bronchioles
what is the site of bronchi division into the primary bronchi called?
carina
what are the two chambers of the chest?
what are these chambers surrounded by?
- parietal pleura - lining of the walls of the thoracic cavity
- visceral pleura - covering the lungs
*a serous membrane
the right lung has ___ lobes
the left lung has ____ lobes
right - 3
left - 2
what is the hilum in the lung?
an opening on either lung for the bronchi, pulmonary vessels, lymphatic vessels and nerves to enter and exit
what is the pleural cavity?
a cavity that is between the layers of the serous membrane
contains pleural fluid
what does the pleural fluid do?
reduces friction between the membranes to allow for the membranes to slide over one another during breathing
what are the 3 lobes of the right lung called and where are they situated?
superior (anterior)
middle (anterior)
inferior (posterior)
what are the two fissures that separate the three lobes in the right lung?
- horizontal fissure
- oblique fissure
what are the 2 lobes of the left lung called and where are they situated?
superior (anterior)
inferior (posterior)
what is the fissure that divides the 2 lobes in the left lung called?
oblique fissure
what is the flow of the microscopic airway?
respiratory bronchioles –> alveolar ducts –> alveolar saccules –> pulmonary alveoli
what are the three types of alveoli cells?
- type I alveolar cells (pneumocyte type I)
- type ii alveolar cells (pneumocyte type ii)
- fixed alveolar macrophages
which type of alveolar cells secrete alveolar fluid? what does the fluid do?
type ii
keeps the surface between cells and air moist; contains surfactant to lower surface tension of alveolar fluid
which type of alveolar cells are the site of gas exchange?
type i
approximately how many alveoli are there? what does that equate in terms of surface area?
~300 million
750 sq ft
what are the two sets of arteries that supply blood to the lungs?
- r/l pulmonary arteries
- bronchial arteries
blood returns to the heart by the ______ as well as some draining into the the SVC by the _______.
return to heart by pulmonary veins
drain into SVC by bronchial veins
what is ventilation-perfusion coupling?
the idea that if the lungs are well ventilated, perfusion should match.
in the upright position, due to gravity, ventilation ___ from ____ to _____;
perfusion ____ from ____ to _____.
ventilation increases from apex to base
perfusion increases from apex to base
in the supine position, what is the relationship between ventilation/perfusion at the base/apex?
base ventilation = apex ventilation
base perfusion = apex ventilation
what is respiration?
the process of gas exchange in the body
what are the three steps of respiration?
- pulmonary ventilation
- external respiration
- internal repsiration
what is pulmonary ventilation?
exchange of air between the atmosphere and the alveoli of the lungs
inhalation and exhalation*
what is external respiration?
gas exchange across resp membrane IN THE LUNGS (from the alveoli (lung) into the pulmonary capillaries (blood)
what is internal respiration?
has exchange between tissue capillaries and tissues
systemic capillaries <–> tissue cells
when does air move into the lungs?
when does air move out of the lungs?
in - when pressure inside the lungs is less than atmospheric pressure
out - when the pressure inside the lungs is greater than atmospheric pressure
what does Boyle’s law describe?
the pressure of gas inside a closed system is inversely proportional to the volume of the container
P1V1=P2V2
describe inhalation/inspiration.
- active process as it requires contraction of muscles (external intercostal and diaphragm)
- increases lung volume
- overcoming the surface tension of the narrowed alveolus
what is quiet inhalation?
- when the diaphragm drops ~1cm and the pressure inside the lungs decreases
- ~500 ml of air flows into the lungs
____ of air enters by the contraction of the diaphragm
___ of air enters due to the contraction of external intercostals
~75% diaphragm
25% external intercostal
what role does intrapleural pressure have on respiration?
it is the pressure between the parietal and visceral layers of pleural cavity
- always subatmospheric
- due to the surface tension between the layers and the negative vacuum, the visceral pleural will pull on the lungs when the thoracic cavity increases
describe exhalation/expiration.
- normal exhalation is passive, it is just the recoiling of the lung tissue and relaxation of the intercostals and diaphragm.
- when the pressure in the lungs are greater than atmospheric
what aids in the recoiling of the lungs during exhalation?
- elastic fibers recoiling
- inward pull of surface tension due to the film of the alveolar surfaces (~2/3 of the recoiling of lungs)
is forced exhalation also passive?
no. muscles are recruited and contacted using energy
what muscles are involved in forced exhalation?
- abdominal
- INTERNAL intercostals
what are some other factors that affect pulmonary ventilation?
- surface tension = inward pulling (thin layer of alveolar fluid coating the luminal surface of the alveoli)
- compliance
- airway resistance
what does the body do to combat the surface tension?
by surfactant that is secreted by type ii alveolar cells
what are the surfactants? what do they do?
- phospholipid and protein
- acts like a detergent to reduce surface tension
____ compliance = easy to stretch
____ compliance = hard to stretch
↑ compliance = easy to stretch
↓ compliance = hard to stretch
what may cause compliance to decrease?
- scar tissue
- edema
- muscle paralysis
- decrease surfactant
do normal lungs have low or high compliance?
high.
- elastic fibers are easily stretched
what is compliance?
the effort required to stretch lungs and chest
what is the air flow equation?
air flow = (P(alveoli) - P(atmosphere))/resistance in the airways
↑ resistance in airways = _____ air flow
↑ pressure difference = ____ airflow
↑ resistance = ↓ airflow
↑ pressure difference = ↑ airflow
inhalation = ____ resistance, why?
exhalation = ____ resistance, why?
inhalation = decrease resistance because bronchioles increases in diameter
exhalation = increase resistance because bronchioles decrease in diameter
___ stimulation causes _____ of smooth muscles = _____ of airway diameter
sympathetic stimulation = relaxation of smooth muscles = bronchodilation = increase airway resistance = increase flow
tidal volume
volume of air delivered to lungs with each breath
total lung capacity
volume of air in the lungs upon the maximum effort of inspiration
*inspiratory reserve volume + tidal volume + expiratory reserve volume + residual volume
vital capacity
total amount of air exhaled after maximal inhalation
*inspiratory reserve volume + tidal volume + expiratory reserve volume
functional residual capacity
volume remaining in the lungs after a normal, passive exhalation
*residual volume + expiratory reserve volume
inspiratory capacity
maximum volume of air that can be inhaled
*sum of the TIDAL VOLUME + INSPIRATORY RESERVE VOLUME
residual volume
volume of air remaining in the lungs after maximum forceful expiration
expiratory reserve
extra volume of air that can be expired with maximum effort beyond the level reached at the end of a normal, quiet expiration
inspiratory reserve
maximum volume of air that can be inspired after reaching the end of a normal, quiet expiration
gas exchange is when O2 diffuses from the air to the pulmonary capillaries until…?
Pressure of O2 in blood = pressure of o2 in air
at rest, ~___% of the o2 in our blood is needed
therefore, the “deoxygenated blood” is actually ____% oxygenated.
what does this percentage become during exercise?
~25% o2 needed at rest, 75% deoxygenated blood is actually oxygenated
then during exercise, we can use 75% of the o2 in the blood, therefore, ~25% o2 will be part of the deoxygenated blood
What does the rate of gas exchange depend on?
- partial pressure of gases
- surface area for exchange
- diffusion distance
- molecular weight and solubility
the greater difference of the partial pressure between the sites = _____ rate of exchange
greater difference = increased rate of exchange
due to the vast SA of the lungs’ capillary network, what is the amount of blood exchanging at any given time?
~900 mL
low molecular weight = ___ diffusion
high solubility = ____ diffusion
low mw = increases diffusion
high solubility = increases diffusion
molecular weight of ___ > ____
solubility of ____ > _____
what does this mean then?
mw CO2 > O2
Solubility CO2 > O2
co2 diffuses out 20x more rapidly than o2 (making hypoxia more prevalent than hypercapnia)
what is oxyhemoglobin?
the binding of O2 to Hb (~98.5%) because O2 doesn’t dissolve well in H2O and blood is mostly H2O
what are factors that affect Hb affinity for O2?
- partial pressure of O2
- acidity
- partial pressure of CO2
- temperature
- bisphosphoglycerate (BPG)
____ o2 = ___ Oxygen-Hb binding
increased o2 (seeing from chart, oxygenated blood = higher pO2) = increased oxygen-Hb binding
____ acidity = _____ oxygen-Hb binding
decreased acidity = increased oxygen-Hb binding
____ pCO2 = ____ Oxygen-Hb binding
lower pCO2 = increased oxygen-Hb binding
____ temp = ____ oxygen-Hb binding
lower temps = increased oxygen-Hb binding
*but based on chart, as temp increases, the pO2 has an “ending amount” in comparison to normal the,p and higher temp
what is bisphosphoglycerate?
it binds to Hb and makes it more unlikely to unload O2.
BPG has a low affinity for O2.
what are the three ways in which co2 is tranported in blood?
- dissolved co2 in blood (7%) - reaching lungs and being expelled
- carbamino compounds (23%) - co2 binding to amino acids and proteins (most being Hb!)
- bicarbonate ions (70%) - co2 entering rbc and reacting with H2O
what is occurring with CO2 and Cl- in rbc?
the cl- moves from the plasma into the rbc and the HCO3- moves out
HCO3- is the product when CO2 interacts with H2O in rbc.
HCO3- then reaches pulmonary capillaries and the reaction is reversed and co2 is then expelled during exhalation
what is the CO3 reaction that occurs in the RBC and in the pulmonary capillaries?
H2O + CO2 –> H2CO3 –> H+ + HCO3-
*in pulmonary capillaries, it’ll be reversed to get CO2 and expelled out
where are the respiratory centres in the brain?
- pontine resp group is between midbrain and pons
- resp center/ pre-botzinger complex, dorsal and ventral resp group is in the medulla oblongata
what does the medullary respiratory center control? what are the two groups it breaks into?
the basic breathing rhythm
- dorsal respiratory group (DRG)
- ventral respiratory group (VRG)
what does the DRG drive?
drg - normal quiet breathing
~2 sec inhalation, at the end of 2 secs, drg stops ap for the ~3 sec passive expiration
what is the role of pre-botzinger complex?
important to set the basic breathing rhythm
- has pacemaker cells that are thought to provide input to drg on the rate in which to fire ap
what does vrg control?
vrg neurons are active in forceful breathing (inhalation and exhalation)
- ap sent from drg to vrg to accessory inhalation
- vrg just sends impulses to accessory muscles of exhalation *note no impulse from drg
what does the pontine respiratory group control?
MODIFIES BREATHING RHYTHM by working with the centers in the medulla to adjust respiration during active inhalation and exhalation
input from = _______ –> pontine resp. group —> ______ = to adjust depth and length of respiration
input from cerebral cortex, limbic system and hypothalamus
pons to medulla
what are some factors that influence rate and depth of breathing?
cortical influences, chemoreceptor regulation, proprioceptor stimulation, inflation reflex, limbic system, temp., pain, anal sphincter stretching, airway irritation, bp
what does pain do to respiration?
short sharp pain = apnea
long/chronic pain = increased breathing rate
what do cortical influences do?
they help with consciously controlling breathing
where are chemoreceptor regulations occurring?
O2, CO2, and H+ is measured in medulla, aortic and carotid bodies
