Respiratory Physiology Flashcards
what is resperation
exchange of respiratory gases
oxygen and carbon dioxide with the environment
why is there a constant urgent need of O2 in animals
-because they need it for metabolic processes
-they need it for aerobic respiration
-which produces 34 ATP
-anaerobic respiration only produces 4 ATP
what are the three types of respiration
-external
-internal
-cellular
what is external respiration
transport of O2 into and CO2 out of the body
what is internal respiration
transports O2 into and CO2 out of the cells
what is cellular respiration
-intracellular reactions that convert stored energy to ATPe
how does external respiration work
-has a gas-exchange (repritory) membrane
-it separates internal tissue form environmental medium (air or water)
-process in which:
-environmental O2–> membrane–> tissues
-dissolved CO2–> membrane–> environment
what is a gas exchange membrane
(respritory) membrane is a thin layer of one or two epithelia
what is the formula for the diffusion rate of ficks law
j=D.A. C1-C2/X
what is the formula for the diffusion rate
J=D.A. P1-P2/X
what is C1-C2
-regions of high and low conc of solute
-C1= higher conc
what is the A
diffusion area
what is the X
distance separating the concentration regions
what is the D
-diffusion co-efficent, influenced by physico-chemical properties of the solute, & temp
-constant if other factors stay constant
what is P1-P2
-regions of high and low partial pressure
-P1 is the higher pp
how do gas molecules relative to conc graidents
-they move because of partial pressure not nessisarly conc graident
how small does an animal need to be to rely of diffusion of O2 alone
-using flicks law: vert muscle requires O2 pp or 40mmHg
-rearranging the eq: the distance inside the tissue where O2 PP reaches a min of 40mmHg=1mm
-so diffusion alone is sufficent only for very small animals such as rotifers
what happens to oxygen requirements as an organism gets larger
-O2 requirements increase with mass
-diffusion distance increases
-their surface area gets proportionately smaller
-thus a need for respiratory organs with larger SA and shorter diffusion area
why do mammals and birds have a higher SA for gas exchaneg
because they are warm blooded and need more O2
why do brids and mammals have thinner gas exchange membrane
because they are endothermic (warmblooded)
-birds require alot of O2 to fly which requires alot of ATP
restoration in larger animals requires multiple steps. what are they
-most vertebrate gas transfer system involves:
-breathing movements–> ventilation
-diffusion of gasses across the respiratory epithelia
-circulatory system–> bulk transport of gases (perfusion)
-diffusion of gases across capillary wall
what is ventilation
breathing movements
what is perfusion
bulk transport of gases
what is the structures of the gas exchange system of an animal influenced by
-properties of the medium—> air vs water
-requirements of the animal
what does daltons law state
that the total pressure exerted by a gas mixture (e.g atmosphere) is the sum of individual pressures ecerted by each gas mixture
what is the partial (Pg) pressure of a gas
its its individual pressure in a mixture
what is the rate of diffusion of a gas proportional to
its partial pressure within the total gas mixture
how will O2 and CO2 flow
based on their pressure praident (high to low)
what is the total atmospheric pressure
1atm=760mmHg at sea level
how would u calculate the partial pressure of N2 in atmospheric air of the precent is 79
760mmHg x 0.79 = 600mmHg
what does the higher altitude do to oxygen pressure
it reduces the inspired pressure of the oxygen not the precent of oxygen in the atmosphere
how does the property of gasses change in air vs water
how does the temperature alter the the dissolves O2 level in water
higher temp=water solubility goes down
what are some other influences of dissolved O2 in water
salinity and pressure
resp gas exchange occurs through…
-diffusion
-following the differences of their partial ressure between environment and animals body
why is water breathing energetically more expensive than air breathing
-water is a denser and viscous medium
-O2 is less soluble in water then air (30x less soluble)
what are gills
-invaginations of the body
-respritory surfaces
-branches and folded
-increased diffusion area
what is the basic overview of how gills work
-water moves over gills
-beating of cilia; and contractions of body muscles pump water over gills
what are external gills
they extend out from the body and do not have protective coverings
what are internal gills
-located within the body
-protected by chambers of the body
-currents of water to be directed over the gills
what is an example of an aquatic creature with external gills
-nudibranch
what is are some example of aquatic creatures with internal gills
-clam
-cuttle fish
-fish
what things have a double pumping mechanism
bony and cartilaginous fish
in double pumping fish what are the two pump cavities
-buccal cavity
-opercular cavity
in double pupming fish what is the water entrance and exit
mouth and operculum
in double pumping fish what are the two different pumps
buccal pump
opercular pump
what does the double pump use to create pumping
pressure graident
where is ram ventilation found
-pelagic fish like some sharks and mackerel
what happens if mackerel stop swimming
they cant fully oxygenate there blood
how does water flow through gills
it flows over filaments of gils, then out as mouth closes and operculum opens
how does blood and water flow in the gills
in opposing directions
how does the blood leaving the capillaries and oxygenated water compare in O2 content
they have the same O2 content
how does the concurrent and counter current of blood and water absorption of O2 compare
in concurrent-50%
in countercurrent-90%
why is counter gas exchangers so efficent in fish
in the gill the PaO2(arterial) is higher then the PeO2(expired water)
what is the P1-P2 constant with in the gills
along the length of the secondary lamella
kill fish can live in aquatic and fresh water and different temps. how does the gill change in warmer vs colder water? how does this help their respiration?
the lamella are much thicker in the colder water. in warm its very thin. this is because O2 is less soluble in warm water and by being thinner it creates less area to have to diffuse through
what is the trachea in isects
-windpipe
-invaginations of the outer epidermis that branch repeatedly
-trachea branches into tracheoles
how does air enter and leave in insects
air enter and leave through spiracles
what happens to O2 and CO2 in insects (where does it go)
O2–extra cellular fluid–cells
CO2–ECF–tracheoles
in insects what limits the size if the tissue
length of tissue diffusion path
in insects does simple diffusion in tracheoles work for all
no only smaller ones. larger ones use vantilation
how does ventilation in larger insects work
it involves opening/closing of spiracles and abdominal muscles
what structures do birds have for resperation
lungs and air sacs
what are the two air sacs birds have
anterior (front) posterior (back)
how many air secs to birds have
5-9 depending on the species
explain the cross current exchange of birds during cycle 1 of inhalation
-during fist inhalation most of the oxygen flows directly to the posterior air sac
-during the following exhalation both anterior and posterior air sacs contract
explain the cross current exchange of birds during cycle 2 of inhalation
-second inhalation air form lungs (now deoxygenated) moves into anterior air sacs
-in second exhalation air from anterior sacs in expelled to outside through trechea
what air does the posterior sac store
fresh incoming air
what air does the anterior sac store
holds deoxygenated air
where does gas exchange in the birds lungs occur
parabronchi
how does cross current gas exchange happen in birds
-blood flow branches into multiple streams, each of which meets the air along only part of the airs path
-blood farther down the tubes run alongide O2-poor medium
where is the PO2 higher? blood leaving the breathing organ or the exhaled medium
-blood leaivng the breathing organ
how high can bird fly
-higher then everest
-this is the human dead zone
-we would die in 30mins
how does the vertebrate resp system have blood and air interact
-through a pool system
-air/blood go in/out in the same spot
-there is a mixing of oxygen and blood
nasal passage
chamber in which air is moistened, warmed, and filtered and in which sounds resonate
pharynx (throat)
airway connecting nasal passages and mouth with larynx, enhances sound, also connects with esophagus
epiglottis
closes off larxyn during swallowing
larynx
airway where sound is produced; closed off during swallowing
trachea
-wind pipe
-airway connecting larynx with two bronchi that lead into the lungs
lungs
lobed, elastic organ of breathing that exchanges gases between internal environment and outside air
bronchi
increasingly branched airways leading to alveoli of lung tissue
mouth
supplemental airway
pleura
-double layered membrane that separates lungs form the wall of the thoracic cavity
-fluid between its two layers lubricates breathing movements
intercostal muscle
skeletal muscle between ribs that contracts to fill and empty lungs
diaphram
muscle sheet between the chest cavity and abdominal cavity that contracts to fill lungs
what is red and blue blood
blue=deoxy
red=oxy
how does the mammal lung branch
-it consists of sequentially branching airways; the trachea divides to form two primary bronchi
-primary bronchi branch and rebranch into bronchioles
-bronchioles branch multiple times and eventually end in tiny outpocketings known as alveoli
how many alveoli does an adult human have. what is the total gas exchange mem area
-about 700 million alveoli
-total gas exchange mem area of 100 square meters (SA if completely stretched out)
what is the inner and outer pleura
parietal pleura (outer)
visceral pleura (inner)
what is the fluid that fills the pleural cavity
intrapleural fluid
what is the point of interpleural fluid
makes friction with thoracic wall less harsh (protects lungs)
what does boyles law explain
-Boyle’s law is a gas law, stating that the pressure and volume of a gas have an inverse relationship
-P1xV1=P2xV2
inhalation
-diaphragm contracts and moves down
-intercostal muscles contract and lift rib cage upward and outward
-lung volume expands
exhilation
-diaphragm and external intercostal muscles return to the resting positions
-rib cage moves down
-lungs recoil passively
what is the active process
deep breathing
what are lung volumes
TV
IRV
ERV
RV
what are lung capacities
IC
VC
FRC
TLC
TV
tidal volume = 500ml
IRV
inspiratory reverse volume = 3000ml
ERV
exploratory reverse volume = 1000ml
RV
residual volume* = 1200ml
IC
inspiratory capacity=Vt+IRV=3400ml
VC
vital capacity=Vt+IRV+ERV=4500ml
FRC
functional residual capacity=ERV+RV=2200ml
TLC
total lung capacity =Vt+ERV+IRV+RV+4700ml
total lung capacity
max amount of air that the lungs can hold (~5.7L)
tidal volume
volume of air entering or leaving the lung during a single breath (RESTING Tv~0.5ml)
functional residual capacity
volume of air in the lungs at the end of a normal passive expiration (~2.2L)
residual volume
minimum volume of air remaining in the lungs after maximal expiration (~1.2L)
what happens if you didnt have residual volume
couldnt exhale if dont have this lungs would colapse
vital capacity
maximum volume of air that can be moved out during a single breath following a maximal inspiration (~1.2L)
tidal ventilation
fresh inhaled air mixes with stale air left behind form previous breath
where is PO2 of air lower? air adjacent to the respiratory membrane or in external environment
air adjacent to resp membrane
how does O2 leave the breathing organ get into the blood
PO2 in blood leaving the organ must be lower
a partial pressure gradient is necessary for O2 to diffuse across the membrane into the blood
what is PIO2
partial pressure of incoming air
what is PEO2
partial pressure of exiting air
what is PaO2
partial pressure blood leaving the the lung
what is PvO2
partial pressure of blood entering lung
what is more efficient cross current gas exchange or tidal gas exchange
cross current gas exchenge
cross current gas exchenge
seen in the avian lung-very efficent
where is tidal gas exchange seen
seen in mammalian lung
how is ventilation in the lung regulated
-sensors (chemoreceptors, lung and other receptors)
-which inputs to;
-central controller (brain) which produces;
-output (by efferent nurons) to;
-effectors
what triggers the chemoreceptors for lung ventilation regulation
-CO2, pH, O2 (partial pressure)
-peripheral & central (brain) types
what parts of the brain receives sensors to regulate lung ventilation
pons, medulla and other parts
during regulation of ventilation what does the brain effect for the output
respiratory muscles which monitors the stretch of lungs
where are peripheral chemoreceptors found
in the aortic bodies within the aortic arch, and also at the bifurcation of common carotid arteries
what is the first response for chemoreceptors to control breathing
PCO2, pH
what is the second response for chemoreceptors to control breathing
-PO2
when it comes to regulating breathing how does information get from chemoreceptors to the brain
information travels via vagus & glossopharyngeal nerves to the respiratory centres in the medulla and pons
why is the PCO2 easier to detect
CO2 is more soluble- CO2 dissolves which creates bicarbonate which drops pH
why and how does corona virus disrupt O2 uptake in our lungs
-virus attacks alveoli cells
-when cell is attacked intracellular fluid leaks into alveoli
-pneumonia
-reduces SA and cant uptake O2
how is O2 carried in the blood
-by RBC- bound to Hb (>98%)
-dissolved O2 in plasma (<2%)
what form of O2 in the blood accounts for the PO2
the O2 dissolved in the plasma
what is the solubility of O2 in the blood
-at PO2 of 100mHg, O2 solubility is 0.003ml/100ml
-so we can only transport 0.3ml of O2/100ml of arterial blood
-an athlete may need 14ml O2/100ml of blood
why is hemoglobin needed in the blood
oxygen isnt very soluble in plasma water
why does O2 diffuse from alveolar air into blood
partial pressure of O2 is higher in alveolar air than in the blood in the capillary network surrounding alveoli
what is hemoglobin
iron-containing O2-transport metalloprotein
how much does Hb help with O2 solubility in the blood
-it can transport lots of O2 at arterial PO2 to the tissues
-1 g of Hb combines with 1.39ml O2
-typically human blood contains 15g Hb/100ml
-therefore at arterial PO2 the blood can transport 1.39x15=> 20.85+0.3=21.15 ml O2/100ml of blood
where are RBC present
in almost all vertebrates
where does O2 diffuse from to get into blood
alveolar air into blood
what happens to most of the O2 that enters the blood
it combines with hemoglobin inside RBC
in mammals how much of the RBC’ dry content
96%
what metal does hemoglobin contain
a ferrous (Fe2+) ion
how does O2 bind to Fe2+
-in a reversible manner; hemoglobin can bind up to 4 oxygen molecules
what kind of graph relationship is oxygen binding to hemoglobin
sigmoid shaped curve
what does a sigmoid shape curve mean for O2 binding
binding for O2 in one site increases the affinity of the other sites for O2
what helps to maintain a large partial pressure gradient between O2 in alveolar air and in blood plasma
large quantities of O2 combined with hemoglobin
what is affinity of Hb for oxygen affected by
-temprature
-pH
-CO2
where is there a higher temprature
in the systemic capillaries
where does the affinity for O2 binding to Hb increase and decrease
favours O2 binding in the respiratory epithelial and O2 release in tissue
on a O2 binding curve what happens if curve shifts to the right. what would cause this kind of shift
-reduced affinity
-produced by CO2, H+, temp
-at PO2 in lungs shift is not as important
-at PO2 in tissue capillaries the shift is most dramatic
what is the PO2 in the body tissue
20-40 mm Hg
what is the PO2 in the alveoli
80-100 mm Hg
what does a low pH do to hemoglobins affinity for O2
reduces the affinity, O2 is released
what is the pH in the capillaries
the pH is 7.2 so hemoglobin can hold less O2
what is the optimal pH for hemoglobin
7.4
how does the PO2 in interstitial fluid and body cells compare to PO2 in the blood plasma
PO2 in interstitial fluid and body cells is lower then in blood plasma
how does O2 diffuse from blood plasma, interstitial fluid and body cells
blood plasma–>interstitial fluid–>body cells
where is PCO2 higher. blood or tissue
it is higher in the tissue
what happens to CO2 in the body
-10% is dissolved in blood plasma
-70% is converted into H+ and HCO3- (bicarbonate ions)
-20% combines with hemoglobin
how many reactions is there to transfer CO2 from the body cells to RBC
two reactions; a fast and a slow
what is the fast reaction to transfer CO2 form the body cells to RBC
-CO2 diffuses into RBC and combines with hemoglobin forming carbaminohemoglobin
-some CO2 combines with H2O to form HCO3- and H+
-H+ cobines with hemoglobin
-HCO3- is transported out of RBC to plasma
what is the slow reaction to trasfer CO2 form the body cells to RBC
some CO2 released into the blood and combines with plasma H2O to form HCO3- and H+
what is carbonic anhydrase
-a metalloenzyme that requires Zn2+
-catalyzes the rapid interconversion of CO2 and H2O to bicarbonate and H+
-contributes to transporting CO2 out of the tissue
-maintains acid base balance in blood and other tissue
how fast is the carbonic anhydrase reaction
it is capable of converting one million molecules of CO2 per second
how does CO2 transfer in the lungs
-PCO2 is higher in blood than alveolar air
-reactions packing CO2 in to blood are reversed
-CO2 is released from blood into alveolar air
how does CO2 transfer form blood to air
-goes form lungs
-to RBC
-to aveolar air
what reaction does CO2 transfer use to get from blood to air
-there is 2 rxns
-fast;
-most of the HCO3 in RBC combines with the H+ released form hemoglobin to form CO2 and H2O
-CO2 is released from hemoglobin
-slow;
-plasma CO2 diffuses to the alveolar air
