Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
106 Cards in this Set
- Front
- Back
Functions of the respiratory system |
1) Gas exchange 2) Acid-base balance: pH 7.4 3) Communication: sound and smell 4) Metabolism of endogenous and exogenous substances; Ex) angiotensin converting enzyme 5) Thermoregulation 6) Immune Function |
|
Vocabulary Eupnea Dyspnea hyperpnea polypnea apnea tachypnea bradypnea |
normal breathing difficulty breathing increased depth and frequency of breathing rapid, shallow breathing stopped breathing increase in respirotory rate decrease in respiratory rate |
|
3 steps of Gas Exchange |
Step 1) ventilation = inhalation and exhalation of air 2) External respiration = pulmonary gas exchange, O2 diffusion into pulmonary capillaries, CO2 diffusion in to alveoli 3) Internal Respiration = systemic tissue gas exchange = deliver O2 to support tissue metabolism and eliminate CO2 from tissues |
|
Tidal Volume ? Functional Residual Capacity ? |
Volume of each breath the air an animal lives off of during the pause btw breaths = ERV + RV |
|
IVR = inspiratory reserve volume = ? ERV = Expiratory reserve volume =? RV = Residual Volume =? |
Extra volume that can be inhaled after a normal inhalation Extra volume that can be exhaled after a normal exhalation Volume in the lungs after complete exhalation |
|
Barometric pressure ___ with increasing altitude at sea level = |
decreases 760 mmHg |
|
Gauge pressure = ? |
pressure in alveoli - atmospheric pressure |
|
Boyle's Law states that volume and pressure are ____ proportional As volume ____ pressure ______ |
inversely proportional increases; decreases |
|
Transpulmonary pressure is the amount of pressure needed to keep ____ at its _____ volume without _____. Atelectasis = ? |
alveolus; smallest; collapsing collapse of alveoli |
|
Surfactants help to.... |
1) reduce collapse of alveoli 2) help with even distribution of alveoli ventilation 3) improvement in lung compliance |
|
According to Poiseulle's Law, as radius ____ resistance ____ |
decreases increases |
|
Regulation of airway diameter: parasympathetic system = sympathetic = |
constriction dilation |
|
Complete connective tissue septa = each bronchiole is separate, so no gas exchange btw alveolar units = helps keep infection from spreading |
In the Cow and Pig |
|
No ct septa = air can move from alveoli to alveoli = collateral ventilation = infection can spread to whole lobe |
In the dog, cat, and primate |
|
Partial ct septa = some collateral ventilation = infection spreads more slowly |
Horse and Sheep |
|
vasodilators |
Nitric Oxide sildenafil PGI2 beta-AR MR |
|
vasoconstrictors |
ETA ETB alpha-AR PDE5 |
|
Alveolar hypoxia = potent vasoconstrictor generalized lung hypoxia = generalized vasoconstriction = ? |
pulmonary hypertension |
|
Brisket Disease
|
cattle at high altitude = lower at. pressure = more difficult ventilation and poor perfusion due to less O2 = Right heart failure and edema in the brisket |
|
EIPH = exercise induced pulmonary hemorrhage |
CO Increases during exercise pulmonary vascular resistance decreases = vessels dilate pulmonary artery pressure Increases = cause rupture of the thin capillaries around alveoli |
|
Respiratory Airways: conducting portion = |
NO gas exchange nasal cavity, nasopharynx, larynx, trachea, bronchus, bronchiole, terminal bronchiole |
|
Respiratory Airways: respiratory portion = |
gas exchange area respiratory bronchiole, alveolar duct, sac, and millions of alveoli |
|
Fxns of airways: |
1) brings appropriate amount of cleansed and conditioned air into close contact w/ capillaries, so Gas Exchange of O2 & CO2 by passive diffusion can occur efficiently 2) Olfaction 3) sound production |
|
Nasal Cavity 3 regions = ? and their epithelium |
1) cutaneous = stratified squamous keratinized to non-keratinized 2) Respiratory = ciliated pseudostratified columnar Olfactory = ciliated pseudostratified columnar |
|
Respiratory region of nasal cavity = ciliated pseudostratified columnar
Fxns: |
humidifies inhaled air traps particulates and microbes and cilia move mucous (= produced by goblet cells) material in one direction where it can be swallowed |
|
olfactory epithelium |
olfactory cells sustentacular cells basal cells ciliated pseudostratified epithelium |
|
epithelium of epiglottis and vocal folds of larynx |
non-keratinized stratified squamous NO secretory glands |
|
Trachea = |
respiratory ep.: cilia, goblet cells, serous cells Propria-submucosa = loose ct. = seromucous glands and elastic fibers cartilage w/ adventitia around it = loose ct. trachialis m. |
|
Bronchi = |
Resp. ep. = fewer seromucous glands and thinner Smooth m. cartilage |
|
Bronchioles & term. bronchioles |
ciliated simple columnar ciliated cuboidal clara cells No Cartilage No glands |
|
Alveolus is a sphere made of _____ |
pneumocytes |
|
Type I pneumocytes |
gas exchange simple squamous |
|
Type II pneumocytes |
secrete surfactant = decreases surface tension cuboidal epithelium |
|
Blood-gas barrier |
1) endothelium 2) basement membranes/basal laminae 3) type I pneumocytes |
|
Ficks Law Daltons law Henry's Law |
defines optimal diffusion defines partial pressure MW and solubility used to determine concentration of gas in a liquid |
|
Application of Henry's law Hyperbaric oxygenation therapy How does it work? What can it treat? |
pressure raised = tissues absorb more O2 and more O2 dissolves in the blood anaerobic bacterial infections heart disorders, CO poisoning, cerebral edema, bone infections, gas emboli, crush injuries |
|
gases move from _____ to ____ pressure |
HIGH to LOW |
|
Hypoventilation = ______ in PA O2 and _______ in PA CO2 Hyperventilation = ______ in PA O2 and _______ in PA CO2 |
Decrease and Increase Increase and Decrease |
|
Ideal Lung function: PA O2 ____ Pa O2 |
= equal to |
|
______ ______ is best for evaluating lung function |
Arterial Blood |
|
Compare PO2 and PCO2 in alveolar gas, arterial blood, and venous blood....lowest to highest |
PO2: Venous; Arterial; Alveolar = Highest PCO2: Alveolar = Arterial; Venous = Highest |
|
Define perfusion |
perfusion is adequate blood flow to tissues |
|
What effect does perfusion rate have on PA O2 and Pa O2? |
decrease/ rest = Pa O2 and PA O2 = 100 increase/ exercise = Pa O2 and PA O2 = decrease b/c more mixed blood in the capillaries due to the more rapid blood flow |
|
What does the ventilation/perfusion ratio determine? What does a low ratio mean? a high ratio? |
the adequacy of pulmonary gas exchange by quantifying the amount of alveolar ventilation in relation to pulmonary capillary flow = ventilation blocked; PCO2 = higher; PO2 = lower = perfusion is blocked; PCO2 = lower; PO2 = higher |
|
What does PO2 determine? |
the quantity of dissolved oxygen in the plasma the higher the partial pressure, the more O2 will be dissolved in plasma |
|
Saturation of Hb = |
describes the % oxygen binding sites on Hb occupied by oxygen |
|
How do we determine the saturation of Hb? Name 3 points on the oxygen-hemoglobin curve.... If PaO2 = 100 mmHg, then %Hb = If Pa O2 < 60 mmHg |
using the oxygen-hemoglobin dissociation curve 30-60 40-75 60-90 100 % %Hb saturation < 90% and the animal will need supplemental O2 |
|
What are the reasons for RIGHT Oxygen-Hemoglobin Dissociation Curve Shifts (= Hb releases O2 more readily)? |
Increases in: 2,3 BPG [H+] (= Low pH) CO2 Temperature |
|
What are the reasons for LEFT Oxygen-Hemoglobin Dissociation Curve Shifts (= Hb releases O2 LESS readily)?
|
Decreases in: 2,3 BPG [H+] (= High pH) CO2 Temperature |
|
The Bohr effect |
In an acid environment (low pH), O2 splits more readily from hemoglobin, and hemoglobin is thus less saturated with O2 |
|
What is the concentration of Hb in g/dl in... normal? anemia? polycythemia? |
15 10 20 |
|
Why should any vertebrate care about carbon monoxide poisoning?
|
CO binds 200x more effectively to Hb than O2
|
|
What effect does CO poisoning have on [Hb] when 50% of Hb is bound to CO?
|
The curve shifts down when compared with the normal [hb] curve decreasing the total oxygen content. A decrease in PaO2 also occurs with decreasing [Hb] levels. Thus, O2 will have a difficult time binding to Hb at such a low PaO2.
|
|
Total Oxygen Content =
|
The amount of O2bound to hemoglobin (Hb) + The dissolved O2 due to the PaO2
|
|
Haldane effect |
relates to the shift in CO2 content curve with changes in PO2 beneficial for picking up more CO2 when it's in the tissues |
|
Hypoxemia |
less than normal arterial oxygen partial pressure = < 60 mmHg Normal = 80-100 mmHg |
|
Five causes of Hypoxemia |
1) Hypoventilation 2) Low PlO2 3) V/Q Mismatch 4) Right to Left Shunt 5) Diffusion Limitation |
|
What is the significance of a normal V/Q ratio? |
The amount of alveolar ventilation in relation to pulmonary capillary blood flow determines the adequacy of gas exchange.
Normal V/Q = 0.8 |
|
The most common cause of hypoxemia in diseased states |
Low V/Q Mismatches = low to no ventilation |
|
True or False Regions w/ V/Q > 1.0 do NOT contribute to hypoxemia |
True |
|
True or False Shunts are responsive to increasing Fi O2/ Oxygen therapy |
False |
|
What are the possible causes of hypoxemia if there's an A-a O2 difference? How else could you narrow down these possible causes? |
Diffusion impairment Low V/Q Shunt Response to Oxygen therapy, Shunt is unresponsive to O2 therapy |
|
What are the possible causes of hypoxemia if there's NO A-a O2 difference?
|
hypoventilation high altitude/ low PiO2 |
|
Control of ventilation a) in the pons? b) in the medulla oblongata? |
= more of the fine tuning of breathing = neurons that generate regular bursts of activity to initiate breathing = btw medulla and spinal cord |
|
How is breathing regulated? |
1) Receptors (sensors) that gather info. and send it via the afferents to the brainstem 2) Controller = brainstem coordinates the info. and sends impulses via efferents to the effectors 3) Effectors (respiratory muscles) adjust ventilation and Decrease PaCO2, which decreases the sensor input |
|
Name the function of the breathing reflexes of the nose, pharynx, and larynx |
Sneeze reflex: remove particulates/irritant Dive reflex: prevent H2O from entering lungs aspiration/sniff: clear the nose of mucous and obstructions swallowing: coordinated muscle contractions to propel into esophagus mechanoreceptors = detect changes in pressure and temperature irritant receptors = couch and apnea in response to irritant to clear airway water sensitive receptors = close larynx and prevent water getting into lungs |
|
explain the function of... 1) slow adapting receptors 2) rapid adapting receptors |
1) are in the lung and respond to stretching of airways sending an impulse in vagus n. to prevent over expansion of the lungs by monitoring lung volume 2) mechanoreceptors in the airway epithelium = cause cough, bronchoconstriction, mucus secretion, & rapid shallow breathing |
|
What are C fibers? Where are they? |
non-myelinated axons = pain receptors = respond to mechanical, thermal, chemical changes 1) pulmonary interstitium = monitor distension of interstitium 2) walls of airways = stimulated by allergic or infectious diseases = causes tachypnea 3) respiratory muscles = control of muscle contraction strength |
|
What is the significance of the Hering-Breuer Inflation Reflex? Deflation reflex? |
*Inflation and deflation reflexes that help regulate the rhythmic ventilation of the lungs. This prevents over-stretching or extreme deflation of the lungs.
*The Hering-Breuer Inflation reflex prevents damage from over stretching the lung by inhibiting inspiration and stimulating expiration * The deflation reflex prevents over deflation by inhibiting expiration and stimulates inspiration |
|
Thermoregulation response to heat stress cold stress |
small tidal volume, tachypnea, vascular engorgement of respiratory and oral mucosa large tidal volume, bradypnea |
|
Name the peripheral chemoreceptors? What do they do? |
carotid bodies: at the bifurcation of the carotid a. aortic bodies: above and below aortic arch respond to changes in PaO2, PaCO2, and pH decrease in pH or PaO2, increase in CO2 & H+ = increase ventilation increase in pH, decrease in CO2 & H+ = decreases ventilation |
|
Where is the central chemoreceptor? What does it do? |
It's in the retrotrapezoid nucleus of the brainstem, bathed in brain interstitial fluid responds to changes in CO2 (enters via blood-brain barrier), H+, HCO3-, to increase or decrease ventilation |
|
What blood gas parameters increase ventilation? |
Increase PaCO2 Increase H+ Decrease PaO2 |
|
what is cyanosis? SpO2? CRT? |
a bluish or purplish discoloration (due to deficient oxygen) Saturation of Hemoglobin with oxygen capillary refill time = time for color to return to an external capillary bed after pressure is applied to cause blanching = indicates perfusion > 2 secs = poor perfusion |
|
What is... Complementary breathing? biot breathing? Kussmaul's breathing? cheyne-stokes breathing? apneustic breathing? |
= sign; mechanism to reinflate alveoli = group breathing = uncontrolled, abnormal breathing, caused by metabolic acidosis, increase in tidal volume = waxing and waning of breathing, Vt does up&down, poor feedback loop prolonged inspiration inhibiting expiration; allows more gas exchange |
|
Name some non-respiratory functions of the lung |
thermoregulation filter the blood metabolism: angiotensin converting enzyme Defense: ciliary escalator, macrophages acid-base balance |
|
What is Starling’s Law of the Capillaries? Where does the rest of the fluid get absorbed? |
= the filtered fluid produced by pulmonary capillaries (arterial side) is almost as much as the volume of fluid reabsorbed by the pulmonary capillaries (venous side) stays in the interstitium or goes to the lymphatics |
|
What is the difference between pleural effusion and pulmonary edema?
|
Pulmonary edema = excess fluid inside lungs; Clinically pink, frothy fluid coming from nose and treat with diuretic.
Pleural effusion = excess fluid btw visceral and parietal pleura; treat with thoracentesis |
|
What pressure promotes filtration? Filtration occurs at the arterial or venous end of capillary?
|
Fluid production = Fluid filtration: High to low pressure (mm Hg) due to high hydrostatic pressure in the capillary and low hydrostatic pressure in the interstitium.
arterial |
|
What pressure promotesreabsorption? Reabsorption occurs at the arterial or venous end of capillary?
|
Fluid removal = Fluid reabsorption: Low to high pressure (mm Hg) due to low oncotic pressure in interstitium and high oncotic pressure in the pulmonary capillary. The pulmonary and lymphatic capillaries will eventually reabsorb the excess pleural fluid.
venous |
|
How does fetal circulation occur? |
1. The uteroplacental circulation starts with the maternal blood flow into the intervillous space through decidual spiral arteries. Exchange of oxygen and nutrients take place as the maternal blood flows around terminal villi in the intervillous space.
2. The in-flowing maternal arterial blood pushes deoxygenated blood into the endometrial and then uterine veins back to the maternal circulation. 3. The fetal-placental circulation allows the umbilical arteries to carry deoxygenated and nutrient-depleted fetal blood from the fetus to the villous core fetal vessels. After the exchange of oxygen and nutrients, the umbilical vein carries fresh oxygenated and nutrient-rich blood circulating back to the fetal systemic circulation. |
|
Describe the three types of shunts
|
1. Ductus arteriosus • Connects pulmonary artery and aorta; Blood flows from Rt to Lt in fetus • Bypasses the lungs • Allows developing heart and brain to get HIGHER PO2
2. Foramen Ovale• Opening btw the atria• One way Rt to Lt shunt, due to thin flap on the left side 3. Ductus Venosus• Bypass of the fetal liver• Connects umbilical vein to caudal vena cave• |
|
The fetus exists in a state of hypoxemia. How can the fetus grow and survive with such a low PO2?
|
Hemoglobin has a higher affinity for oxygen and a low 2,3 BPG in their RBCs, meaning fetal Hb has a higher percent saturation, and the fetus has a higher Cardiac Output.
|
|
Acid Base balance |
relatively constant [H+] due to regulation |
|
What is pH? |
-log10 of [H+] |
|
what is an acid? base? buffer? |
donates [H+]/proton to a solution accepts [H+]/proton from a solution a mixture of a weak acid and its conjugate base |
|
Is water an acid or base? |
it's amphiprotic and can function as both acids and bases |
|
What is the relationship between pH and [H+]? |
they're inversely and exponentially proportional to each other |
|
What is a normal pH? acidemia? alkalemia? |
7.35-7.45 7.35 7.45 |
|
acidosis = acidemia = |
all of the physical processes & chemical reactions that result in an abnormally pH low blood pH; can Not have acidemia w/o acidosis |
|
What are some causes and symptoms of acidosis? |
causes: ethylene glycol (antifreeze); Aspirin; chronic kidney disease; hypoventilation symptoms: depression, rapid & deep breathing, diarrhea, confusion, fever |
|
What are some causes and symptoms of alkalosis?
|
causes: vomiting, increased loss of H+, hypoalbuminemia, kidney retention of HCO3- symptoms: weakness, irregular heart beats, muscle twitching, dehydration, seizures |
|
What factors affect pH? |
PCO2 Strong Ion Difference: difference btw the sums of concentrations of the strong cations and anions Weak Acid Buffer (Atot = total weak non-volatile acid) |
|
Increase in Atot = ______H+ = _____ Decrease in Atot = _____H+ = _____ |
Increase = Metabolic Acidosis Decrease = Metabolic Alkalosis |
|
Increase in SID = _____ Decrease in SID = _____ Normal SID = _____ |
alkalinizing acidifying 0 |
|
What is the Henderson-Haselbach equation? |
pH = pK + Log (Base/Acid) |
|
What do buffers do? bicarbonate buffer? phosphate buffer? |
exchange a strong acid or base for a weak one = results in less of an increase in [H+] due to incomplete dissociation CO2 & HCO3- can be independently regulated Major intracellular buffer pKa 6.8 = near normal |
|
Acid-base imbalance what is the 1st line of defense? 2nd line of defense? |
1) Chemical buffers = bicarbonate, protein, & phosphate buffer system = instant response 2) Physiological buffers = lungs excreting CO2 = takes mins to hrs = kidneys excreting H+ = hrs to days |
|
What is.. Metabolic acidosis? Respiratory acidosis? metabolic alkalosis? respiratory alkalosis? |
HCO3- < 24 mM -> respiratory compensation (decrease PCO2) PCO2 > 40 mmHg -> renal compensation (H+ excretion & increase in HCO3-) [HCO3-] > 24 mM -> respiratory compensation (increase PCO2) PCO2 < 40 mmHg -> renal compensation (decrease in HCO3-) |
|
Birds have longer and wider trachea , so do they have more airway resistance than mammals? |
No, due to the increase in both length and width |
|
Do birds have a higher Vt? Do they spend more energy overall? |
Yes, 1.7 x higher No, they spend less energy due to a greater compliance of the respiratory system |
|
In birds, gas exchange occurs at the ______, which are ____ in contact with fresh air. Gas exchange involves ______ air flow and it's ______ efficient than in mammals. |
parabronchi always cross-current more |
|
In birds, the blood gas barrier is 60% thinner compared to mammals. How does this help with gas exchange? |
According to Fick's Law, the rate of diffusion will increase with an increase in cross sectional area and/or a decrease in the distance of the diffusion path. |
|
Name some other reasons bird respiration is different from mammalian? And how might it be a disadvantage? |
unidirectional air flow air sacs expand, but lungs are rigid They have 2 types of hemoglobin (Hb A & D) increased incidences of infection and apnea is more dangerous due to the almost lack of residual volume |
|
What happens during the mammalian diving reflex? And how do diving mammals deal with N2? |
1) bradycardia 2) peripheral vasoconstriction 3) blood shift to lungs 4) switch to anaerobic metabolism * they also have increased hematocrit values and large spleen = more blood reserve *elastic aorta to keep blood pressure high dive = collapse lung, so air, inc. N2, is in dead space = no gas exchange |
|
What type of flow is gas exchange in the gills of fish? |
counter current |