Respiratory Learning Objectives- big list

Question 1

relate form to function in describing the physiologic roles of the nasal cavities

Answer 1

turbinates/conchas and sinuses allow air to swirl around and filter and warm and also the olfactory nerves are right there

Question 2

describe the movements of the epiglottis, the body of the larynx, and the vocal folds that protect from aspiration

Answer 2

during breathing:
soft palate ventral
epiglottis folded over soft palate to direct air into larynx
arytenoids open to decrease air resistance

during swallowing:
soft palate dorsal
epiglottis rotates up to cover airway/arytenoids
arytenoids rotate down to open esophagus for snacks

Question 3

compare the differences in function between the oronasal, conducting, and respiratory zones

Answer 3

oronasal: olfaction, humidify and warm air, thermoregulation, filter air, slow airflow (50-70% of resistance), phonation, protection from aspiration during swallowing

conducting: further slow airflow (provides the rest of resistance), also filter air via mucociliary apparatus

respiratory: gas exchange!!

Question 4

identify the components of the immune system active in the oronasal, conducting, and respiratory zones and describe their roles

Answer 4

in blood and tissues: PRRs, antimicrobial peptides, alveolar macrophages, monocytes, dendritic cells, neutrophils, lymphocytes, antibodies (produced by BALTs)

BALTs for immunity in the conducting zone; mucociliary apparatus

also lumen gets smaller as move down the tract, physically filtering foreign particles

respiratory zone: alveolar macrophages phagoctyose particles and send to conducting zone; type I alveolar cells can also endocytose and process through lymphatics or make them enter circulation and leave

Question 5

moving from the trachea to the terminal airways, contrast length, total cross-sectional area, resistance to air flow, and air velocity

Answer 5

length: decreases
total/cumulative cross-sectional area: increases (so many fucking capillaries)
resistance to airflow: decreases (parallel series)
air velocity: decreases

Question 6

name the components of the mucociliary apparatus and describe how each contributes to clearing particles from the airways

Answer 6

1. fluid layer:
   a. gel layer, very viscous, traps particles, dilutes toxins, has antibodies
   b. sol layer: less viscous
2. ciliated epithelium: beat constantly to clear mucus from tract
3. goblet cells and mucous glands: secrete mucous for gel layer
4. BALT: secretes antibody

Question 7

define ventilation and distinguish between inspiration, passive expiration, and active expiration

Answer 7

ventilation: physically moving air in and out of lungs
inspiration: inhale air into lungs, an active process
passive expiration: due to recoil
active expiration: actively forcing air out of lungs

Question 8

identify the muscles actively involved versus passively involved with each phase and how each muscle group contributes to air movement

Answer 8

inspiration:
1. external intercostals contract to elevate ribs
2. diaphragm contracts to pull down

also outward recoil of chest wall

quiet/passive exhalation: due to inward recoil of
1. lungs
2. rib cage
3. diaphragm

active expiration:
1. internal intercostals actively contract to pull ribs down
2. abdominal muscles actively contract to pull ribs down and compress abdominal contents

Question 9

on a normal spirogram, distinguish between tidal volume, inspiratory reserve volume, expiratory reserve volume, and residual volume

Answer 9

tidal volume: inspiration + passive exhale
inspiratory reserve volume: biggest breath in after regular inhale
expiratory reserve volume: active expiration after passive expiration
residual volume: air left in lungs after active exhale

Question 10

on a normal spirogram, distinguish between total lung capacity, inspiratory capacity, vital capacity, and functional residual capacity and ID which of the lung volumes comprise each

Answer 10

total lung capacity: all air in and out of lungs
inspiratory capacity: all air that can be inhaled (regular + inspiratory reserve volume)
vital capacity: TV + IRV + ERV
functional capacity: ERV + RV

Question 11

define and contrast minute ventilation and alveolar ventilation

Answer 11

minute ventilation is all air that enters the lungs per minute (VD + VA)
alveolar ventilation: the air that enters the lungs AND participates in gas exchange, subtracting all dead space air

Question 12

define and contrast anatomic and physiologic dead space and how each relatively compares to tidal volume

Answer 12

anatomic: air in oronasal and conducting zones
physiologic: air in alveoli that are not well perfused with blood

tidal volume is volume of dead space plus volume of air actually participating in gas exchange

Question 13

describe how the parietal and visceral pleurae in the thorax interact to create the negative space within the intrapleural space and how air or fluid accumulating in the intrapleural space affects inspiration and that negative pressure

Answer 13

the potential space (don’t want it to be an actual huge space) between the visceral and parietal pleura is filled with a tiny volume of parietal fluid (serous-like) that not only reduced friction but also generates its own force, where the polarity of water attracts the west surfaces of the membranes together, keeping the two pleura stuck together as lungs try to pull inward from chest wall and chest wall tries to pull outward by generating negative pressure between them

this suction aids the outward elasticity of the thoracic wall (ribcage/muscles) which tends to pull the lungs outward

if air or fluid accumulates, destroys this negative pressure and makes breathing hard

Question 14

relate Boyle’s law to the sequential changes in volumes and pressures that occur during inspiration and expiration

Answer 14

Boyle’s is P1V1=P2V2 so as the thoracic cavity expands during inhalation and pressure drops as volume increases, air will flow from high to low and flow in to try to establish equilibrium with the atmosphere, and save into alveoli, and then back out again

Question 15

define compliance, elastance, surface tension, and airway resistance and explain how each is related to the others and affects inhalation and deflation of the lungs

Answer 15

elastance: recoil force
compliance: how responsive the object is to force
surface tension: reduced by surfactant, but must be overcome to inflate alveoli
airway resistance: directly proportional to length, inversely proportional to radius to the 4th power

compliance is how easy it is to stretch the rubber band of the lungs, elastance takes care of passive exhalation and airway resistance is how easy air can get through system during inhalation

Question 16

describe how pulmonary surfactant facilitates alveolar expansion and affects alveolar surface tension

Answer 16

surface tension makes water molecules want to clump together, making alveoli want to deflate but surfactant reduces that surface tension just enough so that alveoli are open

Question 17

describe how the pressure gradient in the airways and airway resistance affect the rate or velocity of air flow in and out of the lungs moving from the trachea to the terminal airways

Answer 17

PO2:
pulmonary
inspired air: 160
alveoli: 100
O2 flows into alveoli
systemic:
arteries: 95
tissue capillaries: 40
O2 flows into tissue capillaries

PCO2:
pulmonary:
inspired air: 27
alveoli: 40
CO2 flows out of alveoli
systemic:
tissue capillaries: 45
systemic arteries: 40
CO2 flows out of capillaries into venous blood

bulk flow drives gases down to alveolar level, diffusion takes care of alveolar level gas exchange

Question 18

compare the relative levels of O2 and CO2 in the arterial and venous sides of the pulmonary, systemic, and bronchial circuits

Answer 18

pulmonary:
arterial: deoxygenated
venous: oxygenated

systemic and bronchial:
arterial: oxygenated
venous: deoxygenated

Question 19

compare flow, pressure, resistance, and response to hypoxemia in the pulmonary vascular circuit versus the systemic circuit

Answer 19

systemic: vasodilation to increase blood delivering oxygen to starved tissues

pulmonary: vasoconstriction to decrease blood flow to give alveoli more time for gas exchange

Question 20

describe where the bronchial circulation can enter and leave both pulmonary and systemic circuits

Answer 20

bronchial artery: branches from aorta
bronchial postcapillary venules merge with pulmonary venules, then pulmonary veins and azygous veins, then back to left atrium

Question 21

describe the mechanisms by which pulmonary vasculature accommodates increased cardiac output

Answer 21

pulmonary veins can expand to accommodate the increased flow (delta P = Q x R)

Question 22

describe the effects of inspiration and expiration on blood flow in pulmonary capillaries and extra-alveolar vessels (arterioles and veins) in the lungs

Answer 22

inspiration: thoracic cavity volume increases, extra-alveolar vessels expand, intra-alveolar vessels are compressed (increased vascular resistance)

expiration: thoracic cavity volume decreases, extra-alveolar vessels are compressed, intra-alveolar vessels expand

Question 23

describe how starling’s forces impact the movement of fluid between the pulmonary capillaries, the interstitial space, and alveolar lumen; compare the relative differences of these forces to those in systemic vasculature

Answer 23

hydrostatic pressure is lower than systemic (blood pressure);m because don’t want a bunch of fluid exiting the pulmonary capillaries because that would overwhelm the pump that removes fluid from alveoli and lead to pulmonary edema

Question 24

explain what happens to partial pressures for a total gaseous mixture and for individual gases if one gas is added or subtracted

Answer 24

add: decrease partial pressure of all other gases in the mixture
subtract: increase partial pressure of all other gases in the mixture

Question 25

describe how humidification with water vapor affects partial pressures of gases of inspired air

Answer 25

adding H2O is gas form, so decreases the partial pressures of all other gases in the mixture

Question 26

describe the difference between bulk flow and diffusion including whether each changes the concentrations of gas particles in the air or liquid medium; indicate where each occures

Answer 26

bulk flow: requires a pressure gradient, all molecules move together, is fast, occurs everywhere above the level of alveoli
diffusion: requires a concentration gradient, molecules only move if down their concentration gradient, is slow, occurs in alveoli

Question 27

describe how changes in each of the factors in Fick’s law affect diffusion of gases across membranes

Answer 27

rate of transport across a membrane is directly related to
1. difference in partial pressures across the membrane (greater difference means faster transfer)
2. membrane’s diffusing capacity, dependent on
membrane solubility, membrane area, membrane thickness, molecular weight of the gas

Question 28

describe the 2 methods by which O2 is carried in the blood and indicate the relative importance of each

Answer 28

1. less than 2% dissolved in plasma; this is measured when we measure PO2
2. more than 98% is in RBCs bound to hemoglobin, participating in gas exchange

Question 29

describe how hemoglobin and iron in the heme molecule function to carry O2

Answer 29

each molecule has 4 hemes with an iron molecule in the center that reversibly binds O2; meaning 1 molecule of hemoglobin can bind up to 4 molecules of oxygen

Question 30

describe the oxygen-hemoglobin saturation curve and the relationship between partial pressure of oxygen and percent oxygen saturation

Answer 30

higher PO2 means higher percent saturation of hemoglobin with O2

Question 31

explain allosteric effect of oxygen binding hemoglobin

Answer 31

one oxygen binding to hemoglobin causes a conformational change in the molecule, making it easer for more O2 to bind

Question 32

explain how the oxygen-hemoglobin saturation curve reflects the physiologic movement of O2 between the pulmonary and systemic capillary beds

Answer 32

the curve is shifted to the left meaning that more O2 is bound when PO2 is high in pulmonary circulation and shifted to the right meaning that more O2 is dropping off (less bound) in systemic circulation

Question 33

describe the 4 factors that influence the oxygen-hemoglobin saturation curve

Answer 33

1. temperature: higher means less O2 bound
2. ph: more acidic means less O2 bound
3. 2,3-DPG: more present means less O2 bound
4. pCO2: if high means less O2 bound

Question 34

identify the respiratory centers in the brain involved in controlling breathing rate and depth; indicate the main role of each center

Answer 34

the 3 respiratory centers involved in controlling involuntary/basal breathing are:

1. medulla oblongata
   1a. dorsal respiratory group of medulla oblongata: initiates and maintains inspiration
   1b. ventral respiratory group: inactive during normal quiet breathing, but during exercise is activated by forceful inspiration and signals to abdominal muscles to contract for expiration
2. pons:
   2a. pneumotaxic center: inhibits medullary inspiratory center to increase respiratory rate
   2b. apneustic center: stimulates inspiratory center to prolong the inspiratory period
3. hypothalamus and other portions of the limbic system take over in emotional states, clinically important to separate stress from an actual issue in the clinic

(basic rhythm is generated by medulla and adjusted by pons; at rest expiration is PASSIVE!)

Question 35

describe the roles of central and peripheral chemoreceptors in detecting changes in O2 and CO2 levels and blood pH

(include the relative sensitivity of each type of chemoreceptor of O2, CO2, and pH and how the chemoreceptors integrate with the respiratory centers)

Answer 35

central: detect increased CO2 and H+ but most sensitive to CO2

central chemoreceptors detect increased CO2 (can cross the blood brain barrier, H+ cannot) and create a respiratory drive to increase ventilation, but need carbonic anhydrase for this to occur

peripheral: detects decreased O2, increased CO2, and increased H+ (the only chemoreceptors sensitive to O2)

two main peripheral chemoreceptors:
1. carotid (uses CN IX)
2. aortic bodies (use CNX)
both have glomus cells that sense changes in blood, signal to medullary respiratory center to increase ventilation, have a very fast response

example is how the carotid body chemoreceptors are at an area of very high blood flow, so if detect MAJOR increases in CO2 and H+ or even minor decreases in O2, will increase ventilation

Question 36

how are the medulla and pons integrators attached to the muscles they control?

Answer 36

1. pontine respiratory group (pneumotaxic and apneustic) connect to the phrenic nerve which innervates the diaphragm
2. the dorsal respiratory group of the medulla connects to the phrenic nerve which innervates the diaphragm
3. the ventral respiratory group in the medulla connects to the phrenic nerve (to diaphragm) and also to intercostal nerves to both internal and external intercostal muscles

Question 37

describe the major peripheral neural sensors that monitor breathing and the changes each one affects when stimulated (5)

Answer 37

1. stretch receptors (slowly adapting pulmonary stretch receptors/ PSRs): mechanoreceptors located in smooth muscle of bronchial and bronchiolar walls that, when the lungs are overstretched, signal the DRG via the vagus nerve and increase expiratory time
2. pulmonary irritant receptors (PIRs): nerve endings in airway epithelium that detect irritants and initiate coughing and sneezing, as well as bronchoconstriction, mucus secretion, and hyperpnea (also called rapidly-adapting pulmonary stretch receptors that detect the rate of lung inflation, facilitating inspiration and counteracting the action of PSRs)
3. bronchial C fibers: also sense chemical insults and inflammatory mediators; facilitate inspiration similar to PIRs
4. J receptors in lungs (juxta-capillary receptors): in alveolar interstitium, respond to pathologic stimuli and cause shallow, rapid breathing
5. muscle and joint proprioreceptors: increase ventilation during exercise

Question 38

explain how arterial blood gas measurements reflect oxygenation and ventilation

Answer 38

increased O2: could indicate exposure of air to the sample (air bubble if super high) or supplemental O2
decreased O2: could indicate: damage to respiratory membrane, increased tissue demand for oxygen (either from exercise, septic shock, etc.)

increased CO2: increased cell respiration, respiratory membrane unable to diffuse CO2, or decreased ventilation (could be due to anesthesia)

Question 39

understand the differences and similarities in respiratory tract anatomy in birds, reptiles, amphibians, and fish

understand the unique differences in respiratory function, control of ventilation, and gaseous exchange in birds, reptiles, amphibians, and fish

(both are in this answer but rly just look over the ppt)

Answer 39

this is a lot; summary, see ppt!

birds: have a nasal salt gland, do not have an epiglottis or a soft palate (rima glottis regulates passage of air), trachea has complete cartilaginous rings, have a syrinx, lungs have a fixed volume, have air sacs (no gas exchange at air sacs), cross current blood flow and unidirectional airflow, respiratory muscles are smooth muscles so will continue breathing when anesthetized, do not have a diaphragm

reptiles: no muscular diaphragm (cannot cough, exudate can accumulate), lower oxygen demands and reduced ventilation (NVP), lungs are more simple, sac-like, withr educed gas exchange ability, ventilation under skeletal intercostal control, hypoxia increases ventilation frequency, hypercapnia increases tidal volume

amphibians: have reduced oxygen demands, can utilize gills, lungs, cutaneous respiration (species dependent), lungs similar to lizard, no diaphragm, ventilation through gular pumping (ribbit motion), have VP and NVP, have external, simplified, feathery gills if present, cutaneous respiration is the most important in some species due to unique vasculature of skin with a thin permeable epidermis

fish: water is much denser and less oxygenated than air, so need a high throughput system with minimal resistance (uniflow), have a concurrent gas exchange system to maximize O2 extraction, gills are where gas exchange occurs, secondary lamellae in contact with countercurrent blood flow for exchange

Question 40

understand how the differences in respiratory tract anatomy and physiology can be important when investigating disease or performing anesthesia

Answer 40

birds:
1. don’t used cuffed ET tubes bc of complete tracheal rings
2. the syrinx is a common site for foreign body obstruction, granulomas, or infections
3. the lung system is so efficient that if see open-mouth breath, bird is 80-90% dead
4. since have smooth respiratory muscle, will keep ventilating under anesthesia
5. can cannulate air sacs to provide alternative airway in cases of tracheal/syringeal obstruction

reptiles:
1. chelonians have complete tracheal rings so don’t use cuffed ET tubes
2. masking down is a waste of time for anesthesia because can hold breath for hours and also cardiac shunting
3. ventilation is controlled by smooth muscle, so must ventilate for them in anesthesia
4. all should be apneic at surgical plane of anesthesia; if breathing, DONT CUT
5. when recovering from anesthesia, decrease O2 by switching to room air and increase CO2 by decreasing ventilation frequency or won’t take a breath for hours
6. lack of muscular diaphragm means any disease in coelom can affect respiration and also don’t place in lateral or sternal recumbency until in a surgical plane of anesthesia

amphibians: due to ability of cutaneous respiration, if just using intubation may not fully anesthetize; and also very sensitive to environmental toxins