Respiratory Flashcards
how do cells primarily obtain energy
-aerobic metabolism
flow of air
-nose, pharynx, larynx, trachea, right and left bronchi, lobar branches, respiratory bronchioles, alveoli
what are respiratory broncholes wrapped in
-smooth muscle, capillaries, and elastic fibers
surfactant
-oily secretion with phospholipids and proteins
-are lipoproteins that are secreted by type II alveolar cells
-coats and lowers alveolar surface tension
-helps maintain lung stability
surfactant coats and lowers alveolar surface tension, how?
-by increasing pulmonary compliance
-reducing recoil pressure of smaller alveoli
external respiratorion
-all processes involved in exchange of O2 and CO2 with external environment
internal respiration
-uptake of O2 and release of CO2 by cells
-cellular respiration
external respiration steps
-Pulmonary Ventilation (breathing)
-exchange of O2 and CO2 betweena ir in alveoli and blood within the pulmonary capillaries
-transport of gases by the blood between lungs and tissue
-exchange of O2 and CO2 between tissues and blood
pulmonary ventilation
-physical movement of air into and out of respiratory tract
-provides alveolar ventilation
atomospheric pressirre
-weight of earth atmosphere
-has several important physiological effects
one respiratory cycle consists of
-an inspiration and expiration
pulmonary ventilation role in chamging pressure
-pulmonary ventilation causes volume changes that crete changes in pressure
-the volume of the thoracic cavity changes with expansion or contraction of disaphragm and rib cage
echalation and inhalation active or passive
-inhalation is active always
-exhalation can be active or passive
what is the external intercostal muscles innervated by
-intercostal nerves-
-diaphragm
-dome shaped sheet of skeletal muscle seperateing thoracic cavity from the abdominal cavity
-innervated by the phrenic nerve
muscles of inspiration
-external intercostal
-diaphragm
muscles of expiration
-internal intercostal
-abdominal muscles
boyles law
-gas molecules in a closed container bounce around and create pressure
-make container larger, molecules become further apart and create less pressure
-make container smaller, molecules closer together and create more pressure
inhalation process
-elevation of the rib cage and contraction of diaphragm to increase volume of thoracic cavity
-air flows in because of pressure outside if greater than inside
-when pressure increases to level below atmospheric pressure, air is driven in and inhalation occurs
exhalation process
-relaxation of diaphragm and muscles of chest wall plus the elastic recoil of the alveoli decrease the size of chest cavity
-lungs are compressed and intra alveolar pressure increases
-when pressure increases to level above atmospheric pressure air is driven out
4 pressures
-atmospheric pressure
-alveolar or intra alveolar pressire
-plueral or intraplueral presure
-transpulmonary pressure
alveolar or intra alveolar pressure
-pressure inside alveolus
-less than atmospheric (negative) during inspiration and positive during expiration
plueral or intraplueral pressure
-pressure between parietal and visceral pluer
-remains lower than atmospheric pressure throughout respiratory cycle
-change in intraplueral pressure creater respiratory pump
-assisys in venous return to the heart
transpulmonary and recoil pressure
-pressure difference between alveolar and plueral pressure
-negative due to properties of lung and chest wall
-lungs want to collapseand chest wall want to expant
-positive so it keeps the lungs and alveoli open
forced breathing
-involve active inhalation and exhalation
-assisted by accessory muscles
queit breathing
-involves active inhaltion and passive exhalation
-diaphragmatic breathing/deep breathing is dominated by the diaphragm
-codtal breathing or shallow breathing is dominated by rib cage movements
elastic rebound
-when muscles of inhalation relax the elastic components of tissues recoil
-diaphragm and rib cage return to original positions
-responsibel for lungs returning to their pre-inspiratory volume when inspiratory muscles relax at end of inspiration
elastic recoil depends on two factors
-highly elastic connective tissue in the lungs
-alveolar surface tenion
complian e
-ability of lungs to stretch and expand
-less compliancy = more work to produce inflation
-high complaince = pliable lung = low elastic recoil
-low compliance = stiff lung = high elastic recoil
factors effecting compliance
-connective tissue of lungs
-level of surfactant production
-mobility of thoracic cage
airway resistance
-air flow depends on the differences in atmospheric and intra-alveolar pressure and the resistance or airways to airflow
role of ANS in respiration
-control luminal diamter of bronchioles by regulating smooth muscle
-controls airflow in lungs
bronchodilation
-enlarged luminal diameter of airway
-caused by sympathetic activation
-reduces resistance to airflow
bronchoconstriction
-reduced luminal diamter of airway
-caused by PSNS activation and histamine release
Low O2 demands PSNS or SNS
-PSNS
-vagus nereve secretes ACh–> stimulates broncholar smooh muscle –> decreases airways radii
high O2 demands PSNS or SNS
-SNS dominates when ventilatory demand is increased
-NE and E from adrenal medulla –> stimulates B2 receptors on bronchiole smooth muscles –> increase airway radii
respiraory rate
-number of breaths per minute
respiratory minute volume (VE)
-amount of air moved/min
-measures pulmonary ventilation
anatomic dead space
-amount of air that doesnt particpate in gas exhange
-remains in conducting airways
alveolar ventilation
-amount of air reaching alveoli each minute
-alveoli contain less O2 than atmospheric air because inhaled air mixed with used air
-respiratory rate x (tidal volume - anatomic dead space
what is total lung volume measured with
-spirometer
tidal volume
-amount of air moved into or out of lungs in 1 breath
expiratory reserve volume
-additional amount of air capable of being exhaled
-residual volume
-amount of air in lungs after maximal exhalation
-minimal volume in a collaped lung
inspiratory reserve volume
-additional amount of air that can be inhaled
functional residual capacity
-exhalatory reserve volume + residual volume
vital capacity
-exhalatory reserve volume + tidal volume + inspiratory reserve volume
total lung capacity
-vital capacity + residual volume
relationships among Vt, Ve, Va
-for a given respiratory rate: increasing tidal volume increases alveolar ventilation rate
-for a given tidal volume: increasing respiratory rate increases alveolar ventilation rate
diffusion depends on
-partial pressure of gas across membrane
-resistance to diffusion of gas across membrane
factors that affect the rate of gas exchange
-as partial pressure gradient increases rate of diffusion increases
-greater differences in pp of gases the rate of diffusion increases
-as SA increases, the rate of diffusion increases
-increase in thickness of barrier separating air and blood decreases rate of gas exchange
reasons for efficiency of gas exchange
-differences in pp across BAB are large
-distances involved in gas exchange are short
-O2 and CO2 are lipid soluble
-Total SA is large
-blood flow and airflow are coordinated
-because distance for diffusion is short
-O2 and CO2 are small
blood air barrier
-alveolar layer
-capillary endothelial layer
-fused basement membrane between them
external respiration photo
what transports gas to and from tissues
-red blood cells
-plasma cannot transport enough O2 or CO2
fully, partially and unsaturated hemoglobin differences
-just as it sounds
-SaO2 = oxygen saturation
-want 93-95% saturation
factors affecting Hb saturation
-PO2 of blood
-Blood pH
-Temperature
-Metabolic activity within RBCs
oxygen-hemoglobin saturation curve
-a graph relating hemoglobin saturation to partial pressure of oxygen
-higher PO2 results in greater Hb saturation
-Curve rather than a straight line because Hb changes shape each time a molecule of O2 binds
-Each O2 bound makes next O2 bind more easily
Oxygen-Hb saturation curve when fluctuations happen
-when pH drops or temp rises: more O2 released, curve shifts to the right, Hb gives up O2 easily
-when pH rises or temp drops: less oxygen released, curve shifts left, Hb holds O2 tightly, less O2 released
what is the main factor when determining the Hb saturation percentage
-O2 partial pressure
-% saturation high when partial pressure O2 high (lungs)
-% saturation low where PP of oxygen is low (tissue)
hemoglobin and temp
-high temp encourages O2 lrelease
-low temp discourages )3 release
-temperature effects are siginficant only in active tissues that are generating large amounts of heat
BPG
-RBCs use glycolysis which produces lactate and BPG as a biproduct
-BPG rises due to increase in pH or some hormones
-higher BPG means hogher O2 release
-if BPG levels are too low, hemoglobin will not release oxygen
carbon monoxide
-binds strongly to hemoglobin
-takes the place of O2
-can result in CO posioning
3 ways that CO2 can be carried in the bloodstream
-Converted to carbonic acid
-bound to hemoglobin within RBC forming carbaminohemogloobin
-dissolved gas in plasma
carbonic acid fate
CO2–> Carbonic acid –> H+ + HCO3 by carbonic anhydrase –> binds to hemoglobin as bicarbonate
how do capillaries maintain equilibirum of diffusion
-local changes in O2 delivery to tissues
-local changes to ventilation to perfusion ratio in the lungs
-changes in depth and rate of respiration (brain)
ventilation to perfusion ratio
-coordinated lung perfusion with alveolar ventilation
Rising CO2 levels effect on smooth muscle
-relax smooth muscle in arterioles and capillaries increasing blood flow
respiratory rhythmicity centers
-MO
-establish rate and rhytym of breathing
-DRG and VRG
Dorsal respiratory group
-inspiratory center
-functions in quiet and forced breathing
-quiet: brief activity in DRG stimulates inspiratory muscles, DRG nuerons become inactive allowing passive exhalation
ventral respiratory group
-inspiratory and expiratory centers
-functions only in forced breathing
-increased activity in DRG stimulates VRG and activates accessory inspiraotry muscles
-expiratory center nuerons stimulate active exhalation
fucntions of apneustic and pneumotaxic center of pons
-paired nuclei that adjust output of respiratory rhytmicity centers that regulate depth and rate of respiration
apneustic center provides continous stimulation to
-its DRG center
pneumotaxic center inhibits
-apneustic centers
-promotes passive or active exhalation
-modify rate
respiratory centers of the brain photo
respiratory centers respond to what sensory info
-chemo receptos sensitive to PCo2, PO2, pH of blood and CSF
-stretch receptors responds to lung volume
-irritating stimuli in nasal cavity, and broncholes
-other sensations including pain, temp, abnormal visceral sensations
resp center highly influenced by chemoreceptor input from
-glossopharyngeal IX (changes in blood pH or PO2 in carotid boddies)
-vagus nerve (changes in blood pH or PO2 in aortic bodies)
what chemoreceptors responds to CSF
-central chemoreceptors on ventrolateral surface of MO
chemoreceptor stimulation effects
-increased depth and rate of respiration
hypercapnia
-increased aterial PCO2
-caused by hypoventilation
-chemoreceptors stimulate respiratory centers to increase rate adn depth of respiration
hypocapnia
-abnormally low PCO2
-caused by hyperventilation
-chemoreceptor activity decreases and respiratory rate fally
blood pressure and respiration
-carotid and aortic baroreceptors stimulation affects blood pressure and respiratory centers
-blood pressure falls = respiratory rate increases
-blood pressure increases = respiratory rate decreases
hering-breuer reflexes
-inflation reflex = prevents overexpansion of lungs
-deflation relfex = inhibits expiratory centers and stimulates inspiratory centers during lung deflation
protective reflexes
-sneeze, cough , laryngeal spasm
-triggered when epithelium encounters toxic vapour, chemical irritants, mechanical stimualtion
voluntary control of respiration
-strong emotions increase (hypothalamus)
-emotional states can activate both divisions of ANS causing bronchodilation or constriction
-anticipation of excersize can increase RR and CO by SNS stimulation
