RS Flashcards
what is the function of the upper resp tract
filters
humidifies
warms air
and voice production
what are the 2 functions of voice production
- voice production
- reduces weight of skull
what does the frontal sinus drain into
middle meatus
what does the ethmoid sinus drain into
superior and middle meatus
what do the sphenoid n maxillary sinus drain into
sphenoethmoidal sinus
what is the nasopharynx innervated by
maxillary branch of CNV
what is the oropharynx innervated by
CN IX
what is the laryngopharynx innervated by
CN X
what are the single cartilages of the larynx
epiglottis
thyroid
cricoid
what are the paired cartilages of the larynx
cuneiform
corniculate
arytenoid
what does the carotid sheath contain
common carotid artery
interna jugular vein
vagus nerve
what are the 2 lobes of the thumbs connected by
isthmus
what is the arterial supply of the thyroid
superior and inferior thyroid arteries
what 3 things happen at t4/5
- sternocostal angle
- trachea bifurcation
- division btwn sup n inf mediastinum
what is the blood supply of the pharyngeal constrictor muscles
ext carotids
what does the hilum of the lung contain
bronchus 1 pul artery 2 pul veins bronchial arteries plexus of nerves n lymphatics
where is the caval opening
t8
what runs through the caval opening
IVC
where is the oesophageal hiatus
t10
what runs through the oesophageal hiatus
oesophagus
vagus nerve
what runs through the aortic hiatus
aorta
thoracic duct
azygous vein
where is the aortic hiatus
t12
how many lobes does left lung have
2 - sup n inf
how many lobes does the right lung have
3 - sup, mid n inf
what are the fissures of the left lung
oblique
what are the fissures of right lung
oblique n horizontal fissure
what does the visceral pleura cover
lung
what does parietal pleura cover
int thoracic cavity
what is in the potential space btwn 2 layers of viscera
serous fluid - lubricité n produces surface tension so lungs can expand
what is the parietal pleura innervated by
phrenic n intercostal nerves
what is the pump handle mechanism
elevation of rib causes anterior part to move forward as well as up
what is the bucket hand mechanism
middle part of rib move out as well as up during inspiration
what are the normal muscles involved in passive exp/insp
external intercostals
diaphragm for inspiration
which extra muscles are involved in active breathing
internal intercostals
SCM
pec major
what is the innervation of the diaphragm
c3, 4, 5
what is the innervation of intercostals
T1-11
describe inspiration (4)
- diaphragm and ext intercostals contract - thoracic expansion
- pressure of pleural fluid becomes sub-atmospheric
- transpulmonary pressure increases (pressure difference btwn inside n outside lung) –> lungs expand
- alveolar pressure becomes sub-atmospheric –> air flows into alveoli
describe expiration (5)
- diaphragm n ext intercostals stop contracting
- chest wall recoils inwards
- pleural fluid pressure increases –> trans pulmonary pressure decreases
- lungs return to pre-inspiration volume –> alveolar air compressed
- alveolar pressure > atmospheric pressure –> air flows out of the lung
what is the loop for resp control
sensor (peripheral/central chemoreceptors) - controller (medulla/pons) - effector (diaphragm/intercostals)
what are the 2 parts to the medullary resp centre
inspiratory group - inspiration
expiratory group - sends inhibitory impulse to apneustic centre
what are the inspiratory and expiratory group a part of
medullary resp centre
what does the inspiratory group of medullary resp centre do
inspiration
what does the expiratory group of medullary resp centre do
sends inhibitory impulse to apneustic centre
what does the pontine resp centre do
helps inspiration - expiration transition
what are the 2 parts to the pontine resp centre
apneustic centre - fine tunes inspiratory groups output
pneumotaxic centre - inhibits inspiratory neurone for expiration
what does the apneustic centre of pontine resp centre d
fine tunes inspiratory groups output
what does the pneumotaxic centre of the pontine resp centre do
inhibits inspiratory neurone for expiation
where are central chemoreceptors found
medulla
what do central chemoreceptors respond to
hydrogen ion conc in csf
where are peripheral chemoreceptors found
aortic arch
carotid sinus
what do peripheral chemoreceptors respond to
H+ conc (90%)
arterial oxygen conc (10%)
what are the 3 types of stretch receptors
slow adapting stretch receptors (SASR)
fast adapting stretch receptors (FASR)
c fibres j receptors
where are SASR found
smooth muscle
discuss SASR (4)
- found in smooth muscle
- activated by lung distension
- high SASR activity inhibits insp - begin exp
- adaptive receptors over chronic inflation
discuss FASR (3)
- found btwn airway cells
- activated by irritants
- brief sharp bursts of activity –> bronchodilation
where are SASR found
smooth muscle
where are FASR found
btwn airway cells
which receptors are activated by irritants
FASR
which receptors are activated by lung distension
SASR
what are c fibres j receptors (2)
type of stretch receptor
- activates by an increase in interstitial fluid
- causes hyperventilation and bronchoconstriction
which receptors are activated by increase in interstitial fluid
c fibres j receptors
which receptors cause bronchoconstricton and bronchodilation
bronchoconstriction - c fibres j receptors
bronchodilation - FASR
what is alveolar recruitment
during high oxygen requirement (exercise) alveoli that were shut off from air supply are recruited - increases gas exchange
what is the oxygen dissociationn curve shape
non linear
sigmoid
what does a left shift in the sigmoid curve mean
higher affinity
less dissocation
increased CO conc
what does a right shift in the sigmoid curve mean
lower affinity
more dissocation
increased H ion conc
increased temp
what are the 7 layers of gas exchange
- surfactant
- type 1 pneumocystis (alveolar membrane - squamous epithelium)
- interstitial fluid
- capillary endothelium
- blood plasma
- RBC membrane
- RBC cytoplasm
what is ventilation
rate of air flow to lungs
what is perfusion
rate of blood flow to alveoli
what is V/Q mismatch
when rates of ventilation and perfusion are not equal
list 3 causes of V/Q mismatch
shunting (blood doesn’t get to capillaries)
bronchial artery occlusion
pulmonary oedema
what is the equation for Boyle’s law
V1 x P1 = V2 X P2
what is Boyle’s law
vol and pressure are inversely proportional
what is the equation for Dalton’s law
P1 + P2 + P3 = P(1+2+3)
what is dalton’s law
total pressure = sum of gas partial pressure
what is the equation for Henry’s law
PAO2 = PaO2
what is henry’s law
amount of oxygen dissolved in blood is proportional to partial pressure of oxygen in alveoli
what is the alveolar gas equation
- PAO2 = PiO2 - PaCO2/RQ
what is Laplace’s law (2)
air will travel from smaller alveoli to bigger alveoli - larger radius = lower pressure
surfactant abolishes surface tension - all alveoli are same size, homogeneous aeration of lungs
what is acid base balance
H2O + CO2 H2CO3 H+ + HCO3-
what is the dissocation equation catalysed by
carbonic anhydrase
what is the Henderson hasselbach equation
pH = 6.1 + log([HCO3-]/[PaCO2x0.03])
what is resp acidosis
incr PaCO2
decr pH
hypoventilation
what is resp alkalosis
decr PaCO2
incr pH
hyperventilation
what is met alkalosis
incr HCO3-
not enough H+
incr pH
vomiting
what is met acidosis
decr HCO3-
decr pH
renal failure
what is hypoxia
not enough oxygen
what is hypercapnia
too much carbon dioxide
what is t1 resp failure
hypoxia (PaO2 < 8kPa)
can’t get enough oxygen into blood
what is t2 resp failure
hypoxia (PaO2 < 8kPa)
hypercapnia (PaCO2 > 6kPa)
list some causes of t1 resp failure
high altitude v/q mismatch pulmonary embolism hypoventilation pneumonia
list some causes of t2 resp failure
can’t get rid of CO2 - COPD, asthma
define tidal volume (TV)
vol of air inspired n expired in normal breathing (500ml)
define vital capacity (VC)
max vol of air that can be expired (3000-5000ml)
define total lung capacity (TLC)
total vol of air in lungs (6000ml)
define residual volume (RV)
volume of air remaining in lungs after forced expiration
define functional residual capacity (FRC)
vol of air remaining in lungs after tidal expiration
define inspiratory capacity (IC)
vol of air that can be inspired after tidal expiration
define inspiratory reserve volume (IRV)
vol of air that can be inspired after tidal inspiration
what is FEV1
FEV in 1 second
what is FEV6
FEV in 6 seconds (basically FVC)
what is the peak expiratory flow (PEF) on a flow/volume graph
highest point on graph
what is obstructive lung disease
patients cannot expire air quickly completely - airways are too constricted
what is restrictive lung disease
patients cannot inspire enough air - lungs do not expand fully
what is the diff btwn obstructive and restrictive lung disease
obstructive - constricted airways, cannot expire
restrictive - lungs don’t expand fully, can’t inspire
what is the FEV1/FVC ratio in obstructive lung disease
<0.7
bc reduced FEV1 - can’t exhale 70% of air in 1 second
what are examples of obstructive lung diseases
COPD
asthma
bronchitis
what is the FEV1/FVC ratio in restrictive lung disease
> 0.8
bc reduced FVC - air can get out fine
what is an example of restrictive lung disease
pulmonary fibrosis
how does blood travel in pulmonary vessels
at low pressure bc p BV have thin, poorly muscularised walls
what is the effect of oxygen in systemic circulation and thus pulmonary
systemic - vasoconstrictor
pulmonary - vasodilator
reverse in hypoxia
what is the Gell and Coombs classification for hypersensitivity
t1-4
igE
igM
IgG
T cells
what happens type 1 in g and c hypersensitivity classification
involves IgE
- fast allergic response
eg hayfever
what happens in t2 g and c hypersensitivity classification
involves IgM
- immune system thinks cells are foreign
eg blood transfusion
what happens in t3 g and c hypersensitivity classification
involves IgG
- complex deposits and causes inflammation
eg lupus
what happens in t4 g and c hypersensitivity classification
involves t cells
- part of learned immune response
eg contact dermatitis
what happens in a t1 IgE reaction (3)
- IgE binds to mast cells n basophils
- cells degranulate - release histamine n prostaglandins
- local response - vasodilation leads to inflammation
does the SNS cause bronchodilation or constriction
bronchodilation
what neurotransmitter is involved in brochodilation
Ad
does the PNS cause bronchodilation or constriction
bronchoconstriction
which nerve involves PNS and bronchoconstriction
vagus nerve
which neurotransmitter is involved in bronchoconstriction
ACh
what are the 2 cholinergic receptors
nicotinic and muscarinic
what are the muscarinic receptors n what do they cause
m3
bronchoconstriction
what are the 2 adrenergic receptors
alpha n beta
what are the beta receptors n what do they cause
beta 2
bronchodilation
what happens during the sympathetic response
- Ad released from adrenal glands
- binds to beta 2 receptors
- bronchodilation
what happens during parasympathetic response
- ACh released
- binds to m3 receptors
- bronchoconstriction
what do beta 2 agonists do
stimulate bronchodilation
what do m3 antagonists do
inhibits bronchoconstriction
what is innate immunity
non specific and generic response to pathogens
what is the muco-ciliary escalator
- mucous is elastic n viscous (secreted by goblet cells in resp epithelium)
- upper mucus n lower surfactant layer
- resp epithelium cilia beat in upwards direction - moves mucus from lower resp tract to pharynx
what is mucous secreted by
goblet cells in resp epithelium
which direction does cilia beat in
upwards
describe the coughing mechanism (4)
- afferent impulse from vagus n glossopharyngeal to medulla
- epiglottis n vocal cords shut, abdominal n intercostals contract
- intrathoracic pressure increases –> epiglottis n vocal cords suddenly open
- large pressure diff causes rapid expulsion of air through trachea
what are the 3 types of cells in alveolar epithelium
type 1 pneumocytes
type 2 pneumocytes
alveolar macrophages
name 3 features of t1 pneumocytes
- simple squamous
- 90% SA (form walls)
- thin blood gas barrier
name 2 features of t2 pneumocytes
- secrete surfactant
- less SA but 60% of cells
what are alveolar macrophages
resident macrophages of lung
phagocytose foreign material
what are the 2 main occurrences in inflammation
- alveolar macrophage responds to damaged tissue, releases cytokines - mast cells release histamine
- neutrophils n basophils migrate to damaged cite - involved in phagocytosis of foreign materials and sticks to endothelial walls
where are B cells produced
bone marrow
where do B cells mature
lymph nodes n spleen
where are T cells produced
bone marrow
where do T cells get released from
thymus
what does a B cell differentiate into to release specific antibodies
plasma cell
what do t helper cells do
- cd4 receptors recognise antigen presenting cells
2. cytokines are released which stim B cells and cytotoxic t cells
what do cytotoxic T cells do
- cd8 receptors recognise foreign pathogen
- cause perforin release
- thus cell lysis
why do memory cells remain after infection elimination
to allow fast response to future infection
what is an antibody
unique receptor (IgG) that binds to foreign pathogen n can agglutinate or active T killer cell for destruction
describe immunisation
- uses dead or attenuated pathogen
- memory cells remain –> protection from actual infection
- herd immunity –> if enough ppl get vaccinated, nobody will get disease
what is dead space
vol of air inhaled that does not take part in the gas exchange
why is there dead space (2)
- remains in conducting airways
2. reaches alveoli that are not/poorly perfused
