ch 17 +18 Flashcards
first function of respiratory system
exchange of gases btw atmosphere and blood
second function of resp system
homeostatic reg of pH
third function of respiratory system
protection from inhaled pathogens
fourth function of respiratory system
vocalization
bulk flow
flow from high to low pressure
how does bulk flow occur
muscular pump
what provides resistance to air flow
diameter
ventilation
inspiration and expiration
upper respiratory tract
mouth
nasal cavity
pharynx
larynx
lower respiratory tract
tracea, 2 primary bronchi, branches, lungs
alveoli
site of gas exchange
thoracic cage
bones and muscle of thorax and abdomen
what protects lungs
bones and muscle of the thorax
what are the bones of the thorax
spine and rib cage
what are the muscles of the thoracic cage
Diaphragm, intercostal muscles, sternocleidomastoids, scalenes
what encloses the lungs
pleural sacs
point of pleural fluid
lowers friction btw membranes
what holds lungs tight to thoracic wall
pleural fluid
airway order
Pharynx larynx trachea
what contains vocal cords
larynx
primary bronchi lead to
bronchioles
what do airways have to do to air to not shock the body
warm, humidify, and filter air
Type 1 alveolar cells
gas exchange
type 2 alveolar cells
produce surfactant
connective tissue
elastin and collagen
pulmonary circulation
Right ventricle pulmonary trunk pulmonary arteries lungs pulmonary veins left atrium
what is blood flow through lungs/min equal to
blood flow through rest of body/min
average pulmonary blood pressure
25/8 mmHg
is distance between alveoli and capillary endothelium very long or very short
short
Dalton’s law
Total pressure equals sum of all partial pressures
Boyle’s law
PV1=PV2
v
1/p
partial pessure of a gas
Patm= %gas in atmosphere
Pgas in humid air
(Patm-Ph2o) x % of gas
lung volume
changes during ventilation
pulmonary functions
spirometer
tidal volume
volume that moves during a respiratory cycle
inspiratory cycle
additional volume above tidal volume
expiratory reserve volume
forcefully exhaled after the end of a normal
residual volume
volume of air in the respiratory system after maximal exhalation
vital capacity
IRV+ERV+ V
total lung capacity
IRV +ERV+ V+ residual volume
tidal volume number
500 mL
inspiratory reserve volume number
3000mL
expiratory reserve volume number
1100 mL
residual volume number
1200 mL
Flow
P/R
when does inspiration occur
when alveolar pressure decreases
expiration occurs when
alveolar pressure increases
subatmospheric intrapleural pressure
keeps lungs inflated
pneumothorax
air leaks from the lung into the space between the lung and chest wall
intrapleural pressure
pressure changes in response to inhalation /exhalation
compliance
ability to stretch
high compliance
easy to stretch
low compliance
requires more force
what kind of disease has low compliance
restrictive lung disease
elastance
ability to return to resting volume when stretching
surfactants
surface active agents
why do alveolar cells need surfactant
disrupt cohesive force of water
premature babies
inadequate surfactant concentration
airway diameter
R=Lmu/r^2
bronchoconstriction
increases resistance
histamine
bronchoconstrictor
bronchodilation
decreases resistance
is bronchoconstriction para or symp
parasympathetic
is bronchodilation para or sym
sympathetic
total pulmonary ventilation
ventilation rate x tidal volume
alveolar ventilation
ventilation rate ( Vt- dead space)
anatomical dead space
part of the airway where air does not reach
fresh air into lungs
10% total lung volume at the end of inspiration
ventilation is matched with
alveolar blood flow
what does vent/blood flow ensure
efficiency of gas exchange
what happens if alveolar exchange decreases
blood flow is diverted away from damaged tissues
obstructive lung disease
increased airway resistance
examples of obstructive lung disease
asthma, COPD, obstructive sleep apnea
restrictive lung disease
reduced lung compliance
examples of restrictive lung disease
pulmonary fibrosis, scoliosis
forced vital capacity
Taking in as much air as possible and then breathing it out as quickly as possible.
what is the procedure for FEV1
The volume of air leaving the airway in the first second
FEV1/FVC
used to distinguish between obstructive and restrictive diseases
FEV1/FVC for restrictive
does not change
FEV1/FVC for obstructive
<80% what it should be
3 regulated variables that body has to respond to
O2, CO2, pH
breathing
bulk flow in and out of lungs
total pressure of mixed gas
sum of partial pressures of individual gases
gas exchange between alveoli and blood
PO2 is less in blood than alveoli (GRADIENT)
gas exchange between blood and tissues
blood is greater than tissue (GRADIENT)
what does higher altitude do
decrease PO2
what happens when alveolar ventilation is inadequate
hypoventilation
diffusion rate
surface area x barrier permiability
constants in diffusion rate equation
surface area
barrier permeability
diffusion distance
what is the primary factor affecting gas exchange
concentration gradient
what is movement of gas directly proportional to
pressure gradient of gas
solubility of gas in liquid
temp
where does gas first entering capillaries go
dissolve into plasma
how much does dissolved gas account for
<2% of O2 in blood
PO2 determines what
oxygen- Hb binding
what is O2 binding dependent on
Hb in RBCs
oxygen binding is expressed as
%
what do oxyhemoglobin sat curves display
relationship between saturation and PO2
what is the cool part of hemoglobin
its cooperative , as one oxygen binds it is encouraged to bind more
what does Hb binding depend on
Plasma O2 and amount of hemoglobin
what shifts Hb curve to the right( more O2 released)
dec pH , inc temp, inc PO2
what shifts Hb curve to the left(less O2 released)
inc pH , dec temp, dec PO2
bohr shift
a shift in hemoglobin saturation curve resulting from. pH change
maternal vs fetal hemoglobin
fetal Hb left shifted
how does curve shift as pH increases
LEFT
how does curve shift as temp increases
RIGHT
how does curve shift as PCO2 increases
RIGHT
how does curve shift as 2,3 BPG increases
RIGHT
carbonic anhydrase
enzyme in charge of converting CO2 to HCO3-
chloride shift
exchanges HCO3- for Cl- to maintain electrical neutrality
hemoglobin and H+
react to form respiratory acidosis
hemoglobin and CO2
carbaminohemoglobin
CO2 removal at the lungs
diffusion of CO2 down PCo2 gradient
what maintains breathing rhythm
neural networks
what do respiratory neurons in medulla control
inspiratory and expiratory muscles
what do neurons in the pons integrate
sensory info and interact with medullary neurons to influence ventillation
where does rhythmic pattern of breathing come from
neural network spontaneously discharging neurons
what is ventilation subject to
continuous modulation by chemoreceptor and mechanoreceptor linked reflexes and high brain centers
dorsal respiratory group
to muscles of inspiration
what nerve activates the diaphragm
phrenic nerve
what nerve activates intercostal muscles
intercostal nerve
sensory input from chemo and mechanoreceptors go to
the PONS
which two nerves fall under category of sensory input
vagus and glossopharyngeal
ventral respiratory group
basic pacemaker activity
what is VRG responsible for
greater-than-normal inspiration active expiration
what does the ventral respiratory group innervate
larynx, pharynx, and tongue
peripheral chemoreceptors
located in carotid bodies
what do peripheral chemoreceptors sense
changes in PO2,pH and PCO2
specialized glomus cells
dec PO2, inc pH, inc PCO2 increase in ventilation
O2 must fall below what value to trigger reflex
60 mmHg
central chemoreceptors
located in CNS
what do central chemoreceptors respond to changes in
PCO2
when arterial PCO2 increases, CO2 could do what
cross into brain ECF
what can change control of brainstem on breath rate and depth
cerebrum and hypothalamus
what can affect breathing rate and depth
limbic system
what can the limbic system directly bypass
brain stem
what cannot be overridden
chemoreceptor reflexes
cystic fibrosis
CFTR cl- channel is broken, mucus is clumpy trapping bacterial and offering grounds for infection
lymphatic system
removes excess water and fluid
