Respiratory System (Chapter 7) Flashcards
Structures
- nose
- nasal cavity
- pharynx
- larynx
- trachea
- bronchi
- alveoli
- diaphragm
Functions
- conducts air in and out of lungs
- gas exchange between air and blood
- humidifies air to prevent membrane from drying out
- warms air to maintain body temp and dec vasoconstriction
- filter air by mucus and cilia
Pressure changes
air moves high to low
Inspiration
- inc intrathoracic cavity volume
- diaphragm contracts (lowers pressure)
- muscles elevate ribs
What muscles elevate the ribs
- external intercostals
- scalenes
- sternocleidomastoid
- pectoralis minor
Expiration
- dec intrathoracic cavity volume
- diaphragm relaxes (inc pressure)
- muscles lower ribs
What muscles lower the ribs
- internal intercostals
- rectus abdominals
- internal obliques
Airflow
pressure difference (P1-P2) / resistance of airway
Airflow resistance
- inc by inc pressure diff/dec resistance
- diameter of airway effects airflow
- during exercise, bronchodilation dec = inc airflow
Measuring pulmonary (respiratory variables)
- tidal volume (air moved per breath)
- frequency (# of breaths per min)
- volume of air expired (Ve) (total volume of air expired per min) (tidal volume x frequency)
Lung capacity
- volumed measured with spirometry
- vital capacity is max tidal volume
- reserve volume is vital capacity - resting tidal volume
Residual volume
- air left in lungs after max expiration
- keeps lungs from collapsing
- allows for gas exchange between breaths
Total lung volume
Vital capacity + residual volume
Anatomical dead space
- not all the air reaches alveoli (in air body with no function)
- high tidal volume dec dead space (plateaus at high intensity)
Frequency/depth of breathing
- inc depth occurs before inc frequency
- frequency is the only thing left to inc Ve
Exercise induced bronchospasm
inflammation due to aggravation
Chronic obstructive pulmonary disease (COPD)
Asthma
overall inflammation at airway when worked
- causes bronchospasm
Bronchospasm
muscles that line your bronchi (airways in your lungs) tighten
Bronchitis
inflamed bronchi (chronic bronchospasm)
Emphysema
damaged/enlarged alveoli
Pulmonary fibrosis
scarred tissue, stiff lung tissue
Promoting diffusion
- large surface area
- thin respiratory membrane
- pressure difference of O2 and CO2
Dalton’s Law
total pressure = sum of partial pressure
Henry’s Law
amount of gases dissolved in any liquid depends on temp, solubility, and partial pressure
Oxygen diffusion
partial pressure of O2 needs to be higher in alveoli then blood and higher in blood then tissues
Carbon dioxide diffusion
partial pressure of CO2 needs to be higher in blood then alveoli and higher in tissue then blood
What determines lung blood flow
cardiac output
Inc blood flow
- inc gas diffusion
- dec time for equilibration
how long does diffusion take
about 0.25 sec
Blood pressure in pulmonary
dec vascular resistance = dec damage to respiratory membrane
Oxygen transport
> 98% is transported by hemoglobin
dec O2 on hemoglobin is caused by what
inc temp and acid
Inc O2 on hemoglobin is caused by what
dec temp and acid
Carbon dioxide transport
- 70% is transported as bicarbonate in plasma
- 20% is transported by hemoglobin
- 7-10% is dissolved in plasma
What does CO2 bond to in blood
H2O = H2CO3
Gas exchange at muscles
occurs due to pressure difference between blood and tissues
Myoglobin
- O2 transport molecule
- found in skeletal and cardiac muscles
- reversibly binds to O2
- O2 storage
Respiratory control center
- a portion of the medulla oblongata and pons
- “pace maker”
- controls respiratory muscles based on input/feedback
Higher brain centers
temporarily overpowers involuntary actions
Central chemoreceptors
measures PCO2 in CSF
PO2 receptors in aortic arch and carotid body
protects against disease and elevation
Peripheral inputs
- plasma chemoreceptors (H+, K+, and PCO2)
- stretch receptors in lungs
- proprioceptors in muscles and joints
- temp receptors
Pulmonary ventilation is (invol/vol)
involuntary but can be temporarily voluntary by higher brain centers (hyperventilation)
Plasma CO2 build up
biggest impact on ventilation (hypoventilation)
Phases of ventilation (phase 1)
vent inc before and at onset
-motor cortex activity and proprioceptors
Phases of ventilation (phase 2)
exponential rise to steady state
-motor cortex activity and proprioceptors and peripheral chemoreceptors
Phases of ventilation (phase 3)
fine tuning during steady state
-central and peripheral receptors
Phases of ventilation (Recovery)
elimination of motor cortex and proprioceptors
Respiratory muscle training
> 85% max, sympathetic stimulation of respiratory muscles max out
-causes norepinephrine spillover, constricting blood flow to active muscles
Training inspiratory and expiratory
- resistance, pressure loaded valves to inc work of respiration
- endurance, hyperventilation
Above steady state
disproportionate inc Ve relative to intensity
Ventilatory equivalents
- volume of air needed to get 1L of O2 (Ve/VO2) or expire 1L of CO2 (Ve/VCO2)
dec Ve/VO2 and Ve/VOC2 does what to ventilation
- deeper breaths
- both stop at 50% of VO2 max
Ve/VCO2 during exercise
- plasma CO2 levels impact Ve (plasma CO2 inc with intensity)
- levels off before inc during exercise
Ve/VCO2 inc when
acid exponential inc
Ve/VO2 during exercise
- inc after short level of exercise and continue until max VO2
- intensity and VO2 inc linearly together
- Ve only reacts with CO2 plasma levels
Ventilatory threshold
point when Ve/VO2 inc with no change in Ve/VCO2
- RER of 1.0
- estimates LT
Respiratory compensation point (RCP)
point when both Ve/VO2 and Ve/VCO2 inc
- anaerobic
- acidosis occurs exponentially (sharp inc in VCO2)
- hyperventilation at vital capaity
- estimates OBLA
Training Zones
- VT and RCP are used to create 3 training zones
Light intensity training zone
< (less then) VT
Moderate intensity training zone
between your VT and RCP
High intensity training zone
> (greater then) RCP
Ventilation limits
Ve=tidal volume x frequency
-tidal volume inc first then frequency
-3-5% VO2 used below VT
-8-10% used at high intensity
Bigger Ve max help what
inc exposure of air to alveoli
Efficient CV system transports O2 to what
muscles
Efficient muscles use a lot of what
O2
-results in inc a-v O2 difference
