respiratory 1: ventilation Flashcards
what does pulmonary ventilation refer to
the mechanical mvmt of air in and out of the body
describe eupnea
- quiet breathing
- inspiration is active - involves the diaphragm and the external intercostals
- expiration is passive
describe hyperpnea
- increased expiration to match metabolic demands
- inspiration is active - involves the diaphragm, external intercostals, scalenes and the sternocleidomastoid
- expiration is active - involves the abdominals and the internal intercostals
define tidal volume
volume of each breath
define breathing frequency/respiratory rate
number of breaths per min
describe minute ventilation and state its formula
the total amount of air that we inspire/expire every minute
Ve = Vt x Fb
describe alveolar ventilation and state its formula
- amount of air that reaches the alveoli and can participate in gas exchange
- effective ventilation - what we care about
Va = (Vt - Vd) x Fb
define dead space, anatomical dead space, and physiological dead space
dead space (Vd): portion of each breath that gets wasted
anatomical dead space: air that never reaches alveoli - always there - assumed to be 150mL
physiological dead space: air that reaches the alveoli w/ no or poor perfusion (blood flow)
describe the Ve response to dynamic exercise
PA increases Ve
phase 1: immediate increase
- fast component - ~10 s
phase 2: exponential increase
- slow component - ~1 min (more at increased intensities)
phase 3: steady state
- appropriate for MR unless intensity is too high to be supported aerobically
describe exercise-induced bronchodilation
- happens immediately
- smooth muscle lining’s airways relax
- increased airway diameter
- decreased airway resistance
- easier to breathe
- respiratory muscles don’t need to work as hard
- saves energy
- smooth muscle lining’s airways relax
