Respiratory System 9.2

parts of respiration

pulmonary ventilation, external respiration, respiratory gas transport, internal respiration

pulmonary ventilation

air is continuously moved into and out of the lungs

external respiration

fresh oxygen from outside to the body fills lungs and alveoli, allowing gas exchange netween alveoli and pulmonary blood

respiratory gas transport

the oxygen and carbon dioxide gases in the blood are transported between the lungs and differend body tissues

internal respiration

gas exchange occurs internally between the tissues and capillaries

Boyle’s Law

the volume of a gas is inversely proportional to its pressure; as the volume of a gas increases, the pressure decreases

inspiration (inhalation)

the process by which air flows into the lungs, thoracic cavity expands

expiration (exhalation)

the process by which air is expelled by the lungs; passive process, thoracic cavity decreases space

nonrespiratory air manuvers

cough, sneeze, hiccup, yawn

cough

caused by a need to clear debris from the lower respiratory tract, results in closing the epiglottis and forceful exhalation being performed

sneeze

caused by a need to clear the upper respiratory passageways of debris, results in uvula closing off oral cavity and air going through the nose

hiccup

caused by an irritation of the phrenic nerves, diapragm muscle spasms, results in sudden inspirations against the vocal cords of a closed glottis

yawn

caused by a need for increased oxygen in the lungs, results in prolonged, deep inspirations (taken with the jaw widely open)

neural breathing centers

medulla oblongata and pons

Hering-Breuer reflex

prevents overinflation of the alveolar sacs

central chemoreceptors

constantly monitor changes in cerebrospinal fluid pH

peripheral chemoreceptors

sensitive to changes in blood oxygen level

mechanoreceptors

located in muscles and joints, mechanoreceptors detect muscle contraction and force generation during exercise

static lung volume

measures only volume

dynamic lung volume

measures volume based on time

spirometer

measures static lung volume

flow volume meter

measures dynamic lung volume