Respiratory System Flashcards
nares
air is drawn through the nares
pharynx
where it is warmed and humidified
visbrissae
nasal hairs
alveoli
small sacs that interface with the pulmonary capillaries, allowing gases to diffuse across a one-cell-thick membrane
surfactant
the alveoli reduces surface tension at the liquid-gas interface, prevent collapse
visceral pleura
lies adjacent to the lung itself
parietal pleura
lines the chest wall
intrapleural space
lies between the visceral pleural and the parietal pleura and contains a thin layer of fluid that lubricates the two pleural spaces
diaphragm
thin skeletal muscle that helps to create the pressure differential required for breathing
inhalation
an active process, diaphragm and external intercostal muscles expand the thoracic cavity, increasing the volume of the intrapleural space, this decreases the intrapleural pressure
this pressure differential ultimately expands the lungs, dropping the pressure within and drawing in air from the environment. This mechanism is termed negative-pressure breathing
exhalation
may be passive or active
in passive exhalation, the relaxation of the muscles of inspiration and elastic recoil of the lungs allow the chest cavity to decrease in volume, reversing the pressure differentials seen in inhalation
in active exhalation, the internal intercostal muscles and abdominal muscles can be used to forcibly decrease the volume of the thoracic cavity, pushing out air
Spirometer
can be used to measure lung capacities and volumes
total lung capacity (TLC)
the maximum volume of air in the lungs when one inhales completely
residual volume (RV)
the volume of air remaining in the lungs when one exhales completely
vital capacity (VC)
the difference between the minimum and maximum volume of air in the lungs
tidal volume (TV)
the volume of air inhaled or exhaled in a normal breath
expiratory reserve volume (ERV)
the volume of additional air that can be forcibly exhaled after a normal exhalation
inspiratory reserve volume (IRV)
the volume of additional air that can be forcibly inhaled after a normal inhalation
ventilation center
a collection of neurons in the medulla oblongata
can be controlled by the cerebrum, but medulla oblongata will override it during extended periods of hypo or hyper ventilation
Chemoreceptors
respond to carbon dioxide concentrations, increasing the respiratory rate when there is a high concentration of carbon dioxide in the blood (hypercarbia or hypercapnia)
pulmonary arteries
deoxygenated blood with a high carbon dioxide concentration is brought to the lungs by pulmonary arteries
pulmonary veins
oxygenated blood with a low carbon dioxide concentration leaves the lungs via the pulmonary veins
vasodilation
helps body lose heat
vasoconstriction
helps body maintain heat
Mucociliary escalator
helps filter the incoming air and trap particulate matter
lysozyme
in the nasal cavity and saliva attacks peptidoglycan cell walls fo gram-positive bacteria
macrophages
can engulf and digest pathogens and signal to the rest of the immune system that there is an invader
mucosal surfaces
covered with IgA antibodies
Mast cells
have antibodies on their surface that, when triggered, can promote the release of inflammatory chemicals, mast cells are often involved with allergic reactions
What happens when blood pH decreases?
Respiration rate increases to compensate by blowing off carbon dioxide,
CO2 + H2O H2CO3 HCO3- + H+
This causes a left shift in the buffer equation, reducing hydrogen ion concentration
What happens when blood pH increases?
When blood pH increases, respiration rate decreases to compensate by trapping carbon dioxide.
CO2 + H2O H2CO3 HCO3- + H+
This causes a right shift in the buffer equation, increasing hydrogen ion concentration
