Chapter 42.5 Flashcards
Gas exchange
supplies O2 for cellular respiration
supplies O2 for cellular respiration
gas exchange
What is partial pressure
the pressure exerted by a particular gas in a mixture of gases
What do partial pressures also apply to?
gases dissolved in liquids such as water
how do gases undergo net diffusion
from a region of higher partial pressure to a region of lower partial pressure
What can animals use as their respiratory medium
air or water
respiratory medium
O2 source
The difference between obtaining O2 from water or from air
Obtaining O2 from water requires greater efficiency than air breathing
What do animals require for the exchange of gases between their cells and the respiratory medium (air/water)
large, moist respiratory surfaces
How does gas exchage across respiratory surfaces take place
by diffusion
Respiratory surfaces vary by animal and can include…
skin, gills, tracheae, and lungs
What are gills
outfoldings of the body that create a large surface area for gas exchange
outfoldings of teh body that create a large surface area for gas exchange
gills
what does ventilation do
moves the respiratory medium over the respiratory surface
moves the respiratory medium over the respiratory surface
ventilation
What do aquatic animals do for ventilation
move through water or move water over their gills
What do fish gills use
a countercurrent exchange system
a countercurrent exchange system
blood flows in the opposite direction to water passing over the gills; blood is always less saturated with O2 than the water it meets
In fish gills, what percent of the O2 dissolved in the water is removed as water passes over the respiratory surface
more than 80%
What does the tracheal system of insects consist of
a network of branching tubes throughout the body
what do tracheal tubes supply directly to the body cells
O2
the respiratory and circulatory systems are…
separate
What must larger insects do to meet O2 demands?
ventilate their tracheal system
what are lungs
an infolding of the body surface
an infolding of the body surface
lungs
what does the circulatory system do
transports gases between the lungs and the rest of the body
what do the size and complexity of lungs correlate with
an animal’s metabolic rate
What does a system of branching ducts do
conveys air to the lungs
What do nostrils do
filter, warm, and humidify inhaled air, as well as sample for odors
What does the pharynx do
direct air to the lungs and food to the stomach
what does swallowing do
moves the larynx upward and tips the epiglottis over the glottis in the pharynx to prevent food from entering the trachea
What does air pass through
the pharynx, larynx, trachea, bronchi, and bronchioles to the alveoli
what occurs at the alveoli
gas exchange
Where does exhaled air pass over to create sound
the vocal cords in the larynx
What do cilia and mucus like and do
the epithelium of the air ducts; move particles up to the pharynx
what does this “mucus escalator” do
cleans the respiratory system and allows particles to be swallowed into the esophagus
Where does gas exchange take place
in alveoli
what are alveoli
air sacs at the tips of bronchioles
where does oxygen diffuse through
the moist film of the epithelium and into capillaries
Where does carbon dioxide diffuse from
the capillaries across the epithelium and into the air space
what do alveoli lack and what are they susceptible to
cilia; contamination
what do surfactants do
coat the surface of the alveoli and reduce the impact of liquid surface tension that might otherwise cause the alveoli to collapse
What do preterm babies lack and what are they vulnerable to
surfactant; respiratory distress syndrome
What is treatment for respiratory distress syndrome provided by
artificial surfactants
