12.1 Structure and Function of the Respiratory System Flashcards
All cells need ______ in order to produce _____
oxygen; energy
The transfer of gases occurs in three phases:
breathing, transport of gases, and gas exchange
Respiratory surfaces are thin, moist, selectively ________ membranes with a large ____________.
permeable; surface area
The level of carbon dioxide in the blood controls
the breathing rate
Your cells require oxygen to obtain ____ from nutrients (food)
energy
Energy production (cellular respiration) occurs in the ________
mitochondria
Cells must always have ____ and produce ___________
oxygen; carbon dioxide
Gas exchange occurs along a special membrane called
the respiratory surface
To ensure diffusion occurs efficiently:
A very thin and moist membrane permeable to gases being diffused
Large surface area to maximize diffusion
Diffusion gradient must be maintained
(Must be a difference in relative concentration of CO2 and O2)
in gas exchange in aquatic animals, where is the source of useful gas?
dissolved in water
Large volume of water must come into close contact with the ___________________
thin respiratory membranes (gills)
gills
Folds in the body surface specialized for gas exchange
what do gills enable water to do?
Enables water to flow so that gases can diffuse from the water and across the respiratory membranes
O2 diffuses directly ______________ and CO2 diffuses ________________________
into the capillaries; out of the capillaries and into the environment
2 advantages that gas exchange in terrestrial animals have over aquatic animals
1.) Higher concentration of O2 in air than in water
2.) Air is both lighter and easier to move than water
-Therefore spend less energy in exchanging gases across respiratory surface
1 disadvantage that gas exchange in terrestrial animals have over aquatic animals
One disadvantage is the loss of moisture in their environment
Therefore, evolved internal respiratory systems (e.g. tracheal system and lungs) to help minimize the loss of moisture
Many insects have a _______________ that extend through their bodies
system of tubes
tracheal system
Many insects have a system of tubes that extend through their bodies
Air enters and leaves through openings in the body surface
Tracheae branch into smaller tracheoles, which extend to nearly every cell in the body
Gas exchange occurs along the moist membrane at the tip of the tracheoles
Tracheae branch into smaller ________, which extend to nearly every cell in the body
tracheoles
Gas exchange occurs along the ________ at the tip of the __________
moist membrane; tracheoles
Reptiles, birds, mammals, and some amphibians gas exchange occurs in _____________
internal lungs
lungs
Reptiles, birds, mammals, and some amphibians gas exchange occurs in internal lungs
Surrounded by fluids or by moist tissue and blood vessels
O2 diffuses into the blood and CO2 diffuses out of the blood by the mechanics of breathing
Aquatic reptiles and aquatic mammals (e.g. whales) breath with lungs and must hold their breath under water
O2 diffuses _______________ and CO2 diffuses ____________ by the mechanics of breathing
into the blood; out of the blood
Aquatic reptiles and aquatic mammals (e.g. whales) breath with ________ and must _________________
lungs; hold their breath under water
Nose hair and mucus filter ________________-
bacteria and dirt
The nose also warms ____ and adds ______
air; moisture
Passageways for air and food intersect at the
pharynx
Pathway in the pharynx is always open except
when you swallow
what does the epiglottis do when you swallow?
When swallowing occurs, the epiglottis covers the air pathway to prevent food from entering the trachea
Your _____ is your voice box
larynx
how does your larynx produce sounds?
vocal cords in your larynx vibrate, producing sounds
Trachea
ring-shaped due to circular shaped rings of cartilage that help maintain shape
Bronchi: (s. bronchus)
air tubes that connect the trachea to the lungs
Within each lung, the bronchus branches into finer and finer tubes called __________
bronchioles
Bronchi and bronchioles are covered by ____________ that contract and relax to control ______________
smooth muscle; size of airways
alveoli
Alveoli are grapelike clusters of super-tiny air sacs
Lungs contain millions of alveoli (s. alveolus) which _____________________________
maximizes surface area for gas exchange
entire respiratory system is lined with ____________________
moist epithelial tissue
Cells of trachea and bronchi are covered with ____ and a fine layer of ______
cilia; mucus
mucus
Mucus traps foreign particles from air
cilia
Cilia move particles up towards pharynx where they can be expelled or swallowed.
Subconscious controlled by the _____________
medulla oblongata
On average we take __ breaths per minute and roughly _______ per day!
15; 21, 000
On average we take __ breaths per minute and roughly _______ per day!
15; 21, 000
how big is the size of a lung?
about the size of a football
how much can each lung hold?
Can hold 6L each
___________ in the blood are what control breathing
CO2 levels
regulating breathing
CO2 levels in the blood are what control breathing
When CO2 dissolves in water, it forms carbonic acid H2CO3 (aq)
As CO2 diffuses through capillary walls, it dissolves in the plasma
Carbonic acid lowers the overall pH of blood
M.O. detects increased [CO2] and sends nerve impulses to muscles and diaphragm to move more rapidly
Homeostasis (the state of internal stability maintained by the body) is reached
_________ in aorta and carotid arteries detect O2 pressure stimulating ______ to increase ________ rate
Chemoreceptors; medulla oblongata; respiration
When you take a deep breath in, __________ in walls of alveoli fire impulses to M.O. which tells respiratory system to ________-
stretch receptors; stop inhalation
Lungs are subject to
air pressure
Structures such as the _______ and the _________ can increase/decrease volume
diaphragm; rib muscles
diaphragm
a large dome-shaped sheet of muscle that forms the bottom wall of the chest cavity
tidal volume (TV)
the volume of air inhaled/exhaled in a single, regular breath
inspiratory reserve volume (IRV)
the volume of air that can be forcibly inhaled after a normal tidal inhalation
expiratory reserve volume (ERV)
the volume of air that can be forcibly exhaled after a normal tidal inhalation
residual volume (RV)
the volume of air that remains in the lungs after forcible exhalation
inhalation
Diaphragm and rib muscles contract
Expansion of chest cavity, increasing volume of lungs
Increased volume = decreased pressure within the alveoli
Air moves from higher pressure to lower pressure, air rushes in through nose/mouth and fills alveoli
exhalation
Diaphragm and rib muscles relax, lung volume decreases
Decreased volume = increased air pressure in the alveoli
Air rushes from lungs out through your nose or mouth as you exhale
In gas exchange, the inner surface of each alveolus is lined with a layer of ______, and ____ dissolves across this moist layer
moist epithelial cells; oxygen
in gas exchange, O2 then diffuses into a web of ______ surrounding each alveolus and enters the red blood cells, binding to __________
capillaries; hemoglobin
hemoglobin
a quaternary structure protein that aids in O2 binding in RBCs
(The quaternary structure of a protein is the association of several protein chains or subunits into a closely packed arrangement)
Hemoglobin creates a
diffusion gradient
how does hemoglobin create a diffusion gradient?
When O2 binds to Hb it removes O2 from plasma
O2 then keeps diffusing from the alveolus into the plasma because the O2 is at a lower concentration in the plasma than the alveolus
By binding O2, Hb increases the blood’s ability to transport O2 by 60 times!
Cells access O2 they need from
nearby blood vessels
cellular respiration
Cellular respiration is the process of cell energy production
what is a by product of cellular respiration?
CO2
true or false: CO2 diffuses the opposite way of O2
true
how does CO2 diffuse?
CO2 diffuses the opposite way of O2
From capillaries, across epithelial cells, into alveoli
CO2 is deposited into lungs
CO2 then expelled back up trachea, and through nose or mouth
true or false: Insects do not need a circulatory system to exchange gases.
true
why don’t insects need a circulatory system to exchange gases?
Smaller insects can receive enough O2 and get rid of enough CO2 through diffusion across their membranes.
Larger insects sometimes pump in more air through rhythmic body movements that compress and expand the air.
Insects consume much more oxygen when they fly than when they are at rest.
Their flight muscles help to rapidly pump air through their tracheal systems
an insects ____________ help to rapidly pump air through their tracheal systems
flight muscles
Aquatic reptiles and aquatic mammals such as whales breathe with ________ and must _______________ under water
lungs; hold their breath
_______________ maintain the tubular shape of the trachea.
C-shaped rings of cartilage
The trachea forks into ________ which are
_________ that connect the trachea to the lungs
two bronchi; air tubes
The bronchi and bronchioles are surrounded by _______________. As the muscles contract or relax, they control ____________________.
smooth muscles; the size of the airways
Why do your cells need oxygen?
to obtain energy from molecules of carbohydrates, fats, and proteins during the process of cellular respiration
What is cellular respiration?
a process that produces the energy needed to fuel all cell activities.
-this process occurs in the mitochondria in cells
Approximately what percentage of air is oxygen?
Typically, about 21 percent of a sample of
air is oxygen
What are the three phases of transferring gases
between the environment and the cells?
breathing, transport of gases, and exchange of gases in cells
Define “respiratory surface.”
In multicellular organisms, gas exchange usually occurs along a special membrane called the respiratory surface
What process governs the function of the
respiratory surface?
Although animals live in a wide
variety of environments, the process of diffusion governs the function of
their respiratory surfaces
Describe three characteristics of the structure
of a respiratory surface that ensure efficient
diffusion
*A respiratory surface is a very thin and moist membrane that is permeable to the gases being diffused.
- The surface area of the membrane is large so as to maximize diffusion.
- A diffusion gradient must be maintained since diffusion moves gases from higher concentration to lower concentration
-in other words, there needs to be a difference
in the relative concentration of oxygen and
carbon dioxide on either side of the membrane
surface
-in most organisms, the circulatory system
serves to transport gases to and from the
membrane so that appropriate gas
concentrations can be maintained
Why do earthworms need to live in damp
places?
Earthworms and other animals that
breathe through their skin live in damp places or in water to keep their entire body surface moist.
What are gills?
folds in the body surface that are specialized
for gas exchange
How does the design of gills enable their
function?
The design of the fish gill enables water to
flow so that gases can diffuse from the water and across the respiratory membranes
In terms of exchange of gases, what two
advantages do terrestrial animals have over
aquatic animals?
*There is a higher concentration of oxygen in air than in water.
*Air is both lighter and easier to move than water.
-this means that terrestrial animals need to
spend less energy than aquatic animals in
exchanging gases across their respiratory
surface
In terms of the respiratory surface, what is
one advantage that aquatic animals have
over terrestrial animals?
they have moisture in their environment
(but most terrestrial animals have evolved internal respiratory surfaces, such as tracheal systems and lungs, to help minimize the loss of moisture)
Where does gas exchange occur in most insects?
Gas exchange occurs along the
moist membrane at the tips of the tracheoles.
How do larger insects and flying insects receive
enough O2 to support their functions?
Larger insects sometimes pump in more air through rhythmic body movements that compress and expand the air.
Insects consume much more oxygen when they fly than when they are at rest.
Their flight muscles help to rapidly pump air through their tracheal systems
Where does gas exchange occur in reptiles,
birds, mammals, and some amphibians?
For reptiles, birds, mammals, and some
amphibians, gas exchange occurs in lungs, which are internal, thin-walled sacs with a large surface area
What are six main structures of the human
respiratory system?
mouth, nose, pharynx, larynx, trachea, and lungs
What is another name for the following?
(a) windpipe
(b) voice box
a) trachea
b) larynx
What is the difference between the bronchi and
the bronchioles?
The trachea forks into two bronchi (singular, bronchus), which are air tubes that connect the trachea to the lungs
Within each lung, the bronchus branches repeatedly into finer and finer tubes called bronchioles
Why does air rush in through the nose or
mouth to fill the alveoli during inhalation?
Since air tends to move from an area of higher pressure to an area of lower pressure, air rushes in through your nose or mouth and fills the alveoli.
What is the role of hemoglobin in the blood?
Hemoglobin increases the efficiency of gas exchange by creating a diffusion gradient
(when the hemoglobin in a red blood cell binds to the oxygen, it removes the oxygen from the plasma)
(a) What is the medulla oblongata?
a part of the brain located near the top of the spinal cord
(b) What is the role of the medulla oblongata in the breathing process?
The medulla oblongata sends nerve signals to
the diaphragm and rib muscles, causing them to contract and relax
Describe the role of carbon dioxide in
controlling breathing.
The level of carbon dioxide (CO2) in our body is what controls your breathing.
When carbon dioxide reaches a certain level, a signal is sent from the breathing centre in your brain stem to the breathing muscles, which triggers an inhalation.
Upon exhalation, we exhale carbon dioxide and a new breathing cycle starts.
How is the respiratory system of a fish similar
to that of a mammal? (structure + function)
function:
With humans, the lungs extract oxygen from the air we breathe and transfer it into the bloodstream, at the same time releasing carbon dioxide from the system.
With most fish, the gills do the same thing. Fish take water into their mouth, passing the gills just behind its head on each side.
structure:
Gills are similar to lungs in that they have branches that split. Gill arches branch to form gill filaments.
How do cilia and mucus help your respiratory
system to function efficiently?
Cilia are short, hair-like structures protruding from a cell that move fluid and particles over the cell’s surface.
The mucus traps foreign particles and
removes them from the air.
The cilia then sweep the mucus-trapped particles
up toward the pharynx where they can be expelled or swallowed
Explain how the movements of the diaphragm
and rib muscles can increase the volume of the
chest cavity during inhalation.
When your diaphragm and rib muscles contract, you inhale.
Your inhalation expands your chest cavity, which increases the volume of your lungs, resulting in reduced air pressure within the alveoli.
Since air tends to move from an area of higher pressure to an area of lower pressure, air rushes in through your nose or mouth and fills the alveoli
