Chapter 8 Flashcards
Respiration is the process of supplying the body
with O2 and removing CO2.
* It has three basic steps:
1. Pulmonary ventilation or breathing
2. X (pulmonary) respiration
3. Internal (tissue) respiration
External
Pulmonary ventilation or breathing: is the
inhalation (inflow) and exhalation (outflow) of air
and involves the exchange of air between the
atmosphere and the X. Inhalation
permits O2 to enter the lungs and exhalation
permits CO2 to leave the lungs.
alveoli of the lungs
- External (pulmonary) respiration: is the exchange of gases between X and the
X across the
respiratory membrane. In this process, X gains O2 and loses CO2.
the alveoli of the lungs and the blood in pulmonary capillaries
pulmonary capillary blood
- Internal (tissue) respiration: is the exchange of
gases between X and
X. In this step the blood loses O2 and
gains CO2. Within cells, the metabolic reactions
that consume O2 and give off CO2 during the
production of ATP are termed cellular respiration.
blood in systemic capillaries and tissue cells
The respiratory system consists of the nose, …. (throat), ….. (voice
box), trachea (windpipe), bronchi, and lungs.
pharynx
larynx
Structurally, the respiratory system consists of two parts:
upper and lower
The upper respiratory system includes the nose, nasal cavity, pharynx, and
associated structures;
(2) The lower respiratory system includes the larynx, trachea, bronchi, and lungs.
Functionally, the respiratory system also consists of two parts (or ‘zones’):
(1) The X zone: interconnecting cavities and tubes (outside and within the
lungs) that filter, warm, and moisten air and conduct it into the lungs. These include
the nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and terminal
bronchioles.
(2) The X zone: tubes and tissues within the lungs where gas exchange occurs.
These include the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.
conducting
respiratory
Functions of the respiratory system:
- Provides for gas exchange: intake of O2 for delivery to body cells and removal of CO2
produced by body cells. - Helps regulate X (Chapter 6).
- Contains receptors for sense of smell, filters inspired air, produces vocal sounds
(phonation), and excretes small amounts of water and heat.
blood pH
In pulmonary ventilation, air flows between the atmosphere and the alveoli of the
lungs because of X differences created by contraction and
relaxation of respiratory muscles.
alternating pressure
The air flows from HIGHER to LOWER pressure.
The rate of airflow and the
amount of effort needed
for breathing are also
influenced by:
- alveolar surface tension
- compliance of the lungs
- X
airway resistance
Boyle’s law: the pressure of a gas in a closed container is inversely proportional to
the X of the container
volume
For air to flow into the lungs, the pressure inside the alveoli must become higher/lower than the atmospheric pressure.
lower
And, according to Boyle’s law, for the pressure of the gas (air inside the lungs)
to decrease, the volume of the container (lungs) must increase. how?
- Contraction of
- Contraction of
diaphragm and external intercostals (=muscles)
Because both, normal quiet inhalation
and inhalation during exercise or
forced breathing, involve muscular
contraction, the process of inhalation
is said to be active.
true/false
true
Normal exhalation during quiet breathing, unlike inhalation, is a passive process
because no muscular contractions are involved.
true/false
true
- lung volumes: can be measured directly by use of a spirometer
- lungs capacities:X
are combinations of different lung volumes
The apparatus used to measure volumes
and capacities is called a spirometer or
respirometer.
* The record is called a spiroX
gram.
Tidal volume (VT): the volume of X
one breath
Respiratory dead space (DS): portion of the tidal volume that X
remains in the conducting
airways does not take part in gas exchange
- Effective tidal volume (ETV): volume of air actually X
reaching the alveoli in each
inspiration:
Respiratory Rate (RR): x
Number of breaths per minute
Minute Ventilation (MV): x
the total volume of air inhaled and exhaled each minute
The alveolar ventilation (AV): the volume of air per minute that actually reaches x
the
respiratory zone
Inspiratory Reserve Volume (IRV): Maximum volume of air taken in a forceful
inhalation (except the tidal volume).
- Expiratory Reserve Volume (ERV): Maximum volume of air that exits the lungs in
a forceful exhalation (except the tidal volume). - Forced Expiratory Volume in 1 second (FEV1): the volume of air that can be
exhaled from the lungs in 1 second with maximal effort following x
a maximal
inhalation.
SEE P 28
What volume cannot be measured by spirometry?
Residual Volume: Volume of air remaining in the lungs at the end of a maximum
exhalation unable to be released from the lungs
Inspiratory capacity (IC) is the sum of tidal volume and inspiratory reserve volume.
* Functional residual capacity (FRC) is the sum of residual volume and expiratory reserve
volume.
* Vital capacity (VC) is the sum of inspiratory reserve volume, tidal volume, and expiratory
reserve volume.
* Total lung capacity (TLC) is the sum of vital capacity and residual volume.
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If the thoracic cavity is opened, the intrapleural pressure rises to equal the
atmospheric pressure and forces out some of the residual volume. The air
remaining is called the minimal volume. Should the volume of the lungs fall
below this value, the lungs will X
collapse
(minimal volume can not be measured by spirometry).
Each lung is enclosed and protected
by a double-layered serous
membrane called the pleural
membrane.
- Parietal pleura vs visceral pleura:
which is it?
- superficial
layer, lines the wall of the
thoracic cavity/deep layer
covers the lungs - Visceral pleura: deep layer,
covers the lungs.
parietal = superficial
visceral = deep
The air passes through the airway branching: starting from the trachea, put in right order:
segmental bronchi
right and left main bronchi
bronchioles
lobar bronchi
terminal bronchioles.
right and left main bronchi
lobar bronchi
segmental bronchi
bronchioles
terminal bronchioles.
The portion of lung tissue that each segmental bronchus supplies is called a
bronchopulmonary segment. they each have lobules, which contain a lymphatic vessel, an X, a venule,
and a branch from a terminal
bronchiole.
arteriole
Terminal bronchioles and lobule
subdivide into microscopic branches
called X. They also
have alveolibudding from their walls
- X in turn
subdivide into several alveolar ducts. - The terminal dilation of an alveolar duct
is called an alveolar sac. - Each alveolar sac is composed of
outpouchings called alveoli.
respiratory bronchioles
- The wall of each alveolus consists of:
- Epithelial cells type I: sites of X
- Epithelial cells type II: secrete
alveolar fluid: keeps the surface
moist and contains surfactant
(lowers the surface tension of
alveolar fluid, which reduces the
tendency of alveoli to collapse). - Macrophages (dust cells):
phagocytes that remove fine dust
particles and other debris.
gas
exchange.
Exchange of gases takes place in the respiratory membrane: a very thin membrane (<0,5
μm) which consists of four layers (from the alveolar air space to blood plasma):
- Epithelial basement membrane
underlying the alveolar wall. - Alveolar wall: type I and type II
alveolar cells and associated alveolar
macrophages. - Capillary endothelium.
- Capillary basement membrane: often
fused to the epithelial basement
membrane.
put in right order
- Alveolar wall: type I and type II
alveolar cells and associated alveolar
macrophages. - Epithelial basement membrane
underlying the alveolar wall. - Capillary basement membrane: often
fused to the epithelial basement
membrane. - Capillary endothelium.
The exchange of O2 and CO2 takes place by
active diffusion across the respiratory
membrane.
true/false
false: passive
Passive diffusion is governed by the
behavior of gases as described by two
gas laws:
1. Dalton’s law: important for
understanding how gases move
down their pressure gradients by
diffusion
2. Henry’s law: helps explain how
the solubility of gas relates to diffusion
ok
External respiration or pulmonary
gas exchange is the diffusion of O2
from air in the alveoli of the lungs to
blood in pulmonary capillaries and
the diffusion of CO2 in the opposite
direction.
- It converts deoxygenated blood
coming from the right side of the heart into
oxygenated blood that returns to the left side of
the heart. - Although this process is commonly
called an “exchange” of gases, each
gas diffuses independently from the
area where its partial pressure is
higher to the area where its partial
pressure is lower.
ok
Internal respiration or systemic
gas exchange is the exchange of
O2 and CO2 between X and X.
* As O2 leaves the bloodstream,
oxygenated blood is converted
into deoxygenated blood.
* Unlike external respiration, which
occurs only in the lungs, internal
respiration occurs in tissues
throughout the body
systemic
capillaries and tissue cells
The size of the thorax is altered by
the action of the breathing muscles,
which contract as a result of nerve
impulses transmitted from centers in
the brain and relax in the absence of
nerve impulses.
the region taking care of this is called the X center
respiratory
Activity of the respiratory center can be modified in response to:
- Inputs from other brain regions:
cerebral cortex - X
- Other factors
receptors
Chemoreceptors in two locations of the respiratory
system monitor levels of CO2, H+, and O2 and provide
input to the respiratory center:
- X chemoreceptors:
- Peripheral chemoreceptors:
Central
In/decreased PCO2, in/decreased pH (in/decreased H+), or in/decreased PO2, input from the central and
peripheral chemoreceptors causes the respiratory center to become highly active.
Increased PCO2, decreased pH (increased H+), or decreased PO2
As soon as you start exercising, your rate and depth of breathing increase, even before changes
in PO2, PCO2, or H+ level occur.
- The main stimulus for
these quick changes in
respiratory effort is input
from Xceptors,
which monitor movement
of joints and muscles. - Nerve impulses from the
proprioceptors stimulate
the respiratory center of
the medulla. - Upper motor neurons that
originate in the primary
motor cortex also feed
excitatory impulses into
the respiratory center.
proprio
Stretch-sensitive receptors (baroreceptors) are located in the walls of bronchi and bronchioles.
- When stretched during overinflation of the lungs, nerve impulses are sent along the vagus (X)
nerves to the respiratory center. resp center is inhibited -> inflation reflex
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