Chapter 23 - The Respiratory System - Part 3 Flashcards
The general term “respiration” includes 2 integrated processes:
external respiration
internal respiration
external respiration includes…
all of the processes involved in the exchange of oxygen and carbon dioxide between the body’s interstitial fluids and the external environment
what is the PRIMARY FUNCTION of the respiratory system? (both internal and external respiration)
to meet the respiratory demands of cells
What is INTERNAL respiration?
the absorption of oxygen and the release of carbon dioxide by those cells (whose respiratory demands we aim to meet_
NAME THE 3 INTEGRATED STEPS IN EXTERNAL RESPIRATION
- Pulmonary ventilation (breathing) which physically moves air into and out of the lungs
- Gas diffusion across the respiratory membrane between alveolar air spaces and alveolar capillaries and across capillary walls between blood and other tissues
- Transport of oxygen and carbon dioxide between alveolar capillaries and capillary beds in other tissues
What will happen if there are abnormalities in any of these 3 steps of external respiration?
it could ultimately affect the concentration of gases in interstitial fluids, and thus cellular activities as well
What will result if oxygen level declines and the tissues are starved for oxygen?
hypoxia
What results if the oxygen supply is cut off completely to the tissues?
ANOXIA - kills cells very quickly
The damage due to local anoxia could lead to…
strokes and heart attacks
Define external respiration and internal respiration
external respiration - all of the processes involved in the exchange of carbon dioxide and oxygen between the body’s interstitial fluids and the external environment
internal respiration - the absorption of oxygen and the release of carbon dioxide by the body’s cells
Name the integrated steps involved in external respiration
- Pulmonary ventilation (breathing)
- diffusion of gases
- Transport of oxygen and carbon dioxide
What is the PRIMARY FUNCTION of pulmonary ventilation (breathing)
to maintain adequate alveolar ventilation (movement of air into and out of the alveoli)
Alveolar ventilation prevents…
the buildup of carbon dioxide in the alveoli
Alveolar ventilation ensures….
a continuous supply of oxygen that keeps pace with absorption by the bloodstream
Name one of the most basic principles that governs the movement of air
the weight of earth’s atmosphere compresses our bodies and everything around us (atmospheric pressure)
Explain how the concept of atmospheric pressure plays a very important physiological role
air moves into and out of the respiratory system as the air pressure in the lungs cycles between below atmospheric pressure and above atmospheric pressure
how does the cardiovascular system assist the respiratory system?
by transporting gases
What is Boyle’s law?
For a gas that is in a closed container and at a constant temperature…..
PRESSURE IS INVERSELY PROPORTIONAL TO VOLUME
if you double the external pressure on a flexible container, what will happen to its volume?
it will drop by half (1/2)
Name the equation for Boyle’s law
P=1/v
The greater the number of collisions between gas particles, the ____ the pressure
greater
Air tends to flow between areas of ___ pressure to ____ pressure
from high pressure to low pressure
____ + _____ provides the basis for pulmonary ventilation
Boyle’s law + the tendency for directed airflow
a single respiratory cycle consists of….
an inhalation (inspiration) and an exhalation (expiration)
inhalation and exhalation involve changes in ______ of the lungs
volume
These volume changes in the lungs create……
pressure gradients that move air into or out of the respiratory tract
the surface of each lung sticks to…..
the inner wall of the chest and to the superior surface of the diaphragm
Movements of the diaphragm or rib cage that change the volume of the thoracic cavity also changes….
the volume of the lungs
the diaphragm forms the ____ of the thoracic cavity
floor
The relaxed diaphragm has the shape of a _______
dome that projects superiorly into the thoracic cavity
When the diaphragm contracts, what happens to it?
it tenses and moves inferiorly
When the diaphragm contracts, explain what happens to the thoracic cavity
the VOLUME INCREASES so the PRESSURE DECREASES
Explain what happens when the thoracic cavity enlarges when we are taking a breath
When the thoracic cavity enlarges, the lungs expand to fill the additional space. This increase in volume LOWERS THE PRESSURE inside the lungs. Then, air enters the respiratory passageways because the pressure inside the lungs is lower than the atmospheric pressure.
Air continues to enter the lungs until their volume stops increasing and the pressure inside is the same as outside
Explain what happens when the thoracic cavity decreases in volume
the pressure inside the thoracic cavity increases, forcing air out of the respiratory tract
what does the “compliance” of lungs mean?
how easily the lungs can expand (expandability)
The greater the compliance, the ______ it is to fill the lungs
easier
name 3 factors affecting compliance of the lungs
-the connective tissue of the lungs
-the level of surfactant production
-the mobility of the thoracic cage
“the connective tissue of the lungs affects compliance”
explain this statement
the loss of supporting tissues due to alveolar damage (as in emphysema), increases compliance
“The level of surfactant production affects compliance”
explain this statement
the alveoli could collapse upon exhalation if not enough surfactant is produced. This REDUCES compliance
“The mobility of the thoracic cage affects compliance”
explain this statement
arthritis or other skeletal disorders that affect the articulations of the ribs or spinal column REDUCES COMPLIANCE
If compliance of a person’s lungs is significantly reduced, what could happen to them?
they may become exhausted by simply continuing to breathe
What is the most common method of reporting blood pressure and gas pressure?
millimeters (mm) of mercury (Hg)
the direction of airflow is determined by the relationship between _____ pressure and _____ pressure
intrapulmonary pressure (or called intraalveolar pressure) and atmospheric pressure
what is meant by intra-alveolar/intrapulmonary pressure?
the pressure inside the respiratory tract (at the alveoli)
When we are relaxed and breathing quietly, what can you say about the relationship between the atmospheric and intrapulmonary pressure?
the difference is relatively small
when we breathe in, does the intrapulmonary pressure increase or decrease?
decreases to 759mmHg (1 mmHg below atmospheric pressure)
what is the value for atmospheric pressure?
760 mmHg
on exhalation, what happens to the intrapulmonary pressure?
it increases to 761mmHg, so air is forced out