Week 10 - Respiratory System Flashcards
What is the function of the respiratory system?
Function to take oxygen into the body and expel carbon dioxide
What is the function of the oral and nasal cavities?
- Oral - Allows for the passage of air
* Nose - Warm, moisturizes and filters air (cilia)
What is the function of the pharynx?
Takes in food (digestion) and air (respiration)
What is the function of the larynx?
Contains the voice box and allows for the passage of air into and out of the trachea to produce speech.
What is the function of the trachea?
Transports air into and out of the bronchus, containing hair that prevents particles entering the lungs
What is the function of the primary bronchus?
To transport air into the left and right lungs
What is the function of the diaphragm?
To alter the volume of the pleural cavities to control the pressure and consequently the flow of air into and out of the lungs.
What are some structural changes that occur as the conducting tubes of the lungs get smaller?
- Epithelium type changes
* Surface area increases
What is the main function of the alveoli?
Allows for the exchange of O2 and CO2 with capillaries
What is the respiratory zone and what structures make it up?
The respiratory zone is the area involved in gas exchange and is made up of the bronchioles and alveoli
What is the conducting zone and what structure make it up?
The conducting zone is responsible for moving air into and out of the lungs, however they aren’t directly involved in gas exchange. It consists of the oral and nasal cavaties, pharynx, larynx, trachea and bronchus
What structures make up the upper and lower respiratory tracts?
- Upper - Oral and nasal cavities, pharynx
* Lower - Larynx, trachea, bronchus, bronchioles and alveoli.
Why is the respiratory membrane so large
Large surface area maximizes diffusion so that the body can obtain the necessary gases to meet the demands of the body (O2) as well as to remove the appropriate wastes (CO2).
What is the function of the following cells in the respiratory membrane? In what proportions are they found (SA)?
• Type I Alveolar cells
• Type II Alveolar cells
• Alveolar macrophages
- Type I Alveolar cells (95% SA)- Thin walled to allow for the rapid diffusion of gases
- Type II Alveolar cells (5% SA) - Repair alveoli and secrete pulmonary surfactant to lower surface tension of lungs (prevent lung collapse during expiration)
- Alveolar macrophages - phagocyte foreign particles
Rank the following cells from least to most abundant:
• Type I Alveolar cells
• Type II Alveolar cells
• Alveolar macrophages
- Type I Alveolar cells - Least abundant
- Type II Alveolar cells
- Alveolar macrophages -Most abundant
What is Boyles law?
The pressure of a gas in a closed system in inversely proportional to volume
What is the equation of Boyles Law
P1 V1=P2 V2
Relate Boyles law to respiration
Changing the lung volume changes the pressure of the lungs which consequently regulates the flow of gases into and out of the lungs.
List the 5 events that occur during inspiration
1) Diaphragm contracts downwards
2) Intercostal muscles contract to expand chest outwards
3) Lungs increase in volume
4) Lungs decrease in pressure
5) Gases from the external environment flow into the lungs down the pressure gradient until the pressure in the lungs is equal to atmospheric pressure
List the 5 events that occur during expiration
1) Diaphragm passively relaxes
2) Intercostal muscles relax
3) Volume of lung decreases
4) Lung pressure increaes
5) Gases in the lungs move out into the external environment down the pressure gradient
Define Tidal Volume (TV)
Is the volume of air inhaled and exhaled with each breath under normal resting conditions.
Define inspiratory reserve volume (IRV)
Is the volume of air that can be forcefully inhaled after a normal tidal volume inspiration
Define expiratory reserve volume (ERV)
Is the volume of air that can be forcefully exhaled after a normal tidal volume expiration
Define residual volume (RV)
Is the volume of air that is left in the lungs after a forced expiration.
Define vital capacity (VC) and what volumes make it up
Is the volume of air that can be expelled from the lungs after a maximum inspiration.
• IRV
• TV
• ERV
Define inspiratory capacity (IC) and what volumes make it up
Is the volume of air that can be inspired after a normal tidal volume expiration.
• TV
• IRV
Define fFnctional Residual Capacity (FRC) and what volumes make itup
Is the volume of air left in the lungs after a normal tidal volume expiration.
• ERV
• RV
Define total lung capacity (TLC) and what volumes make it up
Is the amount of air that is contained in the lungs after a maximum
• All volumes
Define forced vital capacity (FVC)
Is the volume of gas that can be forcibly expelled from the lungs after a maximum inspiration.
Define breathing frequency
Is the number of breaths per minute
Define forced expiratory volume 1 (FEV1)
Is the volume of gas that can be forcibly expelled in one second after a maximum inspiration.
Define minute ventilation (MV)
Is the total amount of air flow into or out of the respiratory tract in one minute.
What is the equation of MV?
MV = breaths per minute x tidal volume
Define alveolar ventilation rate (AVR)
Is the flow of gas into and out of the alveoli in one minute
Why is AVR a better indication of respiration efficiency that MV?
Some of the inhaled has remains in the conducting zone and doesn’t reach the respiratory one to participate in gas exchange.
What is the formula for AVR?
AVR = breaths perminute x (tidal volume - dead space (150ml).
What is the difference between obstructive and restrictive pulmonary disease?
- Obstructive diseases block the flow of air into the lungs and thus reduce FEV1, however the capacity remains relatively similar (asthma)
- Restrictive diseases inhibts the ability to fully expand the lungs, however the flow of air (FEV1) remains relatively similar.
List and derive the two ways that oxygen is carried in the blood?
1) Dissolved in plasma (2%)
2) Red blood cells (98% - bound to haemoglobin
What part of haemoglobin does oxygen bind to?
Heme
How many oxygen molecules can one haemoglobin bind?
4
When oxygen is bound to haemoglobin what is the resulting molecule called?
oxyhaemoglobin
When oxygen is not bound to haemoglobin what is the molecule called
deoxyhaemoglobin
What is the benefit of oxygen binding to haemoglobin rather that just being dissolved in the blood plasma?
It allows for more oxygen to be transported around the body as only a limited amount of oxygen can be dissolved in blood plasma
Where does haemoglobin pick up oxygen from?
blood plasma
Where does hameoglobin typically detach oxygen?
capillaries
Describe the factors that encourage oxygen release from haemoglobin
- Partial pressure of oxygen in the surrounding blood plasma
* Metabolic wastes such as CO2, H+ , temperature and BPG
Describe the relationship between oxygen and haemoglobin saturation in the oxygen-haemoglobin dissociation curve
As the partial pressure of oxygen increases, so does the percent saturation of haemoglobin.
In metabolically active cells what happens to the haemoglobin molecule and how does it affects its function?
Metabolic waste products change the shape of the haemoglobin molecule when in turn decreases its affinity to oxygen which consequently causes oxygen to be released into the surrounding blood plasma.
In terms of the dissociation curve, what effect does metabolic waste products have?
The curve shifts to the right which indicates more oxygen release (decreased oxygen saturation).
Where does carbon dioxide come from?
It is a byproduct of cellular respiration
List the three ways that carbon dioxide is transported in the blood and their respective percentages
1) Dissolved in plasma (10%)
2) Bound to globin of the haemoglobin found in red blood cells (20%)
3) Bicarbonate ions (70%) - CO2 is converted into carbonic acid by carbonic anhydrase which dissociates into bicarbonate ions and H+
What molecule is formed when co2 binds to haemoglobin?
carbaminohaemoglobin
Where is carbonic anhydrase found?
red blood cells
How would pneumonia effect the diffusion of gases across the respiratory membrane?
It would thicken the respiratory membrane which in turns makes it more difficult for O2 to diffuse from the alveoli into the capillaries, and CO2 from the capillaries into the alveoli.
How does increasing red blood cells enhance athletic performance.
Increasing red blood cells increases the amount of haemoglobin present in the body and this increases the amount of oxygen that can be carried to muscles to sustain performance.
What volume of air is dead space?
150mL
What is BPG and what effect does i have on oxygen affinity to haemoglobin?
Its a metabolic waste produce that decrease O2 affinity to haemoglobin
