is the difference in the oxygen content of the blood between the arterial blood and the venous blood | Arteriovenous oxygen difference or a-vO2 diff |
-Men 5.7L -Women 4.2L | Average Lung Volumes |
are the airways that lead from the trachea into the lungs, and then branch into smaller bronchioles. Made of cartilage and smooth muscle rings. Flexible and do not collapse. | Bronchi (bronchus) |
are tubes in the lungs which branch off from the larger bronchi that enter each lung and branch into alveoli. | Bronchioles |
exchange of O2 and CO2 between the capillaries and metabolically active tissues. | Capillary Diffusion |
intracellular metabolic reactions that use O2 and CO2 during ATP production. | Cellular Respiration |
Hb not combined with oxygen. | Deoxyhaemoglobin or reduced haemoglobin |
measure of fitness and lung volume.
-measures how well the system works
-depends on volume and speed
-air flow is reduced for people with asthma etc. | Dynamic Lung Volumes (4 points) |
take during abnormal breathing. A sharp inhale and slow exhale. E.g. FEV, FEV1 and FVC. | Dynamic Measurements |
-diffusion must be very short
-barriers e.g. cell membranes must be very thin
-gas exchange surfaces must be moist | Efficient Gas Exchange (3 points) |
-air moving out of the lungs.
-purely passive process
-chest wall and lungs undergo elastic recoil
-pressure inside lungs increases > atmospheric pressure = air leaves lungs | Expiration (4 points) |
the transfer of O2 and CO2 between the external environment and tissue cells. | External Respiration |
FEV after 1 second. Used as a diagnostic tool | FEV1 |
diagnostic tool for respiratory illnesses. Around 0.85 is healthy. <0.70 unhealthy. Ratio is age dependent. | FEV1/FEV ratio (x 100 for %) |
speed of air coming out of the lung during the middle portion of a forced expiration | Forced Expiratory Flow (FEF) |
volume of air expired after maximum inspiration | Forced Expiratory Volume (FEV) |
maximum volume forcible expired after max inspiration (in L) | Forced Vital Capacity |
protein responsible for transporting oxygen in the blood. When combined with oxygen it is called oxyhaemoglobin. | Haemoglobin (Hb of Hgb) |
-moves air into the lungs. The ribs move out and the diaphragm contracts.
-Thorax volume increases.
-lungs expand and the pressure drops inside
-pressure in atmosphere > pressure in lungs so air comes rushing in. | Inspiration (4 points) |
involved in breathing, producing sound and protecting the trachea against food aspiration | Larynx or voice box |
e.g. asthma, chronic bronchitis, cystic fibrosis and emphysema. | Lower Airway Obstruction |
measure how much capacity the lungs have but not how fast- so not a measure of fitness | Lung Volumes |
or Maximal Breathing Capacity (MBC) is the maximum minute volume of ventilation that the subject can maintain for 12 to 15 s. | Maximum Exercise Ventilation (VEmax) |
measure of the maximum amount of air that can be inhaled and exhaled within one minute. | Maximum Voluntary Ventilation (MVV) |
Total volume of air entering the lungs in a minute (in L/min). Calculated by frequency (e.g. 12 bpm) x Tidal volume (e.g. 0.5L) = MV e.g. 6L/min | Minute Ventilation |
unit of pressure measurement | MmHg |
Hb combined with O2 | Oxyhaemoglobin |
maximum expiratory flow during a forced expiration from the point of maximum inspiration (TLC) expressed in L.min-1 or L.s-1 . Used to give a measure of airway calibre (diameter) and airflow. Less specific than FEV1 due to dependency on patient effort and cooperation. | Peak Expiratory Flow (PEF) |
each of a pair of serous membranes lining the thorax and enveloping the lungs. Can only be separated by considerable force. Protects the lungs from ribs and lubricates the outside of the lungs which causes suction during respiration. | Pleura |
pressure of O2 | PO2 |
(or Gaseous Exchange) is the process of removing CO2 from blood and replenishing oxygen supply. It occurs between alveoli and the blood of lungs. Pulmonary gas exchange occurs by diffusion and depends on pressure gradient. Gas moves from high concentration to low concentration | Pulmonary Diffusion |
in the medulla (brain). Chemoreceptors responded to changes in blood pH (caused by acidification by CO2). Triggers increased or decreased breathing to remove Carbon Dioxide and bring in oxygen. | Respiratory Centre |
-in quiet breathing, the lungs are moderately inflated throughout the cycle
-changes in lung volume that occur under different respiratory effects can be measure by a spirometer | Respiratory Cycle |
is the proportion of CO2 produced to O2 volume consumed. Determined by the proportion of carbohydrates and fats oxidised (used as fuels). Energy produced differs for each food. Can be used to calculate BMR and determine fuel use. | Respiratory Exchange Ratio (RER) |
the proportion of CO2 volume generated to the O2 volume consumption at cellular levels | Respiratory Quotient RQ |
allows static lung volumes to be measured | Spirometry |
any taken during normal breathing, displayed as a normal wave function. E.g. ERV, TV, RV, IRV and VC | Static Measurements |
the chest | Thorax |
links larynx to the lungs | Trachea |
e.g. Epiglottitis, foreign body obstruction or upper airway tumour | Upper airway obstruction |
Tidal Volume. Volume in and out at rest. 0.5L | TV |
Expiratory Reserve Volume. Deep breath out. 1L | ERV |
Inspiratory Reserve Volume. Deep breath in. 2.5L | IRV |
Residual Volume. Amount of air left in the lungs after maximal expiration. 1.2L | RV |
Inspiratory Capacity. volume of air that can be inspired following a normal, quiet expiration and is equal to tidal volume + inspiratory reserve volume. 3L | IC |
Vital Capacity. Volume of deep breath in and out. 4.8L | VC |
Total Lung Capacity. An estimated volume. 6L | TLC |
Functional Residual Volume. volume of air present in the lungs at the end of passive expiration. 2.4L | FRC |
IC (inspiratory capacity) | the total amount of air that can be drawn into the lungs after normal expiration |
FRC (functional residual capacity) | the volume of air present in the lungs at the end of passive expiration |
FEV1 (forced expiratory volume at 1 second) | the gas exhaled in the first second of forced expiration following full inspiration |
SVC (slow vital capcity) | this measures the amount of air you can slowly exhale after inhaling as deeply as possible |
IRV (inspiratory reserve volume) | the maximal amount of air that can be drawn into the lungs forcefully after normal inhalation |
VC (vital capacity) | the volume of air that can be expelled from the lungs from a position of full inspiration , with no limit of duration for inspiration. |
TV (tidal volume) | the air moved in and out of the lungs during quiet breathing |
TLC (total lung capacity) | the maximum amount of air that can fill the lungs |
RV (residual volume) | the amount of air remaining in the lungs after maximal expiration |
ERV (expiratory reserve volume) | the maximal amount of gas that can be exhaled from the resting end expiratory level |
Tidal volume | 0.5L |
ERV | 1L |
IRV | 2.5L |
RV | 1.2L |
IC | 3L |
VC | 4.8L |
TLC | 6L |
FRC | 2.4L |