Exercise Physiology Flashcards
List the principal structures of the ventilator system
Nose, mouth, pharynx, larynx, trachea, bronchi, bronchioles, lungs, alveoli
Outline the functions of the conducting pathways
Low resistance pathway for airflow
Defense against chemicals and other harmful substances that are inhaled
Warming and moistening the air
Ventilatory Measurments
Static Measures of Lung Volume
Pulmonary ventilation: volume of air moved into or out of the total respiratory tract each minute
Tidal volume (TV): Volume of air breathed in and out in any one breath (0.4 to 1.0 L of air per breath)
Inspiratory reserve volume (IRV): additional inspired air over and above tidal volume. Inspiring as deeply as possible following a normal inspiration (2.5 to 3.5 L above inspired tidal air)
Expiratory reserve volume (ERV): volume of air in excess of tidal volume that can be exhaled forcefully (close to 1.5L)
(Forced) Vital capacity (VC): Maximum volume of air that can be exhaled after a maximum inhalation (4 to 5 L in young men) and (3 to 4 L) in young women
Residual volume (RV): volume of air still contained in the lungs after a maximal exhalation
Averages 0.8 to 1.2 L for healthy college-aged women, and 0.9 to 1.4 L for college- aged men
Total lung capacity (TLC):
volume of air in the lungs after a maximum inhalation. The sum of the Vital capacity and residual volume (close to
Forced Vital Capacity
Functional 6L) Residual
FACTORS THAT AFFECT LUNG VOLUMES
Age
- Sex
- Height * Weight * Race
- Disease
Explain the mechanics of ventilation in the human lung
Air flows because of pressure differences between the atmosphere and gases inside the lungs.
• During inhalation the intercostal muscles (between the ribs) and diaphragm contract to expand the chest cavity. The diaphragm flattens and moves downwards and the intercostal muscles move the rib cage upwards and out. - This increases the space for the lungs.
• This increase in size decreases the internal air pressure and so air from the outside (at a now higher pressure than inside the thorax) rushes into the lungs to equalize the pressures.
When we exhale the diaphragm and intercostal muscles relax and return to their resting positions. This reduces the size of the thoracic cavity, thereby increasing the pressure and forcing air out of the lungs.
Describe the nervous and chemical control of ventilation during exercise
For example, lung inflation stimulates stretch receptors mainly in the bronchioles. These receptors act through afferent fibers to inhibit inspiration and stimulate expiration.
This is called “Hering–Bauer Reflex”
Increase in movement stimulates hyperpnoea (increased depth and rate of breathing)
As arterial pH declines (increase in CO2) and hydrogen ions accumulate, ventilation activity increases to eliminate carbon dioxide and reduce arterial levels of carbonic acid. Acidity of the blood is detected by chemoreceptors which send nerve impulses to the respiratory muscles which increase the rate of ventilation (faster/deeper);
Outline the role of hemoglobin in oxygen transportation
Hemoglobin is composed of a protein (globin) and a pigment (heme). Heme contains iron, which binds oxygen.
Each red blood cell contains approximately 250 million hemoglobin molecules, each able to bind four oxygen molecules—so each red blood cell can bind up to
a billion molecules of oxygen!
Hemoglobin is the protein that allows oxygen to bind to a red blood cell. When oxygen is attached, it changes to oxyhemoglobin. These oxygen atoms are then diffused into the tissues (like the working muscles) once they reach their target. While they are diffusing they are also picking back up CO2 & returning it back to lungs so you can exhale it into the atmosphere.
Explain the process of gaseous exchange at the alveoli
Gas exchange is carried out by a complex of structures at the end of each bronchioles in a process called “pulmonary diffusion”.
• The oxygen exchange in the lungs takes place across the membranes of small balloon-like structures called alveoli attached to the branches of the bronchial passages. It occurs at the respiratory membrane
• These alveoli inflate and deflate with inhalation and exhalation. The elastic recoil of these helps in the exhalation.
• Gases move by diffusion from where they have a high concentration to where they have a low concentration:
- The alveoli create a pressure gradient.
- Once the alveoli fill up with air during inhalation the oxygen diffuses from the air in the alveoli and into the capillaries (blood) – where the partial pressure of O2 is lower; The carbon dioxide diffuses from the arriving venous blood and into the air in the alveoli (where the PP of CO2 is lower) which exits the body during exhalation.
Analyse systolic and diastolic blood pressure data at rest and during exercise.
This is the ideal balance to permit efficient emptying and filling of the heart, but with enough pressure in the system to maintain blood flow to the tissues of the body. The pressure (and extent of the fluctuations) lessens as the blood goes from the arteries to arterioles and then capillaries. The pressure in the venules and veins is comparatively low and consistent, but it is the arterial pressure that is most important and this is what is routinely measured by physicians.
Discuss how systolic and diastolic blood pressures respond to dynamic and static exercise
Vasodilation in the active muscles reduces total peripheral resistance to enhance blood flow through large portions of the peripheral vasculature.
https://en.wikipedia.org/wiki/Skeletal-muscle_pump
Muscle Pump - Alternate muscle contraction and relaxation also provide an effective force to propel blood through the vascular circuit and return it to the heart.
Increased blood flow during rhythmic, steady-rate exercise rapidly increases systolic pressure during the first few minutes of exercise. Blood pressure then levels off at 140 to 160 mm Hg for healthy men and women.
After an initial rapid rise from the resting level, systolic blood pressure increases linearly with exercise intensity, while diastolic pressure remains stable or decreases slightly at the higher exercise levels.
Healthy, sedentary and endurance- trained subjects demonstrate similar blood pressure responses.
Continuous, graded treadmill exercise up to maximum
During maximum exercise by healthy, fit men and women, systolic blood pressure may increase to 200 mm Hg or higher, despite reduced total peripheral resistance.
Compare the distribution of blood at rest and the
redistribution of blood during exercise
At Rest 5L
During Exercise
Blood is redirected to the areas where it is needed most. This increase in cardiac output, allows up to 5 times more blood flow to active muscles (from 5L to 25L)
Active muscles can demand as high as 90% of the total blood flow during exercise compared to only 20% at
At rest, under normal conditions, the most metabolically active tissues receive the greatest blood supply.
The liver and the kidneys combine to receive almost half the blood being circulated, and resting skeletal muscles receive only about 15% to
20%.
John Sproule. IB Sports, Exercise and Health Science (Oxford Ib Diploma Programme Course Companion) (Page 42). OUP Oxford. Kindle Edition.
rest.
Describe the cardiovascular adaptations resulting from
endurance exercise training.
Arteriovenous Oxygen Difference
- The myocardium (muscular tissue of the heart) increases in thickness - The left ventricles internal dimensions increase
- Heart Rate will return to normal quicker than an untrained person
Explain maximal oxygen consumption
“A maximum quantifies the maximum rate that an individual can take in, transport and use oxygen”
Discuss the variability of maximal oxygen consumption in
selected groups
As more muscle mass is being used during running (compared to cycling the upper body and
postural muscles are being used more as this is a weight-bearing activity) it would be expected
that a higher VO2max would be recorded compared to cycling.
