Cardio-respiratory exercise physiology (topic 2) Flashcards
What is homeostasis?
the maintenance of a constant internal enviroment
What is gas exchange?
the transfer of oxygen and carbon dioxide between the systems
How is movement in and out of the lungs achieved?
the repeated contraction and relaxation of muscles in the base of the chest cavity (diaphragm) and chest wall, alternatly increase and decrease the volume of, and therefore the pressure in the lungs
For inhalation to occur…
the diaphragm contracts lowering the pressure to lower than the atmosphere.
For exhalation to occur…
diaphragm relaxes, increasing the pressure to higher than the atmosphere.
Air will flow from…
high to low pressure
What does the body do when more O2 is needed and more CO2 is being produced during exercise?
More air needs to be inhaled and exhaled at a faster rate so more muscles are used to expand and contract the chest cavity. (external intercostal muscles, abdomen, and even the shoulders)
How does air enter the ventilatory system?
- passage through the conducting airways (nasal/oral, trachea to bronchi) which warm, filter and moisten the air
- airways branch into smaller bronchioles and then into alveoli where the gas exchange takes place.
Gasses move by a passive process called…
diffusion (high to low pressure)
tidal volume
“size” of each breath
breathing frequency
number of breath per min
what is the primary function of blood during exercise?
transport gases, nutrients, waste products, hormone to and from tissues
composition of blood
erythrocytes, leucocytes, platelets, plasma
function of erythrocytes
(red blood cells) contain a protein called hemoglobin, which carries oxygen from the lungs to all parts of the body.
function of leucocytes
(white blood cells) protect you against illness and disease
function of platelets
to prevent and stop bleeding by clotting
function of plasma
take nutrients, hormones, and proteins to the parts of the body that need it
blood transports…
nutrients, hormones, proteins, gases, waste products, electrolytes
carbon dioxide is transported in the form of…
bicarbonate
types of blood vessels
arteries, capillaries, and viens
What are arteries?
relatively large in diameter, pump oxygen rich blood, responsible for transport away from the heart to tissues (Arteries take blood Away)
What are capillaries?
smallest vessels, connect arteries and veins, exchange of materials between the blood and tissue cells
What are veins?
deliver de-oxygenated blood back to the heart, flexible and have valves to prevent back flow
What is pulmonary circulation?
delivers de-ox blood from the right to the left side of the heart to the lungs for oxygenation then back to the left side of the heart
What is systemic circulation?
delivers oxygenated blood from the left side of the heart to the other tissues then delivers the de-ox blood back to the right side of the heart
What controls the contraction of the heart?
sinoatrial node (SA node) and atrioventricular node (AV node)
What does the SA node do?
generates electrical impulses, thereby setting the normal rhythm
What does the AV node do?
synchronisation of atrial and ventricular contractions by a varying delay
What is blood pressure?
the pressure of circulating blood against the walls of blood vessels
How is blood pressure (BP) measured?
Systolic (contracting)/diastolic (relaxing) pressures
healthly BP for adults
120/80 mmHg
During exercise how is more blood distributed towards the muscles?
by dilation of the arterioles supplying the muscles and opening more of the capillary network within the muscles
What is cardiac output?
the quantity of blood pumped by the left side of the heart in a given period measured in liters per minute.
cardiac output equation
= (heart rate * stroke volume) / 100
How does the heart adjust to exercise and need for a higher cardiac output?
the heart beats faster (increase HR) and the heart fills and empties more during each contraction (stroke volume)
What happens when max cardiac output is reached?
exhaustion and exercise cannot continue
what is cardiovascular drift?
when cardiac output stays constant for an extended period of time while exercising, the HR starts to increase slightly which suggests a decline in stroke volume
what is VO2 max?
(aerobic capacity) maximal oxygen uptake
What happens if the oxygen demand exceeds the VO2 max?
the person can no longer continue
Fick equation
shows the relationship for VO2 max
VO2 max = max cardiac output * max aterio-venous oxygen difference
What is the difference between absolute and relative VO2 max?
absolute - L/min
relative - ml/kg.min (normalized according yo body mass)
What effects VO2 max?
Gender - VO2 max is lower in females because of body comp and size
Age - increases up until age 20 (males)/ mid-teens (females)
What limits VO2 max?
the ability of the cardiorespiratory system to deliver oxygen to the exercising muscles
How does training increase VO2 max?
Aerobic training can increase VO2 max. Increasing stroke volume and adaptations to the cardiovascular and muscular systems also contribute
what is inspiratory reserve volume
The extra volume of air that can be inspired with maximal effort after reaching the end of a normal, quiet inspiration.
what is expiratory reserve volume?
The extra volume of air that can be expired with maximum effort beyond the level reached at the end of a normal, quiet expiration
What is residual volume?
the volume of air remaining in the lungs after maximum forceful expiration. without this your lungs would collapse
what is vital capacity?
the greatest volume of air that can be expelled from the lungs after taking the deepest possible breath
what is total lung capacity?
the amount of air that the lungs could possible contain
what is tidal volume?
the amount of air that moves in or out of the lungs with each respiratory cycle
