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217 Cards in this Set
- Front
- Back
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Inertia
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Tendency of a body to remain motionless or at constant velocity
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Mass
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Quantity of matter contained in an object
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Weight
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Gravitational force exerted on a body
Newtons = kg*m/s2 = kg*9.81 |
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Measure of force.
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Newtons
kg*m*s-1 |
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Force
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push or pull on an object
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Energy and unit
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Capacity to do work
Joules = (mv2)/2 |
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Potential energy
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Stored energy
weight*height = mass*acceleration*height |
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Kinetic energy
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Energy as a result of linear motion
(mv2)/2 |
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Mechanical energy
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Potential + Kinetic
law of conservation of mechanical energy |
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Momentum
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Quantity of motion of an object
mass*velocity |
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Levers
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- First: Fulcrum between the force and the resistance points
- Second: Resistance point is between the fulcrum and the force (door) (force advantage) - Third: Force point is between the fulcrum and the resistance (speed advantage) (most joints in the body) |
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What is mechanical advantage?
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Ratio between the length of the force and resistance arms
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Work
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Force * distance (Nm)
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What does Joule measure?
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Energy or work
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Power
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Work per unit of time
Force * velocity J * m/s = watt |
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Kinematics vs kinetics
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Kinematics: appearance of motion, esp bodies (time, pattern, speed)
Kinetics: study of forces associated with motion (optimal or intended movement) |
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Torque
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Force associated with something's rotation, twisting…
Newton metres |
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Pressure
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Force over a given area
F/area (Newtons per area) |
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Tension
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Pulling or stretching directly through a body
- opposite of compression |
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John and Bill both have a body mass of 75kg, yet John is on average 40% stronger than Bill. Give three reasons why john could be stronger than Bill. Explain
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His limbs are shorter, he has higher proportion of muscle and less bone mass because of his shorter height.
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3 factors affecting an object's stability
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lower centre of gravity, enlarged base of support, more friction
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Lifting a heavy object
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- face object, feet flat
- stable base, avoid twisting - keep close to body - good grip - bend at knees and hips, straight back - engage abs - use knee and hip extensors |
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Trace the route of air from outside the nose to the alveolus
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Nasal cavity - pharynx - larynx - trachea - bronchi - lungs
- primary bronchi (main) - Secondary - tertiary bronchi - terminal bronchioles - respiratory bronchioles - alveolar ducts - alveoli |
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Describe the relationship between airway resistance and the actions of smooth muscle in the bronchioles.
- In what illness is this relevant? |
- Contraction/relaxation of smooth muscle constricts or dilates the bronchioles = reduces or increases airflow, increasing or reducing breathing resistance.
- This is relevant in asthma, where the smooth muscle contracts excessively |
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What features of the alveoli make them ideal for gas exchange?
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- Thin walls with capillaries in them
- the alveolar-capillary membrane is 0.6 micrometers thick |
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How is air conditioned as it enters the respiratory passages?
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- In the nose, it is saturated with water vapour and warmed to body temperature
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Which muscles are involved in inspiration and expiration?
What causes air to flow in and out of the lungs? |
- Diaphram descends and external intercostal muscles contract to increase volume of the lungs in inspiration
- Internal intercostals are involved in expiration, also passive recoil of the elastic lungs - Also ab muscles involved during exercise - Pressure gradients related to the volume of the lungs move air in and out of the lungs |
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What is boyle's law?
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The pressure of a gas is inversely proportional to its volume
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Name and define 6 measures of lung volumes and capacities.
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- Total lung capacity: forced inspiration and expiration + residual volume
- Vital capacity: 3/4 of total capacity = inspiratory reserve + expiratory reserve + tidal volume - Tidal volume: overlap between expiratory and inspiratory capacities - Minute ventilation: Amount of air inspired/expired in one minute 6-8L - Residual volume: 20-25% total capacity, what remains after forced expiration - Functional residual capacity: remaining after passive expiration |
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How do you calculate minute ventilation (2 factors)
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Tidal volume * breaths per minute
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Two criticisms for the norms of pulmonary function tests
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- Don't consider the size of the subject (chest circumference)
- also don't consider the bias of the sample (race, smokers, athletes etc) |
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What is alveolar ventilation and how do you calculate it?
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- Volume of air that reaches the alveoli per minute and undergoes gas exchange
- equal to minute ventilation - dead space ventilation or tidal volume * breaths/min -- dead space - no gas exchange happens in the deadspace of the respiratory tree |
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Why do most lung volumes/capacities decrease when a person lies down?
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- Abdominal contend push up against the diaphragm and the diaphragm can't descend as far
- lying down increases intra-pulmonary blood volume and this decreases space for pulmonary air |
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What is the relationship between minute ventilation and exercise intensity?
Why is it non linear at high intensity exercise? |
- Positive relationship, linear up until about 60% of VO2max in untrained and 75-80% in endurance athletes.
- Then ventilation increases more than O2 consumption does… |
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Distinguish between obstructive and restrictive lung disease, give examples.
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Obstructive: blocking or narrowing of airways = airway resistance
- inflammation or edema (fluid collection) or smooth muscle constriction or bronchiolar secretion - asthma, bronchitis, emphysema Restrictive: airways are normal but lung tissue is damaged - loss of elasticity or compliance, limits lung expansion - Stiff and fibrous lung tissue, all volumes reduced - pulmonary fibrosis, pneumonia |
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What is the thing that divides the heart into two pumps?
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The septum
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What is the cause of a heart murmur?
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Faulty leaky valves not closed properly
(tricuspid on the right, bicuspid (mitral) on the left) |
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Describe the conduction system of the heart (as in AP conduction)
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- Sinoatrial node (right atrium, posterior) (pacemaker cells) contracts at a specific rate, spontaneous without neural input
- The APs travels from SA node through: atrial muscle fibres - atrioventricular node - atrioventricular bundle - along purkinje fibres (through ventricular myocardium) - These allow for the simultaneous contraction of left and right ventricles |
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What is the purpose of the atrioventricular node?
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In heart conduction, the AV node is where the depolarization from the atria is delayed (plateau stage) for 0.1s, giving the atria time to contract and empty while the ventricles fill before contraction.
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How does the cardiac muscle receive its blood supply?
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Left and right coronary arteries, originating from the aorta above the aortic valve
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What is an ECG and how is it recorded
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- records the wave of depolarization through the heart, uses electrodes on body surface
- detects abnormalities in rhythm or contractions, indicates conduction problems |
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What is ventricular fibrillation?
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serious heart conduction abnormality
- no effective pumping in or out of chambers due to uncoordinated contractions |
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What are the components of an ECG waveform
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- p-wave: atrial depolarization
- P-R interval: conduction from atria to purkinje cell plexus in ventricle - QRS complex: ventricular myocardium depolarization - S-T segment: continuing period of ventricular depolarization - T-wave: upward prolonged deflection, recovery, reflects ventricular depolarization (atria fill with blood here) - QT interval: ventricular depolarization and depolarization, corrected for heart rate - PQ, ST and TP segments are all isoelectric = horizontal lines |
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Describe the differences between arteries, arterioles, capillaries, venules and veins.
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- Arteries go away from heart, veins toward heart
- Arteries/ioles have higher pressure and ticker walls and more muscle than veins/ules - Capillaries are smallest, walls a single layer of cells (exchange with interstitial fluid) - Veins have valves to prevent back flow |
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Why are artery walls so much thicker than corresponding veins?
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Because they have to withstand more pressure.
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What 3 mechanisms aid venous return from the legs to the heart?
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- Pressure difference between left ventricle and right atrium = driving force
- Active contraction of skeletal muscle squeezes veins - Inspiration decreases pressure in the thoracic cavity, which increases return through inferior vena cava |
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How is O2 transported
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It bonds to hemoglobin when O2 concentration is high, travels and is released when O2 concentration is low
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Why do you need iron?
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You need iron for hemoglobin to bond with O2
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Where do you find hemoglobin?
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In mature red blood cells
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What is partial pressure of a gas? What formula is used to calculate it?
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The pressure of a specific gas in a mixture of gases
- total barometric pressure * percent concentration of the specific gas |
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What is barometric pressure at sea level in dry ambient air?
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760mmHg
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What are the %s of O2, CO2 and N
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O2 = 20.93%
CO2 = 0.03% N = 79.04% |
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What are the normal ranges for systolic and diastolic pressures? What is the pulse pressure?
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Systolic: 100-140mmHg
Diastolic: 60-90mmHg Pulse pressure is the difference between systolic and diastolic pressures |
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What are the partial pressures of O2 and CO2 in the alveoli and pulmonary capillary blood?
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Alveoli: O2-104 and CO2-40
Capillary: O2-40 and CO2-45 |
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Name the 4 factors affecting gas exchange in the blood.
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1. partial pressure gradients
2. Thickness of respiratory membrane (restrictive lung disease) 3. number of RBC, haemoglobin or both 4. Surface area of respiratory membrane available |
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Define diffusion capacity
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- Volume of O2 that crosses the alveolar-capillary membrane per minute per mmHg pressure difference between the alveolar air and pulmonary capillary blood
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How and why does diffusion capacity change during exercise?
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- It can increase by 3x in heavy aerobic exercise
- Due to increased lung volumes, increased surface area, opening of more capillaries in the lung, greater volume of blood flowing through the lung |
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What are:
Oxygen carrying capacity of hemoglobin? Percent saturation of hemoglobin? |
Carrying capacity = 1.34mm O2 per 1g of hemoglobin
- the carrying capacity of blood is therefore based on the concentration of hemoglobin (which is multiplied by the above value) Percent saturation: amount of O2 actually combined with hemoglobin relative to max capacity of hemoglobin to carry O2 |
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What is the oxyhemoglobin dissociation curve?
- axes and what it shows and its shape |
- x axis is arterial partial pressure of O2
- y axis is percent saturation - positive curve reaching plateau at the top (above 60mmHg, saturation is about the same |
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What is the primary factor determining % saturation of hemoglobin?
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- O2 partial pressure is the main factor
- Lower O2 concentration results in dissociation of O2 from hemoglobin - Saturation doesn't fall until O2 pressure falls below 60mmHg |
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How do blood acidity, temperature and CO2 affect oxyhemoglobin dissociation?
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- Increased acidity or temperature reduce the effectiveness of the binding between O2 and hemo, so the curve moves down and to the right.
- Increased acidity means increased CO2, so CO2 also increases dissociation |
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How can one increase the temperature and acidity in peripheral tissues?
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exercise
- this increases O2 release from hemoglobin |
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What does exercise do to cardiac output, O2 transport, blood pressure, blood flow to different places (including skin)?
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- Cardiac output is increased
- Blood diverted to working skeletal muscles and to skin (to facilitate more heat release through sweat evaporation) - diversion away from the gut - Blood pressure increases with cardiac output |
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What is the percent of systemic blood flow to the skeletal muscles at rest and during max exercise?
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- 15-20% at rest
- up to 85% during max exercise |
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Why is the heart considered a functional syncytium?
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Because the fibers of its muscle are anatomically interconnected, so that when one contracts, they all do.
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What is an erythrocyte?
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A red blood cell
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What is the bohr effect?
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When increased acidity and temperature cause increased dissociation between O2 and hemoglobin.
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What do systole and diastole mean?
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Systole: contraction
Diastole: relaxation (ventricular diastole is between beats) |
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What is the stroke volume?
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The amount of blood pumped by either the left or right ventricle per beat
- affected by the ability of the heart to contract forcefully and fill up with blood during relaxation |
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What is a person's hematocrit?
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- The ratio of the volume of RBCs to total blood volume.
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What is Ejection Fraction?
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- percentage of the blood in the ventricle that is pushed out by a contraction
- stroke volume / end-diastolic volume (amount in the ventricle after it's filled) |
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How do endurance athletes manage to obtain very high max O2 uptake values?
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- They have higher max stroke volumes
- Their max heart rates are only slightly lower - Cardiac output is much higher for endurance ppl than trained and untrained - ANSWER: they are able to pump much more blood, transport much more O2 to working muscles per minute due to higher max stroke values |
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What happens to diastolic pressure during exercise? why?
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Don't change much, but systolic does increase.
Because the increase in cardiac output is combined with reduced total peripheral resistance so diastolic pressure remains relatively constant. |
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What happens to systolic pressure during exercise and why?
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- it increases
- heart rate, stroke volume, cardiac output and BP all increase - vasodilation in active muscles, constriction in others - Higher volumes of blood are pumped through the arteries = more pressure on the walls |
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Define blood pressure and mean arterial blood pressure (include calculation).
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BP is the arterial pressure of systemic circulation, varying from systolic max to diastolic min
Mean arterial pressure: average arterial pressure during a cardiac cycle = [(SBP - DBP)/3] + DBP (estimation) |
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What is hypertension and why is it dangerous?
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- Either resting systolic pressure over 140, or resting diastolic pressure over 90mmHg
- Increases risk for cardiovascular disease (heart attack, failure, stroke, and kidney disease) |
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What is the relationship between BP, cardiac output and peripheral resistance
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BP = cardiac output * total peripheral resistance
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What is the pulse pressure and mean arterial pressure for someone with BP of 124/73
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- pulse pressure = 124 - 73 = 51
- MAP = (51/3) + 73 = 17 + 73 = 90 |
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What factors affect resistance to blood flow?
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- radius of vessel
- length of vessel - viscosity of blood (based on RBC concentration) |
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Why does the average male have higher max O2 uptake (VO2max) than the average female?
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- 40-50ml*kg*min-1 vs 30-40 for women
- Men have more muscle and less fat (more active tissue to take up O2) - Men have ~14% higher hemoglobin concentration, increasing O2 delivery |
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What is an ergometer?
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measures work or energy expended during a period of exercise
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What is a MET level?
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- MET level for a specific activity is a multiple of the resting metabolic rate
- amount of O2 required per kg per minute under quiet conditions |
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What is the respiratory exchange ratio?
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Ratio of CO2 production to O2 consumption
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What are the physiological determinants of VO2max
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- ability to ventilate lungs and oxygenate their blood
- cardiac output - O2 carrying capacity of blood - Ability of working muscles to accept O2, and fibers to extract it - mode of exercise, heredity, age, gender |
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What are the three criteria for reaching VO2max in a test of max aerobic power?
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1. O2 consumption stops increasing linearly with work rate, plateaus, with last two values agreeing within +/- 2ml O2*kg/min
2. Heart rate approaches age-predicted maximum (220-age) 3. Subject looked exhausted 4. Respiratory exchange ratio exceeds 1.10 |
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What are the advantages and disadvantages to using a bicycle ergometer compared to treadmill
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advantages:
- they are less expensive, portable, don't require electricity - subject is more stable, easier to collect data - easier to calculate work rate Disadvantages: - VO2max on a cycle is typically lower than on a treadmill - Cycle is not a common movement, walking is |
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What happens to VO2max with aging?
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- increases and peaks between 18-25 years, then declines by ~1% per year
- because of decreasing physical activity with age - reducing other components of the O2 transport system - reduced ventilation and gas exchange in the lungs, for one. |
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What are 3 reasons to choose a sub maximal test to predict VO2max.
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- less expensive, less special equipment/personnel
- increased safety factor, decreased liability - less motivation required from the subject |
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What are the major divisions and subdivisions of the nervous system
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1. Central nervous system: brain and spinal cord
2. Peripheral nervous system 2a. Afferent (sensory and visceral stimuli) 2b. Efferent 2bi. Somatic (motor neurons) 2bii. Autonomic (smooth/cardiac muscles and glands) - sympathetic and parasympathetic |
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Describe 3 functional classes of neurons.
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Efferent (away from CNS to effectors)
Afferent (toward CNS from sensory receptors) Interneurons (within CNS, connections between neurons) |
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How are signals transmitted from one nerve fiber to another?
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APs transmitted at the synapses between the axon of one nerve and the dendrite of another by means of neurotransmitters
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How many pairs of spinal nerves are there? How long is the spinal cord?
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- 12 pairs cranial nerves, 31 pairs spinal nerves
- It goes to the 2nd lumbar vertebra |
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What are the cervical and lumbar enlargements of the spinal cord?
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They coincide with the brachial and lumbosacral plexus
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Distinguish between the dorsal and ventral roots of the spinal cord.
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- Each spinal nerve has a dorsal and ventral root connected to the cord
- Dorsal (on posterior surface of body) roots contain afferent fibres, and the ventral ones (anterior) contain efferent fibers |
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What are grey and white matter composed of? How do they differ in the spinal cord and cerebral hemispheres?
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- Gray matter: nerve cell bodies
- white matter: interconnecting tracts of nerve fibers (axons) and their myelin sheaths - Spinal cord: butterfly bray matter surrounded by outer white matter - In the brain, the white matter is surrounded by grey matter |
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Where are the highways of nerve conduction?
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- in tracts of white matter in the spinal cord
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What's the function of the spinal cord?
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- Bundle of fibers in ascending and descending tracts transmitting specific types of info between CNS and PNS
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Distinguish between quadriplegia and paraplegia and the location of injuries associated with each.
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- Quadriplegia: paralysis of both upper and lower limbs, transection superior to C5
- Paraplegia: transection between T1 and L1 |
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What are golgi tendon organs? What are they for?
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- proprioceptive sensor located near junctions of muscle and tendon fibers
- When muscle contracts, GTO is stretched and sends APs to CNS, causing muscle to relax (reflex inhibition) and protecting muscle-tendon unit from damage |
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What is alpha-gamma motor neuron coactivation in a stretch reflex?
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- This is a mechanism for maintaining muscle spindles at peak operating length even while the skeletal muscle is contracting.
- Stretching the muscle activates the spindle - you'll have to look this up. http://vimeo.com/28475051 |
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What do alpha motor neurons and gammas do?
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Alpha: innervate extrafusal muscle fibers of skeletal muscle are initiate their contraction
Gamma: innervate intrafusal muscle fibers of muscle spindles |
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Define and list the 5 components of a reflex arc.
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- Arc is all the neurons activated in the reflex response, the pathway
1. receptor detects the stimulus 2. Afferent neuron transmits to CNS 3. Integrating centre (gray matter in CNS) where afferents synapse with efferent or with interneurons 4. Efferent neurons transmit to effector 5. Effector responds to the impulse (muscle or gland) |
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What is reciprocal inhibition?
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- Inhibition of one muscle while another is contracting so that a reflex can happen
- relaxation of the trice while the bicep flexes. |
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What are the lobes of the cerebrum, and a function for each.
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Frontal: speech formation
Parietal: primary motor cortex, voluntary movement Temporal: hearing, memory Occipital: sight |
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How do the cerebellum, primary motor cortex and premotor cortex control motor functions?
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- Cerebellum: feedback circuits to coordinate other parts of the brain, receives sensory and proprioceptive input from the body
- Primary motor cortex (posterior frontal lobe): controls movement in different specific areas of the body, but no coordinated movement - premotor cortex: commands the PMC, affects lower motor neurons in the spinal cord especially |
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What is the homunculus and where is it
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map of the body in the primary motor cortex
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Name the location and some functions of the cerebellum. What are the consequences of injury here?
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- Posterior and inferior to cerebrum
- motor coordination, coordination of movements, postural adjustment, locomotion - injury results in jerky movements, tremors, awkward walking, balance difficulties, incoordination, difficulty starting/stopping movements |
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What is the neurotransmitter involved in muscle finer synapses?
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Acetylcholine
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What is the pyramidal tract?
What is the extrapyramidal tract? |
Pyramidal: Long efferent axons from primary motor cortex to interneurons or lower motor neurons
Extrapyramidal: from premotor to lower motor neurons |
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What are spatial and temporal summation?
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Spatial: way of achieving an AP in a neurone by combining potentials from different areas of input to reach a threshold
Temporal: way of achieving AP by increasing the strength of a signal by transmitting signals with increased frequency |
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Ganglion
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Collection of nerve cell bodies located outside the CNS (gray matter)
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Ability vs skill
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Ability: enduring trait affected by learning and heredity (balance)
Skill: specific to a task, gained through experience/practice, not inherited |
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Paint a picture of a skilled athlete
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Fast output of high quality
apparent ease, smoothness of movement able to anticipate variations makes quick choices, responses |
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Gross vs fine motor skills
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Gross: large muscle groups, precision is less important than smooth coordination
- ex running, throwing, most sports skills Fine: control of small muscles, requires hand-eye coordination and high precision, used in adapted phys ed or rehab - ex. piano, writing |
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Serial vs continuous motor skills
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Serial: series of discrete skills having beginning and end points
- dance routine as a series of dance moves Continuous: arbitrary beginnings/ends, usually repetitive, series over a long time - steering a car, swimming |
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Closed vs open motor skills
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Closed: fixed static environment, predictable cues for performance, internally paced
- ex. bowling, swimming Open: dynamic environment, variable and changing cues for performance, unpredictable, externally paced - ex. hockey |
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Name and describe the three stages of skill acquisition.
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1. Cognitive stage: understanding which movements to make, not how; mental plan of performance
- large, frequent errors - may give KR in this stage 2. Associative stage: production of a reasonable approximation of desired movement - working to refine, small errors - concern with the how - learning by proprioception 3. Autonomous stage: advanced, automated responses - rapid, unconscious - after much practice - now focused on other tasks like strategy |
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What should the coach do during the cognitive stage?
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visual demonstrations, verbal explanations, diagnostic knowledge of results
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How does knowledge of results improve learning? (3)
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1. guides error correction
2. reinforces correct performance 3. motivates toward goals |
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How should KR be given to unskilled vs skilled players?
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unskilled: after the movement, small doses that the learner can handal
Skilled: specific KR on direction and amount of error |
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Intrinsic vs extrinsic KR
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Intrinsic: sensory knowledge during task, own perception, fallible
Extrinsic: external course, usually following task |
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Concurrent vs terminal KR
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Given during or after movement is performed
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KR intervals
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KR- delay interval: between completion of response and presentation of KR
post-KR interval: between KR and next response Inter-response interval: between two responses |
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Name the 3 forms of transfer of learning and give examples.
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Transfer: influence of a previously established skill on the learning of another
- Positive transfer: learning is facilitated by established skill (skating and rollerblading) - negative transfer: learning is impeded by established skill (a stroke in tennis vs badminton) - Zero transfer: no influence (skiing and driving) |
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What is bilateral transfer? Why does it occur?
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- Improvement in performance of one limb through practice with the opposite one
- Visual cues, knowledge of body position, confidence, techniques in eye movements |
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What factors affect motivation? (5)
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1. knowing one is being evaluated
2. when the outcome is success or failure 3. individual responsibility of outcome (vs chance) 4. risk or uncertainty 5. immediate knowledge of the outcome |
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How can goal setting be used as motivational tool?
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1. objective goals (number, easily evaluated)
2. set meaningful goals to performer 3. set challenging but obtainable goals 4. set according to individual differences 5. set short- and long-term goals |
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Define motor learning vs motor development
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Learning: permanent change in performance through practice
Development: complex processes of growth/maturation of nervous and motor systems from conception to adulthood |
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What is boyle's law? How is it relevant underwater?
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At constant temperature, the pressure of a given mass of gas is inversely related to its volume
- Under water, there is pressure of the column of air above sea level, plus the weight of the water above. - pressure increases at a rate of one atmosphere for every 10m of depth, plus the atmosphere above it. |
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What is the pressure at 20 below sea level?
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1 atmosphere of air, plus 2*10m at 1 atmosphere/10m
= 3 atmospheres of pressure |
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why is 10m water equal to one atmosphere?
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because water is denser than air
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At 33 ft below sea level, what is the barometric pressure?
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1520mmHg
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Is water compressible?
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nah.
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How does a scuba diver get an air embolism?
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- Embolus = material that obstructs a blood vessel
- if a diver holds his/her breath and doesn't exhale during ascent, as pressure decreases, the air in the alveoli expands (boyle's law) and the alveoli rupture - Air bubbles then enter and may lodge in vessels, and obstruct blood blow to organs |
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What is spontaneous pneumothorax and how is it treated?
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- lung collapse
- if alveoli rupture, air can escape from the lung to the chest cavity, forming a pocket between chest wall and outer lung tissue - continued expansion of this trapped air during ascent causes the lung to collapse - air can be reabsorbed on its own, or removed with a needle or chest tube, or surgery can close the leak |
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What is the effect of Nitrogen narcosis on a diver?
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- increased N in blood and tissues produces an anaesthetic effect on CNS
- decreased attentiveness/aware of cold, recklessness and hallucination |
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How can you avoid getting the bends (Decompression sickness) during a dive?
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- Slow ascension in stages so that nitrogen can diffuse from tissues to blood and does not form bubbles in the body tissues and fluids
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symptoms of the bends? treatment?
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- pain, blocking an arter = damage or death
- treatment: recompression and slow decompression |
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What is the Eustachian tube?
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- it equilibrates pressure in the ear cavity by transferring air to or from the lungs and decreasing pressure against the eardrum
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How to prevent mask squeeze while diving?
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- Use a mask that covers the nose too, so that pressure can be equalized by blowing air out the nose
- don't use goggles below 2m |
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What is middle ear squeeze?
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If the eustachian tube is blocked (respiratory infection or anatomical problem), increased pressure in depth creates a vacuum in the middle ear.
Tissues may haemorrhage or eardrum rupture, pain |
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What two factors limit the size of a snorkel?
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- higher pressure and deadspace volume with increasing length
- increasing pressure with depth requires the lungs to overcome greater pressure, but they can't do more than 50cm below the surface - Longer snorkel = more dead space, which means that more air has to be inspired to achieve same alveolar volume |
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Why is it dangerous to hyperventilate before breath-hold diving?
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- Because the diver can then tolerate lower pO2 than normal, but might go unconscious as pO2 decreases before pCO2 rises enough to stimulate breathing (paradoxical drowning)
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Why does pO2 decrease as altitude increases?
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- %O2 stays the same, but the column of air is shorter, reducing its weight
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Why does exercise seem more tiring at altitude than sea level?
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- Because you need to inhale more air, breathe faster to get the same amount of oxygen
- Required O2 uptake is the same for a given work rate, but ventilation must increase to attain the same level |
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How does the physical environment change at altitude?
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- Decreased air density and resistance
- decreased force of gravity - decreased air temperature - increased dryness and solar radiation |
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What are the immediate and long-term physiological adjustments that occur following exposure to reduced O2 pressure (hypoxia)?
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- Increased cardiac output at rest and sub maximal exercise
- CO will fall to normal after 7+ days as O2 extraction by peripheral tissues increases - Long-term: increased blood carrying capacity (increased hemoglobin concentration) - and 2,3 - biphosphoglyceric acid (BPG acid) increases, allows more oxyhemoglobin dissociation |
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What mechanisms allow the peripheral tissue to extract more O2 after acclimation to altitude?
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- 2,3 biphosphoglyceric acid (BPG acid) allows more oxyhemoglobin dissociation at a given O2 partial pressure in the capillary
- plus increased hemoglobin concentration = increased O2 delivery |
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What happens to VO2 max at altitude?
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it decreases and stays there even after months
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Why is exercise performance reduced at altitude?
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Decreased pO2 reduced inspired partial pressure O2 and decreases oxygenation of blood
- this decreases saturation of hemoglobin and dissociation |
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How are sprint, endurance and throwing events affected at altitude?
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- Sprint: Less air resistance so activities can be improved
- Endurance: increased water loss and dehydration in dry air, increased solar radiation, great reduction in performance - throwing: less air resistance against projectiles, lower force of gravity (longer falling time), improvement in activities |
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Does training at altitude benefit performance at altitude, and on returning to sea level?
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- If athlete acclimatizes, improvements at altitude are possible
- There will be no increase in VO2max at sea level though in the long-term - although hemoglobin concentration increases at altitude, this will decrease to normal after a few weeks |
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What factors impede performance upon returning to sea level?
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- Instead:
- decreased max stroke volume and heart rate will persist for a few weeks - initially decreased ventilation in absence of hypoxia = rise in paCO2 = chemoreceptor stimulation = increased work of breathing - reduced buffering capacity of blood for lactic acid following prolonged altitude exposure - Training at altitude is at lower absolute work rate = impairment upon return |
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How can you reduce onset and severity of altitude sickness?
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- slow ascension, acclimatization at moderate before high altitudes, especially in extreme cold/exertion
- work high, sleep low - don't exercise in first hours - drug prophylaxis - drink enough water - stop ascent, possibly descend - rest, aspirin, fluid intake - Acetazolamide (elevates CO2) - Increasing car intake may help |
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What is high altitude pulmonary edema?
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- accumulation of fluid in alveoli, reduces diffusion capacity for O2 during too quick ascent
- treat with descent, diuretics with fluid replacement, avoiding alcohol/sedatives |
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4 principles for treatment of altitude sickness
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- stop ascent if any symptoms
- Descent if worsening or no improvement - Descent if HAPE, loss of coordination, changes in consciousness - Do not leave ill people behind or descending alone |
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By how much does VO2 max decrease with increasing altitude?
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3-3.5% for every 300 above 1500m
so for 2100m: 2100 - 1500 = 600 = 300 * 2 so 2* 3-3.5% = 6-7% decrease in VO2 |
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After 2 weeks, what is a person's VO2max at altitude? Why
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It does not improve from the original decrease at altitude.
Because CO doesn't normalize, and there is preferential routing of CO to non exercising tissues. says the internet. |
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Unit 15 levers
What are the force and resistance point in the human body lever system? Fulcrum? |
Resistance: the centre of gravity of the moving body segment plus any external weight.
Force: insertion of the muscle into the bone. Fulcrum: the joint |
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Example of each class of lever in the body?
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First: Triceps acting at the elbow
Second: may not exist in the body Third: most of the body's levers. |
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What is the law of levers equation?
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F + FA = R + RA
nb unit of force is not kg but N (kg*m/s2) |
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Define mechanical advantage.
What causes it What is the opposite? |
The ability of a lever to magnify forces
If the FA is longer than the RA Calculate it as FA/RA The opposite is speed advantage |
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Define centre of gravity
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This is the point where the sum of all the turning moments of the particles acting individually is exactly zero…
The point through which the resultant of the gravitational force always acts |
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What is the centre of gravity in the human body?
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point of intersection of the 3 cardinal planes
- exact centre, around which the body may rotate evenly… - weight is equal on all sides |
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How can you determine the centre of gravity of the human body? When it is moving, or still?
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Reaction board method when it is still
Frame by frame analysis when it is moving |
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What do you need to perform the reaction board method?
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- weighing scale
- reaction board (knives on the underside at each end and one footboard) - tape measure - block of wood at height of weigh scale |
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What vessels enter or exit the atria and ventricles?
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Right atrium: venas cava, coronary sinus --tricuspid
Left atrium: 4 pulmonary veins -- bicuspid Right ventricle: tricuspid -- pulmonary trunk Left ventricle: bicuspid -- Aorta |
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Discuss the importance of the elasticity and contractility of the arteries
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- They stretch when ventricles pump blood through them and recoil when the pressure falls bak down
- this prevents drastic changes in blood pressure and maintains blood flow |
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Pathway of blood from the aortic arch, to the right ankle, and back to the left ventricle again.
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Aortic arch - thoracic aorta - abdominal aorta - common iliac artery - internal iliac - femeral - popliteal - anterior or posterior tibial to the ankle
- anterior or posterior tibial veins - popliteal - femoral - external iliac* - common iliac - inferior vena cava - right atrium or *thoracoepigastric - axillary - subclavian - brachiocephalic - superior vena cava |
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Why should one cool down after vigorous exercise?
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- To move skeletal muscles which constrict veins and help push blood up against the force of gravity to the heart
- if blood stops moving, it will not clear waste products from the muscles |
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Describe the location of the heart in the thoracic cavity.
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- In the mediastinum between the lungs
- surrounded by pericardial cavity - lies obliquely, apex to the left with 2/3 of mass to the left of centre - base of the heart deep to the sternum |
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Why is the left ventricle wall thicker than the right ventricle wall?
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- because the left ventricle contracts more forcefully, has more muscle, and generates greater pressure
- because it has to pump the same amount of blood to a bigger system than the right |
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Why are artery walls thicker than the walls of corresponding veins?
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Because they need to withstand higher pressure
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Give 2 equations for cardiac output.
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Q = stroke volume * heart rate
Q = mean arterial blood pressure/total peripheral resistance |
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What instrument generates an electrocardiogram?
Where are the electrodes placed? |
an electrocardiograph
- Left wrist (LA), right wrist (RA), left ankle (LL), right ankle (RL) - exploring electrode on the chest |
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What are the parts of the respiratory system
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nasal passages
larynx trachea bronchi and alveoli thoracic cage Respiratory muscles of the thoracic cage |
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Why does atmospheric pressure decrease as altitude increases?
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Earth's gravitational field produces an increasing force nearer to toe earths centre.
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What is the barometric pressure at sea level?
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760mmHg
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What is charles' law?
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Volume of a gas increases with temperature
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What is STDP? and BTPS? ATPS?
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Standard pressure and pressure dry (a constant number of molecules in these conditions. 6.02*10^23)
Body temperature and pressure saturated (intrapulmonary volume occupied by exhaled gas at ambient pressure, saturated with water vapour, at body temperature) Ambient temperature pressure saturated (conditions in which measurements are taken) |
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What is relative humidity?
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The amount of water vapour in the air relative to the amount that could be in that volume of air if it was saturated.
expressed as % or sometimes pressure |
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What are the values of STDP?
What is the STDP factor? |
0 celcius, 273 K
and 760 mmHg Factor used to calculate the volume of a gas from ATPS to what it would be in STPD conditions. |
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How do you convert from ATPS to STPD?
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VeSTPD = VeATPS * (Pb - Ph2o)/760 * (273/(273+T))
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How and why do you convert from ATPS to BTPS?
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When you want to know the volume of gas that is ventilated by the lungs, rather than the number of gas molecules present
VeBTPS = Vatps * (Pb - Ph2o)/(Pb - 47) * (273 * 37)/(273 + T) |
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Vital capacity definition
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Max volume that can be forcefully exhaled after forceful inhalation.
inspiratory capacity + expiratory reserve volume |
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Inspiratory capacity
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Max volume that can be inspired that can be expelled after resting-end expiratory position
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Expiratory reserve volume (ERV)
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is the maximal volume that can be exhaled from the resting end-expiratory position.
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Functional residual capacity (FRC)
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is the volume of gas remaining in the lungs at the end of a quiet exhalation. It is composed of the expiratory reserve volume plus the residual volume
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Residual volume
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volume remaining after forced expiration
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Total lung capacity
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Volume at the time of max inspiration
- vital capacity + residual capacity |
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Tidal volume
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volume inspired or expired with each breath at rest
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Minute ventilation
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volume inspired or expired in one minute
#breaths/minute |
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Maximum breathing capacity
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Max volume that can be breathed during one maximal effort
- usually estimated from 12s period of hyperventilation - converted to volume/minute |
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Forced expiratory volume in one second
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Vol expired during 1s of forced vital capacity manoeuvre (hardest, fastest expiration for 4 seconds)
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What does the soda lime canister do for a collins respirometer?
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- Soda lime pellets absorb carbon dioxide from the subject's exhaled air
- results in resistance against breathing and therefore slower ventilation |
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Examples of restrictive and obstructive lung disease?
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Restrictive: Asthma or chronic bronchitis
Obstructive: pneumonia or pulmonary fibrosis |
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How do restrictive and obstructive disorders affect pulmonary function?
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Restrictive: all lung volumes are reduced
Obstructive: Increase the residual volume, though vital capacity remains the same, so total lung capacity increases but expiratory airflow is reduced = low max voluntary ventilation and FEV1s |
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Why is it important to have the bell of a collins 9L respirometer filled with O2 rather than room air
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Because prolonged breathing manoeuvres will reduce O2 concentration in normal air below self levels
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What is the procedure for measuring blood pressure?
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- Rest for 5 minutes
- Put the deflated cuff around the subject's arm, 2.5cm above the elbow, with rubber bag over the arm's inner aspect. - have the arm elevated to heart-level - place the stethoscope over the brachial artery (antecubital space) - Inflate the bag ~30mbHg above point where radial pulse disappears, then release pressure at 2-3mmHg/s - Listen for the Korotkoff sounds to begin - this is systolic pressure - when they disappear again - diastolic pressure |
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What is the blood pressure cuff technically called?
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Sphygmomanometer
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Don't forget the name of the sounds that you here when taking a blood pressure?
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Korotkoff
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Why can you not hear sounds higher than systole and lower than diastole?
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- No blood flow through constricted artery above systolic
- Below diastolic pressure, the flow is no longer turbulent and so there are no sounds |
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Measuring BP from calf vs arm?
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- calf will be slightly higher (higher SPB and lower DPB)
- The blood at the calf is deeper in the liquid than in the arm, and pressures are higher at lower depths |
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4 sources of error when measuring BP?
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1. exercised right before
2. Eaten/smoked right before 3. Equipment error 4. Error with inflation or deflation of the bag 5. elevating or lowering the arm when reading |
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Why does systolic but not diastolic pressures change in intense exercise?
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- Systolic: increased stroke volume
- diastolic: TPR decreases in general with changes in vasomotor tone in various parts of the body, but combined with increased cardiac output/heart rate, DBP remains the same. |
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Why does stroke volume increase during exercise?
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- End-diastolic volume in the heart increases with exercise, stretching the muscle fibers thus increasing the force of contraction
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What are VO2max measurements used for?
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- distinguishing high endurance ability from lower
- evaluate different training practices on endurance - some other things |
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Is the bike ergometer test a well-designed test?
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- When done right
- work rate should be measurable and reproducible - though it is predictive - conditions need to be consistent |
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Why is it more accurate to use VO2max as expressed per kg*min vs just per minute>
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Heavier people have larger tissue mass = larger VO2
So measuring per kg controls for this |
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What are the methods of measuring VO2 max?
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- meteorological balloons and analyzing gas through ventilation meter
- through a pneumotachograph or turbo device |
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VE(O2) - oxygen consumed is equal to?
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amount O2 inhaled - O2 exhaled
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How does the tendon tap reflex work? aka patellar tap?
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When the tendon is tapped, the muscle fibers are stretched, stimulates stretch receptors in spindles, which sends APs from the afferent axons of muscle spindles to the motor neurons in the spinal cord
- efferent axons of motor neurons connect with the muscle, resulting in a knee jerk |
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What happens in the achilles tendon reflex?
Pupillary? Consesnsual light reflex? |
- the foot should plantar flex
- Pupil contracts/both pupils contract |
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Muscle groups innervated by
- medial nerve - brachial plexus - lumbar plexus - sacral plexus - musculocutaneous - ulnar - radial - femoral - sciatic - tibial - common perineal |
- median: wrist/hand flexors, thumb
- brachial plexus: upper limb - lumbar plexus: Anterior thigh - Sacral plexus: posterior thigh, lower leg, foot - Musculocutaneous: upper arm - ulnar: flexors of the hand, and wrist, anterior forearm - radial: triceps, wrist and digit extensors in posterior forearm - femoral: quadriceps femoris and sartorius - sciatic: posterior thigh, leg and foot - Tibial: posterior leg muscles, planters of the foot - common perineal: anterio-lateral and lateral leg |
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Effects of injury at the 5th cervical vertebra?
|
- quadriplegia
- complete paralysis of body and legs, sympathetic nervous system compromised, but able to breath |
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How many spinal nerves are there?
(How many vertebrae are there?) |
- 31
- 8 cervical (7) - 12 thoracic (12) - 5 lumbar (5) - 5 sacral (5) - 1 coccygeal (4) |
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What is a cranial nerve? How are they named and numbered?
|
- Nerves that emerge directly from the brain rather than the spinal cord
- 12 pairs of nerve - names according to general vs special; somatic vs visceral; afferent vs efferent |
