Physiology Flashcards
Term for EE above resting rate post exercise?
EPOC/Excess post-exercise oxygen consumption
What is relative VO2max?
Total volume of oxygen consumed related to body weight (in kg)
Formula for calculating VO2max?
Relative VO2max = L/min x 1000 divided by body weight
Why is it important to measure EE?
Your diet revolves around the things you do everyday
Why is it good to eat a decent amount of carbs and protein post-workout?
Stimulates MPS, improves recovery and enhances the quality of the next workout
Minutes of aerobic activity recommended per week for 18-65 year olds?
150 mins moderate/75 mins vigorous/equivalent combinations of both
Formula for calculating respiratory exchange ratio?
RER = VCO2 produced divided by VO2 consumed
Oxygen (L/min) needed per min to satisfy resting energy requirements?
0.2-0.35 L/min
Formula for calculating METs?
METs x 3.5 x Body Weight (kg) divided by 200 = kcal/min
What is the equivalent of foodstuff + oxygen?
Water + CO2 + ATP + Heat
What units can energy be reported in?
Joule (J) & kilocalorie (kcal)
What are the main purposes of energy?
Growth, repair, digestion, and storage
What is the 1st law of thermodynamics?
Energy can be changed from one form to another, but it cannot be created or destroyed
What is 1kcal in Joules?
4186J
What is the ratio of CO2 expired to O2 consumed at the level of lungs?
The respiratory exchange ratio
What is the average total metabolic rate of an individual engaged in normal daily activities?
1800-3000kcal
What is direct calorimetry?
The measurement of heat production from an individual, in calories, when placed in an insulated chamber.
Where does direct calorimetry usually take place?
In a professional medical setting and on a treadmill.
How is the volume of oxygen consumed measured in direct calorimetry?
Measured through the exhaled air.
How is heat production measured in direct calorimetry?
The temperature of water (which travels through the room via pipes) is measured before and after the subject enters the room.
What are the limitations of direct calorimetry?
- A small percentage of heat will be lost by friction
- A small percentage of heat will still be stored in sweat molecules
- The method wouldn’t be relevant to measuring EE of stop/start sports
What is indirect calorimetry?
The method by which measurements of the RER are used to estimate the EE.
What is the principle of indirect calorimetry?
Energy releasing reactions in the body depend upon oxygen utilised and carbon dioxide produced.
What is the assumption of indirect calorimetry?
Rate of oxygen and carbon dioxide exchanged in the lungs = Rate of usage and release by body tissues.
What is an example of indirect calorimetry?
Spirometry
What is closed circuit spirometry?
- ) Subject inhales via a face mask from a container full of oxygen.
- ) Exhaled air goes back to the container via soda lime, which absorbs CO2.
- ) This changes the volume of oxygen in the container and is recorded as volume of oxygen consumed.
Equipment for open circuit spirometry?
- Treadmill
- Low resistance 2 way valve
- A nose clip
- Low resistance falconia tubing
- Douglas bag
What is meant to occur in open circuit spirometry?
- Exhaled oxygen = decrease
- CO2 = increase
- Nitrogen = stays at a similar percentage compared to inhalation
Why isn’t all oxygen used up in spirometry or exercise?
Oxygen still provides for other bodily functions, such as the function of your organs, and cannot all be used for exercise
What is the oxygen consumption formula? Units?
Volume of oxygen in - Volume of oxygen out = Oxygen consumption (VO2) (L/min)
What is VO2? VCO2?
VO2 = Oxygen consumption VCO2 = Carbon dioxide output
Other terms/abbreviations for carbohydrates?
- CHO
- Glucose
What factors influence energy expenditure?
- Gender
- Age
- Body mass
What is ATP?
- Adenosine Triphosphate
- Important to all life as it stores and releases energy for many cellular processes
What does a fixed amount of energy expenditure always produce?
A fixed amount of heat
Ways of measuring energy expenditure?
- Amount of movement
- Weight gain/loss
- Calorimetry
Source of recommended activity guidelines? Year?
Gary O’Donovan, Journal of Sport Sciences, 2010
What RER suggests that fat is the predominant source fuel? Carbs?
- Fat = 0.7
- Carbs = 1.0
What are the names of the key connective tissue in muscle?
Epimysium Perimysium Fascicle Endomysium Muscle cell
What is epimysium?
The connective tissue around muscle
What is total muscle?
Groups of fascicles
What is perimysium?
The connective tissue around fascicles
What are fascicles?
Groups of muscle cells
What is endomysium?
The connective tissue around muscle cells
What are muscle cells?
The cells that make up muscle
Easy sentence to remember the structure of muscle?
Even Pulis Finds Emery Mad
3 key features of skeletal muscle?
- ) Movement of skeleton
- ) Under voluntary control
- ) Rapid and forceful contractions for short durations
What is a sarcomere?
The functional unit of striated muscle (the most basic unit that makes up our skeletal muscle).
How many different parts does the sarcomere have? Names?
5 parts:
- ) A Line
- ) H Line
- ) I Line
- ) M Line
- ) Z Disc
Easy sentence to remember the structure of a sarcomere?
I must have a zebra
What is the A Line in a sarcomere?
Thick filaments (myosin) length
What is the H Line in a sarcomere?
Thick filaments (myosin) but no thin filaments (actin)
What is the I Line in a sarcomere?
Thin filaments (actin) but no thick filaments (myosin)
What is the M Line in a sarcomere?
Supporting proteins holding the thick filaments (myosin) in place
What are Z Disc’s?
Defines the boundaries of an individual sarcomere
What are the 5 key ingredients required for muscle contraction?
- ) Action potential
- ) Calcium
- ) ATP
- ) Actin
- ) Myosin
First step of the sliding filament theory?
Action potential causes the release of calcium from the sarcoplasmic reticulum.
Where is calcium stored?
In the sarcoplasmic reticulum
Chemical name/abbreviation for calcium?
Ca2+
Chemical name/abbreviation for inorganic phosphate?
Pi
What is troponin?
Protein in muscle fibres that help to regulate muscle contraction.
What is actin?
The thin filaments in a sarcomere
What is myosin?
The thick filaments in a sarcomere
4 key steps for initiating a contraction?
- ) A stimulus to the skin is received by a sensory receptor
- ) The action potential travels through sensory neurons to the CNS
- ) The CNS interprets the information and the most appropriate motor response is derived
- ) The motor action potential travels out from the CNS through motor neurons to the appropriate point
What are action potentials?
Nerve signals.
What is resting membrane potential?
The difference in sodium and potassium ions inside and outside a neuron (nerve cell) = -70mV (millivolts)
Chemical name/abbreviation for sodium?
Na+
Chemical name/abbreviation for potassium?
K+
Key parts of a neuron (nerve cell)?
- Cell Body
- Dendrites
- Axon
- Synaptic end bulb
How can you measure the voltage across a neuron (nerve cell)?
Using a voltmeter
What happens to a neuron (nerve cell) when a stimulus occurs?
- Sodium (Na+) moves into the cell and Potassium moves out
- Inside of the cell becomes less negative
What is depolarization?
When the inside of a neuron (nerve cell) becomes less negative due to a stimulus
What happens when you get a depolarization greater than or equal to 15-20 mV?
- Threshold occurs
- Action potential is generated
How is action potential generated?
- ) -70mV is the resting membrane potential
- ) If the stimulus is sufficient to cause a depolarization greater than or equal to 15-20 mV (e.g. membrane potential becomes -55mV to -50mV) threshold occurs
- ) Action potential is generated
How does depolarization occur?
- ) Voltage gated sodium channels open after a stimulus
- ) Rapid sodium entry into the neuron occurs, making the inside less negative
- ) Voltage gated potassium channels open
- ) Potassium leaves the neuron to the outside extra cellular fluid
What are voltage gated sodium/potassium/calcium channels?
Small compartments on the membrane of a neuron (nerve cell) which allow the movement of sodium/potassium/calcium in/out of the cell
What occurs after depolarization in a neuron (nerve cell)?
- ) Voltage gated potassium channels remain open after depolarization allowing additional potassium to leave the neuron (nerve cell) = hyperpolarization
- ) Eventually the channels close
- ) Less potassium leaves the cell
- ) Sodium is pumped out of the cell
- ) Cell returns to its resting membrane potential
What is hyperpolarization?
When additional potassium leaves a neuron (nerve cell) due to the voltage gated potassium channels remaining open after depolarization
Where does action potential move to and from along a nerve cell?
Axon hillock to the axon terminal
What is the term for the process of a substance being produced and discharged by a cell?
Secretion
What is the term for the process of action potential moving from one node of ranvier to the next?
Saltatory conduction
What separates each node of ranvier along a neuron (nerve cell)?
Myelin sheath
What is the myelin sheath?
A waxy substance secreted by the schwaan cell that separates the nodes of ranvier
What are the nodes of ranvier?
The regions of the cell where there is no myelin sheath
What is the schwaan cell?
A cell that secretes myelin sheath
How does action potential move along a neuron (nerve cell)?
- Opening of the voltage gated sodium channels
- Action potential develops as an electrical impulse
- Action potential jumps from one node of ranvier to the next