A.2 Environmental factors and physical performance

Created by

Ellie gould

Cards (44)

Where does all energy in the human body originate from?
From the sun as light energy
How do plants convert light energy?
Through chemical reactions that convert light into stored chemical energy
How do humans obtain energy?
By eating plants or animals containing energy
What is required for the body to produce energy?
Oxygen and food, dependent on macro and micro nutrients
Which hormones control energy metabolism?
Insulin, glucagon, adrenaline, and growth hormones
What is the basal metabolic rate?
The amount of energy expended daily at rest for basic daily routine
What is cellular metabolism also known as?
Metabolic rate
How is energy released from food in the body?
Through chemical reactions within our cells
What is the more dense energy compound that stores energy in the body?
Adenosine triphosphate (ATP)
What provides energy to muscles for contraction?
The splitting of ATP
What happens to heat produced by metabolism?
It must be transferred away from the core and redistributed to the skin
What occurs when metabolism increases?
More heat is produced
What is the normal internal body temperature humans maintain?
Around 37°C
What is the efficiency of muscle contraction?
About 20% efficient, with 80% released as heat
What are the methods the body uses to remove excess heat?
Conduction
Convection
Radiation
Evaporation
What is the physiological range for core body temperature?
37 degrees with ±0.6 degree of error
Where are thermal receptors located?
In the hypothalamus and in the skin
What do thermal effectors respond to?
Stimuli sensed in the thermal receptors
What happens to muscles in cold conditions?
Muscles shiver
What occurs to skin blood supply in cold conditions?
It is reduced (vasoconstriction)
What is the effect of prolonged exposure to cold?
Increased metabolic heat production due to thyroxin and epinephrine
What is conduction in terms of heat transfer?
The transfer of heat from one object to another through direct contact
How does convection work in heat transfer?
It involves the transfer of heat between the body and a moving liquid or gas
What is radiation in terms of heat loss?
The loss of heat through the movement of infrared rays from the skin
What is evaporation in the context of heat loss?
The process where water on the skin is transformed into water vapor
What happens in hot and humid conditions?
It becomes difficult to lose heat, leading to heat exhaustion
What happens in hot and dry conditions?
Increased water loss through sweat can lead to dehydration and heat exhaustion
How does humidity affect heat loss?
It imposes a barrier to the evaporative process
What physiological response occurs during exercise in heat?
Vasodilation directs warm blood towards the skin surface
What is the effect of wind on evaporation?
Wind increases the speed of evaporation by carrying sweat particles away
What is the role of sweating in temperature regulation?
Sweating causes a decrease in core temperature
What happens to heat stored in the blood during sweating?
It is sent to the skin by vasoconstriction to escape the body
Why is sweating more common in hot environments?
To maintain optimal body temperature through homeostasis
What factors influence sweating rate?
Intensity of activity, environmental conditions, fitness, acclimatization, and clothing
What are the physiological adaptations during prolonged exercise in heat?
Maximal sweat rates can reach 2-3 L per hour
What are the consequences of high sweat rates?
Fluid loss, decreased plasma volume, and altered electrolyte balance
What happens to blood volume during prolonged exercise in heat?
Central blood volume and stroke volume decrease
What health risks are associated with exercising in the heat?
Heat cramps, heat syncope, and heat exhaustion
What are heat cramps and their symptoms?
Painful cramps in muscles due to sodium depletion
What is the treatment for heat cramps?
Move to a cool place, rest, and drink sports drinks containing salt and sugar