LEWIS: Thermoregulation

Question 0

Necessary to lose that heat in order to keep body temperature constant so blood is moved from the core to close to the surface of the skin, from here heat can be lost to surrounding environment by 4 mechanisms:

Answer 0

1) CONDUCTION
2) CONVECTION
3) RADIATION
4) EVAPORATION

Question 1

During exercise heat is produced as a waste product of

Answer 1

Muscle contraction

Question 2

Conduction involves the

Answer 2

Transfer of heat through direct contact, from warm skin to clothes and air

Question 3

Convection involves transfer of heat by

Answer 3

Gases

Air passing over our skin takes away air molecules that have been warmed by the skin

Question 4

Radiation is the main way we lose heat when we are

Answer 4

resting

Question 5

Evaporation is the main way we lose heat during exercise

As fluid evaporates from the skin

Answer 5

Heat is lost

Question 6

Sweating, to work as a cooling system, the sweat must evaporate from the

Answer 6

Skin’s surface

Question 7

Sweat that stays on the skin’s surface or that drops off provides little or
No

Answer 7

Cooling effect

Question 8

Humidity of surrounding air is high, sweat evaporation is

Answer 8

Limited

Question 9

Humidity is low, sweating becomes

Answer 9

Easier

Question 10

Internal body temp =

Answer 10

37•C

Question 11

Changes in body temperature are detected by receptors and information is sent to the hypothalamus, which starts mechanisms such as

Answer 11

Sweating
Vasodilation (increases blood flow to skin)
Shivering (when cold)

Question 12

BLOOD, during exercise has 2 main functions:

Answer 12

1) supply muscles with nutrients and oxygen

2) supply the skin to allow heat to be lost

Question 13

Blood - when exercising in a warm environment a large proportion of the cardiac output must be shared by the skin and the working muscles, this in turn

Answer 13

Reduces the volume of blood returning to the heart and so reduces the stroke volume

Question 14

The heart, in order to maintain cardiac output required there has to be a gradual increase in heart rate (cardiovascular drift)

But these changes are limited in their effectiveness in terms of performance

The combination of a high rate of heat production from the exercise and a restricted capacity for heat loss can lead to

Answer 14

Hyperthermia (high body temperature)

Question 15

Heat exposure combined with exercise results in hypohydration if fluid losses are not

Answer 15

Replaced

Question 16

Fluid loss can lead to:

Answer 16

Symptoms of dehydration such as lethargy, nausea, loss of appetite, anxiety, inability to concentrate

Question 17

Dehydration can eventually lead to

Answer 17

Exhaustion

Heat stroke

Question 18

Dehydration limits performance by:

Answer 18

Decreasing blood plasma volume which results in less oxygen being delivered to the exercising muscles and increase breathing & heart rates

Question 19

In order to prevent dehydration, attention to fluid intake:

Answer 19

Before
During
After

Question 20

Drinks containing carbohydrate and electrolytes are useful for

Answer 20

Recovery, providing carbs for glycogen storage and promoting fluid retention

Question 21

Performance deteriorates in cold environments, the body attempts to gain heat by

Answer 21

Shivering and by vasoconstriction of arteriolar near skin surface

Question 22

Heat loss is increased by wind, which increases convection

This effect is known as

Answer 22

Wind chill

Question 23

Cold reduces the strength of muscles - they can

Answer 23

Generate less force

Produce more lactate

Question 24

During continued exercise in the cold, energy supplies quickly reduce and exercise intensity declines, and the performer becomes increasingly likely to suffer from

Answer 24

Hypothermia