Environmental Effects on Body Systems

Question 1

define acclimatisation to warm temperatures

Answer 1

adapting to the changes in environment in high temperatures

Question 2

define thermoregulation

Answer 2

the process of maintaining internal core temperature

Question 3

define thermoreceptors

Answer 3

sensory receptors which sense a change in temperature and relay information to the brain

Question 4

define dehydration

Answer 4

loss of water in body tissues largely due to sweating

Question 5

define hyperthermia

Answer 5

a significantly raised core body temperature

Question 6

what are the most common causes of hyperthermia

Answer 6

• high temperature and prolonged exercise
• high air temperature
• high relative humidity

Question 7

describe and explain the effect of humidity and heat on the heart and body’s temperature response on the respiratory system

Answer 7

• dehydration and drying of the airways in temperatures above 32 degrees makes breathing difficult leading to increased mucus production, constriction of the airways and decreased volume of air for gaseous exchange
• increased breathing frequency to maintain oxygen consumption leading to increased oxygen ‘cost’ of exercise
• high levels of sunlight increase the effects of pollutants in the air, causing increased irritation of airways, leading to coughing and wheezing

Question 8

describe cardiovascualr drift

Answer 8

an increase in heart rate and decrease in stroke volume

Question 9

explain cardio-vascular drift

Answer 9

• occurs after 10 ins in warm conditions
• caused by a reduction of fluid in the blood plasma due to an increase in sweating
• the blood becomes more viscous and consequently nervous return decreases so heart rate increases to maintain cardiac output

Question 10

draw and label a graph showing cardiovascular drift

Answer 10

Question 11

what should happen pre-competition to combat the effect of heat on performance

Answer 11

acclimatisation should occur 7-14 days before event to increase tolerance to the heat:

• increased plasma volume, the onset and rate of sweating and efficiency of cardiac output, decreased loss of electrolytes, decreased HR at a given pace
• use cooling aids like ice vests

Question 12

what are some strategies an athlete should use during competition to combat the effect of heat on performance

Answer 12

use pacing strategies , wear appropriate clothes, rehydrate

Question 13

what are some strategies an athlete should use post- competition to combat the effect of heat on performance

Answer 13

cooling aids, rehydrate with isotonic solutions, glucose and electrolytes

Question 14

what is the effect of altitude on the atmosphere

Answer 14

as altitude increases, biometric pressure decreases. The composition if the air is the same but the ppO2 decreases

Question 15

describe the acute effects of altitude on body systems

Answer 15

• decreased PO2 in alveolar air
• decreased diffusion gradient to capillary blood
• decreased haemoglobin and O2 association
• decreased O2 transportation to muscle tissue
• decreased diffusion gradient to muscle tissue
• decreased O2 supply for aerobic energy production
• increased breathing frequency and increased heart rate
• decreased VO2max

Question 16

describe the benefits of acclimatisation for the cardiovascular and respiratory system

Answer 16

• release erythroprotein, which increases red blood cell production
• breathing rate and ventilation stabilise, however remain elevated at rest and during exercise when compared with sea level
• stroke volume and cardiac output reduce as oxygen extraction becomes more efficient
• there is reduced incidence if altitude sickness, headaches, breathlessness, poor sleep and lack of appetite