Shared Flashcard Set

Details

cold environemnts and human performance
gagag
20
Anatomy
Undergraduate 2
12/11/2009

Additional Anatomy Flashcards

 


 

Cards

Term

 

 

 

 

what are the mechanisms of heat loss?

Definition

 

 

 

1. radiation

2. convection

3. conduction

4. evaporation

Term

 

 

 

 

what is radiation?

Definition

 

 

 

 

the exchange of electromagnetic energy waves from one object and absorbed by another

 

 

Term

 

 

 

 

 

what the manhattan effect?

Definition

 

 

 

@ room tem and naked. 60% of heat loss will be because of radiation

Term

 

 

 

 

what is conduction ?

Definition

 

 

 

 

when two surfaces with differing temps are indirect contact.

 

Term

 

 

 

what are insulators?

 

why is heat conduction in wter 25x greater than in air?

Definition

 

 

dont conduct heat readily - air and water is an excellent insulator.

 

the rate of conductive heat exchange in related to the thickness of the insulating substance.

 

Term

 

 

 

 

what is convection ?

what is the wind chill index?

Definition

 

 

 

one of the media be moving as occurs with fluid or gaseous mediums..

 

gives the equivalent still air temp for a particular ambient temp at differnt wind velocities

Term

 

 

 

 

what is important in determining convective heat oss btween win and air?

Definition

 

 

 

 

temp gradient and air velocity

Term

 

 

 

 

 

what is evaporation?

Definition

 

 

 

 

transfer of heat from the body surface through the change of liquid water on the skin to vapour

Term

 

 

 

what are the two primary physiological response used by humans to defend agains the cold?

 

explain

Definition


1. increase metabolic rate: voluntary - exercise -- increases 10-20x the basal rate


involuntary -- shivering - increase basal by 3-4x


2. increase tissue insulation: vasoconstriction of peripheral blood vessels and shunting blood into deeper vessels

superficial dont constrict ; like the heat loss from the head

Term

 

 

 

 

what are the factors that affect response to cold?

 

Definition

 

 

 

  1. skinfold thickness -- the ticker the better
  2. gender -- females have more fat = better insulation
  3. clothing -- thickness of clothes traps heat

 

Term

 

 

what is hypothermia ?

 

what does body core mean?

 

where do you lose heat the most?

Definition

 

 

body core goes below 35

 

body cores means brain heart lungs liver and kidneys

 

critical areas ; head and neck, sides of chest and groin

Term

 

 

 

 

when will you stop shivering?

Definition

 

 

 

 

if core temp goes below 32-34

Term

 

 

 

 

what are the factors that are associated with hypothermia?

Definition

 

 

1. immersion in cold water or wet clothes

2. wind

3. physical exhaustion

4. inadequate clothes for cold weather

5. lower % of body fat

6. hyopglycemia

7. alcohol consumption - decreases blood flow to skin

Term

 

 

 

 

 

what is hypoglycemia?

Definition

 

 

 

 

no shivering

Term

 

 

 

 

what happens during hypothermia?

Definition

 

 

oxyhemoglobing curve shifts to the left --> increase hemoglobin affinity for o2 --> less o2 to the tissues --> body tissues shift to anaerobic --> hypoxia of the har and brain plus metabolic acidosis--> depressed brain function and Q --> ventricular fibrilation and death

Term

 

 

 

 

what happens when you get a frostbite?

Definition

 

 

it is the freezing of superficial tissues when the temp is -2 -6

 

many people dont know they are frostbit because sensory nerves are blocked and skin is numb

Term

 

 

 

 

explain cold exposure and and the respiratory tract

Definition

 

inhaled air enters the upper respiratory passage - warmed to 37 and is saturated with water

 

** you cant freeze ur lungs when exercising in the cold

 

if the air is cold, you can cause the rp to be come dry and have irritation of the throat

Term

 

 

 

 

what are the effectos of cold on performance?

explain them

Definition

 

 

1. cardivascular endurance -- vo2mx decreeased because hr shift to the left

look at diagram.. find it...

reduce blood flow --- more anaerobic metabolism

 

2. strength, power and flexibility

 

 

Term

 

 

 

what decreases with strength power and flexibility in the cold?

Definition

 

  • strength and power
  • nerve condunction velocity
  • reaction time
  • manual dextrity
  • flexibility
Term

 

 

 

 

name those cold injuries

Definition

 

 

hypothermia

frostbite

cold exposure to respiratory tract

 

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