Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BPK 142 > week 12 cold and underwater : environmental physiology > Flashcards

week 12 cold and underwater : environmental physiology Flashcards

1
Q

What is core temp

A

The temperature of the hypothalamus (where temp regulation occurs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How do we measure the temperature of the core

A

rectal and esophageal probes or a pill

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 4 mechanisms of heat loss

A
  1. radiation
  2. conduction
  3. convection
  4. evaporation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is radiation

A

The exchange of electromagnetic energy waves that are emitted by one object and absorbed by another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is conduction

A

what occurs when two surfaces with different temperatures are in direct contact (stovetop)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does not heat easily

A

insulators eg: air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What determines the rate of conductive heat exchange

A

thickness of the insulating substance eg: body fat, multiple layers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is convection

A

requires that one of the media be moving, as occurs with fluid or gaseous medium
eg: heat from a fire moves up and heats your hands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the wind chill index, and what does it measure

A

it tells us the still air temperature for the ambient temperature at different wind velocities

  • “Wind chill is how cold it feels when wind combines with the actual air temperature. Wind removes body heat, making it feel colder than the thermometer shows. It tells us the equivalent temperature in still air that would cause the same heat loss.”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the main factor that causes convective heat loss

A

The temperature gradient between skin and air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is evaporation

A

The transfer of heat from the body surface through the change of liquid H20 to gas in the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the two physiological responses of humans to the cold

A
  1. increase in metabolic rate
  2. increased tissue insulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how does the body increase metabolic rate (cold)

A

excersise
or
shivering raises basal rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how does the body increase tissue insulation

A

through the vasoconstriction of peripheral blood vessels and the increase of blood flow to deeper vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the 3 factors affecting responses to cold

A
  1. skinfold thickness
  2. Gender
  3. clothing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how does skinfold thickness help our reaction to the cold?

A

the thicker the fat layer the greater the insulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how does gender impact our response to the cold?

A

females have more fat, therefore more insulation but they also have larger surface area to mass ratios. means more rapid heat loss
women essentially loose heat more rapidly than men

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how does clothing impact our response to the cold?

A

Insulation of clothing is a function of the air layer next to the skin, the thickness of the clothing and the air trapped between the layers
- reduced when clothing becomes wet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

in the cold what should your innermost layer consist of

A

material that provides insulation but also gets rid of moisture from skin, this reduces evaporative heat loss
eg: polyester

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What temperature is hypothermia

A

below 35 degree cel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what organs are the body core

A

brain heart lungs blood liver and kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

where do we loose heat

A

head and neck, sides of chest and groin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

when does shivering stop and what temp is death

A

shivering stops when core temp is blow 32-34
death at 24-28

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are the 7 factors assoicated with hypothermia

A
  1. immersion in cold water or wet clothes
  2. wind
  3. exhaustion
  4. inadequate clothes
  5. low percent body fat
  6. hypoglycemia
  7. alcohol consumption
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How can alcohol consumption increase the risk of hypothermia
causes a decrease in shivering, increased blood flow to skin, impairs judgment
26
What does hypothermia do to the oxyhemoglobin dissociation curve and why?
shift to the left
27
what temperature does frost bite occur at and why are people usually unaware when it happens
-2 to -6 degrees many people are unaware because the nerves are blocked and the skin is numb
28
what decreases when muscle and nerve temperature decreases
- strength and power -nerve conduction speed -reaction time -dexterity and flexibility
29
how does the cold effect performance
- when temperature drops, there is a reduction in aerobic performance
30
what happens during cold water immersion
more dramatic heat loss
31
what is more conductive water or air
water is 25 times more conductive
32
what is the pressure of air at sea level
1.0 atmosphere
33
when does pressure increase by one atmosphere
every 10m of depth
34
what does pressure do to the bodies air cavities
the volume and pressure will change with increases or decreases in diving depth
35
what is Boyle's law
the volume of any gas varies inversely with the pressure on it, if the pressure is doubled the volume is halved
36
What are the two limits to snorkeling
1. pressure effects 2. increase in pulmonary dead space
37
how does pressure effect snorkeling
- diver must breath in air at atmospheric pressure at 3 ft the compressive force of water against the chest cavity is so large that the muscles can't overcome the external pressure and expand the thoracic cavity
38
what is dead space
air that doesn't participate in gas exchange
39
what happens when you have a long/bigger snorkel
The more dead space Must breathe deeper to maintain alveolar ventilation More work = higher energy demand
39
what is lung squeeze
the air in the lungs is compressed as divers descend
39
When does lung damage occur when diving
when the lung volume is compressed below residual volume (blood is sucked from pulmonary capillaries into alveoli)
39
how does drowning occur
PaO2 decreases below critical point diver loses consciousness and drowns
39
what happens to gases in the lungs when diving
ases in the lung are compressed and partial pressures are increased holds breath as long as possible and partial pressure of gases in lung decrease on ascent
39
what is paradoical drowning
when someone drowns after surfacing or escaping the water, usually because water in their lungs or airway causes them to stop breathing later on — even though they seemed okay at first. - hyperventilate, holds breath and dives down a certain depth
39
what does scuba stand for
self-contained underwater breathing apparatus
39
how do scuba regulators allow us to breath under water
reduce the air pressure in the tank from approximately 2500 to exactly the ambient pressure at the diver's mouth
40
what do underwater breathing systems have to overcome
must supply air at sufficient pressure to overcome the force of water against the divers chest
41
what are open circuit scuba
sports divers use - slighlty negative pressure air enters lungs and exhalation is discharged into the water
42
what are the 7 potential medical probelms associated with scuba diving
1. air embolism 2. pneumothorax lung collapse 3. nitrogen narcosis 4. the bends 5. oxygen poisoning 6. mask squeeze 7. middle ear squeeze
43
what is air embolism
embolus - any material that enters and obstructs a blood vessel (blood clot)
44
how does air embolism occur
- diver inflates lungs and begins ascent, doesn't exhale (DONT HOLD YOUR BREATH) pressure decreases as he ascends and the air in alveoli expands (boyles law) and alveoli rupture this causes air bubbles in blood which block
45
what is Pneumothorax Lung Collapse
when the alveoli is ruptured - air pockets in the chest wall and lung tissue - the continued expansion of trapped air causes ruptured lung to collapse during ascent
46
what is nitrogen narcosis
when you are at depths over 100ft (30m) the increase in partial pressure and quantity of dissolved nitrogen has a anesthetic effects on the CNS - similar to alcohol
47
what are the bends
"decompression sickness" when the diver ascends to rapidly after a deep long dive and the dissolved nitrogen moves out of solution and forms bubbles in body tissues
48
where is pain first felt from the bends
around the joints 4-5 hours after the dive
49
what happens if the bends bubble get in an artery
permanent damage or death
50
what is the treatment for the bends
recompression in a hyperbaric chamber to force the nitrogen gas back into solution, then slow decompression
51
how to prevent the bends
ascend to the surface in stages and allow for decompression stops for time for nitrogen to diffuse from tissues to the blood without bubbles forming
52
What is oxygen poisoning
when PO2 inspired exceeds 1520 mm Hg for 30-60 min longer - irritation of the respiratory passages, which leads to pneumonia
53
what is PO2
partial pressure of oxyegn (how much oxygen is in your blood) - how much oxygen is available for your body to use
54
what is mask squeeze
- occurs in descent, mask must cover eyes and nose so it can be equalized with outside ambient pressure by occasionally blowing out the nose - if pressure in not equalized mask vaccums and blood vessels in and around the eyes rupture
55
what is the eustachian tube
a small membrane lined passage that connects the middle ear cavity and the back of the throat - aids in equilibrate the pressure in the ear with the outside by transferring air to or from lungs
56

BPK 142 (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions