Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology > L26 - Thermoregulation 1 > Flashcards

L26 - Thermoregulation 1 Flashcards

1
Q

At what temperature are proteins denatured?

A

41˚C

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

At what body temperature will a person die?

A

43˚C

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

At what temperature will all cells in the body die?

A

50˚C

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

At what temperature do you start to “feel cold” when nude?

A

25˚C, initiating a physiological response

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

Above which temperature are you safe while wearing light clothing?

A

0˚C

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

Above which temperature are you safe while properly clothed?

A

-29˚C

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

At which temperature does the respiratory tract begin to freeze?

A

-50˚C

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

Which structures/processes must be involved in thermoregulation?

A

ANS, skin, motor cortex, hypothalamus, renin angiotensin aldosterone system, ANP, vasopressin, cardiovascular system, respiratory system

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

What are the two types of regulation that thermoregulation requires?

A

autonomic regulation and behavioural regulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does autonomic regulation involve?

A

redistribution of blood (CVS), perspiration, fluid balance (renal and endocrine), metabolic changes (respiratory system), non-voluntary skeletal muscle effects

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

What does behavioural regulation involve?

A

changing environment, altering clothing, adjusting fluid/food intake, skeletal muscle effects

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

What is core temperature?

A

temperature inside the chest, abdomen and brain

maintained at ~37˚C ± 0.5˚C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the normal core temperature range?

A

35.5 - 37.7˚C

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

What is peripheral (shell) temperature?

A

can vary broadly
skin temperature varies with environment
working muscles during exercise may reach 41˚C

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

What is the physiological aim of the body in regards to body temperature?

A

maintain a stable core temperature, especially in the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What temperature results in hypothermia? What about hyperthermia and heatstroke?

A

<35˚C

>40˚C, >42˚C

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

What are the two main classes of thermoreceptors?

A

central thermoreceptors and peripheral thermoreceptors

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

Where are central thermoreceptors located and what is their role?

A

anterior hypothalamus

detect temperature changes in the blood

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

Where are peripheral thermoreceptors located and what is their role?

A

located in the skin and viscera
report to central thermoreceptors
can produce local effects

20
Q

What are the four main subclasses of peripheral thermoreceptor?

A

warm and cold receptors

cold pain and heat pain receptors

21
Q

What are central thermoreceptors physically connected to in the hypothalamus?

A

the thermoregulatory center which indirectly sends out autonomic signals through the ANS to skin arterioles, skeletal muscle and sweat glands in order to maintain core body temperature

22
Q

How is heat generated?

A

internally: metabolism, heat released during muscle contractions
externally: heat input if environmental temperature exceeds body temp

23
Q

How is heat lost?

A

environmental heat loss: radiation, conduction, convection and evaporation

24
Q

What is heat?

A

heat = kinetic energy (momentum) of particles

moves from hotter objects to colder objects

25
Q

What is conduction?

A

transfer of heat from one object to another via direct contact

26
Q

What does it mean if a material is better at transferring heat than other materials?

A

this material is a conductor

opposite is an insulator

27
Q

What is radiation?

A

electromagnetic radiation generated by thermal motion of charged particles

28
Q

What is convection?

A

hot air rises and cold air sinks, thus heat can be “carried away” from the body’s surface

29
Q

What is evaporation?

A

conversion of water from liquid to gas by using energy

at body temperature, 2400 calories are required to evaporate 1ml of water

30
Q

How much heat loss is accounted for by radiation?

A

~60% of heat loss

31
Q

How much heat loss is accounted for by conduction and convection?

A

~20% of heat loss

increased with wind

32
Q

How much heat loss is accounted for by evaporation?

A

not necessary <32˚C

33
Q

How is heat loss maximised by the body?

A

increasing cutaneous blood flow and increase sweating (if necessary)

34
Q

How is cutaneous blood flow increased?

A

under control of hypothalamic thermoregulatory centre
sympathetic cholinergic neurons dilate cutaneous blood vessels
↑ blood flow to skin means cardiac output must ↑ to maintain BP (HR + SV ↑)

35
Q

How is sweating increased? How does sweating maximise heat loss?

A

sweat production activated by sympathetic cholinergic neurons
cooling by evaporation: enhanced by ↑ air flow, inhibited by humidity
can increase heat loss ~20 fold

36
Q

What would happen to ventilation (at rest) when body temperature rises?

A

increase
this is because as temperature ↑, enzymatic activity ↑ as well resulting in ↑ metabolism and therefore ↑ requirement for O2 ∴ ventilation ↑

37
Q

What are some behavioural adaptations to increasing heat loss?

A

seek shade, wearing loose/light clothing, inactivity, decreasing food intake, eating food with high water content (becomes more appealing)

38
Q

What is heat syncope? What is “prickly” heat?

A

excessive blood diverted to skin reduces blood flow to brain

inflammation of sweat glands - itchy “pimply” rash

39
Q

What is heat exhaustion?

A 
moderate hyperthermia (core temp 37˚C - 40˚C)
dizziness, fatigue, nausea, possible collapse
40
Q

What is heatstroke?

A

severe hyperthermia (core temp >40˚C)
common during heat waves and in athletes
kills more Australians than all other natural hazards combined

41
Q

Which characteristics would be anatomically advantageous for maintaining a low body temperature in the heat?

A

long, lean extremities, a high surface-area-to-volume ratio and thick hair only on regions facing the sun

42
Q

How do long, lean extremities increase heat loss?

A

increase surface-area-to-volume ratio and increases conduction/radiation hence heat loss

43
Q

Why is an insulating fat layer which is consolidated to one area beneficial to heat loss?

A

allows more heat loss from extremities

also to put it simply there is insulation from heat of sun

44
Q

Which characteristics would be anatomically advantageous for maintaining a high body temperature in the cold?

A

low surface-area-to-volume ratio reduces heat loss

subcutaneous fat evenly distributed as insulation to retain heat

45
Q

How have humans evolved to different climates?

A

humans evolved primarily in an African climate, however, some anatomical adaptations have evolved between races based on climate (environmental) differences

Physiology (33 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions