Brainscape's Knowledge GenomeTM

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


See full index

Human Physiology > W6 - Thermoregulatory System > Flashcards

W6 - Thermoregulatory System Flashcards

1
Q

Contributing factors to heat loss

A

Radiation

Conduction

Convection

Evaporation

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

How does heat conservation happen?

A

When blood is quickly shunted to the deep cranial, thoracic + abdominal cavities.

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

Contributing factors to heat gain

A

BMR

Muscular activity

Hormones

Thermic effect of food

Postural changes

Environment

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

During heat conservation, why is blood rapidly shunted to the deep cranial, thoracic + abdominal cavities?

A

To optimise insulation from subcutaneous fat + other components of the bodys shell.

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

What does an increase in internal heat do to the bodys peripheral vessels?

A

Dilates them as warm blood flows to the cooler periphery.

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

What contains the central coordinating centre for temperature regulation?

A

Hypothalamus

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

What are the 2 ways in which the bodys heat-regulating mechanisms can be activated?

A

Thermal receptors in skin

Changes in temp of blood that perfuses the hypothalamus

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

Where do the thermal receptors in the skin provide input to?

A

Central coordinating centre in hypothalamus

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

What plays the primary role in maintaining thermal balance?

A

The central hypothalamic regulatory centre

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

What do cells in the anterior portion of the hypothalamus detect and what do they receive?

A

Slight changes in blood temp

Receive peripheral input.

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

What is the result of the cells activity in the anterior portion of the hypothalamus being heightened?

In regards to the anterior hypothalamus

A

Initiates coordinated responses to facilitate heat loss = cooling

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

What provides as the primary monitoring system to asses body warmth?

A

Temp of blood that perfuses the hypothalamus.

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

What are the organism types for thermoregulation?

A

Homeotherms

Endotherms

Ectotherms

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

Define homeotherms

A

Have a constant internal body temp regardless of external stimuli

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

Define endotherms

A

Generate heat internally

Maintain high basal heat prod

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

Define ectotherms

A

Depend on external heat sources

Temp changes w/ env

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

What is our core body temp?

A

36.5-37.5

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

What is the optimal function for our temp?

A

36.5-40.0

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

When can hypothermia be established?

A

When body temp is <35.0

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

What is the lowest survivable internal core temp?

A

~14.4

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

Effects from hypothermia

A

Loss of motor skills

Shivering

⬇️ blood circulation

⬇️ skin temp

Confusion/fatigue

Loss of consciousness

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

When can hyperthermia be established?

A

When body temp is >38.0

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

What is the highest survivable internal core temp?

A

~46.5

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

At what body temp does damage to cells occur?

A

42.0 + above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Biggest effects of hyperthermia

A

Heat exhaustion

Heat stroke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Symptoms of heat exhaustion

A

Faint/dizzy

Excessive sweating

Cool, clammy skin

Nausea

Rapid,weak pulse

Muscle cramps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Symptoms of heat stroke

A

Throbbing headache

No sweating

Red, hot, dry skin

Nausea

Rapid, strong pulse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Factors affecting core body temp

A

Body morphology

Environnent

Skin

Metabolic heat production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What comes under body morphology?

A

Body mass

Body composition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Factors affecting core body temp

What comes under skin?

A

SA

Temp

Skin wettedness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Factors affecting core body temp

What comes under environment?

A

Temp

Humidity

Air velocity

Air density

Clothing properties

32
Q

Define specific heat capacity

A

Amount of energy req to raise the temp of a given substance by 1 degree celsius

33
Q

What are the 2 types of heat production?

A

Voluntary

Involuntary

34
Q

What comes under voluntary heat production?

A

Exercise

35
Q

What comes under involuntary heat production?

A

Shivering

Hormones (thyroxine + catecholamines)

36
Q

How many kJ of heat does 1l of O2 produce?

A

~20kJ

37
Q

How can you measure core body temp?

A

Using thermometer probe

38
Q

Where can the thermometer probe be used to measure core body temp

A

Hypothalamus

Oesophagus

Rectum

Intestinal

Oral under tongue

Ear drum

39
Q

What does measuring skin temp depend on?

A

Ambient temp

Distance from core

Skin bf

40
Q

In what ways can we externally gain heat?

A

Sky thermal radiation

Solar radiation

Ground thermal radiation

41
Q

What does the thermal gradient state?

A

Heat transfer is always from higher to lower temps

42
Q

% heat loss at rest from evaporation

A

~25

43
Q

% heat loss during exercise from evaporation

A

~85

44
Q

How many kJ of heat comes from 1g of sweat?

A

2.41

45
Q

When sweating, what are the sweat glands stimulated by?

A

Sympathetic nervous system. (SNS)

46
Q

What factors influence evaporation + how?

A

Air temp (humidity) = ⬇️ it

Convection currents (winds) = ⬆️ it

Skin exposure = ⬆️ it

47
Q

How is sweat loss calculated?

A

Change in mass + fluid intake - urine

48
Q

What does the sweat rate depend on?

A

Body size

Absolute VO2

Aerobic fitness

Heat acclimatisation

Env

49
Q

Define radiation

A

Transfer of heat in form of electromagnetic waves

50
Q

% of heat loss at rest at room temp from radiation

A

~60

51
Q

Define conduction

A

Heat transfer from body to object w direct contact

52
Q

% of heat loss at rest at room temp from conduction

A

~3

53
Q

Define convection

A

Heat transfer from 1 place to another by movement of fluids (air/H20)

54
Q

% of heat loss at rest at room temp from convection

A

~12

55
Q

What happens to heat dissipation by convection during exercise?

A

Reduced

56
Q

Actions of the hypothalamus following hypothermia

A

Cutaneous vasoconstriction

Shivering

Catecholamine release

Thyroxin release

57
Q

Areas of body w. greater heat loss

A

Skull

Groin

Armpits

Extremities

58
Q

What does hyperthermia do to sprint + power performance?

A

Improves it

59
Q

How does hyperthermia improve sprint + power performance?

A

⬇️ resistance of muscles/joints

Faster nerve conduction velocity

Improvement in muscle contractile elements

Faster metabolic rate

⬆️ SNS activity

60
Q

Define Q10 temp coefficient

A

Measure of rate of change of system as a consequence of increasing temp by 10C.

61
Q

What does hyperthermia do to endurance performance?

A

Impairs it

62
Q

What does hyperthermia do to repeated sprint ability?

A

Impairs it

63
Q

Overall why is performance impaired by ⬆️ core temp + sweat rate?

A

⬇️ plasma vol

⬇️ blood vol

⬇️ venous return

⬇️ end diastolic vol

64
Q

Cognitive consequences of core temp ⬆️

A

Fatigue perception ⬆️

Impairment in:

Scanning vigilance
Reaction time
Attention
Visual motor tracking

65
Q

Order of warning signs for hyperthermia

A

Heat cramps –> Heat Exhaustion –> Heatstroke

66
Q

Treatment to heat exhaustion

A

Cooler env

Elevate feet

Saline (orally or intravenous)

67
Q

Treatment for heat stroke

A

Cold water

Ice bath

Wet towels

68
Q

Methods to reduce hyperthermia during exercise

A

Heat acclimatisation

69
Q

Effects of heat acclimatisation

A

⬇️ body temp at given heat

⬆️ sweat rate + more dilute

⬇️ Skin bf = ⬆️ to muscles

SV maintained

70
Q

What is the result to the stimulation of cutaneous cold receptors?

A

Constricts peripheral bv = ⬇️ bf of warm blood to bodys cooler surface + redirects it to warmer core.

71
Q

What does shivering do?

A

Generates metabolic heat

72
Q

Thryoxine

A

Thyroid hormone that ⬆️ resting metabolism

73
Q

What 2 competitive CV demands does the body encounter when exercising in the heat?

A
  1. Muscles req delivery of arterial blood to sustain energy metabolism
  2. Arterial blood diverts to periphery to transport metabolic heat for cooling at skin surface (this blood can’t deliver O2 to active muscle)
74
Q

What effect does ageing have on thermoregulation?

A

Delays onset of sweating + blunts the magnitude of the sweating response in 1 of 3 ways.

75
Q

What are the 3 ways in which ageing can blunt the magnitude of the sweating response?

A
  1. Modified sensitivity of thermoreceptors
  2. Limited sweat gland output
  3. Dehydration-limited sweat output w. insufficient fluid replacement
76
Q

Functions of the posterior portion of the hypothalamus

A

⬆️ blood pressure

Shivering or body heat conservation (thermoregulation).

77
Q

What does damage or destruction to the posterior region of the hypothalamus cause?

A

Hypothermia

Human Physiology (16 decks)

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