Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Animal Physiology > Regulation Of Body Temperature > Flashcards

Regulation Of Body Temperature Flashcards

0
Q

Ectotherm

A

An organism that regulates its body temperature by exchanging heat with its surroundings

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

Endotherm

A

An organism that generates heat to maintain its body temp at constant level

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

Temperature regulation and mitochondria surface area

A

Larger mitochondria surface area permits larger cytochrome oxidase activity to produce more ATP

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

Perfect ectotherm

A

Lizard

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

Perfect endotherm

A

Cat

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

Temporal heterothermy

A

Reducing metabolic rate by being at rest, allowing body temp to drop close to surrounding environment

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

Regional heterothermy

A

Maintain different temperature zones in the body

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

Core temperature

A

Temperature of internal organs, should remain at constant rate (37C)
Can fluctuate between 13-60Cat rest

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

Skin temperature

A

Changes with temp in the surrounding

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

Metabolic rate

A

Rate of energy expenditure (usually per hour)

Measured by calorie consumption (direct) or oxygen consumption (indirect)

4.8 ca, of best/L of oxygen

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

Basal metabolic rate

A

Rate of energy expenditure in a post absorptive condition (following a rest period)

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

Surface area : Volume ratio and BMR

A

Increase ratio = higher BMR

Lower ratio = low BMR

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

Factors affecting BMR

A 
Surface area to mass ratio
Age
Gender
Build 
Stress
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Total metabolic rate

A

Total rate of energy expenditure during ongoing involuntary and voluntary activities

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

What affects total metabolic rate

A

Exercise
Hormones (thyroid, catecholamines, sex, growth)
Both increase TMR

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

Non shivering thermogenesis

A

Hormone mediated increase in TMR

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

Heat production

A

Heat is byproduct of metabolism
Hormones
Sympathetic activity
Muscle activity

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

Heat loss

A

Though the skin

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

Heat conductance

A

Ability to control amount of heat loss or gain between core and skin

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

Skin insulation

A

Blubber reduce best conductance via vasoconstriction.

Fur reduces heat conductance because it disrupts the heat gradient.

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

How does altering blood flow help thermoregulation?

A

Decrease external temp = vasoconstriction = reduce heat loss

Increase external temp = vasodilation = increase heat loss

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

Areas of highest heat conductance

A

Ears, face, hands

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

Heat loss by skin is affected by…

A

Radiation
Conductance (heat gradient)
Evaporation (breathing, sweating, increased via convection)

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

Why is sweating an important cooling mechanism?

A

Sweat is carried to surface of skin through duct

Sweat is isotonic to blood plasma excluding proteins

Most ions are reabsorbed

Keeps body cool because water is cool

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Aldosterone and sweat
Reduces Na Cl excretion
25
Control of sweating
Cholinergic sympathetic pathway
26
Piloerector muscle
Surround hair follicles
27
Temperature regulatory center
Posterior hypothalamus Receives negative feedback signals from sensory thermo receptors at skin that relay stimulus to anterior hypothalamus
28
Thermo receptors
Cold pain Cold Warm Hot pain
29
Ratio of cold to hot receptors
10:1
30
Adaptation of thermo receptors
Response of receptors fades gradually if exposed to same temperature continuously
31
Spatial summation of thermo receptors
Thermal sensation is proportional to number of thermo receptors stimulated
32
Hyoothalamus thermo receptors
Hot to cold = 3:1
33
Set point
Determined by degree of activity of temp receptors in the hypothalamus. Temperature deviating from set point elicit response
34
How does skin temp affect set point
Increase skin temp = decrease set point Decrease skin temp = increase set point (reduce heat loss) Change in set point is to initiate thermo response sooner
35
Specific response to heat
Inhibit thermo receptors in posterior hypothalamus Sweating Vasodilation Decreased heat production
36
Specific response to cold
Stimulate thermo receptors in posterior hypothalamus Vasoconstriction Piloerection (related to fur) Shivering Chemical thermogenesis
37
Prolonged exposure to cold
Increase thyroid releasing hormone Increase thyroid stimulating hormone Increase secretion of thyroid Increase metabolic rate May enlarge thyroid gland
38
Cold stimulate thermo center in posterior pituitary
True
39
Heat stimulate thermo center in post pituitary
False
40
Pyrexia
Fever State of increased body temp beyond normal range due to infection or injury or cancer Caused by response to pyrogens
41
Most common pyrogens
Bacterial lipopolysaccharide toxin (LPS) Viral polyribonucleotide pyrogen (poly I or C) Cytokines from injured cells
42
What receptors do pyrogens act on?
Toll receptors Conserved cross species
43
What do pyrogens activate?
Cyclo oxygenase 2 which produces prostaglandins
44
Function of prostaglandins
Increase hypothalamic set point Increase body temp Inhibited by arachidonic acid like aspirin
45
Hypothermia
Extreme cold causes decrease in body temp
46
Extreme hypothermia
Can disrupt thermo system Resist sleep to survive because you can enter comatose Frost bites cause tissue damage by killing cells Vasodilation causes momentary to permananent paralysis.
47
Why is vasodilation important during extreme cold?
Blow flow to skin increase heat to prevent frost bite
48
Why does the body raise set point due to infection?
Raising set point makes person feel colder so they shiver to generate heat rich raises their temp that is associate with a fever. This rise in body host is suppose to kill infections. Increase neutrophil migration Activate genes via heat shock Survival is better when warm
49
Why are fevers dangerous?
Can cause body to reach temp beyond critical range which can cause brain damage
50
Hyperthermia
Extreme heat that causes body to reach upper temp limit due to insufficient cooling mechanisms
51
Sustained hyperthermia results in...
Hemorrhage Degeneration of cells Damage to vital organs like liver, kidney, etc.
52
How do mammals manage to sustain running while preventing heat stroke?
Anatomical adaptions Counter current best exchange: carotid artery pass sinus with blood returning from nasal cavity. Close proximity cause exchange of heat. Cool blood moves to brain.
53
Adaptations of marine mammals to extreme cold
Blubber increase insulation. Counter current blood flow to extremities reduce heat loss.
54
Adaptation of land mammals to extreme cold
Counter current heat exchange of blood moving to brain Regional heterothermy Low temp lipids Fur Heat shock enzymes make polyunsaturated lipids
55
Temporal heterothermy: Dormancy
Deep sleep Torpor Hibernation Allows body to drop to lower temp during times of non feeding to avoid energy lost
56
Large animals and very small animals cannot hibernate, they exhibit deep sleep
True
57
Marmots, ground squirrels, and some ectotherms hibernate
True
58
Torpor
Short term change in body temp to help body survive in cold climate ``` Reduce core temp Decreased metabolic rate Decreased heart rate Decrease breathing rate Decrease O2 consumption Blood supply restricted to vital organs ```
59
Hibernation
Set point set really low Maintain temp 1C above environment Metabolism keeps temp above freezing
60
Poikilotherm
Ectotherm
61
Q10 effect
For every 10 degrees reaction rate doubles
62
Biochem response in poikilotherms
Acclimatization increase O2 consumption | Heat shock change metabolic rate
63
Freezing extracellular compartment
Poikilotherm survive cold by frees if their extracellular fluid compartment Increases osmotic pressure in extracellular compartment which dehydrates cells Increase intracellular concentration reduce freezing point so cells do not freeze.
64
Super cooling
Prevent ice nucleating centres to prevent ice formation in cold temps
65
Partial freeze tolerance
Produce cyroprotectants: trehalose and proline Forms gel that stabilize cell membranes Prevent formation of ice crystals
66
Freeze avoidance
Produce antifreeze Ie. glycoprotein prevent ice crystals from growing Ie. sorbitol, glycerol increase osmotic pressure of fluid and decrease freezing point
67
Behavioural and Physical mechanisms
Ex. Honey bees Cold cause condensed swarming to reduce heat loss. Bees circulate from inside to outside of swarm to keep warm. Heat cause loose swarm Others: shivering, brown fat, circulation

Animal Physiology (5 decks)

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