Thermoregulation

Question 1

Poikilothermic

Answer 1

Temperature conformer: body temperature conforms to the external temperature (ex: lizard) (varied heat)

• ectothermic
• bradymetabolic: relatively low metabolic rate
• regulate temperature through behavioral processes

Question 2

Homeothermic

Answer 2

Temperature Regulator: internal temperature says the same even when outside changes (similar heat)

• temperature regulated to some extent by autonomic and/or behavioral processes
• ectothermic & endothermic
• tachymetabolic: relatively high metabolic rate

Question 3

Tachymetabolic

Answer 3

relatively high metabolic rate

Question 4

Bradymetabolic

Answer 4

relatively low metabolic rate

Question 5

ectothermic

Answer 5

outside-hot

-regulate by outside means

Question 6

endothermic

Answer 6

within-hot

Question 7

Young Homeotherms

Answer 7

May not be able to regulate their own body temperature at birth (ex: rats and human babies cannot thermoregulate outside of their comfort zone, unlike lambs)

Question 8

Thermoregulatory control systems (Homeotherm)

Answer 8

• controlled system (environment heat exchange impacts this): core temperature
• controlling elements: thermoregulatory effectors
  feedback: peripheral & deep-body thermoreceptors
• comparator: CNS compares temperature to set point

Question 9

Conduction

Answer 9

Transfer of heat between objects:

• warmer to cooler (concentration gradient)
• that are in direct contact with one another

Question 10

Convection

Answer 10

-The transfer of heat energy by air currents.

Question 11

Evaporation

Answer 11

-Conversion of a liquid into a gaseous vapor
- a process that requires heat
– the heat of
vaporization –
-which is absorbed from the skin

Question 12

Radiation

Answer 12

-The transfer of heat energy from a warmer object
to a cooler object in the form of electromagnetic
waves (“heat waves”) which travel through space
-ex: feeling the heat from the sun on a cool day

Question 13

CNS - Comparator

Answer 13

-primarily the hypothalamus controls temperature regulation

Question 14

Thermoreceptors - Feedback

Answer 14

• the feedback to the CNS is from sensors through the body
• from periphery (skin)
• central (inside body)

Question 15

Fever

Answer 15

Regulated core change in temperature

-a symptom of a disease processes

Question 16

Cold fibers vs warm fibers

Answer 16

Warm has a higher impulse frequency between 35-50 degrees compared to cold between 20-45

Question 17

thermo TRP receptors

Answer 17

TPRV1 - painful heat
TPRV2 – painful heat
TPRV3 – non-painful warmth
TPRV4 – non-painful warmth
TPRm8 – non-painful cool
TRPA1 – painful cold

Question 18

effectors - controlling elements

Answer 18

effect changes so that variable return back to set point
-ANS
>brown adipose tissue: non-shivering thermogenesis (adrenergic receptors beta)
>vasomotor system: thermal insulation (adrenergic delta), ex: vaso constriction or dilation
>sweat glands: sweat (ACh)
-SNS
>skeletal musculature: shivering thermogenesis (ACh)
>voluntary movement: behavioral thermogenesis (ACh)

Question 19

brown adipose tissue

Answer 19

non-shivering thermogenesis
>transfer
energy from food into heat
>brown because highly vascolizered
>Mitochondria in eukaryotic cells utilize fuels to produce energy in the form of
ATP primarily via oxidative phosphorylation
>Uncoupling Protein in brown adipose tissue uncouples oxdiative
phosphorylation such that heat rather than ATP is generated

Question 20

vasomotor system

Answer 20

> vasodilation: cool off

>vasocontraction: save heat to warm up

Question 21

Sweat Glands

Answer 21

> Sweat: water goes to the surface of the skin and cools off organism

Question 22

Shivering Thermogenesis

Answer 22

• skeletal musculature
• involuntary trembling caused by contraction or switching of muscles
• not efficient but works
• requires a lot of energy

Question 23

Behavioral Thermogenesis

Answer 23

• voluntary movement

- think rat pups huddling together

Question 24

Core Temperature

Answer 24

• hyperthermia: above set point/too hot
• normothermia: at set point
• hypothermia: below set point/too cold

Question 25

Normothermia

Answer 25

temperature is at set point
-autonomic response
>low metabolism
>high skin blood flow (keeps temperature constant)
>low evaporation 
>low piloerection
>behavioral response: don't move

Question 26

Forced Hypothermia

Answer 26

temperature is forced below set point
>high metabolism
>low skin blood flow
>low evaporation 
>high piloerection
>behavioral response: move to warmer area, try to dry off if you feel into a cold river

Question 27

Regulated Hypothermia (decrease in set point)

Answer 27

temperature is down by following set point
>low metabolism
>high skin blood flow
>high evaporation
>low piloerection
>behavioral response: move to colder area

Question 28

Forced Hyperthermia

Answer 28

temperature is forced above set point
>low metabolism
>high skin blood flow
>high evaporation 
>low piloerection
>behavioral response: move to colder area

Question 29

Regulated Hyperthermia (increase in set point)

Answer 29

ex: fever
were temperature is regulated but above set point
>high metabolism
>low skin blood flow
>low evaporation
>high piloerection
>behavioral response: move to warmer area, maybe drink something hot … etc

Question 30

Human Fever

Answer 30

• morning temperature of 37.2 or higher

- evening temperature of 37.7 or higher