Thermoregulation - 4/12 Karius

Question 1

What do thermoreceptors change their firing rate in response to?

Answer 1

Changes in local temperature

Question 2

Thermoreceptors are presumed to be what?

Answer 2

Bare nerve endings (neurite complex)

Warm or cold sensitive

Question 3

What are the warm sensitive ion channels?

Answer 3

TRP-V1 to V4 (cover different temperature range)

Question 4

What activates Vanilloid?

Answer 4

Capsaicin (hot peppers)

Question 5

What are the cold sensitive receptors?

Activated by what?

When?

Answer 5

TRPM8 and TRPA2

Menthol

Open as Temp Decreases

Question 6

Where are thermoreceptors located?

Answer 6

Skin
Viscera
Brain

Question 7

What does the hypothalamus control?

Answer 7

Hormonal, autonomic, and behavioral changes that are part of thermoregulation

Question 8

Responses to cooling occur where?

To heat?

Answer 8

Posterior hypothalamus

Anterior hypothalamus

Question 9

What happens to temperature with sleep?

Exercise?

Answer 9

Decreases

Increases (set point increases)

Question 10

Describe the characteristics of cutaneous thermoreceptors:

Answer 10

10x as many as cold sensitive

Question 11

Where are the central thermoreceptors in the hypothalamus?

Special characteristic?

Answer 11

Pre-optic and supraoptic

3x as many as warm sensitive

Question 12

What hormones increase heat production?

What ANS system?

Answer 12

Thyroxin (inc BMR)
Epi/NE

Symp

Question 13

What other ways can the body produce heat?

Answer 13

Muscular activity

Non-shivering thermogenesis

Question 14

Where does shivering occur?

Increases what?

Answer 14

Dorsomedial posterior hypothalamus

Motor neuron excitation

Question 15

What ways can heat inc with non-shivering thermogenesis?

Answer 15

Increase food intake

Brown adipose tissue

Question 16

What drives the brown fat low efficiency hydrolysis of ATP?

Answer 16

Symp innervation

circulating Epi

Question 17

What is the main way to lose heat?

What kinds?

Answer 17

Evaporation (heat lost as water evaporates)

Insensible (respiratory)
Sweating (controlled)

Question 18

What is convection?

Conduction?

Answer 18

Movement of molecules away from contact (air is heated and rises)

Transfer of heat between objects in physical contact with one another

Question 19

What is radiation heat loss?

Example?

Answer 19

In fared radiation transferring heat between 2 objects not in physical contact

You and the walls

Question 20

If there is increased core T, how does the body increase heat loss?

Answer 20

Blood to skin
evaporative heat loss (sweat)
Insensible (panting)

Question 21

If there is increased core T, how does the body decrease heat production?

Answer 21

Apathy/inertia

Anorexia

Question 22

What is the innervation of sweating?

What nt?
What receptor?

Answer 22

Sympathetic

ACh
Muscarinic

Question 23

What is the composition of sweat at low flow rates when it is not hot?

High flow rates when it is very hot?

Answer 23

Little water, high sodium

High water, low sodium

Question 24

With a decreased core temperature how do you decrease heat loss?

Answer 24

Blood away from skin

Decrease evaporative heat loss

Question 25

With a decreased core temperature how do you increase heat production?

Answer 25

Shivering

Non-shivering thermogenesis

Question 26

Definition of fever?

Implication of it?

Answer 26

Controlled increase in body temperature

Set point increases via direction from hypothalamus

Question 27

What is the major play in making a fever?

Answer 27

PGE2

Increasing set point

Question 28

What is the definition of hyper and hypothermia?

Answer 28

Uncontrolled changes in body temperature

Question 29

In a feed-forward system, how is information used to change the controlled the variable?

Example?

Answer 29

Prevent changes

Putting on a sweater when feeling cold when walking from house to outside