Thermoregulation

Question 1

What are the relative temperatures of the body from hottest to coldest?

Answer 1

Core>oral>average skin>hands>feet

Question 2

When is the core temperature the lowest during the day?

Answer 2

6 AM

Question 3

When is the core temperature the highest during the day?

Answer 3

Early afternoon

Question 4

Where are thermoreceptors found?

Answer 4

Skin, viscera, and brain

Question 5

Cutaneous thermoreceptors are bimodal. What does this mean?

Answer 5

They are both temperature and touch sensitive

Question 6

Are there more warm or cold sensitive cutaneous thermoreceptors?

Answer 6

Cold sensitive (10x more)

Question 7

What do cutaneous thermoreceptors tell us about?

Answer 7

Environmental conditions

Question 8

What do visceral thermoreceptors sense?

Answer 8

Core temperature and threats to maintenance of the core temperature.

Question 9

What does the visceral thermoreceptors contact about threats to maintenance of core temperature?

Answer 9

The hypothalamus

Question 10

What is an example of a threat to core temperature?

Answer 10

Food intake (ice cream, hot soup, etc)

Question 11

Where are thermoreceptors located in the brain?

Answer 11

Pre-optic and superoptic region of hypothalamus.

Question 12

Are there more warm or cold sensitive brain thermoreceptors?

Answer 12

Warm sensitive (3x more)

Question 13

What is the core temperature of most humans in the morning?

Answer 13

36.7C

Question 14

The hypothalamus has the connections to control the _______, _______, and _______ changes that are part of thermoregulation.

Answer 14

hormonal; autonomic; behavioral

Question 15

The hypothalamus is the controller for body temperature:

1) Determining _____ ______.
2) Receiving info about ______ _______.
3) __________ ______ _____ ____.

Answer 15

set point;
current temperature;
deciding what to do

Question 16

What 3 things change set point?

Answer 16

sleep, exercise, and fever

Question 17

Sleep _____ set point.

Answer 17

decreases

Question 18

Exercise _______ set point.

Answer 18

increases

Question 19

Fever ______ set point.

Answer 19

increases

Question 20

The ______ part of the hypothalamus responds to heat and causes heat loss behaviors.

Answer 20

anterior

Question 21

The ______ part of the hypothalamus responds to cooling and causes heat production behaviors.

Answer 21

posterior

Question 22

What are the 4 mechanisms of heat production?

Answer 22

1) ANS
2) endocrine
3) muscular activity
4) non-shivering thermogenesis

Question 23

Muscular activity increases body temperature by _____ and increasing ______ ______ via the _____.

Answer 23

shivering; voluntary activity; cortex

Question 24

What is shivering mediated by?

Answer 24

the dorsomedial posterior hypothalamus by increasing motoneuron excitation

Question 25

Non-shivering thermogenesis produces heat by a strong ______ ______, increasing _____ _____, and by _____ adipose tissue.

Answer 25

hormonal influence; food intake; brown

Question 26

The hormones that influence non-shivering thermogenesis, are _____, which is stimulated by cold and increases metabolic rate, and ______.

Answer 26

thyroxin; epinephrine

Question 27

Another mechanism of non-shivering thermogenesis is increasing food intake which leads to an _______ ___ ______.

Answer 27

increase in metabolism

Question 28

Brown adipose tissue increases heat production in non-shivering thermogenesis by _______ ________ for initiation.

Answer 28

adrenergic innervation

Question 29

Brown adipose tissue produces heat by ____ _______ ______ of ATP via uncoupling proteins leads to more heat production.

Answer 29

low efficiency hydrolysis

Question 30

What are the two kinds of evaporative heat loss?

Answer 30

Insensible (respiratory) and sweating (controlled)

Question 31

_______ is movement of molecules away from contact.

Answer 31

Convection

Question 32

_______ is the transfer of heat between objects in physical contact with one another.

Answer 32

Conduction

Question 33

______ is the infrared _____ transferring head between 2 objects not in physical contact.

Answer 33

radiation

Question 34

How much blood is sent to the ____ determines how much heat moves from blood to external environment.

Answer 34

skin

Question 35

Innervation of sweat glands is ________ _______.

Answer 35

sympathetic cholinergic (Ach binding to a muscarinic receptor)

Question 36

The sweat gland duct removes ___ followed by ___.

Answer 36

Na+; H2O

Question 37

When there is a high flow rate of sweating, the sweat has a high concentration of ____.

Answer 37

water

Question 38

When there is a low flow rate of sweating, the sweat has a high concentration of ____.

Answer 38

Na+

Question 39

What happens when there is a decreased core temperature?

Answer 39

Increased heat production (shivering & non-shivering thermogenesis) and decreased heat loss (blood away from skin & decrease evaporative heat loss).

Question 40

A _____ is a controlled increase in body temperature.

Answer 40

fever

Question 41

A set point increase is the body temperature doing what the _____ is telling it to do.

Answer 41

hypothalamus

Question 42

Secretion of _______ by "the bug" and _____ by immune cells cause _______ to be released.

Answer 42

endotoxins; cytokines; prostaglandins

Question 43

Prostaglandins _______ the hypothalamic set point for temperature.

Answer 43

increase

Question 44

When one has a fever, the body temperature is _____ ____ the set point temperature.

Answer 44

less than

Question 45

When one is breaking their fever, the endotoxins and cytokines are no longer being released so the hypothalamus tells the set point to _____ ____ ____.

Answer 45

return to normal

Question 46

When one is breaking their fever, the body temperature is _____ _____ the set point temperature.

Answer 46

greater than

Question 47

When one is breaking their fever, their body ______ heat production and _____ heat loss.

Answer 47

decreases; increases

Question 48

In order to decrease heat production, the body becomes _____ and _____.

Answer 48

apathetic and anorexic

Question 49

In order to increase heat loss, the body uses ______, ______, _______ heat loss (sweating and _____ heat loss (panting)).

Answer 49

conduction; convection; evaporative; insensible