Physio Ch 73

Front 1

Range of normal oral temps (Fahrenheit and Celsius)

Back 1

97 (36) to 99.5 (37.5)

Front 2

Difference between measured oral and rectal temps

Back 2

Rectal is one degree higher

Front 3

Areas where muscular arteriovenous anastomoses provide extra blood flow to skin.

Back 3

Hands, feet, ears

(Most exposed areas of the body)

Front 4

Conserve heat using vaso___________

Lose heat using vaso__________

Back 4

Conserve heat using vasoCONSTRICTION

Lose heat using vasoDILATION

Front 5

Explain why a breeze creates a cooling effect

Back 5

Air heated by the skin is replaced by cooler air more quickly, allowing for rapid conduction of heat.

Front 6

Is rate of heat conduction/convection greater when surrounded by water or air?

Back 6

Water

Front 7

At rest and in environment cooler than body, most heat loss is done by ___________

Back 7

Radiation

Front 8

Two sources of heat loss via water evaporation

Back 8

Skin and Lungs

Front 9

When surroundings are at a higher temp than skin, the only method of heat loss is _____________

Back 9

Evaporation

Front 10

Why does wetting clothes make them fail to retain heat?

Back 10

Water increases the rate of heat transmission, so it no logner insulates.

Front 11

Stimulation of this area of the brain causes sweating

Back 11

Anterior hypothalamic and Preoptic nuclei of the hypothalamus

Front 12

Sweating nerve impulses: sympathetic or parasympathetic?

Back 12

Sympathetic

Front 13

Unique feature of sweat gland nerves

Back 13

Secrete acetylcholine but run with sympathetic nerves

Front 14

True or false: sweat glands are stimulated by circulating epinephrine/norepinephrine

Back 14

TRUE (the nerves are cholinergic, but circulating epinephrine/norepinephrine still creates an effect on the glands)

Front 15

Main ions reabsorbed in sweat gland ducts

Back 15

Sodium and Chlorine

Front 16

Effect of profuse sweating on ion reabsorption. Explain why.

Back 16

Reabsorption decreases. More precursor secretion moving more quickly = less time to absorb.

Front 17

Mechanism by which a person acclimated to heat can reabsorb more NaCl from sweat

Back 17

Increased aldosterone secretion

Front 18

Is the body more capable of temperature regulation in dry or wet air?

Back 18

Dry air

Front 19

More hot or cold receptors in the skin and deep organs?

Back 19

Cold

Front 20

Three immediate reflexes when skin is chilled

Back 20

1) Shivering
2) Inhibit sweating
3) Vasoconstriction

Front 21

Part of brain that integrates central and peripheral temperature signals to produce responses.

Back 21

Posterior hypothalamus

Front 22

What normal inhibits the shivering motor center?

Back 22

Signal from the anterior hypothalamic-preoptic area.

Front 23

By what mechanism can the anterior hypothalamic-preoptic area increase long-term heat production to adapt to cold?

Back 23

Increase TRH secretion

Front 24

What is the main way that skin receptors contribute to core temperature regulation.

Back 24

They alter the hypothalamic set-point

Front 25

True or false: localized skin temperature reflexes can occur well independently of hypothalamic input.

Back 25

FALSE. Though local regulation occurs, it is dependent on central input to function.

Front 26

Define: Pyrogen

Back 26

A substance which causes the set-point of hypothalamic temperature regulation to rise.

Front 27

How is it possible for shivering to occur with fever, even though body temp may be at or above normal?

Back 27

Because the hypothalamic set point has been raised, thus the body is trying to raise its temp to the new set point.

Front 28

Leukocyte pyrogen and endogenous pyrogen are alternate names for:

Back 28

IL-1

Front 29

Name one of the most important cytokines for causing fever.

Back 29

Interleukin-1

Front 30

To cause fever, IL-1 must first cause production of ____________

Back 30

Prostaglandins

Front 31

Define: antipyretic

Back 31

A drug which reduces fever

Front 32

Explain the phenomenon of "crisis" aka "flush" with febrile illnesses.

Back 32

The factor raising set-point is suddenly removed, hence the body tries to quickly reduce temperature to normal. Sweating and vasodilation occurs.

Front 33

How long does it take to acclimate to hot/humid conditions?

Back 33

1-3 weeks

Front 34

Ability to regulate body temperature is greatly diminished below ____ degrees and lost below ____ degrees.

Back 34

85; 94

Front 35

What illness often follows thawing of frost bight?

Back 35

Gangrene

Front 36

How can one artificially induce hypothermia?

Back 36

By administering a strong sedative prior to applying ice/cooling blankets.

Front 37

Describe the change in vascular tone that occurs as frostbite onsets.

Back 37

When temperature reaches freezing, the smooth muscles becomes paralyzed and sudden vasodilation occurs.