Week 7 Physio 1 Plfsom Jr

Front 1

How does the set point work in the body to regulate core temperature?

Front 2

Define Radiation

Back 2

lost in heat (eletromagnetic) waves (60%)

Front 3

Define Conduction

Back 3

heat loss to air (15%), 3% to objects

Front 4

Define Convection

Back 4

loss to air currents- contributes to conduction

Front 5

Devine Evaporation

Back 5

22% heat loss due to evaporation of water

Front 6

What is skin temperature (Ts) in relation to core temperature

Back 6

Ts can vary greately from Tc, and the body adjusts for it. As Ts falls, the set-point rises, and vis-versa. The body does this in anticipation of Tc changing.

Front 7

How is core temperature regulated?

Back 7

receptors in the hypothalamus regulate temperature set point

Front 8

How is shivering used to regulate body temperature?

Back 8

Shivering is triggered by an area in the brain. Neural signals are transmitted to the muscle. The tone of the muscle is increased to a point where shivering will start. Can increase body heat production 4-5X normal. Can be used to prevent hypothermia or raise the body to a new set point. This is why we get the chills, causes shivering and the temp raises.

Front 9

How can the set point be altered to induce fever?

Back 9

Stimulation of LPS releases IL1 which stimulates production of PGE2 which raises setpoint temp.

Front 10

Relationship between IL-1 and cyclooxygenase

Back 10

IL-1 increases synthesis of cyclooxygenase

Front 11

What is the release of IL-1 stimulated by?

Back 11

LPS in gram (-) bacteria. Can come from gram - E. coli in GI tract

Front 12

IL-1 and temp. set point

Back 12

IL-1 stimulates the brain to increase set-point through the release of PGE 2

Front 13

Define hyperthermia

Back 13

Hyperthermia is an elevated body temperature due to failed thermoregulation. Above your setpoint.

Front 14

Define Fever

Back 14

increases setpoint

Front 15

Define pyrexia

Back 15

Fever (also known as pyrexia or controlled hyperthermia) is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.

Front 16

What are the pathological causes of fever

Back 16

LPS in gram (-) bacteria. Can come from gram - E. coli in GI tract

Front 17

PGE2

Back 17

raises hypothalamic setpoint in response to IL-1

Front 18

B-Agonists

Back 18

vasodilation, component of sympathetic

Front 19

A-agonists

Back 19

vasoconstriction, component of sympathetic

Front 20

acetaminophen causes what kind of damage?

Back 20

liver

Front 21

Oral Aspirin

Back 21

reduces fever

Front 22

acetaminophen

Back 22

reduces fever

Front 23

NSAIDS

Back 23

antipyretic (reduces fever)

Front 24

Children and Reye's syndrome

Back 24

Aspirin increases risk for Reye's

Front 25

Aspirin and PGE2

Back 25

Aspirin blocks production of PGE2 by blocking cyclooxygenase

Front 26

What are the drug induced causes of fever

Back 26

LPS can be given in small doses.

Front 27

How does sweating lower body temperature?

Back 27

.58 Kcals are lost for every gram of water that evaporate from the skin.

Front 28

What is the effect of sweating on body fluids?

Back 28

sweat is hypotonic, so ECF become hypertonic, causing cells to dehydrate

Front 29

Normal sweating rate

Back 29

100 mL/day

Front 30

Sweating in heavy exercise

Back 30

1-2 L/hour

Front 31

Insensible water loss

Back 31

400mL/day from skin, 400 mL/day from lungs

Front 32

Are sweat glands sympathetically or parasympathetically innervated?

Back 32

sympathetically

Front 33

Do sweat glands work by secretion or filtration?

Back 33

secretion

Front 34

Is sweat hypertonic or hypotonic?

Back 34

Hypotonic

Front 35

Does sweat become more or less hypotonic with time?

Back 35

more hypotonic

Front 36

What is the decrease in [NaCl] in sweat caused by?

Back 36

the effect of aldosterone from the adrenal cortex

Front 37

Is pure water loss possible?

Back 37

No, there is always some other particle lost with is

Front 38

D5W

Back 38

5% dextrose solution. Glucose is metabolized to CO2 and H20. You have essentially given them water and CO2.

Front 39

How does endocrine control of sweating work?

Back 39

epi and norepi from adrenal gland released in fight or flight increases muscle activity, muscle blood flow, leadsd to increased sweating. This helps maintain temp during exercise.

Front 40

neural control of sweat glands

Back 40

sympathetic nervous system releases actetylcholine (not normal, symp. Normally releases norepi) to stimulate sweat gland activity

Front 41

Concept of gain

Back 41

Correction/Error

Front 42

Define Homeotherms

Back 42

animals who maintain body temperature above ambient temperature and within a narrow range

Front 43

Define Poikilotherms

Back 43

animals in shich the body temperature fluctuates more or less with ambient temperatures

Front 44

Define Endothermic

Back 44

Maintain body temperature

Front 45

Define Ectothermic

Back 45

Temperature is allowed to float

Front 46

What are the advantages to endothermic?

Back 46

improved enzymatic activity, grater endurance, withstand change to environment, etc

Front 47

pyrogens

Back 47

Anything that causes fever. Ex: LPS induces release of IL-1.

Front 48

range of skin blood flow

Back 48

0.1-30% of cardiac output. 100mL/min to 6-8L/min

Front 49

Range of being able to maintain core temp

Back 49

55-130 F

Front 50

Temperature can raise to ____ in hard exercise

Back 50

40C

Front 51

Temperature can lower to ____ in cold weather

Back 51

36C

Front 52

define iatrogenic

Back 52

physician induced

Front 53

Why does heat stroke occur more often in cooler climates with a heat wave?

Back 53

We are more acclimatized to increased sweat production and the decrease in NaCl in the sweat

Front 54

Aldosterone/GI tract relation

Back 54

Aldosterone causes the uptake of sodium in the GI tract, pulling water with it. Too much aldosterone = constipation

Front 55

What enzyme converts free arachidonic acid into prostaglandins?

Back 55

cyclooxygenase (inhibited by NSAID's)

Front 56

What enzyme converts free arachidonic acid into leukotrienes?

Back 56

lipoxygenase

Front 57

When does heatstroke start to set in?

Back 57

>41C, 106F. Associated with neurologic dysfunction

Front 58

In what populations does classic heatstroke tend to occur?

Back 58

Individuals who lack the capacity to modulate the environment (infants, elderly, chronically ill)

Front 59

Exertional Heatstroke

Back 59

engaging in strenous physical activity for a prolonged period in a hot environment

Front 60

Classical nonexertional heatstroke (NEHS)

Back 60

commonly affects sedentary elderly individuals, persons who are chronically ill, and very young

Front 61

malignant hyperthermia

Back 61

when anesthetized, your body temp goes up

Front 62

Explain the changes that will occur in sweat production in a hot environment as compared to a cool environment when exercising.

Back 62

Sweat more in heat.

Front 63

Describe how the composition of sweat changes when the volume of sweat is increased significantly.

Back 63

Aldosterone secretion increases in the hotter environment, making the sweat more hypotonic. Losing a lot of water without losing a lot of salt.

Front 64

What is one of the most potent tool we use to control our body’s temperature? Compare this to the mechanisms used by an ectothermic animal.

Back 64

Changing environment.

Front 65

What role may (does) brown fat play in the regulation of body temperature and body weight?

Back 65

uncouple ATP synthesis to simply produce heat

Front 66

Is increased Thyroxine output a short or long term cause of increased heat production?

Back 66

long term

Front 67

What does thyroxine do

Back 67

incrases the rate of cellular metabolism throughout the body. Example of chemical thermogenesis.