Skin + Temperature

Question 1

What is core body temp

Answer 1

37 degrees +- 0.5

Question 2

Why is this important

Answer 2

>41 = proteins denature
<30 = LOC

Question 3

What does body temp vary with

Answer 3

External temp
Activity
Circadian rhythm
Menstrual cycle

Question 4

What do we produce all the time

Answer 4

Heat

Question 5

How do you we manage heat

Answer 5

Conduction - heat transfer between touching
Convection - fluid conduction e.g. wind / water chill
Evaporation - respiration / sweating taking heat energy with it (main loss in body)
Radiation - can be loss or gain

Question 6

What do cold receptors do

Answer 6

Respond to cold temp

Peak fire at 30 degrees (10-40 range)

Question 7

What do warm receptors do

Answer 7

Respond to warm temp

Peak fire at 40 degrees (30-50)

Question 8

How do you tell apart

Answer 8

Dynamic response to change in temp

Warm receptors fire more when temp increases

Question 9

What are peripheral thermoreceptors

Answer 9

Located in the skin
Face and scrotum sensitive
Respond to environmental temp

Question 10

What are central thermoreceptors

Answer 10

Located in spinal cord, abdominal organs and hypothalamus

Tell core temperature

Question 11

What happens

Answer 11

Nerves go to hypothalamic thermoregular centre

Response generated

Question 12

What nerve fibres detect cold

Answer 12

A delta

Question 13

What nerve fibres detect warm

Answer 13

C fibres

Question 14

What is fever

Answer 14

Body’s response to infection

Question 15

What causes fever

Answer 15

Endogenous pyrogenes (IL) Increase set point on hypothalamus of where body temp should be  by producing prostaglandins 
So feel cold when temp increases to this point

Question 16

What helps fever

Answer 16

NSAID + Aspirin

Block cycle-oxygenase which stops prostaglandin production which turns up set point

Question 17

How are prostaglandins produced

Answer 17

Cyclo-oxygenase in hypothalamus

Question 18

How does body generate heat in cold stress

Answer 18

Cell metabolism
Voluntary muscle activity
Shivering thermogenesis - involuntary
Non-shivering thermogenesis in infants

Question 19

What is nonshinvering thermogenesis

Answer 19

Brown adipose tissue

Uses protein gradient to produce heat

Question 20

How is heat loss reduced in cold stress

Answer 20

Sympathetic arteriolar construction - A1

Behaviour - add clothes, move to warmth, reduce SA

Question 21

What is hypothermia

Answer 21

<35 degrees

Question 22

Who is at risk

Answer 22

Neonates
Elderly
Outdoor workers/ North Sea

Question 23

How are neonates at risk

Answer 23

Big SA to volume
Little fat
Don’t shiver

Question 24

How are elderly at risk

Answer 24

Do not detect temp well
Immobile
Less shivering capacity

Question 25

What does cold stress do to vascularity

Answer 25

Vasoconstriction so slow flow Increased viscosity Increased thrombosis Hypoxia

Question 26

What does cold stress to cellular

Answer 26

Ice crystals in extra-cellular space Increased osmotic conc Movement of water from intracellular space Cell dehydration

Question 27

What are complications

Answer 27

Increased heart attack and stroke due to vasoconstriction and viscosity

Question 28

How do you Rx hypothermia

Answer 28

``` Dry + insulate to prevent further loss Slow re-warming Internal rewarming with hot drinks Fast re-warming by immersion in water Extra-corporeal circulation ```

Question 29

How is heat production minister

Answer 29

Decreased physical activity | Decreased food intake

Question 30

How is heat loss increased

Answer 30

Arteriolar dilation Sweating Increase SA Remove clothes

Question 31

How do we sweat

Answer 31

Sympathetic cholinergic fibres Release Ach NOT Na

Question 32

What is heat exhaustion

Answer 32

Body temp >37.5-40 Results in vasodilation and drop in blood volume Distance of fluid / salt balance due to sweat

Question 33

What are the symptoms

Answer 33

``` Headache Confusion Nausea Sweating Clammy skin Tachy as low BP Hypotension Weak pule Faint Collapse ```

Question 34

What is heat stroke

Answer 34

If temp above 40 and body's control measures fail | Hot dry skin as sweating ceased and circulatory collapse

Question 35

Who is at risk

Answer 35

Neonates Elderly Protective clothing Physical work in hot environment

Question 36

How do you Rx

Answer 36

``` Move to cool Remove clothing Fan Sponge with tepid water Give fluids - oral or IV ```