Basic Science of Heat and Cold

Question 1

Epidermis

Answer 1

No BVs or nerve fibers in it

Question 2

Dermis

Answer 2

Two layers
First layer of blood supply
Sweat and sebaceous glands here

Question 3

Three types of cutaneous receptors

Answer 3

Cold receptors
Warm receptors
Pain receptors

Question 4

Cold receptors

Answer 4

10-40 C

50-104 F

Question 5

Warm receptors

Answer 5

30-50 C

86-122 F

Question 6

Pain receptors

Answer 6

below 15 and above 45

below 60 and above 113

Question 7

Firing rates of cutaneous receptors depends on

Answer 7

both temp and duration to adapt

heat and pain adapt quickly

Question 8

Sharp/Dull

Answer 8

Lateral spinothalamic tract

Pain and temp

Question 9

Fibers in lateral spinothalamic tract

Answer 9

Small unmyelinted C fibers

Large myelinated A delta

Question 10

Light Touch

Fibers

Answer 10

Anterior spinothalamic tract

Large myelinated A fibers (a delta and A beta)

Question 11

Effect of local anesthetics

Answer 11

Small unmyelinated nerve fibers are more affected than large myelinated

Question 12

Order from most to least likely for what will be impacted with local anesthetics

Answer 12

C fibers (slow pain and temp warm)
A delta (fast pain, touch, temp cold)
A gamma (proprio, muscle)
A beta (tough and press)
A alpha (motor)

Question 13

Heat

Answer 13

Thermal energy

Question 14

Cold

Answer 14

Less heat (relative term)

Question 15

Temp

Answer 15

Scale to measure heat; not direct

Question 16

Role of perception

Answer 16

everyone perceives differently

Question 17

Conduction

Answer 17

Direct contact

Question 18

Convection

Answer 18

Movement of heated molecules to different site

Question 19

Radiation

Answer 19

Heat transfer via infrared radiation

Question 20

Evaporation

Answer 20

Thermal energy used to vaporize water

Question 21

Conversion

Answer 21

One form of energy is converted to another form

ultrasound electrical –> sound

Question 22

Specific heat

Answer 22

The amount fo energy (heat) needed to increase the temp of 1 gram by 1 C

Question 23

The lower the S, the…

Answer 23

less heat carried by the material

Question 24

Thermal conductivity

Answer 24

Ability of a substance to transfer heat

Unit of measure = k

Question 25

The higher the thermal conductivity…

Answer 25

the higher the rate of transfer

Question 26

What has high thermal conductivity

Answer 26

Water
Muscle
Blood
They have a higher rate of transfer

Question 27

Insulators

Answer 27

Skin and SQ Fat

Question 28

Temp changes associated with heat - superficial heat

Answer 28

Does not affect deep tissue directly
Cutaneous circulation transfers heat to core
VD of deep tissue
Retention of heat in skin/fat

Question 29

Deep heating modalities

Answer 29

Do increase deep tissue temp

Ex = ultrasound and diathermy

Question 30

Temp changes associated with cold - superficial cold

Answer 30

Affects both surface and deep: temp gradient, surface cools faster and more than deep

Question 31

What takes longer?

Answer 31

Re warming takes longer than cooling

Question 32

Influence of heat on blood flow

Answer 32

VD
Inc blood flow
Sweating

Question 33

Influence of cold on blood flow

Answer 33

VC

Dec blood flow

Question 34

Metabolic effects of cold

Answer 34

Inc metabolic heat production but directly dec metabolism

Question 35

Metabolic effects of heat

Answer 35

Dec metabolic heat production but directly inc metabolism

Question 36

Cardiovascular effects - Heat

Answer 36

VD of cutaneous circulation
Dec Blood viscosity
Inc CO and HR

Question 37

Cardiovascular effects - Cold

Answer 37

VC and Inc HR BP and CO

Question 38

Neuronal Effects - Dec temp

Answer 38

Dec conduction velocity

Inc temp = inc conduction velocity

Question 39

Neuronal effects - spasticity and spasms

Answer 39

Heat and cold dec both via spindle activity

Question 40

Neuronal effects - pain

Answer 40

Heat and cold both dec pain