PTA 110 Heat applications

Which sensory receptors respond to changes in temperature

skin, muscles, joints

Where is the temperature regulating center

Hypothalamus

What are the activation of temperature-regulating mechanisms

circulatory changes, shivering and sweating

What do Afferent neurons conduct

sensory information from the periphery to the brain

Afferent neurons conduct sensory information from where

the periphery to the brain

What do Efferent neurons conduct

motor information from the brain to the periphery

Where do Efferent neurons conduct motor information from

the brain to the periphery

Mechanism of Heat Exchange

Temperature difference between the thermal agent and the treatment tissue

What does Adipose tissue acts as

an insulation to underlying tissues, thus limiting the degree of temperature change in deeper tissues

What does Blood and muscle do

absorb and conduct heat

What does blood and muscle contain

high water

Conduction

Heat loss or gain through direct contact between materials with different temperatures

Convection definition

The transference of heat to a body by the movement of air, matter or liquid around or past the body

Radiation definition

Transfer of heat, usually through air, from a warmer source to a cooler source

Conversion defininition

Temperature change that results when energy is transferred from one form to another, such as conversion from mechanical or electrical energy to thermal energy

Evaporation

The transformation from a liquid to gas state in which heat is given off

Superficial therapeutic heat effect

increase the temperature of the skin, with little or no effect on deeper structures

what is an example for superficial therapeutic heat

Hot packs, warm WP, parraffin

Deep therapeutic heat

Can increase the temperature of tissues at depths of 3-5cms

Example of deep therapeutic heat

US and diathermy

Therapeutic levels of heating: A Mild

tissue temperatures are less than 40 degrees Celsius

Therapeutic levels of heating: B Vigorous

tissue temperatures 40-45 degrees Celsius. Hyperemia or redness may be noted secondary to an increase in blood flow

Therapeutic levels of heating: C

Tissue temperatures greater than 45 degrees C may result in thermal pain or irreversible tissue damage

Elevation in tissue temperature results in

increase in blood flow to the area, attributable in part to the vasodilatory response in surface blood vessels

Increase in blood flow removes heat from

the area

Local heat application has what effect

both direct and indirect heating effects

If therapeutic heating levels are reached with local application what may occur

reflex heating in other areas of the body

Superficial heat applications generally do no allow for what

increases in muscle temperature, unless those structures are superficial

An increase in tissue temperature correlates with what

increase in metabolic rate

Heat may have a beneficial role in wound healing based on

the increase in blood flow

What does the increase in blood flow results in

an increase in oxygen supply to the wound

Muscle guarding and spasm may occur in response to

trauma or a painful stimulus

What does the Elevation of muscle temperature do

decreases the firing rate of muscle spindle efferent fibers and increases the firing rate of golgi tendon organs

Muscle relaxation from superficial agents may be an indirect reduction

muscle spindle firing as a direct result of elevating skin temperature

What does Heat application have a direct effect on

pain and muscle spasm such that the pain-spasm-pain cycle can be interrupted by influencing pain as well as the muscle spasm

Temperature range needed for residual length changes is

40-45 degrees Celcius

Arthritic patients may benefit from the use of what type of heat

thereapeutic

What is the direct effect of therapeutic heat for Arthritic patients

increase in the elastic properties of the joint capsule and a decrease in associated pain that may contribute to the resultant increased ROM