Body Temperature

1
Body Temperature

• By Ashley Barnett
• T4 Project

2
Temperature Regulation

• Core Temperature - refers to bodys internal
• temperature as opposed to temperature near
• surface. Core temperature is 98.6 degrees F
• or 37degrees C.
• Temperature regulation is very important to the
• human body.
• enzymes function 0-40 degrees Celsius
• enzymes begin to denature at 40 degrees
  Celsius
• The main source of body heat is your metabolism.
• Your metabolism is messed up when temperature
• exceeds or falls below proper range.

3
Heat

• Heat moves from or to body by
• radiation transfer of energy as
  electromagnetic waves through matter or space
• conduction transfer of energy by direct
  contact
• convection transfer of heat by way of moving
  currents (air or H2O)

• Heat moves away from body by
• evaporation conversion of liquid to gas
• -Evaporation has a cooling effect on the body.
• -Evaporation rate depends on humidity and rate
  of air movement.

4
Classifications

• Some classifications of animals are based on
  body temperature.
• Ectotherms - they obtain their heat from the
  their environment. They move into sun or onto
  heated rocks to warm body move to shade, crawl
  into crevices, etc, to escape heat.
• Ex. Lizards, snakes,
  and other reptiles

5
Classifications

• Endotherms body temperature is controlled by
  metabolic activity and controls over heat
  conservation and dissipation
• Ex. Rabbit
• Heterotherms can allow temperature to fluctuate
  as ectotherms and can control heat as endotherms
  do
• Ex. Hummingbird

6
Responses to Cold Stress
1. Widespread vasoconstriction in skin Adjusted
behavior (minimizing surface parts exposed to
cold) Body heat is conserved. 2. Increased
muscle action shivering nonshivering heat
production Heat production is increased.
7
Responses to Heat Stress
1. Widespread vasodilation in skin sweating
adjusted behavior panting Heat is dissipated
from body 2. Decreased muscle action Heat
production decreases
8
Fever

• During a fever, the hypothalamus (a brain center
  that monitors many things including temperature)
  has reset the bodys thermostat.
• Fever is often a defense mechanism against
  infections.
• The controlled increase in body temperature
  during a fever seems to enhance the bodys immune
  response.
• Usually when a fever occurs we take aspirin or
  other drugs to stop the fever.
• But sometimes taking the medicine will actually
  interfere with the beneficial effects of the
  fever.

9
THE END

• There are many things that contribute to your
  body temperature. We have looked at a few such
  as heat and cold stress and heat loss against
  heat gained.
• Temperature is such an important factor that one
  animal classification is even based on
  temperature.
• Temperature regulation is what keeps your body
  going.

10
TRUE / FALSE QUIZ

• 1. Metabolism is the main source of body heat.
• 2. Reptiles are ectotherms that get body heat
  from the environment.
• 3. Humans are endotherms.
• 4. Shivering is a way to lower body heat.
• 5. Sweating cools the body by evaporation.

11
TRUE / FALSE QUIZ

• 6. The hypothalamus in the brain is the bodys
  natural thermostat.
• 7. Normal human body temperature is 37 degrees
  Celsius.
• 8. Conduction of heat involves air or water
  currents.
• 9. The sun warms us by radiant heat.
• 10. Touching a hot stove is convection heat
  transfer.