Body temperature and balance between heat production and heat loss. Regulation of body temperature.

Question 1

intro

Answer 1

when the body functions to maintain constant internal environment due to changes in internal environment

to maintain dynamic equilibrium (36.7) for cell function

Question 2

list the heat production methods

Answer 2

basal metabolic rate

muscle activity

non muscle activity

food thermogenesis

hormonal thermogenesis

behavioural

vasodilation

piloerection

Question 3

heat production method 1

Answer 3

basal metabolic rate
= energy release when the body is at rest

including
- breathing
- circulation
- cellular metabolism

Question 4

heat production method 2

Answer 4

muscle activity

voluntary = excercise
involuntary = shivering

Question 5

heat production method 3

Answer 5

non muscle activity

common in infants

performed by brown adipose tissue which when burned can produce fatty acids

activated by noradrenaline, SNS

Question 6

heat production method 4

Answer 6

food thermogenesis

process of digestion/ absorption/ metabolisation produces heat

Question 7

heat production method 5

Answer 7

hormonal thermogenesis

hormones like thyroxine + adrenaline increase metabolic rate = increase heat production

Question 8

heat production method - 6

Answer 8

behavioural

going into sun to warmer/ wearing more clothes

Question 9

heat production method 7

Answer 9

vasoconstriction

blood vessels narrow by hypothalamus to reduce blood flow to body surface to prevent heat loss by conduction/ convection/ radiation

Question 10

heat production method 8

Answer 10

piloerection

• hairs stand up as erector pili muscles contract
• form insulation layer to keep heat trapped under

Question 11

heat loss methods list

Answer 11

conduction

convection

radiation

evaporation

respiration

vasodilation

behavioural

Question 12

heat loss method 1

Answer 12

conduction

heat can be directly transferred from a hot person if they are sitting on a cool surface

Question 13

heat loss method 2

Answer 13

convection

heat can be removed from a person by air from fan to blow heat away

Question 14

heat loss method 3

Answer 14

radiation

transfer of heat from hot person to cold object WITHOUT direct contact

Question 15

heat loss method 4

Answer 15

evaporation

heat can be lost from the skin as sweat (liquid) turns into vapor (gas)

when environment temp > body temp

Question 16

heat loss method 5

Answer 16

respiration

hot person breathes out hot air exchanging it for cold air

Question 17

heat loss method 6

Answer 17

vasodilation

blood vessels dilate, more bloodflow to skin surface to be dissipated by radiation/ convection

Question 18

heat loss method 7

Answer 18

behavioural

• seek shade during heat
• remove clothes

Question 19

factors

Answer 19

clothing
- amount/ type of clothing affect heat loss/gain

health
- hyperthyroidism = heat intolerance
- hypothyroidism = cold intolerance

age
- old people/ young babies = less efficient thermoregulation mechanisms

fitness
- more healthy person = better thermoregulation system

environment
- hot environment is less likely to lose heat

Question 20

regulation of thermoregulation - 1

Answer 20

negative feedback

Question 21

regulation of thermoregulation - 2

Answer 21

positive feedback

Question 22

regulation of thermoregulation - 3

Answer 22

set points

• there is an ideal value for the physiological parameter
  body temp = 36.7
  pH = 7.36-7.44
  glucose = 70mg/dL-100mg/dL

Question 23

regulation of thermoregulation - 4

Answer 23

sensors

peripheral thermoreceptor
- located on skin
- detect change external environment

central themoreceptor
- located on hypothalamus
- detect change internal environment

Question 24

regulation of thermoregulation - 5

Answer 24

detection

anterior hypothalamus
- activating heat loss mechanism

posterior hypothalamus
- activating heat gain mechanism

Question 25

regulation of thermoregulation - 6

Answer 25

acclimatisation

long term adaptation overtime = increase efficiency of thermoregulation system