Principles - Feedback control of body temperature

Question 1

What is the core temperature of the body?

Answer 1

37.8ºC

Question 2

What effects do overheating have on the body?

Answer 2

Protein denaturation

Nerve malfunction

Convulsions

Death

Question 3

What is the normal range of temperature measured tympanically?

Answer 3

35.5ºC to 37.5ºC

Question 4

What is the normal range of temperature measured rectally?

Answer 4

36.7ºC to 37.5ºC

Question 5

When is the body temperature normally lowest?

Answer 5

Early morning

Question 6

How is heat gained from the internal environment?

Answer 6

metabolism

Question 7

How is heat gained from the external environment?

Answer 7

Radiation

Convection

Conduction

Question 8

How is heat lost to the external environment?

Answer 8

Radiation

Convection

Conduction

Evaporation

Question 9

Which hormones can lead to an increase in Basal Metabolic Rate?

Answer 9

adrenaline

noradrenaline

thyroxine

Question 10

How can heat production be increased

Answer 10

Muscle activity, either voluntary or through shivering

Question 11

What type of fat may cause thermogenesis?

Answer 11

Brown fat.

Not of great importance in adults

Question 12

How can heat loss occur through evaporation?

Answer 12

Passively - continuous diffusion of water molucules from the skin and airways

Actively - sweating is controlled by the sympathetic nervous system

Question 13

Where is the temperature control centre?

Answer 13

Hypothalamus

Question 14

What are the effectors in negative feedback control of temperature?

Answer 14

Skeletal muscles

Skin arterioles

Sweat glands

Question 15

Which part of the brain is activated by cold?

Answer 15

Posterior hypothalamic centre

Question 16

Which part of the brain is activated by warmth?

Answer 16

Anterior hypothalamic centre

Question 17

How do the skin arterioles affect temperature?

Answer 17

Vasoconstriction - less blood flow to skin surface conserves heat

Question 18

How do the skeletal muscles increase heat production?

Answer 18

Increased muscle tone

Shivering

Question 19

Where are the peripheral thermoreceptors found?

Answer 19

Skin

Question 20

Where are the central thermoreceptors found?

Answer 20

Hypothalamus

Abdominal organs

(and elsewhere)

Question 21

What acts on the hypothalamus to increase the body’s set point?

Answer 21

prostaglandins

Question 22

What causes prostaglandins to be produced?

Answer 22

Pyrogen released from macrophages

Question 23

How are hypothermia, fever and hyperthermia defined?

Answer 23

Hypothermia <= 35ºC

Fever 38ºC - 40ºC

Hyperthermia > 40ºC