18. Temperature Control

Question 1

What is the advantage of being homeothermic?

Answer 1

Can live in cold climates as are unaffected to changes in ambient temperature

Question 2

What are the disadvantages to being homeothermic?

Answer 2

Expends energy

Complex regulation

Question 3

What is the optimal internal temperature range?

Answer 3

35.5-37.7

Question 4

What is the name for an animal that can’t control its own body temperature?

Answer 4

Poikilothermic

Question 5

What is the effect of temperatures between 40 to 44?

Answer 5

Heat stroke

Brain lesions

Question 6

What causes body temperatures between 38 to 40?

Answer 6

Fever

Exercise

Question 7

What happens at temperatures between 34 to 36?

Answer 7

Mild hypothermia

Question 8

What happens at temperatures between 30 to 34?

Answer 8

Impairment of temperature regulation

Question 9

What happens at temperatures between 27 to 29?

Answer 9

Cardiac fibrillation

Question 10

Where can temperature be taken from?

Answer 10

Mouth
Axilla
Rectum (.56 higher)
Ear

Question 11

Where do homeothermic animals get heat from?

Answer 11

Metabolic oxidation of food

Exercising muscle

Question 12

What is the function of the core?

Answer 12

Heat generation

Remains constant at 37.8 degrees

Question 13

What is included in the core?

Answer 13

Internal organs
CNS
Skeletal muscle

Question 14

What is the function of the shell?

Answer 14

Insulation

Exchange of heat depending on ambient temperature

Question 15

What is involved in the shell?

Answer 15

Skin

Subcutaneous fat

Question 16

What is the temperature range of the skin?

Answer 16

20-40

Question 17

What are the 4 methods of heat transfer?

Answer 17

Radiation
Conduction
Convection
Evaporation

Question 18

What form is heat emitted as?

Answer 18

Electromagnetic waves via radiation

Question 19

What is conduction?

Answer 19

Transfer of heat between two objects of different temperatures in direct contact

Question 20

What is the function of convection in heat loss?

Answer 20

Carries heat away from the body

Question 21

Why does sweating help cool us down?

Answer 21

Heat is lost when water evaporates

Question 22

How is temperature controlled through the vasomotor response?

Answer 22

Changing the width of blood vessels regulates the flow of blood in skin

Question 23

What is the thermoneutral zone?

Answer 23

Temperature range at which core temperature is maintained constant by vasomotor responses alone

Question 24

Why does humidity prevent heat loss?

Answer 24

Increased water concentration in the air prevents sweat evaporating
Heat cannot be lost through evaporation

Question 25

What neurotransmitter is used in sweat glands?

Answer 25

ACh

Question 26

What is the primary method of involuntary heat production?

Answer 26

Shivering

Question 27

What is shivering?

Answer 27

Rhythmic skeletal muscle contraction and increased tone | All energy produced is used as heat as no work is done

Question 28

How much can shivering increase internal temperature?

Answer 28

2-5 times

Question 29

How does piloerection promote heat retention?

Answer 29

Heat is trapped amongst hair

Question 30

What does lesion of the anterior hypothalamus result in?

Answer 30

Chronic hyperthermia (loss of heat loss reflexes)

Question 31

Lesion of what part of the brain would cause chronic hypothermia? (due to loss of heat production and conservation)

Answer 31

Posterior hypothalamus

Question 32

What is the function of peripheral thermoreceptors?

Answer 32

Monitor skin temperature

Question 33

Where can core thermoreceptors be found?

Answer 33

Hypothalamus CNS Internal abdominal organs

Question 34

What variations of body temperature is due to diurnal rhythm?

Answer 34

Lowest between 6-7am | Highest between 5-7pm

Question 35

How much can exercise increase body temperature by?

Answer 35

2.3

Question 36

What variations of body temperature is due to the menstrual cycle?

Answer 36

Increase of .5 in 2nd half of cycle

Question 37

What are the secondary causes of hypothermia?

Answer 37

``` Hypothyroidism Hypopituitarism Malnutrition Stroke Trauma Drugs Burns Surgery ```

Question 38

What are the symptoms of hypothermia?

Answer 38

Metabolic processes slow down Higher cerebral functions affected Decreased breathing rate Decreased Cardiac Output

Question 39

What are the pathological causes of hyperthermia?

Answer 39

High TH or adrenaline | Malfunction of hypothalamus

Question 40

What is fever triggered by?

Answer 40

Pyrogens: interleukin-1B, TNFa

Question 41

What releases pyrogens?

Answer 41

Macrophages in response to bacteria or viruses

Question 42

What to pyrogens increase the production of?

Answer 42

Prostaglandins

Question 43

What do prostaglandins induce?

Answer 43

Shivering and vasoconstriction

Question 44

How to paracetemol and aspirin stop fever?

Answer 44

Block pyrogen pathway