Temperature regulation

Question 1

What is temperature?

Answer 1

Heat energy that an object possesses

Question 2

What is a cal?

Answer 2

Heats 1g of water by 1 degree

Question 3

How many joules is in a cal?

Answer 3

4.2

Question 4

How many cal are in a kcal?

Answer 4

1000

Question 5

How many calories does 1mL of oxygen burn?

Answer 5

5

Question 6

Range of ideal body temperature

Answer 6

36.5-37.5

Question 7

What is hypothermia?

Answer 7

<35 degrees

Question 8

What is hyperthermia?

Answer 8

> 38 degrees

Question 9

What is pyrexia?

Answer 9

Hyperthermia

Question 10

What happens when body temperature reaches 35 degrees?

Answer 10

Shivering, peripheral circulation shutdown

Question 11

What happens when body temperature reaches 33 degrees?

Answer 11

Confusion, drowsiness

Question 12

What happens when body temperature reaches 31 degrees?

Answer 12

Unconscious, risk of arrythmia

Question 13

What happens when body temperature reaches 29 degrees?

Answer 13

Respiratory muscle failure

Question 14

What happens when body temperature reaches 27 degrees?

Answer 14

Death

Question 15

What happens when body temperature reaches 39 degrees?

Answer 15

Sweating, vasodilation, breathless

Question 16

What happens when body temperature reaches 40 degrees?

Answer 16

Vomiting, dehydration, weakness

Question 17

What happens when body temperature reaches 41 degrees?

Answer 17

Fainting, confusion, drowsiness

Question 18

What happens when body temperature reaches 42 degrees?

Answer 18

Brain proteins denaturing

Question 19

What happens when body temperature reaches 43 degrees?

Answer 19

Death

Question 20

Characteristics of cold receptors

Answer 20

Peripheral in skin, conducted via myelinated A fibres

Question 21

Characteristics of warm receptors

Answer 21

Central in hypothalamus with few in skin

Question 22

What do nociceptors do?

Answer 22

Identify extremes in temperature, perceive it as pain

Question 23

What are behavioural responses?

Answer 23

Voluntary actions to increase muscle activity or change body’s immediate environment

Question 24

What are physiological responses?

Answer 24

Involuntary actions to increase muscle activity or change body’s immediate environment

Question 25

What is the thermoneutral zone?

Answer 25

Band within which normothermia can be maintained using basal energy production without evaporative heat loss

Question 26

Neurological responses

Answer 26

Sympathetic NS (vasomotor tone, sweating) and motor system (shivering)

Question 27

Hormonal responses

Answer 27

Thyroid (produces thyroxine) and adrenal medulla (produces adrenaline)

Question 28

What is a MET?

Answer 28

A measure of basal metabolism | Metabolic Equivalent of Task

Question 29

How many METs are in walking?

Answer 29

2-4

Question 30

How many METs are in cycling?

Answer 30

6-8

Question 31

How many METs are in sprinting?

Answer 31

10-12

Question 32

How much heat is lost through skin?

Answer 32

90%

Question 33

What is conduction?

Answer 33

Direct contact with adjacent material

Question 34

What is convection?

Answer 34

Warms adjacent air, creates heat-losing current

Question 35

What is radiation?

Answer 35

Transfer through infrared rays to distant objects at lower temperature

Question 36

What is evaporation?

Answer 36

Latent heat of vaporisation lost as sweat/respiratory humidity evaporates

Question 37

Where does sweating occur?

Answer 37

Eccrine/merocrine glands

Question 38

Which system controls sweating?

Answer 38

Sympathetic NS

Question 39

Which neurotransmitter is in sweat glands?

Answer 39

ACh not NA

Question 40

What is a fever?

Answer 40

Elevated temperature from infection or inflammation

Question 41

What are pyrogens?

Answer 41

Cytokines (Il-1, Il-6, TNF-alpha) released by macrophages. They travel to the hypothalamus to add higher value and act via PGE2

Question 42

What is heat stroke?

Answer 42

Rapid, extreme temperature rise, usually exercise related but can be exacerbated by drugs

Question 43

Why are neonates at high risk of hypothermia?

Answer 43

High surface area to weight ratio, unable to make behavioural changes

Question 44

What is brown fat?

Answer 44

Heat source used by neonates, found between scapulae Oxidative metabolism in mitochondria is uncoupled to phosphorylation and produces heat rather than ATP. Activated by thyroid hoemones sensitizing adipocytes to action of adrenaline

Question 45

Why is near-drowning a risk factor for hypothermia?

Answer 45

Increase in heat lost by conduction

Question 46

Why is a drug overdose a risk factor for hypothermia?

Answer 46

Reduced metabolism and heat production, can't make behavioural changes

Question 47

Why is major trauma a risk factor for heat loss?

Answer 47

Exposure increasing heat loss, replacement of blood lost with cold fluid

Question 48

What is induced hypothermia?

Answer 48

Reduced metabolic requirements (e.g. during surgery) achieve by surface cooling and cardio-pulmonary bypass

Question 49

Ways to increase temperature

Answer 49

Warm clothing, vaso-constriction, T3 release, catecholamine release, shivering

Question 50

Ways to decrease temperature

Answer 50

Sweating, vasodilation, exposure, decreased muscle activity