Body Temperature And Its Regulation

Question 1

Conduction

Answer 1

Heat exchange between objects or substances at different temperatures that are in contact with one another

Question 2

Convection

Answer 2

Movement of molecules away from the area of contact

Question 3

Rate of heat loss is determined by 2 factors

Answer 3

Transfer of heat from core to skin
Transfer of heat from skin to surroundings

Question 4

When warm blood goes into the skin

Answer 4

When the cutaneous vessels are dilated

Question 5

When does heat is held centrally in the body

Answer 5

In the vasoconstricted state

Question 6

The reflex responses activated by cold are controlled from

Answer 6

Posterior hypothalamus

Question 7

The activated by warmth are controlled primarily from

Answer 7

Anterior hypothalamus

Question 8

Threshold for sweating and vasodilation

Answer 8

37 Celsius

Question 9

Threshold for vasoconstriction

Answer 9

36.8 Celsius

Question 10

Threshold for non shivering thermogenesis

Answer 10

36 Celsius

Question 11

Threshold for shivering

Answer 11

35.5 Celsius

Question 12

High rate of skin flow causes heat to be conducted from

Answer 12

Core of the body to the skin with great efficiency

Question 13

Reduction in the rate of skin flow can decrease the heat conduction from

Answer 13

Core to very little

Question 14

When does the effectiveness of clothing in maintaining body temperature is almost lost

Answer 14

When clothes becomes wet bc high conductivity of water increases the rate of heat transmission through cloth 20-fold or more

Question 15

Stimulation of which area causes sweating

Answer 15

Anterior hypothalamus-Preoptic area

Question 16

How does the stimulation impulses of the sweating in the autonomic pathways carried

Answer 16

Through the cholinergic sympathetic fibers

Question 17

Which hormones can stimulate sweating

Answer 17

Epinephrine
Norepinephrine

Question 18

Degree of reabsorption of most of the sodium and chloride ions depends on

Answer 18

Rate of sweating

Question 19

1 L of O2 burns how many calories

Answer 19

5 kcal

Question 20

What happens if skin temperature is greater than the temperature of the surroundings

Answer 20

Heat can be lost by radiation and conduction

Question 21

What happens when temperature of the surroundings greater than that of the skin

Answer 21

Body gains heat by both radiation and conduction

Question 22

Thermoregulatory center

Answer 22

Hypothalamus —> anterior hypothalamic Preoptic area

Question 23

Heat sensitive neurons increase discharges as the body temp

Answer 23

Rises

Question 24

Cold sensitive neurons increase discharges as the body temp

Answer 24

Falls

Question 25

2 types of temperature receptors

Answer 25

Cold receptors Warmth receptors

Question 26

Among cold and warmth receptors which one is found more in the body

Answer 26

Cold (x10) > warmth

Question 27

The reflex responses activated by cold are controlled from the

Answer 27

Posterior hypothalamus

Question 28

When the skin is chilled over the entire body what happens

Answer 28

Piloerection Inhibition of sweating Hunger Increased voluntary activity Increase in the rate of body heat production Promoting skin vasoconstriction

Question 29

What happens when body temp becomes too great

Answer 29

Vasodilation of skin BV Decreased appetite Sweating Increased respiration Decrease in the rate of body heat production

Question 30

Fever is caused by what

Answer 30

Release of cytokines —> IL-1 Induction of the formation of PGE2

Question 31

Symptoms of head stroke

Answer 31

Dizziness Vomiting Loss of consciousness

Question 32

Set point increases as the skin temperature ?

Answer 32

Decreases

Question 33

When the skin temp was high sweating began at

Answer 33

Lower hypothalamic temp than when the skin temp was low

Question 34

Sweating is inhibited when

Answer 34

Skin temp is low

Question 35

Who can cause the set point of the hypothalamic thermostat to rise

Answer 35

Many proteins Breakdown products of proteins Lipopolysaccharide toxins released from bacterial cell membranes

Question 36

Pyrogens

Answer 36

Subs that cause the set point of the hypothalamic thermostat to rise

Question 37

Who causes fever

Answer 37

Pyrogens release from toxic bacteria or those released from degenerating body tissues

Question 38

Benefits of fever

Answer 38

Inhibiton of the growth of many microorganisms Ab production is high

Question 39

When does temperature regulation becomes impaired?

Answer 39

Body temp< 35 Celsius

Question 40

When does temperature regulation is lost

Answer 40

Body temp< 28 celcius

Question 41

Artificial hypothermia

Answer 41

Blood pressure is low Bleeding is minimal Metabolism is slow Heart rate is slow