Physiology: Homeostasis

Question 1

what is the normal range for pulse?

Answer 1

60-100 BPM

Question 2

what is the normal range for resting respiratory rate?

Answer 2

12-20 breaths/min

Question 3

what is a normal capillary refil time?

Answer 3

less than two seconds

Question 4

what is a normal oxygen saturation?

Answer 4

over 95%

Question 5

what is average core body temperature?

Answer 5

37.8

Question 6

what is core body temperature?

Answer 6

the temperature of structures deep within the body

Question 7

what is normothermia?

Answer 7

normal core body temperature

Question 8

why is normal core body temperature 37 degrees?

Answer 8

this is the optimum temperature for cellular metabolism and function

Question 9

what effect does increasing body temperature have on metabolism?

Answer 9

speeds it up

Question 10

what can overheating cause?

Answer 10

denaturation of proteins
nerve malfunctions
death

Question 11

what effect can decreased body temperature have on metabolism?

Answer 11

can be fatally slowed down

Question 12

what are the three possible sites for monitoring body temperature?

Answer 12

ear drum
rectal
oral

Question 13

what does tympanic temperature mean?

Answer 13

temperature in the ear drum

Question 14

when is rectal temperature measurement done?

Answer 14

at extremes of body temperature

Question 15

why isnt the mouth a good place to measure body temperature?

Answer 15

the temperature of the mouth is affected by the consumption of food and drinks

Question 16

when is body temperature at its lowest?

Answer 16

very early in the morning

Question 17

what must be balanced for the body to have a constant core temperature?

Answer 17

heat gain and heat loos

Question 18

what causes heat gain from the internal environment?

Answer 18

metabolc heat

Question 19

how is metabolic heat produced?

Answer 19

via oxidation of metabolic fuel derived from food

Question 20

what can increase metabolic heat?

Answer 20

increasing muscle activity

Question 21

what three ways can heat be gained from the external environment?

Answer 21

radiation
convection
conduction

Question 22

what are the four methods of heat loss to the external environment?

Answer 22

convection
conduction
radiation
evaporation

Question 23

what is radiation?

Answer 23

the emission of heat energy in the form of EM waves from a surface

Question 24

how can heat be gained and lost by radiation?

Answer 24

the body can absorb and emit radiant heat

Question 25

how much heat is lost by radiation?

Answer 25

half

Question 26

what is conduction?

Answer 26

transfer of heat between objects in contact

Question 27

what direction does heat move in via conduction?

Answer 27

from the warm object to the cold object

Question 28

what is convection?

Answer 28

the transfer of heat energy by air/water currents that carry the heat away from the body

Question 29

what does convection combine with to move heat away from the body?

Answer 29

conduction

Question 30

describe how convection and conduction work to cause heat loss?

Answer 30

air beside the skin is warmed by conduction, and is moved away by convection

Question 31

what increases the effect of convection?

Answer 31

forced air movement across a surface

Question 32

what decreases the effect of convection?

Answer 32

tight, air trapping clothes

Question 33

what mechanism maintains the bodies core temperature?

Answer 33

a homeostatic negative feedback system

Question 34

what are the sensors for maintaining core temperatture?

Answer 34

central and peripheral thermoceptors

Question 35

where are central thermoreceptors found?

Answer 35

hypothalamus | organs

Question 36

where are peripheral thermoreceptors found?

Answer 36

the skin

Question 37

what is the control centre for maintaining core temperature?

Answer 37

the hypothalamus

Question 38

what are the effectors for maintaining core temperature?

Answer 38

skeletal muscles skin arterioles sweat glands

Question 39

what acts as the body's thermostat and what does this mean?

Answer 39

the hypothalamus maintains the temperature at a set point

Question 40

what part of the hypothalamus is activated by cold?

Answer 40

posterior hypothalamic centre

Question 41

what part of the hypothalamus is activated by heat?

Answer 41

the anterior hypothalamic centre

Question 42

what do skin arterioles do in response to cold?

Answer 42

vasoconstrict to reduce blood flow to the skin and conserve heat

Question 43

what do skeletal muscles do in response to cold?

Answer 43

shiver and move more to produce more heat

Question 44

what do skin arterioles do in response to heat?

Answer 44

vasodilate to increase blood flow to the skin and increase heat loss

Question 45

what do sweat glands do in response to heat?

Answer 45

sweat so this can evaporate and increase heat loss

Question 46

what do skeletal muscles do in response to heat?

Answer 46

decrease tone and movement to decrease heat production

Question 47

what happens to the hypothalamic temperature set point in fever?

Answer 47

it becomes raised

Question 48

what do chemicals released from macrophages in response to inflammation act as in fever?

Answer 48

endogenous pyrogens

Question 49

what do endogenous pyrogens do in fever?

Answer 49

stimulate release of prostaglandins in the hypothalamus

Question 50

what do prostaglandins do in fever?

Answer 50

act on the hypothalamic thermoregulatory centre to reset body temperature at a higher value

Question 51

when is the hypothalamic set point returned to normal in fever?

Answer 51

when there is no pyrogens or prostaglandins being made

Question 52

what temperature is considered to be a fever?

Answer 52

38-40C

Question 53

what is hyperthermia?

Answer 53

temperature over 40

Question 54

what is hypothermia?

Answer 54

temperature under 35

Question 55

what does a group of cells make?

Answer 55

a tissue

Question 56

what is a tissue?

Answer 56

a group of cells with similar structure and specialised function

Question 57

what do our bodies need to do to remain healthy?

Answer 57

maintain tightly regulated optimum physiological conditions

Question 58

what is homeostasis?

Answer 58

the maintenance of steady states within our bodies by coordinated physiological mechanisms

Question 59

what are the two types of homeostatic controls?

Answer 59

intrinsic controls | extrinsic controls

Question 60

what are intrinsic controls?

Answer 60

local controls that are inherent in an organ

Question 61

what are extrinsic controls?

Answer 61

regulatory mechanisms initiated outside an organ

Question 62

what two systems play a role in extrinsic controls?

Answer 62

nervous and endocrine

Question 63

what are the two types of control systems?

Answer 63

feedforward | feedback

Question 64

what is a feedforward system?

Answer 64

one where responses are made in anticipation of a change

Question 65

what is a feedback system?

Answer 65

one where a response is made after a change has been detected?

Question 66

what are the two types of feedback systems?

Answer 66

positive and negative

Question 67

what does a positive feedback system do?

Answer 67

amplifies an initial change

Question 68

what does a negative feedback system do?

Answer 68

opposes an initial change

Question 69

what is the main type of homeostatic control in the body?

Answer 69

negative feedback systems

Question 70

what are the three components of a negative feedback system?

Answer 70

sensors, a control centre and effectors