Chapter 6 - Homeostasis

Question 1

The 3 ways heat gain and heat loss can occur are…

Answer 1

physical processes
physiological processes
behavioural activities

Question 2

The 3 ways heat can be gained from the external environment are…

Answer 2

radiation
convection
conduction

Question 3

what is radiation

Answer 3

radiation is a physical process of the transfer of heat. Heat is transferred from a warmer object to a cooler object and DOES NOT need physical contact.

Question 4

what is convection

Answer 4

convection is a physical process of the transfer of heat. It is the mass movement of air or water passed exposed parts of the body transferring heat as it travels past.

Question 5

what is conduction

Answer 5

conduction is a physical process of the transfer of heat. It occurs when there is physical contact between two objects.

Question 6

what is evaporation

Answer 6

evaporation is the conversion of liquid water to vapour. this process requires an input of energy. Humid air cannot remove as much water as dry air.

Question 7

where does water come from internally?

Answer 7

moist surfaces of the lungs, airways, mouth and nose

Question 8

what are physical processes of heat transfer

Answer 8

where heat transfer occurs with the surrounding environment

Question 9

what are physiological processes of heat transfer

Answer 9

processes that occur automatically in the body. They are controlled by centres in the hypothalamus

Question 10

what are behavioural activities of heat transfer

Answer 10

actions that are under a persons control

Question 11

3 ways of heat gain through physiological processes are…

Answer 11

shivering
metabolism
vasoconstriction

Question 12

how does shivering gain heat

Answer 12

shivering converts almost all energy of contraction to heat energy. it cannot be sustained for very long as it drains the muscles of energy.

Question 13

how does metabolism gain heat

Answer 13

if the body temperature drops, the basal metabolic rate will increase to create more heat.

Question 14

what is vasoconstriction

Answer 14

where blood flow is restricted to only the shunt vessels. This keeps heat from leaving the body as it is being directed away from the surface. this occurs by contracting sphincter muscles.

Question 15

how can sweating result in heat loss?

Answer 15

sweating can result in heat loss as heat is needed to transfer the water liquid into a gas.

Question 16

some behavioural activities that gain heat are…

Answer 16

vigorously exercising

soaking in a hot bath

standing in front of a heater

reducing body surface area by wrapping arms around body

Question 17

some behavioural activities that lose heat are…

Answer 17

cold shower

less layers of clothing/exposing more skin

sitting in front of a fan

maximising body surface area exposed to cooling winds

Question 18

what is homeostatic regulation

Answer 18

the monitoring of a variable,

detecting if it starts to move out of narrow limits,

making adjustments to correct the situation

Question 19

what is thermoregulation

Answer 19

thermoregulation is the homeostatic regulation of body temperature

Question 20

what is a positive feedback system

Answer 20

a mechanism in which the output of the system causes an escalation of the initial response

Question 21

what is a negative feedback system

Answer 21

a mechanism in which the output of the system acts to oppose a detected change. the effect is to stabilise fluctuations

Question 22

What are the 2 types of hypothermia

Answer 22

acute and exhaustion

Question 23

what is acute hypothermia

Answer 23

hypothermia where an organism is exposed to extremely cold conditions. it is so cold that they can die almost immediately.

Question 24

what is exhaustion hympthermia

Answer 24

hypothermia where an organism is in cold conditions as well as exhausted and has no food. an organism cannot generate sufficient metabolic heat to raise the body temperature.

Question 25

what are the symptoms of hypothermia

Answer 25

Shivering.

Slurred speech

Question 26

what are the symptoms of hyperthermia

Answer 26

dehydration

light headedness

Question 27

what happens in hypothermia

Answer 27

q

Question 28

what happens in hyperthermia

Answer 28

q

Question 29

what is osmoregulation

Answer 29

the homeostatic regulation of body fluids.

Question 30

what is water needed for

Answer 30

the absorption of nutrients

cushioning fluid around the brain

lubricant for mucous muscles

Question 31

describe when body fluids are unbalanced

Answer 31

when water is unbalanced, electrolytes are also unbalanced as body water is a solution of many solutes dissolved in it.

little water=more concentrated solute
too much water=dilute solute

Question 32

what are the parts to a stimulus response model

Answer 32

stimulus (causes a change in a level)

receptor (detects change)

control centre (receives information of change and co ordinates steps to regulate it)

effector (performs the regulation)

response (the outcome of the attempted regulation)

Question 33

what is insulin

Answer 33

the hormone, produced in the islet cells of the pancreas, that promotes uptake of glucose into body cells and the storage of glycogen in the liver.

Question 34

what is glucagon

Answer 34

the hormone that stimulates the break down of glycogen back into glucose.

Question 35

define a homeostatic mechanism

Answer 35

a mechanism found in the body that helps regulate specific levels of a variable

Question 36

what is thyroxine

Answer 36

a hormone produced by the thyroid which is responsible for many bodily chemical reactions including body metabolism.

Question 37

what is diabetes melltius

Answer 37

a disease where the body does not produce insulin. this causes a very high blood glucose level. Insulin needs to be constantly injected so this level can be regulated back to the normal level.

Question 38

what is hyperthyroidism

Answer 38

a disease where specific proteins bind to the thyroid causing it to rapidly produce thyroxine. Due to the protein, the negative feedback loop is ignored and therefore the thyroxine production is not regulated.

Question 39

what is ADH

Answer 39

ADH is a hormone produced by the hypothalamus which regulates water levels in the body by telling the kidneys how much water to store.

Question 40

define homeostasis

Answer 40

the maintenance of a relatively constant environment within narrow limits, despite changes in the external environment