Homeostasis

Question 1

any self-regulating process by which an organism tends to maintain stability while adjusting to conditions that are best for its survival

Answer 1

Homeostasis

Question 2

adjusting of physiological system within the body

Answer 2

homeostatic regulation

Question 3

Three parts/ mechanisms of homeostatic regulation

Answer 3

1. Receptor
2. Control center
3. Effector

Question 4

receives information that something in the environment is changing

Answer 4

receptor

Question 5

• aka integration center
• receives and processes information from the receptor

Answer 5

control center

Question 6

responds to the commands of the control center by either opposing or enhancing the stimulus

Answer 6

effector

Question 7

Two (2) types of feedback

Answer 7

1. Negative feedback
2. Positive feedback

Question 8

• the response will reverse or cause the opposite effect of the original stimulus
• the result of a reaction is reduced to bring the system back to a stable state

Answer 8

negative feedback

Question 9

• occurs in nature when the product of a reaction leads to an increase in that reaction
• In homeostasis, it moves a system further away from the target of equilibrium

Answer 9

positive feedback

Question 10

example of negative feedback

Answer 10

regulation of the blood calcium level

Question 11

example of positive feedback

Answer 11

• Childbirth – stretching of uterine walls cause contractions that further stretch the walls (this continues until birthing occurs)
• Lactation – the child feeding stimulates milk production which causes further feeding (continues until baby stops feeding)

Question 12

organisms that keep their internal fluids isotonic to their environment, that is, they maintain an internal salinity similar to their ambient conditions

Answer 12

Osmoconformers

Question 13

organisms that actively regulate their osmotic pressure, independent of the surrounding environment

Answer 13

Osmoregulators

Question 14

Examples of osmoconformers

Answer 14

• starfish
• crabs
• jellyfish

Question 15

Example of osmoregulators

Answer 15

freshwater fish

Question 16

Other homeostatic mechanism

Answer 16

1. Osmoregulation
2. Thermoregulation

Question 17

• maintenance of water balance
• organisms regulate osmotic pressure of their body to prevent body fluids from becoming too diluted or too concentrated

Answer 17

osmoregulation

Question 18

• maintenance of the body temperature
• organisms are able to keep their body temperature within a certain range

Answer 18

thermoregulation

Question 19

animals succeed metabolically only in a ___ range of temperature

Answer 19

restricted

Question 20

too low temperature, metabolism ___ ___, energy production is ___

Answer 20

slows down
reduced

Question 21

too high temperature, metabolism is ___, enzymatic activity is ___

Answer 21

unbalanced
hampered

Question 22

any so-called cold-blooded animal—that is, any animal whose regulation of body temperature depends on external sources, such as sunlight or a heated rock surface

Answer 22

Ectothermic animals

Question 23

examples of ectothermic animals

Answer 23

• fishes
• amphibians
• reptiles
• invertebrates

Question 24

animals that are able to maintain a constant body temperature regardless of their ambient temperature

Answer 24

Endothermic animals

Question 25

examples of endothermic animals

Answer 25

- all birds and mammals - some fishes

Question 26

Two types of adjustment in ectothermic animals

Answer 26

1. Behavioral Adjustment 2. Metabolic Adjustment

Question 27

seeks areas where temperature is favorable

Answer 27

behavioral adjustment

Question 28

adjust metabolic rates to the prevailing temperature

Answer 28

metabolic adjustment

Question 29

body temperature range of mammals

Answer 29

36°C - 38°C

Question 30

body temperature range of birds

Answer 30

40°C - 42°C

Question 31

constant temperature of endothermic animals is maintained by a delicate balance between ___ ___ and ___ ___

Answer 31

heat production heat loss

Question 32

living mainly in the ground

Answer 32

fossorial living

Question 33

active at night

Answer 33

nocturnal living

Question 34

Adaptations for hot environment

Answer 34

1. fossorial living 2. nocturnal living

Question 35

Adaptations for cold environment

Answer 35

1. decreased conductance 2. increased heat production

Question 36

reduction of heat loss by increasing the effectiveness of the insulation

Answer 36

decreased conductance

Question 37

example of decreased conductance

Answer 37

1. fur thickness increases in winter 2. countercurrent heat exchange between outgoing warm blood and returning cold blood

Question 38

example of increased heat production

Answer 38

1. augmented muscular activity through exercise or shivering 2. nonshivering thermogenesis by increased oxidation of foods especially from stores of brown fat

Question 39

an opening beneath the snow where small mammals live during winter, with connecting tunnels made by them to travel through, hunt prey, and gather plant material

Answer 39

subnivean zone

Question 40

entering a prolonged and controlled state of dormancy

Answer 40

hibernation

Question 41

- "summer sleep" state of dormancy on a hot season - slowing down of the activity and metabolism during a hot and dry season (such as summer).

Answer 41

aestivation

Question 42

maintain high body temperature when active, but allow temperature to drop profoundly when inactive and asleep

Answer 42

daily torpor

Question 43

- called daily torpor - provides enormous saving of energy to small endotherms that are never more than a few hours away from starvation at normal body temperatures. Hummingbirds also may drop their body temperature at night when food supplies are low

Answer 43

adaptive hypothermia

Question 44

animals that undergo adaptive hypothermia

Answer 44

- mammals - birds