maintaining internal environment

Question 1

homeostasis

Answer 1

maintenance of constant internal environment

AUTOMATIC - uses nerves/ hormones don’t think

Question 2

what is kept at constant levels

Answer 2

temp
water level
blood sugar level
CO2 level
blood pressure

Question 3

why inputs balance outputs

why we have a constant internal environment

Answer 3

enzymes control all reactions in cells

homeostasis maintains ideal conditions for enzymes

Question 4

ideal body temp

Answer 4

37 °C - core temp

optimum for enzymes

Question 5

how to measure temp

Answer 5

thermometer
temp sensitive strips
digital probes
thermal imaging

Question 6

homeothermic

Answer 6

animal that can keep its temp constant

Question 7

hypothermia

Answer 7

if temp is below 32°
reaction in cells slows
pulse rate slows
can die

Question 8

above 40° body temp

Answer 8

heat stroke/dehydration
enzymes denature (active site changes shape ESCs can’t form)
can die

Question 9

gain heat

Answer 9

• respiration (exothermic)
• shivering + exercise - muscle contraction - increases respiration
• vasoconstriction
• wearing clothes - insulates
• hairs stand in end - trap heat

Question 10

vasoconstriction

Answer 10

when body is cold

• arteriolar in skin get narrower
• less blood flows to skin surface
• less heat loss (by radiation)
• look paler

Question 11

loose heat

Answer 11

• vasodilation
• sweating - evaporates water (uses skin heat)
• wear fewer clothes
• hairs lie flat - heat can escape

Question 12

vasodilation

Answer 12

when body is hot

• arteriolar in skin get wider
• more blood flows to skin surface
• more heat lost (radiation)

Question 13

negative feedback - body temp control - too hot

Answer 13

hypothalamus detects change
- brain sends impulse to skin to cool
- skin sweats or vasodilation
cool down

Question 14

negative feedback - body temp control - too cold

Answer 14

hypothalamus detects change
- brain sends impulse to skin to warm
- skin shivers or vasoconstriction
warm up

Question 15

endotherm

Answer 15

an organism that is internally warmed by heat- generating metabolic process

Question 16

ectothermic

Answer 16

use external environment to maintain temp

Question 17

endothermic regulation +/-

Answer 17

+ can come out in cool night
+ can span diff. habitat/climate
- high energy use to maintain heat
- needs to eat food to provide energy