feedback cycles and thermoregulation

Question 1

what is homeostasis

Answer 1

a process of maintaining a constant internal environment despite changes in the external environment

Question 2

what are ectotherms

Answer 2

The metabolic activity of the organism is dependent on the temperature of environment. When environmental temperature increases, metabolic rates increase.

Question 3

What are endotherms

Answer 3

Organisms that have a constant body temperature regardless of environmental temperature. Organisms expend energy to maintain temperature.

Question 4

How does the body response to heat stress

Answer 4

-temperature coordinating centre in humans = hypothalamus
-sweating (evaporation cools body), blood vessels dilate (more blood to skin cools the body)

Question 5

How does the body response to cold stress

Answer 5

arterioles constrict (less blood flow to skin, prevents heat loss), hairs stand on end for insulation (goose bumps), skeletal muscles contract (shiver) to produce additional heat

Question 6

What is a feedback loop

Answer 6

a feedback loop is any system in which part of an output of the system is connected back into one of its inputs (e.g predator prey cycles)

Question 7

what are parts of a feedback loop?

Answer 7

sensor, control centre, effector

Question 8

what is a sensor?

Answer 8

part that detects a change to homeostasis

Question 9

what is the control centre

Answer 9

part that manages a response and activates the effectors

Question 10

what is effector

Answer 10

part that produces a change to restore homeostasis

Question 11

What is a negative feedback loop

Answer 11

a system that is activated to restore the original condition; for example, pH in the duodenum

Question 12

What is a positive feedback loop

Answer 12

a system which is designed to amplify a small effect