Homeostasis

Question 1

Define Homeostasis

Answer 1

*The condition of a relatively stable environment

Question 2

Describe the difference between Hyperthermia and Hypothermia

Answer 2

*Hyperthermia=too hot
*Hypothermia=too cold

Question 3

What does the Stimulus Response Pathway consist of?

Answer 3

*Stimulus
*Receptor
*Processing Centre
*Effector
*Response

Question 4

Explain the difference between negative and positive feedback systems

Answer 4

*Negative feedback=when the response reduces the effect of the original stimulus.
*Positive feedback=when the response reinforces the original stimulus.

Question 5

Why is it important to maintain our core temperature?

Answer 5

*Homeostasis is important as it maintains optimal conditions for enzyme action throughout the body, as well as cell functions.

Question 6

Define Thermoregulation

Answer 6

*Stimulus response system that maintains the body’s core temperature at a steady state.

Question 7

Describe Hypothalamus & its relevance to Thermoregulation

Answer 7

*It is the control centre for thermoregulation. Receives signals from external & internal cold & hot receptors.

Question 8

Describe what occurs to blood in the body when it is hot vs. cold

Answer 8

*When the body is hot the blood vessels dilate to allow more blood flow through the capillaries and loose heat by radiation. This is called vasodilation.
*When the body is cold the blood vessels constrict to preserve the warm blood and to reduce heat loss through radiation. This is called vasoconstriction .

Question 9

Describe Conduction, Convection & Radiation

Answer 9

*Conduction=movement of heat via touch from warmer areas to cooler areas.
*Convection=movement of heat away from a source via air flow.
*Radiation=natural slow movement of heat away from a source.

Question 10

List the ways of gaining heat

Answer 10

*Basic metabolic processes
*Shivering
*Exercise/muscular activity
*Radiation, convection & conduction to the body
*Vasoconstriction
*Piloerection

Question 11

List the ways of losing heat

Answer 11

*Evaporation of sweat
*Panting
*Radiation, convection & conduction away from the body
*Vasodilation

Question 12

Describe the difference between Endotherms & Ectotherms

Answer 12

*Endotherms generate their own internal heat through metabolic reactions. Have a stable core body temperature.
*Ectotherms rely on external sources to maintain their core body temperature. Have fluctuating body temperatures.