Communication

Front 1

Homeostatis

Back 1

is the maintenance of the internal environment in a constant state despite changes in the environment

Front 2

internal environment

Back 2

tissue fluid surrounding the cells of an organism

Front 3

external environment

Back 3

air, water or soil surrounding an organism

Front 4

Nervous system and endocrine system

Back 4

monitor changes and coordinate responses to those changes through precise cell signalling.

Signals sent from one organ to another can enable these organs to work together to ensure that homestasis is effective.

Front 5

Negative feedback

Back 5

a process that brings about a reversal of any change in conditions.
It ensures that an optimum steady state can be maintained.
It is essential for homeostasis

Front 6

Negative feedback standard pathway

Back 6

stimulus- receptor-communication pathway (cell signalling)- effector- response

Front 7

positive feedback

Back 7

is a process that increases any change detected by receptors. It tends to be harmful and does not lead to homeostasis.
e.g hypothermia!!

Front 8

Ectotherm

Back 8

An ectotherm is an organism that relies on external sources of heat to regulate its body temperature.

tends to fluctuate with temperature

Front 9

Endotherm

Back 9

An endotherm can maintain the temperature of their body within fairly strict limits. They are larely independent of the external temperature.

largely independent of the external temperature.

Front 10

Endothermic

Back 10

warm blooded

Front 11

Ectothermic

Back 11

cold blooded

Front 12

Ectotherm energy

Back 12

an ectotherm can use a greater proportion of the energy obtained from food for growth.
Ectotherms use less of their food for respiration. Therefore a greater proportion of the energy obtained from food can be used for growth

ectotherms are less active in cooler temperatures and may need to warm up in the morning. They may not be capable of activity in the winter

Front 13

Endotherms ---

Back 13

are more able to enhabit colder parts of the climate

Front 14

Lizard

Back 14

ectotherm
The horned lizard can alter its surface area by expanding or contracting its ribcage to absord heat from the sun. When the Lizard is too hot it will increase its breathing rate resulting in a greater evaporation of water which cools the lizard

Front 15

Vasoconstriction

Back 15

reduces the blood flow through capillaries near the surface of the skin. As a result, less heat is regulated.

Front 16

Vasolidation

Back 16

allows more blood into the capillaries near the skin surface. More heat can be radiated from the skin. This may result in the skin looking red.

Front 17

stimulus

Back 17

is any change in the environment that causes a response

Front 18

response

Back 18

is a change in behaviour or physiology as a result of a change in the environment.