Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
Homeostasis |
The maintenance of the internal environment in a constant state despite external changes. |
External |
|
|
Negative feedback |
A process that brings about a reversal of any change in conditions to bring it back to the optimum. It leads to homeostasis. |
|
|
|
Positive feedback |
A process that increases any change detected by receptors. It tends to be harmful. |
|
|
|
Ectotherm |
An organism that relies on external sources of heat to regulate its body temperature. |
|
|
|
Endotherm |
An organism that can use internal sources of heat such as from metabolic reactions to regulate body temperature. |
|
|
|
Hypothalamus |
Measures temperature of blood and causes negative feedback reaction. |
|
|
|
Peripheral temp receptors |
Are located in the extremeties and are an early warning system to the hypothalamus. |
|
|
|
Sensory neurone |
Carries action potential from sensory receptors to the CNS |
|
|
|
Motor Neurone |
Carries action potential from CNS to muscle effector |
|
|
|
Sensory receptors |
Specialised cells that can detect changes in surroundings. Are energy transducers. |
|
|
|
Stimulus |
Change in energy levels in the environment that causes a response |
|
|
|
Polarised membrane |
Has a potential difference across it. This is the resting potential. |
|
|
|
Depolarisation |
The loss of polarisation across the membrane of an axon. When the inside is less negative compared to the outside. |
|
|
|
Generator potential |
A small depolarisation caused by sodium ion channels opening and Na+ entering the cell. |
|
|
|
Action potential |
Is achieved when the membrane is depolarised to +40mv. It is an all or nothing reaction. |
|
