Reading...
Play button
Play button
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;
7 Cards in this Set
- Front
- Back
|
Homeostasis
|
The maintenance of a constant internal environment.
Controlling factors such as body temperature, blood volume, blood pressure and levels of chemicals in the blood and tissues. |
|
|
How is the internal environment maintained
|
Stimulus (change in the internal or external environment) -- Specialised cell or tissues known as receptors detects the stimuli -- Receptor transmits info to the central nervous system -- The CNS coordinates the action to be take and transmits this to the tissue/organ which will respon (effector) -- A response is made
|
|
|
Hormone action
|
Hormones are produced by endocrine glands. They contain no ducts and when stimulated they release hormones into the interstitial fluid and general circulation.
|
|
|
Positive and negative feedback
|
Positive feedback refers to physiological mechanism that enhances further change in a particular variable that provoked the initial change.
Negative feedback refers to a change in a variable and action to produce a change in the opposite direction. |
|
|
Pheromones
|
Chemicals that are released by animals that elicit a response in another animal of the same species; in particular acting as a sex attractant for mating in many insect species.
|
|
|
Plant hormones
|
Auxins - A major action of auxins is to control enlargement and elongation of plant cells. Eg IAA
Cytokinins- Growth promoting hormone that acts on shoots, roots and fruits. |
|
|
Signal transduction pathway
|
1. Messenger
2. Receptors - hormone binds to receptor on cell membrane 3. Transduction 3. Secondary messengers 4. Cell targets |
