Term 3 Flashcards
Define Homeostasis
The maintenance of an internal environment within a living organism despite. Internal or external changes to the environment.
Negative Feedback Loop
Stimulus, regulator, effects, response/communication
Negative Feedback
Some variables triggers a counteractive response, in order to come back to some set points.
Positive Feedback
Instead of getting a counteractive response to some variable, you’re instead intensify the variable.
Chemoreceptor
Chemical
Photoreceptor
Light
Mechanoreceptor
Touch, Pressure, Stretching, Motion, Sandwaves
Thermoreceptor
Heat
Nociceptor
Detects damage
How is Homeostasis Maintained?
Hormonal homeostasis pathways….
… involve the endocrine system, can be slow, chemical messengers, travelling in bloodstream
Natural Homeostasis Pathways
Involves the nervous system, is very rapid, Electric impulse, travelling along the nerves.
What is Hormonal Control?
Hormones are chemical messages produced by an organism to regulate the activity of cells and organs.
Endocrine-Travel long distances through the body to target cells.
The Endocrine System; in mammals
In mammals, hormonal are produced in the endocrine glands which are released directly into the blood vessels.
What systems work together to maintain homeostasis?
Endocrine and Nervous system
What does Hormones affect?
Hormones affects only certain tissue cell or organs called Target Organs.
Target Cells Must Have…. and why do they bind?
They must have protein receptors present on the cell membrane to allow the hormone to attach. Hormones must bind to the target cell to influence the cell.
The Flow of Information along Nervous System (3)
- Receptor detects a change in conditions (Stimulus)
- Receptor to the CNS by a sensory memory (message)
- CNS to an organ an (effector) carries out a response a motor Nevron carries the message.
What does CNS stand for?
Central Nervous System
What does PNS mean?
Peripheral Nervous System
Moto Nevron
Carry messages from the brain to allow us to move our muscles