Communication and homeostasis Flashcards
What is a change to an internal or external environment called?
Stimulus
What detects a stimulus?
Receptors
What are effectors?
Cells that bring a response to a stimulus (muscle cells)
What are photoreceptors?
Receptor cells that that connect to the nervous system
How do receptors and effectors communicate?
Cell signalling
What is the biological word for nearby?
Adjacent
What is homeostasis?
The maintenance of a constant internal environment
What happens to enzymes if the body temp is too high?
Become deantured - molecules vibrate too much - breaks hydrogen bonds - active site shape changes
What happens to enzymes if body temp is too low?
Enzyme activity reduced - Slows metabolic reactions
What is a humans optimum temperature?
37°c
What does the homeostatic system involve?
Receptors
What does the communication system involve?
Effectors
What type of feedback is the controlling of body temperature? Why?
Negative feedback - too hot/cold means effectors respond to decrease/increase temp
What is positive feedback useful for in protecting the body?
To rapidly activate something - blood clot after an injury
What are sensory neurones?
Transmitting nerve impulses from receptors to CNS
What is the CNS?
Central nervous system - brain and spine
What are motor neurons?
Transmit nerve impulses from CNS to effectors
What a relay neurones?
Transmit nerve impulses between sensory and motor neurones
What is the pathway of impulses? (5 steps)
1) Stimulus
2) Receptors
3) CNS
4) Effectors
5) Response
What do sensory receptors do?
Convert the energy of a stimulus into electrical energy
What does sensory receptors act as? And what is that?
Transducers - convert one form of energy into another
What is voltage known as?
Potential difference
What is the potential difference called when a cell is at rest?
Resting potential
What is the change in potential difference due to a stimulus called?
The generator potential