Topic 5 Homeostasis Flashcards
Definition of homeostasis
Maintaining a stable internal environment at optimum conditions.
What are the 3 things the human body needs to take control of ?
- blood glucose conc.
- body temperature
- water levels
what is a stimulus ?
change in the environment
why is homeostasis really important?
so cells can function properly
right conditions for enzyme action
describe the process of negative feedback.
- receptor detects stimulus (change in environment)-level too high /low
- CC receives and processes the information then organises a response
- effectors PROUDUCE the response which COUNTERACTS change and restores optimum level which decreases/increases
what are the types of effectors ?
Muscles and glands
what is the connection between two neurones called ?
a synapse
what do the effectors do?
respond to nervous impulses and bring abut change
how are nerve signals transferred across a synapse?
chemicals which diffuse move across gap?
what is a reflex action?
rapid automatic response that don’t involve the conscious part of the brain
give 2 example of a reflex action ?
- bright light is shone into eye pupils automatically dilate so less light gets in stopping damage
- getting a shock body release hormone adrenaline automatically
purpose of a reflex action?
reduces the chances of being injured
what is a reflex arc?
the passage of information in a reflex from a receptor to effector
differences between nervous system and reflexes?
- reflexes are faster and prevent injury
* Reponses use the conscious part of the brain
why are reflexes faster ?
because you don’t have to think about the response (which takes time)
