Homeostasis and response Flashcards
What is homeostasis?
the regulation of the conditions inside your body to maintain a stable environment
What are the five parts of a negative feedback loop?
- stimulus
- receptor
- coordination centre
- effector
- response
What is the nervous system made up of?
- CNS
-sensory neurons - motor neurons
- effectors
What are some examples of effectors?
muscles and glands
What dos the CNS consist of?
- in vertebrates- brain and spinal cord only
- in mammals the CNS is connected to the body by sensory and motor neurones
What is the order of processes when the CNS coordinates a response?
- stimulus
- receptor
- sensory neurone
- CNS
- motor neurone
- effector
- response
What is a synapse?
the connection between two neurones
How do synapses work?
nerve signal is transferred by chemicals which diffuse across them synapse. These chemicals then set off a new electrical signal in the next neurone
What are reflexes?
rapid automatic responses to certain stimuli that don’t involve the conscious part of the brain
What happens if somebody shines a bright light in your eye?
your pupils automatically get smaller so that less light gets in your eye and stops it from getting damaged
Describe a reflex arc
- A stimulus is detected by receptors
- impulses are sent along a sensory neurone to a relay neurone in the CNS
- When the impulses reach a synapse between the neurones, chemicals are released which cause impulses to be sent along the relay neurone
- When the impluses reach the synapse between the relay and the motor neurone the same thing happens - chemicals are released causing impulses to be sent along the motor neurone
- impulses travel along the motor neurone to the effector where a response is carried out
What are the different parts of the brain and what do they do?
. Cerebral cortex- responsible for things like consciousness, intelligence, memory and language.
. Medulla- controls unconscious activities like breathing and your heartbeat.
. Cerebellum- responsible for muscle coordination
What different methods do scientists use to study the brain?
- studying patients with brain damage
- electrically stimulating the brain
- MRI scans
How do scientists use MRI scans to study the brain?
They can use it to find out what areas of the brain are active when people are doing things like listening to music or trying to recall a memory
How do scientists use electrically stimulating the brain to study it?
The brain can be electrically stimulated by pushing a tiny electrode into the tissue and giving it a small zap of electricity
