B10 The Nervous System Flashcards
What is homeostasis?
Maintenance of constant internal environment in order to maintain optimal conditions for enzyme and cellular functions
The conditions maintained by homeostasis in the body
Blood glucose concentration
Water levels
Body temperature
What 2 types of responses are used in body control system?
Nervous and Chemical responses
What 3 components do all control systems have
Receptors
Coordination centre
Effector
What is the function of a receptor?
Detect changes in the environments (stimuli)
What is the function of a coordination centre?
obtain and process information from the receptors
What is the function of an effector?
Bring about responses to stimuli
What is the function of the Nervous System?
Allow body to react to surroundings and coordinate an appropriate response
How does a stimulus lead to a response being carried out by the body?
Stimulus is converted into a electrical impulse by the receptors
Electrical impulse passes along sensory neurone to the central nervous system
The CNS coordinates an appropriate response and an electrical impulse is sent along motor neurone to the effector which carries out the response
What sequence of events describes how the nervous system works?
Stimulus —–> Receptor —–> Coordinator —–> Effector —–> Response
What is a reflex action?
Automatic and rapid response which does not involve any conscious input from the brain
Why are reflex actions important?
Aid survival by preventing harm from the body
Describe how a reflex action occurs via a reflex arc
Stimulus is detected by a receptor
An electrical impulse passes along a sensory neurone to the spinal cord
At the synapse between a sensory neurone and a relay neurone a chemical diffuses across the gap and stimulates a new impulse which passes along the relay neurone
The same process occurs at the synapse between a relay neurone and a motor neurone
At the effector an appropriate response is carried out
What is the difference between a reflex pathway and a conscious pathway?
Within a reflex pathway the coordination centre is a relay nueron found in the spinal cord/unconscious parts of the brail. In a conscious pathway, the coordination centre is in the conscious part of the brain
What is the function of the cerebral cortex?
Controls consciousness, intelligence, memory and language
What is the function of the cerebellum?
Controls muscular coordination
What is the function of the medulla?
Controls unconscious activiets eg. breathing , heart rate