Nervous System Paper 2 Flashcards
What is homeostasis?
Maintenance of internal conditions of the body
What does homeostasis include?
Blood glucose concentration
pH level
Water content of body
What is the response in a reflex action?
Stimulus
Receptor
Sensory neurone
Relay neurone
(Brain)
Motor neurone
Effector
Response
What is a stimulus?
A change in environment that causes the body to respond
What is a receptor?
The organ (skin) that detects to stimulus by transmitting electrical impulses to the brain
What is a neurone?
A specialised nerve cell that transmits electrical impulses
What is an effector and examples?
The organ that brigs about a response as a result of a stimulus
Glands
Muscles
What is the coordination centre?
Brain, spinal cord
Receives electrical impulses from receptors and generates signals to bring about a response
What is a reflex action?
A subconscious reaction that reducs risk of harm
What makes an reaction reflex?
Through spinal cord
What is a synapse?
Gap between neurones
How are electrical impulses transmitted through neurones?
Pre synaptic neurone has neurone transmitters that release chemicals into synapse
These diffuse over synapse and attach to receptors on post synaptic neurone.
What is the function of the optical nerve?
Sends electrical impulses to the brain
What is hypertopia and myopia?
Long and short sightedness
What are two ways a student can improve a reaction time practical?
Drop the ruler from the same height
Same type/weight of ruler
What does the ciliary muscle do?
Change shape of lens to focus
Define accurate
A measurement close to true value
Define precise
Repeated measurements that are close in value
What is reaction time?
How long it takes for you to react to a stimulus
What does the cerebellum control?
Coordinating muscular activity and balance
What does the cerebral cortex do?
Control consciousness, memory and language
How does the nervous system coordinate a reflex action? (6)
(1)Receptor detects stimulus
(2) causes sensory neurone to send electrical impulses to the spinal cord (3) across a synapse where chemical signals are transmitted to relay neurone. Then electrical impulses are sent to motor neurone where an effector is able to bring about a response
Name method that doctors can use to find out how damaged brain is?
CT scan
MRI scan
Explain why a long sighted person has difficulty seeing near objects clearly?
Light focus behind retina because their lens can’t get thick enough to have light focus on retina
How can lenses correct long sightedness?
Convex lenses allow light to be refracted to move focus of the light to on the retina, creating a clear image
Response is?
Rapid
Effect is?
Temporary and reversible
Transmission and communication?
By neurone through electrical impulses
Response is?
Localised and short lived
Suggest how the fMRI scanner could help to find out more about the brain damage a person has?
You can ask people to do different specific tasks while taking a scan to see which part of the brain is active/ inactive
This allows us to see which part of the brain is working so we can then compare with a person without brain damage to see where the damage is
Describe how the brain receives information about light entering the eye?
retina sensitive to light
allow retina detects light
allow rods / cones to detect light. Then, electrical impulses pass along sensory neurone to optic nerve that sends information to the brain
What does medulla do?
Controls unconscious activities such as heartbeat, swallowing, and breathing
What can brain damage cause?
Loss of specific functions such as damage to cerebellum can cause loss of movement
