B10-Nervous System Flashcards
Define homeostasis
Maintenance of internal environment relatively
Name 3 key internal conditions that need to be controlled through homeostasis
Temperature, water levels, blood glucose levels
What does the receptor do?
That detects stimuli in the internal or external environment
What does coordination centre do?
Processes the stimuli information
What do the effectors do?
It responds to the stimuli
State the function of a neurone
Transmit electrical impulses
What does a sensory neurone do?
Carries impulses to the central nervous system
What does a motor neurone do?
Carries impulses away from the central nervous system
Name 2 types of effectors
Muscle, glands
Name 2 coordination centres that make up the central nervous system
Brain + spinal cord
Where is the cell body found in the sensory neurone
Along the neurone fibre
Where is the cell body found in the motor neurone?
At the beginning of the motor neurone
Name one factor that may affect human reaction time
Energy or sugary drinks/practice beforehand etc
Name the 3 types of neurones that are involved in coordinating reflexes
Sensory, relay, motor neurones
Where is the relay neurone found in a reflex arc?
Spinal cord
Illustrate the reflex pathway in a flowchart, showing all the components
Stimulus–>receptor–>sensory neurone–>relay neurone–>motor neurone–>effector–>response
What are synapses?
The junction/physical gap between neurones
How is information passed through the synapse?
Neurontransmitters are released which travel across the synapse to the receptor sites on the next neurone
Cerebral cortex
The region in the brain that involves consciousness, intellgigence, memory and language
Cerebellium
The region in the brain that coordinates muscular activity and balance
Medulla(oblongata)
The region in the brain that coordinates automatic, unconscious activities eg breathing, heart rate etc
Name a few methods scientists used to find out the functions of each part of the brain
Studying brain damage/electrically stimulating different parts of brain/MRI scans
State the function of the sclera
White outer layer to protect the eyeball
State the function of the cornea
Allows light into the eye; refract/focus light
How is the size of the pupil controlled?
Muscular contraction and relaction of the iris
State the function of the lens
Refracts light to focus the image onto the retina
Name 2 components that change the shape of the lens
Suspensory ligaments+ciliary muscles
What does the optic nerve do?
Carries impulses from the retina to the brain
Describe the state of the ciliary muscles and the lens as the eye focuses on a distant object
Ciliary muscles relax, lens becomes thinner
What is myopia?
Short sightedness, you can see close objects clearly but distant objects look blurred
What is hyperopia?
Long sightedness, you can see distant objects clearly but close objects are blurred
Give 2 possible reasons for myopia
Lens too curved, long eyeball
Describe the state of the lens if more refraction is to happen
More convex/rounded
Name a treatment for myopia or hyperopia
Contact lenses/laser eye surgery/replacement lenses
