B10 Neverous Sytem Flashcards
Describe the pathway of a nerver impulse
- A stimulus is detected by receptors in a sense organ e.g. the eyes.
- The stimulus is converted to an electrical impulse by the receptor.
- The electrical impulse travels along a Sensory neuron to the Brain (CNS).
- The brain decides the correct response that is required. The electrical impulse is
then passed to a relay neuron in the brain. - The relay neuron passes the electrical impulse to a motor neuron.
- The electrical impulse travels along the motor neuron to the effector e.g. a muscle.
- The effector carries out the response
How does an electrical impulse cross the synapse?
1) The electrical impulse reaches the end of the pre synaptic neuron.
2) This stimulates the release of neurotransmitter chemicals from vesicle
3) The neurotransmitter chemicals diffuse across the gap called the synapse
4) The neurotransmitter chemicals bind to specific receptors on the post synaptic neuron.
5) This binding triggers the generation of an electrical impulse (same message) in the post synaptic neuron and it travels along it’s axon
6) The neurotransmitter chemicals then diffuse back into the vesicles and are recycled.
What is the function of the cerebral cortex part of the brain?
Memory, consciousness, language and intelligence
What is the function of the cerebellum part of the brain?
Coordination of muscular activity and movement
What is the function of the medulla part of the brain?
Unconscious activities, such as breathing and heartbeat
What can a MRI can be used to examine?
Almost any part of the body, such as:
Brain and spinal cord
Bones and joint
Heart and blood vessels
How does an MRI work?
Is a type scan that uses strong, magnetic fields and radio waves produce detailed images of the inside of the body
Why is it difficult to study the brain?
It is very complex and a delicate organ.
Different regions can’t be studied in isolation.
There could be damaged during investigation
Name the 9 parts of the eye
Ciliary muscle
Cornea
Pupil
Iris
Suspensory ligament
Optic nerve
Retina
Sclera
Lens
What does the cornea do?
It is transparent and protective layer where light enters through and is refracted/bends
What does the iris do?
Control how much light enters the eye
What does the lens do?
The transparent, convex disk that changes shaped focus light on the retina
What does the retina do?
It has a light receptors
What does the optic nerve do?
Is a sensory neuron which carries electrical between the eye and the brain
What does the ciliary muscle do?
A ring of muscle that contracts and relaxes to change the shape of the lens
