The nervous system Flashcards
How do stimulus to our bodies cause an effect?
The nervous system is made up of neurons linking receptor cells to effector cells. Neurons transmit electrical impulses when stimulated.
How is a nerve cell structured?
The nucleus is in the cell body that is surrounded by branching dendrites. It connects to the axon often surrounded by a fatty myelin sheath. At the other end there are further dendrites to connect to other cells.
What does a myelin sheath do?
It coats the axon in a fatty insulator and increases the speed of transmission of a nerve impulse.
What is a humans nervous system made of?
The CNS, brain and spinal cord, is connected to the body by the PNS, sensory and motor neurons.
What is the pathway of a nerve impulse through the nervous system?
Receptor, sensory neuron, relay neuron, spinal cord, motor neuron, effector.
How do impulses pass between gaps in between neurons?
A synapse is the gap between nerves and impulses cross this gap by the release of chemicals. Certain chemicals will be triggered by different impulses and these chemicals diffuse across the synapse and bond to receptor molecules on the next neuron.
How can drugs affect synapse transmissions?
Ecstasy blocks the sites in the brains synapses where the transmitter substance, serotonin, is removed, causing the chemicals to stimulate receptors over and over as serotonin concentration in the synapse increases.
How can we tell what parts of the brain cause different actions and thoughts?
With scans like MRI we can see what parts of the brain are firing impulses in relation to the activity the subject is doing at the time. We have hence been able to find out that the cerebral cortex is responsible for intelligence, memory, language and consciousness.
