The Nervous System Flashcards
What is the central nervous system (CNS)?
- Consists of brain and spinal cord
2. Processes sensory info to produce appropriate motor responses
What is the peripheral nervous system (PNS)?
- Network of nerves around the rest of the body
2. Connects sensory organs and other organs to the CNS
What is a synapse? How big is it?
A gap between two neurons
- About 20 nanometres wide
What happens in the synapse? (5)
- Nerve impulses cant travel across synapses so info is sent by neurotransmitters (ntmers)
- Ntmers released from synaptic vesicles at the end of presynaptic neuron and diffuse into synapse
- Bind with active site of receptor molecules on membrane of postsynaptic neuron, which stimulates a new nerve impulse
- Ntmers reabsorbed into presynaptic
- Stimulation of postsynaptic ends as levels of ntmers in synapse decreases
Name the parts of a nerve cell.
- Nucleus
- Cytoplasm
- Axon
- Dendrites
- Axon ending
- Fatty myelin sheath
What is the function of a neuron’s nucleus?
- Where electrical impulses start
2. Controls cell’s functions
What is the function of the axon?
- Extension of the cytoplasm
2. Transmits electrical impulses
What is the function of the fatty myelin sheath?
- Made of Schwann cells
- Increases speed of impulse transmission by acting as an insulator that prevents impulses from firing off randomly to uninvolved neurons
What is the function of the dendrites?
Branched ending that synapses with other neurons
What is a neurotransmitter?
Chemical messenger that carries signals between neurons
What is dopamine?
Ntmer involved in attention, concentration and learning
What is serotonin?
Ntmer involved in regulating anxiety, happiness and mood
What is GABA?
- Gamma-aminobutyric acid)
2. Ntmer involved in calming us down
