Module 2, Week 1 (week 4) Flashcards
What is the nervous system?
main controlling/communicating system in the body
How do cells communicate messages?
electrical and chemical signals
Which is the fastest - electrical or chemical signals?
Electrical
How fast do electrical signals travel?
120m/second or 432km/hour
Examples of types of chemical communication are:
hormones, neurotransmitters
The brain and spinal cord make up the central nervous system. What is the main function of the central nervous system?
integrating centers that control and regulate - i.e homeostasis, movement, body functions
Some cells serve the nervous system. What are they called?
Glial cells
Cells of the nervous system are called?
neurons
Neurons are designed to carry signals over long or short distances?
Long
How long can nerve fibres be?
Over 1m
neurons communicate with:
other neurons and effectors - target cells (muscles cells and glands)
In brain and spinal cord which chemical signals are used?
Neurotransmitters
What is a neuron?
The structural unit of the nervous system
What’s the main role of neurons?
To generate electrical signals that can travel rapidly from cell to cell
Neurons have the capacity for?
Excitability
What is a stimulus in relation to the nervous system?
Change in the environment that is strong enough to lead to an Action Potential
What is Action Potential?
A nerve impulse generated by the cycle of depolarisation, repolarisation, after-hyperpolerisation - changes in charge across the cell membrane - moves along the length of the axon.
Are neurons the same size as each other?
No! Some are short (brain), some are up to 1m or more in length, some go from brain to toe.
Name the three parts of the neuron:
cell body, dendrites, axon
Are responses of the nervous system quick or slow?
Quick
Are responses general or targeted/specific?
Targeted/specific
What is the name of the type of cells that assist the nervous system?
Glial cells
What is the name of specific glial cells that assist neurons?
Schwann cells
How do neurons communicate with other neurons/cells?
Neurotransmitters