Neurons Flashcards
What do neurons do?
They conduct electrical impulses.
What word can be used to describe the reproducibility of neurons? What does this mean for damaged neurons?
They are amitotic. They can be repaired, but if they die will not grow back.
What can be said about the resource consumption of neurons?
Neurons have a high demand for glucose and O2.
What are the three functional regions of a neuron?
The receptive region, the conducting region, and the secretory region.
What two pieces make up the cell body of a neuron? What are they called together?
The nucleus and the granular cytoplasm. They are also called the biosynthetic centre.
What is another name for the ribosome clusters of neurons?
Nissl bodies
What are there a lot of in neurons? (3)
Mitochondria, rough ER, and golgi apparatus
What is a nuclei?
A cluster of cell bodies in the CNS.
What is a ganglion?
A cluster of ell bodies in the PNS.
What is a tract?
A cluster of axons in the CNS.
What is a bundle of axons in the PNS called?
A nerve.
What kind of electrical signals do dendrites use?
Graded potentials.
What is the beginning of the axon called?
The axon hillock.
What increases the rate of conduction of an axon?
The diameter of the axon.
How many terminal branches (axonal terminals) are there per axon?
roughly ten thousand
What is the missing organelle from the axon that is in the cell body?
The Nissl body.
What do we call a movement of something from the cell body to the axon?
An anterograde movement.
What do we call a movement of something from the axon terminal to the cell body?
A retrograde movement.
What are the 4 types of supporting CNS cells? Lightly describe them.
- Astrocytes are start shaped and attach neurons to capillaries. They guide growing neurons and facilitate nutrient exchange and clean the environment.
- Microglia are protective cells and touch neurons to monitor well being. They can turn into macrophages.
- Ependymal cells line cavities in the brain and spinal cord. They have cilia.
- Oligodendrocytes provide myelin sheaths to the CNS.
What are the 2 types of supporting PNS cells? Lightly describe them.
Satellite cells surround cell bodies in a ganglia. They are the astrocytes of the PNS.
Schwann’s cells form myelin sheathes. Each sheathe is a wrapped up Schwann’s Cell.
What are the three structural classifications of neurons?
Unipolar, bipolar, and multipolar.
What structural classification of neurons is most common?
Multipolar.
Where are bipolar neurons found?
In some sensory organs.
Where are unipolar neurons found?
Transmitting sensory info towards the CNS.
What are the three functional classes of neurons?
Sensory, Motor, and Association neurons
Which way do sensory neurons fire?
Towards the CNS
Where are motor neurons found?
Muscles and glands
Which nervous system are the cell bodies of motor neurons found?
In the CNS
Where are association neurons found? How abundant are they?
They are between sensory and motor neurons, they are almost entirely in the CNS and make up 99% of neurons.
