Nervous System Quiz Flashcards
Order of Nervous System
Look at “DIVISIONS OF THE NERVOUS SYSTEM” Chart
Soma
Contains organelles.
Produces proteins and molecules needed for a neuron to send/receive an impulse.
Nucleus
Does what you would expect a typical cell body!
Has organelles, such as cytoplasm, a plasma membrane, rough ER, ribosomes, a Golgi apparatus, and more!
Dendrites
Receive impulses from previous neuron.
Short and highly branched.
Axon
Carries impulse away from the soma and toward the next neuron.
Myelin Sheath
Lipid layer.
Insulates the axon.
Speeds up the transmission of action potentials along the axon.
Nodes of Ranvier
Gaps in the myelin sheath along the axon.
Impulses “skip” to them.
Axon Hillock
Where the axon joins the cell body.
Axon Terminals
Fine projections at the end of an axon that pass the impulse to the next neuron.
Synaptic End Bulbs
Store neurotransmitters that are released into the synapse due to impulses.
How long do Neurons live?
Neurons can live a whole lifetime.
Why can’t Neurons be replaced?
They do not divide, and use a constant supply of ATP and oxygen – they cannot survive for more than a few minutes without oxygen
How are Neurons classified STRUCTURALLY?
Multipolar
Bipolar
Unipolar
How are neurons classified FUNCTIONALLY?
Sensory neurons
Motor neurons
Interneurons
Multipolar
Have many processes.
One long axon and multiple dendrites.
More than 99%
These are the most common type of neuron in the central nervous system (brain & spinal cord).
Bipolar
Have two processes.
One branching axon and one dendrite.
Very rare
Only found in the special sense organs (ex. Eye)
Unipolar
Have only one process – an axon.
Mainly found in the peripheral nervous system
Which neurons are part of the SENSORY division?
Mainly UNIPOLAR
Rarely BIPOLAR
Which neurons are part of the MOTOR division?
MULTIPOLAR
Which neurons are part of the INTERNEURON (Integration) division?
INTERNEURONS
Astrocytes
Largest & most numerous.
Anchor neurons to blood capillaries.
(ASTRO= LOOKS LIKE A STAR)
Microglial cells
Sense & approach injured neurons.
Built in “white blood cells” in the nervous system.
Phagocytose bacteria & debris.
(MICRO=MICROFIBER RAG= CLEAN UP= DUSTER = LOOKS LIKE A FEATHER DUSTER)
Ependymal cells
Use cilia to circulate cerebrospinal fluid around the brain & spinal cord.
(Looks like a flipped E)
Oligodendrocytes
Form myelin sheath in the CNS (an insulating covering)
Attacked by the immune system in multiple sclerosis
(autoimmune condition) (that’s so stupid wth).
O= SHAPED LIKE AN O
