Chapter 11 Flashcards
Dentritic spines
Small extensions off a dendrite surface
Nissl body
Rough endoplasmic reticulum of a neuron responsible for protein synthesis
What is another name for soma?
The neuron’s cell body
What is the axoplasm?
Cytoplasm of an axon
WHat is the presynaptic terminal?
it is the enlarged end of axon containing vesicles filled with neurotransmitters
What is the initial segment?
It is the beginning of the axon
Where do action potentials begin?
at the trigger zone of an axon
WHat is the membrane of an axon called?
axolemma
What are dentrites?
the highly branched cytoplasmic extensions of a neuron cell body that are specialized to receive input and conduct signals toward the cell body
What is a synapse?
Space between axon and its target
What is the axon hillock?
cone-shaped area of the neuron body. Beginning of an axon
What are synaptic vesicles?
The small, membrane-bound organelles that are found in the presynaptic terminals and which contain neurotransmitters
What is the trigger zone?
combo of axon hillock and initial segment. It is where action potentials are generated
What is anterograde?
movement away from the cell body
Schwann Cells
The specific cells that are responsible for producing myelin in the PNS
Nodes of Ranvier
On myelinated axons, small gaps exist between adjacent Schwann cells
What is gray matter made up of?
groups of neuron cell bodies and their dendrites. there is very little myelin, resulting in a darker appearance.
Where is gray matter found in the CNS?
It is found on the surface of the cortex . Nuclei are clusters of gray matter deeper within the brain
Where is gray matter found in the PNS?
gray matter consists of clusters of neuron cell bodies, or ganglia
What is white matter made out of?
cell bodies of neurons, but have mylelinated axons. Why theyare white
Where can you find white matter in the CNS?
Nerve tracts: they propagate action potentials from one area of the CNS to another
Where is white matter found in the PNS?
nerves: bundles of axons and their connective tissue sheaths
Which of the glia are found inside the CNS?
astrocytes
WHat is a ganglion?
The knotlike swelling in a nerve where neuron cell bodies are found
WHich ions have a higher concentration in the ECM comepared to ICM?
Na+, Ca++, Cl-
What are electrical signals that are produced by the nervous system?
action or graded potentials
Where are K ions and negatively charged proteins more concentrated?
Inside the cell
WHat cells are responsible for wrapping around axons, and creating myelin sheaths in the PNS?
Schwann cells
WHere are ganglia found?
PNS
What is the resting membrane potential?
Difference in electrical charge across the plasma membrnae in an unstimulated cell
WHat is one factor that is in equilibrium and that contributes to the resting membrane potential?
The tendency for K+ to diffuse out and its attraction to the negative interior of the cell.
What is mostly responsible for establishing resting membrane potential?
Recall that compared to K+, Na+ has a relatively low permeability at rest. K+ movement across the membrane is largely responsible for establishing resting membrane potential.
The sodium-potassium pump is responsible for what portion of the resting membrane potential?
Less than 15mV
WHat is depolarization?
WHen the inside of the cell becomes more positive
Hyperpolarization
when the inside becomes more negative
WHat is the role of calcium on the gated Na+ channels?
It stabilizes the channel. WHen Ca+ is bound, the channel is closed
