Nervous Tissue Lecture Notes

Flashcards for reviewing nervous tissue lecture notes.

Neurons

Cells that receive, process, and send information to other cells.

Glia

Cells that support and help neurons in their function.

Cell body

The part of the neuron responsible for eating, digesting, building proteins, and genetics.

Dendrites

Specialized parts of a neuron that receive information such as light, sound, touch, pain, or chemicals.

Trigger zone (axon hillock)

Part of the neuron that evaluates information from dendrites and decides if the information should be sent down the axon.

Axons

Carries a large positive electrical signal over long distances to the axon terminals

Axon terminals

Tips of the axon that release chemicals called neurotransmitters onto other cells.

Action potential

A large positive electrical signal formed inside the neuron at the trigger zone.

Neurotransmitter

Chemical messenger released from the axon terminal that binds to the next neuron, either exciting or inhibiting it.

Synapse

The space between cells filled with extracellular fluid.

Multipolar neuron

Type of neuron with many processes sticking out of the cell body, located in the brain and spinal cord and used in thinking and sending information to muscles.

Sensory neuron

Type of neuron that sends information UP to the spinal cord and brain.

Astrocytes

Glia in the CNS, part of the blood-brain barrier determining what contents of the blood can reach the neuron.

Microglia

Mobile defensive cells in the CNS that phagocytize cell debris and pathogens.

Schwann cells and Oligodendrocytes

Glial cells that wrap parts of the axon to speed electrical conduction and insulate the axon from its neighbors.

Ependymal cells

Glia that line cavities in the brain to make and circulate cerebrospinal fluid (CSF).

Sodium, Chloride, Calcium, Potassium

Main ions in extracellular fluid.

Membrane Pumps

Mechanism and energy to run it to make an ion gradient where some ions are higher on one side of the membrane than on the other.

MEMBRANE POTENTIAL

This difference in charge between the inside and outside of the cells is known as the __.

Membrane Pump Result

The inside of the cell is now -10mV, since more positive charges are leaving than entering.

Resting membrane potential

electrical values can be measured with a voltmeter! Voltmeters confirm that at REST neurons are more negative inside than outside. This difference in value is called the __.

ATP

Food energy is transferred to molecules of __, which is used to pump Na+ and K+ ions against their concentration gradient.

Neurotransmitters

chemicals released from the axon terminal that diffuses across the space between neurons which then influences the activity of the postsynaptic neuron.

Voltage Gated Sodium Channel Action

If excitatory NT brings the TZ to -55mV, Voltage gated sodium channels open first in the trigger zone and then all along the axon.

Myelin

covers much of the axon, and ions cannot pass through it.

Nodes

TINY SPACES between the myelin wrappings, are called __.