Nervous Tissue Overview

These flashcards cover key vocabulary and concepts discussed in the lecture on nervous tissue, including the structure and function of neurons, neuroglia, action potentials, synapses, and related disorders.

Neurosoma

The control center of a neuron, also known as the cell body, which contains the nucleus and organelles.

Central Nervous System (CNS)

Comprises the brain and spinal cord, enclosed by the cranium and vertebral column.

Peripheral Nervous System (PNS)

Includes all nervous system components outside the CNS, composed of nerves and ganglia.

Neuroglia

Supportive cells in the nervous system that protect and assist neurons; they outnumber neurons by approximately 10 to 1.

Myelin Sheath

An insulating layer around a nerve fiber, formed by glial cells, that enhances the speed of signal conduction.

Action Potential

A rapid change in membrane voltage that occurs when a neuron is stimulated, leading to the propagation of a nerve signal.

Excitatory Postsynaptic Potential (EPSP)

A voltage change in a postsynaptic neuron that makes it more likely to fire an action potential, typically resulting from Na+ influx.

Inhibitory Postsynaptic Potential (IPSP)

A voltage change in a postsynaptic neuron that makes it less likely to fire an action potential, often occurring due to Cl- entry or K+ exit.

Synapse

The junction between two neurons, where neurotransmitters are released to transmit signals.

Neurotransmitter

Chemicals released by neurons that transmit signals across a synapse to other neurons or target cells.

Resting Membrane Potential

The electrical charge difference across a neuron's membrane when it is not actively sending a signal, typically around -70 mV.

Axon

The long, thin structure of a neuron that transmits electrical impulses away from the neuron's cell body.

Dendrites

Branch-like extensions of neurons that receive signals from other neurons and transmit them to the cell body.

Sensory Neurons

Neurons that detect stimuli and transmit information from sensory receptors to the CNS.

Motor Neurons

Neurons that carry signals from the CNS to muscles and glands to elicit a response.

Interneurons

Neurons that connect sensory and motor pathways within the CNS, responsible for processing information.

Cholinergic Synapse

A type of synapse that uses acetylcholine as its neurotransmitter to transmit signals.

Saltatory Conduction

A method of signal transmission in myelinated fibers where the action potential jumps from one node of Ranvier to the next.

Neuroplasticity

The ability of neurons to change their connections and behavior in response to experience or injury.

Alzheimer's Disease

A neurodegenerative disorder characterized by memory loss and cognitive decline, associated with the loss of acetylcholine.

Multiple Sclerosis

A disease in which the myelin sheaths of the CNS deteriorate, leading to disrupted nerve conduction and symptoms such as double vision and tremors.

Long-Term Potentiation (LTP)

The process of synaptic strengthening that underlies learning and memory, involving an increase in synaptic transmission efficacy.

Cessation of Signal

The processes that stop the action of neurotransmitters in the synaptic cleft, including degradation, reuptake, and diffusion.

Summation

The process of adding up postsynaptic potentials to determine if a neuron will fire an action potential, affected by excitatory and inhibitory inputs.