Nervous Tissue

A collection of vocabulary flashcards summarizing key terms and concepts from the Nervous Tissue lecture.

Nervous System

A complex network that helps maintain health and homeostasis by regulating controlled conditions.

Afferent Neurons

Neurons that carry sensory information from receptors in skin and other organs to the central nervous system.

Efferent Neurons

Neurons that carry motor information from the brain to effectors, such as muscles and glands.

Central Nervous System (CNS)

Comprises the brain and spinal cord; responsible for processing sensory information and coordinating the body's response.

Peripheral Nervous System (PNS)

Connects the CNS to the limbs and organs; includes sensory and motor divisions.

Neuron

An electrically excitable cell that transmits nerve impulses.

Synapse

The junction between two neurons or between a neuron and an effector.

Action Potential

A rapid change in membrane potential that occurs when a neuron is activated.

Neurotransmitters

Chemical messengers that transmit signals across a synapse from one neuron to another.

Neuroglia

Supportive cells of the nervous system that are not electrically excitable and can multiply.

Myelin Sheath

A protective covering that insulates axons and increases the speed of nerve impulse transmission.

Resting Membrane Potential

The electrical potential across the plasma membrane of a non-conducting neuron, typically around -70 mV.

Graded Potential

A small change in resting membrane potential that can vary in amplitude depending on the strength of the stimulus.

Saltatory Conduction

The process by which action potentials jump from one node of Ranvier to the next along myelinated axons.

Spinal Nerves

31 pairs of nerves that arise from the spinal cord and transmit information to and from the body.

Cranial Nerves

12 pairs of nerves that emerge directly from the brain, responsible for various sensory and motor functions.

Neuroplasticity

The ability of the nervous system to change and adapt based on experience.

Excitatory Postsynaptic Potential (EPSP)

A depolarizing postsynaptic potential that makes a neuron more likely to fire an action potential.

Inhibitory Postsynaptic Potential (IPSP)

A hyperpolarizing postsynaptic potential that makes a neuron less likely to fire an action potential.

Diverging Circuit

A neural circuit where one neuron influences multiple other neurons.

Converging Circuit

A neural circuit where multiple neurons influence a single postsynaptic neuron.

Chemical Synapse

A type of synapse that transmits signals through the release of neurotransmitters.

Ligand-Gated Channel

An ion channel that opens in response to the binding of a specific chemical messenger.

Voltage-Gated Channel

An ion channel that opens in response to changes in membrane potential.

Nervous System

A complex network that helps maintain health and homeostasis by regulating controlled conditions.

Afferent Neurons

Neurons that carry sensory information from receptors in skin and other organs to the central nervous system.

Efferent Neurons

Neurons that carry motor information from the brain to effectors, such as muscles and glands.

Central Nervous System (CNS)

Comprises the brain and spinal cord; responsible for processing sensory information and coordinating the body's response.

Peripheral Nervous System (PNS)

Connects the CNS to the limbs and organs; includes sensory and motor divisions.

Somatic Nervous System (SNS)

A division of the PNS that regulates voluntary movements by conveying information from sensory receptors to the CNS and motor impulses to skeletal muscles.

Autonomic Nervous System (ANS)

A division of the PNS that regulates involuntary functions, such as heart rate and digestion; composed of the Sympathetic and Parasympathetic divisions.

Neuron

An electrically excitable cell that transmits nerve impulses.

Dendrites

The receiving or input portions of a neuron that conduct signals toward the cell body.

Axon

A long projection of a neuron that conducts nerve impulses away from the cell body toward another neuron, muscle fiber, or gland cell.

Cell Body (Soma)

The metabolic center of the neuron containing the nucleus and other organelles.

Synapse

The junction between two neurons or between a neuron and an effector.

Action Potential

A rapid change in membrane potential that occurs when a neuron is activated.

Threshold

The critical level, typically around -55\text{ mV}, to which a membrane potential must be depolarized to initiate an action potential.

Refractory Period

The time interval following an action potential during which a neuron cannot generate another impulse.

Neurotransmitters

Chemical messengers that transmit signals across a synapse from one neuron to another.

Neuroglia

Supportive cells of the nervous system that are not electrically excitable and can multiply.

Myelin Sheath

A protective covering that insulates axons and increases the speed of nerve impulse transmission.

Nodes of Ranvier

The unmyelinated gaps between segments of the myelin sheath where ion flow and action potentials occur.

Resting Membrane Potential

The electrical potential across the plasma membrane of a non-conducting neuron, typically around -70\text{ mV}.

Graded Potential

A small change in resting membrane potential that can vary in amplitude depending on the strength of the stimulus.

Saltatory Conduction

The process by which action potentials jump from one node of Ranvier to the next along myelinated axons.

Spinal Nerves

31 pairs of nerves that arise from the spinal cord and transmit information to and from the body.

Cranial Nerves

12 pairs of nerves that emerge directly from the brain, responsible for various sensory and motor functions.

White Matter

Tissue in the brain and spinal cord composed primarily of myelinated axons.

Gray Matter

Tissue in the brain and spinal cord containing neuronal cell bodies, dendrites, unmyelinated axons, and neuroglia.

Neuroplasticity

The ability of the nervous system to change and adapt based on experience.

Excitatory Postsynaptic Potential (EPSP)

A depolarizing postsynaptic potential that makes a neuron more likely to fire an action potential.

Inhibitory Postsynaptic Potential (IPSP)

A hyperpolarizing postsynaptic potential that makes a neuron less likely to fire an action potential.

Diverging Circuit

A neural circuit where one neuron influences multiple other neurons.

Converging Circuit

A neural circuit where multiple neurons influence a single postsynaptic neuron.

Chemical Synapse

A type of synapse that transmits signals through the release of neurotransmitters.

Ligand-Gated Channel

An ion channel that opens in response to the binding of a specific chemical messenger.

Voltage-Gated Channel

An ion channel that opens in response to changes in membrane potential.