Flashcards: Nervous System (Chapter 8)

Central Nervous System (CNS)

The part of the nervous system that includes the brain and spinal cord.

Peripheral Nervous System (PNS)

All nervous tissue outside the Central Nervous System.

Somatic Nervous System

Controls voluntary movements by sending signals to skeletal muscles.

Autonomic Nervous System

Controls involuntary functions like heartbeat and digestion.

Multipolar Neuron

A neuron with many dendrites and one axon.

Bipolar Neuron

A neuron with one dendrite and one axon.

Pseudo-unipolar Neuron

A neuron with a single process that splits into two.

Astrocytes

Glial cells that support neurons and form the blood-brain barrier.

Schwann Cells

Cells that provide myelin in the Peripheral Nervous System.

Myelin Sheath

An insulating layer that increases the speed of action potential transmission.

Nodes of Ranvier

Gaps in the myelin sheath.

Saltatory Conduction

The process where action potentials jump from node to node in myelinated neurons.

Resting Potential

The state of a neuron when it is not actively firing an action potential.

Potassium Ion (K⁺)

The ion that is more concentrated inside the cell at rest.

Sodium Ion (Na⁺)

The ion that is more concentrated outside the cell at rest.

Depolarization

The process during which Na⁺ rushes into the cell, making it more positive.

Repolarization

The process during which K⁺ exits the cell, restoring negative charge inside.

Sodium-Potassium Pump

Maintains resting potential by pumping 3 Na⁺ out and 2 K⁺ in.

Gray Matter

The inner portion of the spinal cord containing cell bodies.

White Matter

The outer portion of the spinal cord containing myelinated axons.

Reflex Arc

A neural pathway that mediates a reflex.

Cerebellum

The part of the brain that controls balance, muscle tone, and fine motor coordination.

Frontal Lobe

Part of the cerebrum responsible for voluntary movement, decision-making, and emotions.

Parietal Lobe

Part of the cerebrum responsible for sensory processing such as touch, pain, and temperature.

Occipital Lobe

Part of the cerebrum responsible for processing vision.

Temporal Lobe

Part of the cerebrum responsible for hearing, smell, and memory.

Olfactory Nerve (Cranial Nerve I)

The cranial nerve that controls smell.

Optic Nerve (Cranial Nerve II)

The cranial nerve that controls vision.

Facial Nerve (Cranial Nerve VII)

The cranial nerve that controls facial expressions.

Vagus Nerve (Cranial Nerve X)

The cranial nerve that controls heart rate and digestion.

Sympathetic Division

The division of the autonomic nervous system that prepares the body for action.

Parasympathetic Division

The division of the autonomic nervous system that conserves energy and promotes rest.