Nervous System & Nervous Tissue

These flashcards cover key concepts related to the nervous system, including its structures, functions, and types of cells involved.

Peripheral Nervous System (PNS)

The part of the nervous system that consists of peripheral nerves and ganglia, communicating between the CNS and the rest of the body.

Central Nervous System (CNS)

The integrating and command center of the nervous system, comprising the brain and spinal cord.

Neuroglia

Supporting cells in the nervous system that assist with various functions including the maintenance of homeostasis and support for neurons.

Myelin Sheath

A lipoprotein layer that surrounds thicker axons, produced by oligodendrocytes in the CNS and Schwann cells in the PNS, which insulates the axon and increases the speed of impulse transmission.

Reflex Arc

The neural pathway that mediates a reflex action, involving sensory neurons, interneurons, and motor neurons.

Monosynaptic Reflex

A reflex that involves a single synapse between a sensory and a motor neuron, exemplified by the knee-jerk reflex.

Polysynaptic Reflex

A reflex that involves multiple synapses and one or more interneurons between sensory and motor neurons.

Astrocytes

The most abundant type of glial cell in the CNS, involved in regulating neurotransmitter levels and the ionic environment around neurons.

Microglial Cells

The smallest and least abundant glial cells in the CNS, responsible for engulfing microorganisms and debris.

Ependymal Cells

Glial cells that line the central cavities of the brain and spinal cord, involved in the production and circulation of cerebrospinal fluid.