chp 14 anat

Central Nervous System (CNS)

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

Peripheral Nervous System (PNS)

The part of the nervous system that includes all neural pathways that lie outside of the central nervous system.

Afferent pathway

The pathway that carries sensory information toward the CNS.

Efferent pathway

The pathway that carries motor commands away from the CNS to effectors.

Somatic sensory

Sensory information that is consciously perceived or sensed.

Visceral sensory

Sensory information that is not consciously perceived, often involving the internal organs.

Autonomic nervous system

The part of the peripheral nervous system that controls involuntary bodily functions.

Motor neurons

Neurons that stimulate muscles or glands to produce a response.

Neurons

The basic functional unit of the nervous system that conducts impulses.

Glial cells

Non-excitable cells that support and protect neurons.

Myelin sheath

A fatty layer that insulates axons and increases the speed of electrical impulses.

Synapse

The junction where a neuron communicates with another neuron or effector.

Neurotransmitter

Chemical messengers released at synapses to transmit signals between neurons.

Synaptic cleft

The small gap between the presynaptic and postsynaptic membranes at a synapse.

Saltatory conduction

The process by which nerve impulses are conducted along myelinated fibers, jumping from node to node.

Depolarization

The process of reducing the membrane potential, leading to an action potential in neurons.

Neurolemma

The outermost layer of a nerve fiber, important for regeneration in the peripheral nervous system.

Oligodendrocytes

Glial cells in the central nervous system that form myelin sheaths around axons.

Schwann cells

Glial cells in the peripheral nervous system that form myelin sheaths around axons.

Astrocytes

Glial cells that provide structural support and help form the blood-brain barrier.

Cerebrospinal fluid (CSF)

Fluid that bathes the brain and spinal cord, providing protection and nourishment.

Action potential

A rapid change in membrane potential that propagates along an axon.

Homeostasis

The maintenance of a stable internal environment within the body.

Neurogenesis

The process by which new neurons are formed in the brain.

Resting membrane potential

The baseline electrical charge across a neuron's membrane when it is not actively firing.

Neuropathy

Damage or disease affecting the nervous system, often resulting in loss of function.

Spina bifida

A birth defect where the neural tube does not close completely, leading to spinal cord exposure.

Folic acid

A B vitamin that is essential for proper neural tube development during fetal growth.

Membrane potential

The electric potential difference across a cell's membrane, crucial for signal transmission in neurons.