Functions of Nervous System part 2

Nervous System

Master controlling and communicating system of the body

Electrical and Chemical Signals

Means of communication between cells in the nervous system

Sensory Input

Information gathered by sensory receptors about internal and external changes

Integration

Processing and interpretation of sensory input

Motor Output

Activation of effector organs (muscles and glands) to produce a response

Central Nervous System (CNS)

Brain and spinal cord; the integration and control center of the nervous system

Peripheral Nervous System (PNS)

The portion of the nervous system outside the CNS, consisting mainly of nerves that extend from the brain and spinal cord

Sensory Division

Transmits impulses from sensory receptors to the CNS

Motor Division

Transmits impulses from the CNS to effector organs (muscles and glands)

Somatic Nervous System

Conducts impulses from the CNS to skeletal muscles; responsible for voluntary movement

Autonomic Nervous System

Regulates smooth muscle, cardiac muscle, and glands; responsible for involuntary movement

Sympathetic Division

Activates the body's fight-or-flight response

Parasympathetic Division

Conserves the body's energy; responsible for rest and digest functions

Neuroglia

Small cells that surround and wrap delicate neurons; provide support and protection

Neurons

Large, highly specialized cells that conduct impulses and serve as the structural units of the nervous system

Astrocytes

Abundant, versatile, and highly branched glial cells that support and brace neurons

Microglial Cells

Small cells with thorny processes that monitor neurons and can transform to phagocytize microorganisms and neuronal debris

Ependymal Cells

Cells that line the central cavities of the brain and spinal column, and circulate cerebrospinal fluid

Oligodendrocytes

Cells that wrap CNS nerve fibers, forming insulating myelin sheaths in thicker nerve fibers

Satellite Cells

Cells that surround neuron cell bodies in the PNS, with functions similar to astrocytes of the CNS

Schwann Cells (Neurolemmocytes)

Cells that surround all peripheral nerve fibers and form myelin sheaths in thicker nerve fibers, with a function similar to oligodendrocytes

Extreme Longevity

Characteristic of neurons, lasting a person's lifetime

Amitotic

Characteristic of neurons, with few exceptions

High Metabolic Rate

Characteristic of neurons, requiring a continuous supply of oxygen and glucose