NERVOUS SYSTEM: Neurons and Neuroglia

ASSOCIATION NEURON

A neuron that conducts action potentials from one neuron to another neuron within the CNS.

AXON HILLOCK

Area that marks the end of the cell body and the beginning of the axon.

OLIGODENDROCYTE

Binds together and insulates CNS neurons.

FASCICLE

Bundle of axons.

CENTRAL NERVOUS SYSTEM (CNS)

Consist of the brain and spinal cord. Integrates and commands center of the nervous system. It interprets sensory input and dictates motor responses based on reflexes, current conditions, and past experiences. Motor Division.

NEURON

Consist of three basic units: CELL BODY, AXONS and DENDRITES.

SYMPATHETIC DIVISION

Division of the ANS that generally prepares the body for physical activity.

PARASYMPATHETIC DIVISION

Division of the ANS that regulates resting and nutrition-related functions such as digestion, defecation, and urination.

ACTION POTENTIAL

Electrical signal carried by an axon in a nerve

MICROGLIA

Engage in phagocytosis to fight infections.

MYELIN SHEATH

Fatty wrapping that actually speeds up the transmission of the action potential down the axon.

ASTROCYTES

Form the blood-brain barrier.

NODES OF RANVIER

Gaps in the myelin sheath

SCHWANN CELL

Insulates PNS neurons.

NERVOUS SYSTEM.

Is the master controlling and communicating system of the body.

UNIPOLAR NEURON

It has only one processes and the cell body hangs off that processes.

INTEGRATION

Nervous system processes and interprets sensory input and decides what should be done at each moment .

MULTIPOLAR NEURON

Neuron that has many processes: several dendrites but only one axon.

EFFERENT NEURONS

Neurons which transmit action potentials from the CNS to the effector organs. Can be divided into two sections: the SOMATIC MOTOR NERVOUS SYSTEM (SMNS) and AUTONOMIC NERVOUS SYSTEM (ANS)

AFFERENT NEURONS

Neurons which transmit action potentials from the sensory to the CNS.

FIVE TYPES of NEUROGLIA

Oligodendrocyte, Schwann Cell, Microglia, Astrocytes, Ependymal Cells.

PERIPHERAL NERVOUS SYSTEM (PNS)

Part of the nervous system outside of the CNS. Consist mainly of the nerves that extend from the brain and spinal cord. Spinal nerves carry impulses to and from the spinal cord, and cranial nerves carry impulses to and from the brain. It also has two functions SENSORY or AFFERENT DIVISION.

MOTOR OUTPUT

Response created by the nervous system by activating effector organs.

THREE OVERLAPPING FUNCTIONS OF THE NERVOUS SYSTEM.

Sensory input, Integration, Motor output.

EPINEURIUM

Shiny wrapping where nerves are wrapped.

THRESHOLD STIMULUS

Stimulus is strong enough to trigger the action potential.

SUBTHRESHOLD STIMULUS

Stimulus that does not reach the threshold.

EXCITABILITY

The ability to create an action potential in response to stimulus.

SENSORY OUTPUT

The gathered of information.

SOMATIC NERVOUS SYSTEM

The system that transmits action potentials from the CNS to the skeletal muscles. Controls the voluntary muscles.

AUTONOMIC NERVOUS SYSTEM

The system that transmits action potentials from the CNS to the smooth muscles, cardiac muscles, and glands. Controls the involuntary muscles. It can be divided into two divisions: SYMPATHETIC DIVISION and PARASYMPATHETIC DIVISION.

BIPOLAR NEURON

These neurons have two processes: and axon and a single dendrite split into many branches.

PERINEURIUM

Where the fascicle is wrapped.