Nervous tissue

Response Speed (Nervous)

Provides a fast response to stimuli.

Response Speed (Endocrine)

Provides a slower response to stimuli.

Duration of Effects (Nervous)

Effects are generally short-lasting.

Duration of Effects (Endocrine)

Effects are generally long-lasting.

Signal Type (Nervous)

Uses neurotransmitters for communication.

Signal Type (Endocrine)

Uses hormones for communication.

Targeting (Nervous)

Targets specific cells.

Targeting (Endocrine)

Can affect any cell that has the appropriate receptor.

CNS Components

Consists of the brain and spinal cord.

CNS Primary Functions

Processes and integrates sensory input and motor output; responsible for higher functions like memory and emotion.

PNS Components

Consists of all nervous tissue located outside the Central Nervous System.

PNS Primary Function

Sends sensory information to the CNS and carries motor commands away from it.

Afferent Division (PNS)

Carries sensory information from receptors into the CNS (A = Accept).

Efferent Division (PNS)

Carries motor commands from the CNS to muscles or glands (E = Exit).

Somatic Sensory Subdivision

Monitors conscious sensations from skin, skeletal muscles, and joints (e.g., touch, pain).

Visceral Sensory Subdivision

Monitors unconscious sensations from internal organs, glands, and blood vessels.

Somatic Nervous System (SNS)

The division of the efferent system that controls skeletal muscles (voluntary movement).

Autonomic Nervous System (ANS)

The division of the efferent system that controls smooth muscle, cardiac muscle, and glands (involuntary regulation).

Sympathetic Division (ANS)

Often called the 'fight, flight, or freeze' system; active during stress or emergencies.

Parasympathetic Division (ANS)

Often called the 'rest and digest' system; focuses on conserving energy and body maintenance.

Anaxonic Neuron

Has many processes, but axons cannot be distinguished from dendrites; found only in the CNS.

Anaxonic Function

Fine-tunes local signals within the CNS.

Bipolar Neuron

Features the cell body located between one dendrite and one axon.

Bipolar Function

Specialized for sensory pathways, such as the retina and olfactory system.

Pseudounipolar Neuron

The cell body is located off to one side of a continuous axon.

Pseudounipolar Function

Facilitates rapid sensory signal transduction into the CNS.

Multipolar Neuron

Typically has a single axon and multiple dendrites; the most common type in the CNS.

Multipolar Function

Integrates signals and sends commands within the CNS.

Astrocytes (CNS)

The largest and most numerous glial cells; they form the blood-brain barrier (BBB).

Oligodendrocytes (CNS)

Glial cells responsible for forming the myelin sheath around axons in the CNS.

Microglia (CNS)

Phagocytic cells that remove cell debris, wastes, and pathogens.

Ependymal Cells (CNS)

Line brain ventricles and the spinal central canal; assist in producing and monitoring cerebrospinal fluid (CSF).

Satellite Cells (PNS)

Surround neuron cell bodies in ganglia to regulate nutrient and gas levels.

Schwann Cells (PNS)

Surround and myelinate axons in the Peripheral Nervous System and assist in injury repair.

Myelin Composition

Fatty layers that wrap around axons only.

Myelin Function

Increases the speed of action potential conduction.

Saltatory Effect

The process where an action potential 'jumps' from node to node, accelerating transmission.

Nodes of Ranvier

The small, unmyelinated gaps between internodes where ion channels are exposed.

Gray Matter Composition

Contains neuron cell bodies, dendrites, and unmyelinated axons.

Gray Matter Function

Acts as the site for processing, analyzing, and coordinating information.

White Matter Composition

Composed mostly of myelinated axons.

White Matter Function

Primarily transmits information between different regions of the nervous system.

Nucleus (CNS)

A collection of cell bodies in the CNS with a distinct boundary.

Ganglia (PNS)

Clusters of neuron cell bodies in the Peripheral Nervous System.

Synapse Step 1

An action potential arrives at the presynaptic membrane.

Synapse Step 2

Neurotransmitters are released from vesicles into the synaptic cleft.

Synapse Step 3

The neurotransmitter diffuses across the synaptic cleft.

Synapse Step 4

The neurotransmitter binds to receptors on the postsynaptic membrane.

Synapse Step 5

Binding opens ion channels, causing a change in the membrane potential of the postsynaptic cell.