NERVES, GANGLIA, TRACTS & NUCLEI:
THE NERVOUS SYSTEM'SWIRING & PROCESSING CENTERS
INTRODUCTION: Understanding how the body transmits signals and processes information.
The nervous system is composed of two main parts: the Central Nervous System (CNS) and the
Peripheral Nervous System (PNS),each with distinct structures for communication and integration.
SECTION 1: THE PERIPHERAL NERVOUS SYSTEM (PNS)- NERVES & GANGLIA
NERVES: Bundles of Axons Outside the CNS GANGLIA: Clusters of Cell Bodies Outside
Definition: Nerves are
the CNS
cord-like bundles of Definition: Ganglia are
axons that transmit structures containing
signals between collections of nerve
the CNS and the rest cell bodies (somas)
of the body. They located outside the
carry both sensory CNS. They act as
(afferent) and relaypointsor
motor (efferent) processingcenters for
information. signals.
DAILY LIFE EXAMPLE DAILY LIFE EXAMPLE
A person touching a hot stove; sensorynerves in the During a fight-or-flight response, the autonomic
hand send pain signals to the brain, and motor nerves ganglia process signals to increase and
heart rate
send signals back to withdraw the hand quickly. dilate pupils without conscious thought.
SECTION 2:THE CENTRAL NERVOUS SYSTEM (CNS)-TRACTS & NUCLEI
TRACTS: Bundles of Axons Inside the CNS NUCLEI: Clusters of Cell Bodies Inside
the CNS
Definition: Tracts are Definition: Nuclei are
bundlesof axons organized groups of
located within the nerve cell bodies
CNS (brainand spinal located within
cord) that connect the CNS. They
different regions and serve as
carry information up specialized
and down the spinal processing centers
Cord. for specific functions. Nuclei
DAILY LIFE EXAMPLE DAILY LIFE EXAMPLE
Voluntary muscle movement; the corticospinal tract The processing of visual information; specific nuclei
carries signals from the brain's motor cortex to the in thethalamusand brainstem integrate signals from
spinal cord to control leg muscles for walking. the eyes before they reach the visual cortex.
THE NERVOUS SYSTEM'SWIRING & PROCESSING CENTERS
INTRODUCTION: Understanding how the body transmits signals and processes information.
The nervous system is composed of two main parts: the Central Nervous System (CNS) and the
Peripheral Nervous System (PNS),each with distinct structures for communication and integration.
SECTION 1: THE PERIPHERAL NERVOUS SYSTEM (PNS)- NERVES & GANGLIA
NERVES: Bundles of Axons Outside the CNS GANGLIA: Clusters of Cell Bodies Outside
Definition: Nerves are
the CNS
cord-like bundles of Definition: Ganglia are
axons that transmit structures containing
signals between collections of nerve
the CNS and the rest cell bodies (somas)
of the body. They located outside the
carry both sensory CNS. They act as
(afferent) and relaypointsor
motor (efferent) processingcenters for
information. signals.
DAILY LIFE EXAMPLE DAILY LIFE EXAMPLE
A person touching a hot stove; sensorynerves in the During a fight-or-flight response, the autonomic
hand send pain signals to the brain, and motor nerves ganglia process signals to increase and
heart rate
send signals back to withdraw the hand quickly. dilate pupils without conscious thought.
SECTION 2:THE CENTRAL NERVOUS SYSTEM (CNS)-TRACTS & NUCLEI
TRACTS: Bundles of Axons Inside the CNS NUCLEI: Clusters of Cell Bodies Inside
the CNS
Definition: Tracts are Definition: Nuclei are
bundlesof axons organized groups of
located within the nerve cell bodies
CNS (brainand spinal located within
cord) that connect the CNS. They
different regions and serve as
carry information up specialized
and down the spinal processing centers
Cord. for specific functions. Nuclei
DAILY LIFE EXAMPLE DAILY LIFE EXAMPLE
Voluntary muscle movement; the corticospinal tract The processing of visual information; specific nuclei
carries signals from the brain's motor cortex to the in thethalamusand brainstem integrate signals from
spinal cord to control leg muscles for walking. the eyes before they reach the visual cortex.
