SR

Nervous System Notes (Ch 1-3)

1. Functional Descriptions of Neuron Parts

Neurons transmit electrical and chemical signals.

  • Dendrites: receive signals

  • Soma (cell body): integrates inputs

  • Axon: conducts action potentials

  • Myelin sheath: speeds conduction

  • Axon terminals: release neurotransmitters

2. Classifications of Glial Cells Based on Function

Glia support neuronal function.

  • Astrocytes: regulate ions, form blood
    -brain barrier

  • Oligodendrocytes (CNS) & Schwann cells (PNS): myelinate axons

  • Microglia: CNS immune cells

  • Ependymal cells: produce cerebrospinal fluid

3. Classifications of Neurons by Structure & Function

Neurons vary in shape and role.

Structural types:

  • Multipolar: one axon, multiple dendrites

  • Bipolar: one axon, one dendrite

  • Unipolar: single process splits into two branches

Functional types:

  • Sensory (afferent): toward CNS

  • Motor (efferent): from CNS to effectors

  • Interneurons: connect within CNS

4. Key Components of a Synapse

A synapse is where neurons communicate.

  • Presynaptic membrane: releases neurotransmitters

  • Synaptic cleft: gap for diffusion

  • Postsynaptic membrane: houses receptors

5. Divisions of the Nervous System

The nervous system organizes into central and peripheral components.

  • Central Nervous System (CNS): brain and spinal cord

  • Peripheral Nervous System (PNS):

    • Somatic division: voluntary muscle control

    • Autonomic division: involuntary organ regulation

      • Sympathetic: “fight or flight”

      • Parasympathetic: “rest and digest”

6. Main Anatomical Structures of the Cerebral Cortex

The cortex processes information.

  • Frontal lobe: motor planning, executive functions

  • Parietal lobe: somatosensory processing

  • Temporal lobe: auditory processing, memory

  • Occipital lobe: visual processing

  • Precentral gyrus: primary motor cortex

  • Postcentral gyrus: primary somatosensory cortex

7. Anatomical Naming Conventions

Terms describe direction and location.

Directionality:

  • Anterior (rostral) vs. posterior (caudal)

  • Dorsal vs. ventral

  • Medial vs. lateral

Gray vs. white matter:

  • Gray matter: neuron cell bodies

  • White matter: myelinated axon tracts

part 2 Chapter 1: Structure & Function of the
Nervous System

  • Cerebral Cortex: Understand its cellular organization.

  • Key Brain Regions (Limbic System, Basal Ganglia, Hypothalamus, Midbrain, Hindbrain): Focus on their major functions and anatomical locations.

  • Protective & Fluid Systems: Learn about the meninges and the ventricular system, including their descriptions and functions.

  • Brain Study Techniques: Be familiar with methods used to analyze cellular structure and function, as well as major brain imaging techniques.