behavioral neuroscience exam 1

POWERPOINT 1: BUILDING & ORGANIZING THE NERVOUS SYSTEM

1. What Neurons Do & Why They Exist (Chapter 1–1.4)

Neurons exist to receive, process, and transmit information so the body can function. They do this using:

• Electrical signals within the neuron

• Chemical signals between neurons

This dual system allows the brain to be fast, flexible, and adaptive.

2. Brain Cells as Eukaryotic Cells

All brain cells are eukaryotic, meaning they:

• Have a nucleus

• Contain organelles

Organelles

• Perform life‑sustaining cellular functions

• Mitochondria supply energy needed for signaling

Neural communication requires constant energy.

3. Neuron Structure (Structure → Function)

Dendrites

• Receive chemical input from other neurons

• Large surface area allows many connections

Soma (Cell Body)

• Maintains cell health

• Integrates incoming signals

Axon

• Conducts electrical signals away from soma

• Designed for long‑distance communication

Axon Hillock

• Transition point between soma and axon

• Contains many voltage‑gated Na⁺ channels

• Decision‑making site for firing

Synapse

• Site of neuron‑to‑neuron communication

• Neurons do not touch

• Communication occurs across synaptic cleft

4. Organization of the Nervous System

Central Nervous System (CNS)

• Brain and spinal cord

• Responsible for processing and integration

Peripheral Nervous System (PNS)

• Neurons and glia outside the CNS

• Includes spinal nerves

• Carries sensory input to CNS and motor output away

5. Gray Matter, Axons, and Tracts

Gray Matter

• Cell bodies, dendrites, synapses

• Information processing

White Matter / Axons

• Bundles of axons (often myelinated)

• Fast signal transmission

Ascending Tracts

• Sensory information → brain

Descending Tracts

• Motor commands → body

6. Anatomical Direction & Planes (Slide 67)

Directional Terms

• Dorsal: back

• Ventral: front/stomach side

Planes of Orientation

• Sagittal: left/right

• Coronal: front/back

• Horizontal: top/bottom