lecture 1 notes

Homeostasis

The maintenance of a stable internal environment in a system.

CNS (Central Nervous System)

The part of the nervous system where processing and relaying information occurs, consisting of the brain and spinal cord.

Glial Cells in CNS

Cells in the CNS that support neurons; includes oligodendrocytes, astrocytes, microglia, and ependymal cells.

Oligodendrocytes

Glial cells in the CNS that can myelinate multiple axons.

Astrocytes

Glial cells in the CNS that provide nutrients, maintain the extracellular environment, and offer structural support.

Microglia

Glial cells that function in immune response within the CNS.

Ependymal Cells

Glial cells that circulate and produce cerebrospinal fluid.

PNS (Peripheral Nervous System)

The part of the nervous system where sensory stimuli are collected and transformed into action potentials towards the CNS.

Schwann Cells

Glial cells in the PNS that form myelin for a single axon.

Satellite Cells

Glial cells in the PNS that provide nutrients and structural support to neurons.

Neuron Structure

Comprises an input zone, summation zone, conduction zone, and output zone.

Excitatory Signal

A signal that increases the likelihood of a neuron firing an action potential.

Inhibitory Signal

A signal that decreases the likelihood of a neuron firing an action potential.

Nerves

Structures made up of multiple axons, which can be myelinated or unmyelinated.

Synapse

The junction between two nerve cells where nerve impulses are transmitted.

Electrical Synapse

A fast synapse where ions flow directly from cell to cell, potentially bidirectional.

Chemical Synapse

A slower synapse that relies on neurotransmitters crossing a gap, typically unidirectional.

Somatosensory Cortex

Part of the brain that processes sensory input and retains its spatial relationship along projection pathways.

Afferent Signals

Information flowing towards the CNS.

Efferent Signals

Information flowing away from the CNS.

Enteric Nervous System

A part of the nervous system located in the walls of the digestive system.

Resting Membrane Potential

The electrical potential across the membrane of an inactive nerve cell.

Chemical Signaling

Signaling between nerve cells or between nerve and non-nerve cells, primarily relying on chemical signals.