Chapter 7 (Nervous System)

• Functions of Nervous Tissues

  To conduct messages throughout the body
• When nerve cells are stimulated, an electrical signal quickly travels through the __________ to the __________, triggering events

  Nerve cell, Nerve ending
• Nervous tissue includes


  Nerve tissue, Sense organs
• Functions of Nervous System:

  ______ ___________ – receives information from both outside and inside the body

  _________ the information it receives

  _______ to information – sends out orders

  Senses environment, Processes, Respond
• Two Parts of the Nervous System

  Central Nervous System, Peripheral Nervous System
• Where is the Central Nervous System (CNS) found?

  Brain and Spinal Cord
• Where is the Peripheral Nervous System (PNS) found?

  Outside Brain & Spinal Cord, Sense organs
• Nervous System Cells

  Two types of Nervous Tissue Cells:

  Neurons, Neuroglial Cells
• The cells that are responsible for transmitting messages

  Neurons
• Cells that support the neurons

  Neuroglial Cells
• What are the three Neuroglial Cells?

  Microglia, Astrocytes, Oligodendrocytes & Schwann Cells
• Immune system cells engulf bacteria, and cellular debris

  Microglia
• Provide nutrients to neurons

  Astrocytes
• Form myelin sheaths

  Oligodendrocytes & Schwann Cells
• Parts of a Neuron

  Cell Body, Dendrites, Axons
• Contains the nucleus, main body of the cell

  Cell body
• Projections from the cell body that carry messages TO THE CELL BODY

  Dendrites
• One large projection that CARRY MESSAGES AWAY FROM THE CELL BODY

  Axons
• Neurons carrying TO THE CNS

  Afferent Neuron
• Afferent neuron is also known as

  Sensory
• Neurons carrying messages FROM THE CNS

  Efferent neuron
• Efferent neuron is also known as

  Motor neuron
• Afferent neuron are located in

  Dorsal root ganglion
• Efferent neuron are located in

  Gray matter of Spinal Cord
• Neurons that have axons covered with neuroglial cells that contain the protein myelin are called

  Myelinated neurons
• In saltatory conduction, the nerve impulses jump from one __________ to the next

  Node of Ranvier
• The main benefit of myelin sheaths is that myelinated neurons are able to carry messages ______ than ____________________

  Faster; non-myelinated neurons
• Myelin sheaths from _______ _____ also help regenerate injured PNS neuron axons

  Schwann cells
• Schwann cells and Oligodendrocytes are wrapped around

  Neuronal axons
• Schwann cells are found in the

  PNS
• Oligodendrocytes are found in the

  CNS
• Spaces on the axon between the glial cells

  Nodes of Ranvier
• Caused by the destruction of the myelin sheath that surrounds axons found in the CNS

  Multiple Sclerosis
• Multiple Sclerosis can result in

  Paralysis and loss of sensation, including loss of vision
• Nerve contain ______ _____ are bundled together

  Neuron axons
• Nerve bundles contains:

  Axons, Blood vessels, Connective tissue
• involves sodium ions (Na+) and potassium ions (K+) that cross the cell membrane through the ion channels

  Nerve impulse
• Nerve impulse is also known as

  Action potential
• A nerve impulse, or action potential, involves _______ and ________ that cross the cell membrane through the ion

  channels

  Sodium ions (Na+) & Potassium ions (K+)
• Nerve impulse involves sodium ions (Na+) and potassium ions (K+) that cross the cell membrane through the

  Ion channels