LECTURE 4: Nervous System

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LECTURE 4 Nervous System
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What is included in the Nervous System?

• Neural Tissue
• Blood Vessels
• Connective Tissue

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What are the 2 Cell Types in the Nervous System?

• Neurons
• Neuroglial Cells

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What are Nerves?

• Bundles of Neurons

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What are Neurons?

• Specialized cells that sense chemical and
  physical changes in the surrounding area
• Contains
• Dendrites
• Receive chemical signals
• branches
• Cell Body
• Contains nucleus
• Axon
• Carries information away from cell body
• Nerve impulses

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What are Neuroglial Cells?

• Schwann Cells
• Small cells that surround a neuron
• Nourishes neuron

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What are Schwann Cells?

• Surround axons
• Produce myelin (lipid rich)
• Myelin sheaths
• Gaps between Sheaths
• Nodes of Ranvier

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What is White and Gray Matter?

• Myelinated Axons
• Unmyelinated Axons
• Brain
• Spinal Cord

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What is a Synapse?

• Small space between neurons
• Where chemicals are released by neurons and
  sensed by other neurons

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What are Neurotransmitters?

• The chemicals released and sensed in the synapse

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How are the Organs of the Nervous System
organized?

• Central Nervous System (CNS)
• Brain
• Spinal Cord
• Peripheral Nervous System (PNS)
• Cranial/spinal nerves that connect to other parts
  of the body

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How are Neurons classified according to
Structure?

• Bipolar
• 2 processes
• Eyes
• Ears
• Nose
• Unipolar
• 1 process that divides into 2 branches
• one leads to CNS, one to PNS
• Multipolar
• Multiple processes
• Most Brain/Spinal Cord

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How are Neurons classified according to
Function?

• Sensory Neurons (Afferent Neurons)
• Carry impulses from PNS to CNS
• Unipolar or Bipolar
• Interneurons
• Brain/Spinal Cord
• Multipolar
• Motor Neurons (Efferent Neurons)
• CNS to PNS
• Multipolar

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What are the Functions of the Nervous System?

• Sensory
• Motor

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How does the Nervous System provide Sensory?

• Sensory Receptors at ends of peripheral nerves
• Detect changes inside/outside the body
  (temp/light/heat)
• Send nerve impulses to CNS
• Provide sensations

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How does the Nervous System provide Motor
Functions?

• Nerve impulses from the CNS to effectors
• PNS
• Divided into 2 parts
• Somatic Nervous System
• Skeletal muscle contractions (voluntary)
• 2. Autonomic Nervous System
• Heart/Smooth Muscle/Glands (involuntary)

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What are the Autonomic Divisions?

• Sympathetic
• FIGHT OR FLIGHT
• Arouses the Body
• Parasympathetic
• REST AND DIGEST
• Calms the body after arousal

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