Flash Notes: Structures Of The Nervous System (Vocabulary Terms)

Front 1

Homeostasis

Back 1

State of relative Equilibrium maintained by physiological processes

Front 2

Why is the Nervous System critical for maintaining homeostasis?

Back 2

• It is capable of regulating activities simultaneously by responding to stimuli
• It monitors and controls most body processes (both automatic and involving fine motor coordination)
  

Front 3

The most complex system of any organism.

Back 3

The Nervous System

Front 4

The two major divisions of the Nervous System.

Back 4

• Central Nervous System(CNS)
  
• Peripheral Nervous System(PNS)
  

Front 5

Central Nervous System (CNS)

Back 5

• Integrates and processes information from the nerves
  
• Consists of the brain and spinal cord
  

Front 6

Peripheral Nervous System (PNS)

Back 6

• Consists of nerves that carry sensory information to the CNS and sends information from the CNS to the muscles and glands
• Further divided into the somatic system and autonomic system
  

Front 7

Somatic System

Back 7

• Sensory receptors in the head and extremities
• Nerves that carries sensory information to CNS and carries back instructions from the CNS to the skeletal muscles
  

Front 8

Autonomic System

Back 8

• Controls glandular secretions and the functioning of the smooth and cardiac muscles
• Further divides into the Sympathetic and Parasympathetic divisions of the autonomic system
  

Front 9

Explain the role of the Sympathetic and Parasympathetic divisions of the Autonomic System.

Back 9

Works in opposition to regulate involuntary processes of the body.

Front 10

Divisions of The Nervous System

Back 10

Front 11

Two types of cells composing the nervous system.

Back 11

• Neurons
• Glial Cells
  

Front 12

Neuron

Back 12

Specialized cells to respond to physical and chemical stimuli, conduct electrochemical signals, and release chemicals to regulate various body processes.

Front 13

Glial Cells (Neuroglial Cells)

Back 13

• Provides support and protection for neurons by nourishing them, removing their waste, and defending neurons from infection
• Non-neuronial cells that maintain homeostasis
• Forms myelin
• Outnumbers neurons by 10:1, and accounts for half of the volume of the nervous system
  

Front 14

Nerves

Back 14

• Neurons are grouped into nerve bundles and surrounded by protective connective tissue forming nerves
• Nerves extend the neurons throughout the peripheral nervous system
  

Front 15

Sensory Receptors

Back 15

Receives stimuli and forms a nerve impulse

Front 16

Sensory Neurons

Back 16

Transmit impulses from the sensory receptors to the interneurons.

Front 17

Interneurons

Back 17

Found in the brain and spinal cord: acts as an integration centre

Front 18

Motor Neurons

Back 18

Conducts impulses from the interneurons to the effectors

Front 19

Effectors

Back 19

Muscles, glands, and other organs that respond to impulses from the motor neurons.

Front 20

Sensory Input

Back 20

Sensory neurons gather information from the sensory receptors and transmits these impulses to the CNS.

Front 21

Interneurons

Back 21

• Interneurons are found entirely within the CNS
• Acts as a link between the sensory and motor neurons
• Process and integrate incoming sensory info and relay outgoing motor information
  

Front 22

Impulse Transmittion Pathway

Back 22

Front 23

Reflex Arc

Back 23

• A nerve pathway involved in a reflex action including at its simplest a sensory nerve and a motor nerve with a synapse between
• Simplest connection of nerves
• Moves directly to the brain or the spinal cord before the brain centres involved with voluntary control can process the sensory information
  

Front 24

Reflex

Back 24

A response to a stimulus without conscious thought.

Front 25

Structure of a Neuron

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• Four common features: dendrites, a cell body (soma), an axon, and branching ends
• Have specialized ell structures that enable them to transmit nerve impulses

Front 26

Dendrites

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• Short, branching terminals that receive nerve impulses from other neurons or sensory receptors
  
• Relays impulse to the cell body
• numerous and highly branched to increase surface area available to receive information

Front 27

Cell Body

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• Contains the nucleus
• Site of cell's metabolic reactions
• Processes input from dendrites
• If input received is large enough the cell body relays it to the axon, where an impulse is initiated

Front 28

Axon

Back 28

• Conducts impulses away from the body
• The terminal end of an axon branches into many fibres
• Axon terminals releases chemical signals into the space between it and the receptors or dendrites of neighbouring cells in order to communicate with adjacent neurons, glands, or muscles.
  

Front 29

Myelin Sheath

Back 29

• Encloses the axon in a fatty insulating layer, it gives the axon a glistening white appearance
• Protects the neurons and speed the rate of nerve impulse transmissions
• 
  

Front 30

Schwann Cells

Back 30

• A type of Glial Cell
• Forms myelin by wrapping around the axon

Front 31

In the Central Nervous System(CNS):

Myelinated neurons form ____.

Unmyelinated neurons form ____.

Back 31

Myelinated Neurons form the white matter, and unmyelinated neurons form the grey matter.

Front 32

Neuron Structures and Functions

Back 32

Synapse : communication between neurons

Back 33

Neurons are able to establish a voltage difference between the inside and outside of the cell membrane. They use this voltage difference to generate a neural impulse.