Chapter 9: Nervous System (part 1) Flashcards
Neurons
Nerve cell that sends impulses (cannot undergo mitosis)
Neuroglial Cells (neurglia)
Provide support, insulate, and protect neurons ( can undergo mitosis)
Central Nervous System (CNS)
Brain and spinal cord
Peripheral Nervous System (PNS)
Nerves ( connect CNS with the body)
Subdivisions of the PNS
Sensory Motor Somatic Automatic Sympathetic Parasympthetic Nervous System
Afferent (Sensory) System
Sends information form receptors to the CNS
Efferent (Motor) System
Sends information from the CNS to muscles and glands
Somatic Nervous System
Sends information from the CNS to the Skeletal System to move the body
Automatic Nervous System
Sends information from the CNS to smooth muscles, cardiac muscle, and glands
Sympathetic Nervous System
Sends signals to all parts of the body including
Parasymathetic Nervous System
Sends signals mainly to the viscera of the cardiac muscle, and the glands
Afferent
To the organ
Efferent
Away from the organ
Soma
Cell body
Central structure containing cytoplasm and organelles
Dendrites
Received stimuli (messages) from other neuron's axon Carry messages to the cell body
Axon
Send stimuli (messages) to other neuron's dendrites Carry messages away form the cell body
Amount of axons and dendrites per cell
Dendrites- May have one or many per cell
Axons - only one per cell
Myelin
Fatty substance that insulates axons
Schwann cells (PNS) Oligodendrocyte (CNS)
Support Cells
Cells that cover axons
Myelin sheath
Myelin + Schwann/ Oligodendrocyte cells
Speed up impulse travel
Nodes of Ravier
Gaps in the myelin sheath
White matter
Myelinated axons (faster travel of impulses)
Gray matter
Unmyelinated axons (slower travel of impulse
Sensory Neurons
(Afferent Neurons)
Send messages from body to brain located in our sense organ
