November 3, 2015 Objectives: ◦ Label the structure of a neuron ◦ Explain how the nervous system is broken up into parts ◦ Differentiate between neurons and glial cells Journal: ◦ What makes up the nervous system?
Feb 24, 2016
November 3, 2015Objectives:
◦Label the structure of a neuron◦Explain how the nervous system is broken up into parts
◦Differentiate between neurons and glial cells
Journal:◦What makes up the nervous system?
Nervous System
Functions of the Nervous System:Long-term memoryShort-term memoryThinking and
decision makingInteractions with
the world
Parts of the Nervous System
Central Nervous System (CNS)◦Made up of the brain and spinal cord◦Controls all basic bodily functions and
responds to external changesPeripheral Nervous System (PNS)
◦Made up of all the nerves in the body◦Connects the CNS to the rest of the
body
Motor SystemPart of the peripheral nervous systemCarries out the orders from the brain
and spinal cordMade up of two branches:
◦Somatic Nervous System Controls skeletal muscle Under conscious control
◦Autonomic Nervous System Controls smooth muscle, cardiac muscle, and
glands Not under conscious control
Parts of the Autonomic Nervous System
Parasympathetic◦Resting and
digesting branch ◦Deal with normal
body functions Sympathetic
◦Body’s alert system that kicks in when you are in danger
◦Fight or flight response
Nervous TissueMade up of:
◦Neurons: carry out control functions, amitotic
◦Neuroglia also known as Glial Cells: support cells for the nervous tissue, able to divide
Glial Cell Types in CNS:Astrocytes: metabolic and
structural support cells for the nervous tissue
Microglia: remove debrisEpendymal cells: cover the lining
of cavitiesOligodendrocytes: make a lipid
insulation called myelin
Glial Cell Types in PNS:Schwann cells: make myelin for
the PNSSatellite cells: support cells
Neuron Parts
Neuron body: functions in cell metabolismDendrites: receive signals from the environment and other
cellsAxon: generates and sends signals to other cellsAxon terminal: connects to a receiving cellSynapse: space between the axon terminal and the
receiving cell◦ Called a neuromuscular junction if the receiving cell is a skeletal
muscle cellMyelin sheath: lipid insulation that covers parts of the axonNodes of Ranvier: bare spots between the myelin
Neuron ClassificationNeurons can be classified by
either structure or function
Neuron Structural ClassificationBipolar: one dendrite and one axonMultipolar: many dendrites and one
axonUnipolar: has two projections
extending from the same end of the neuron body
Neuron Function ClassificationSensory neurons: input neuronsMotor neurons: output neuronsInterneurons: carry information
between neurons