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The Brain Symphony of Science
https://www.youtube.com/watch?t=2&v=JB7jSFeVz1U !!
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The Brain Symphony of Science
https://www.youtube.com/watch?t=2&v=JB7jSFeVz1U !!!
Jill Bolte Taylor - My Stroke of Insight http://mystrokeofinsight.com
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Chapter 8 The Nervous System
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Introduction1. Two systems control all cells of the body:
a. Nervous System (Chap. 8) − Rapid by nerve impulses
b. Endocrine System (Chap. 10) − Slower by chemicals secreted by ductless glands into the
bloodstream
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Introduction1. Two systems control all cells of the body:
a. Nervous System (Chap. 8) − Rapid by nerve impulses
b. Endocrine System (Chap. 10) − Slower by chemicals secreted by ductless glands into the
bloodstream 2. Communicate to increase or decrease activities as
needed for survival
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Introduction1. Two systems control all cells of the body:
a. Nervous System (Chap. 8) − Rapid by nerve impulses
b. Endocrine System (Chap. 10) − Slower by chemicals secreted by ductless glands into the
bloodstream 2. Communicate to increase or decrease activities as
needed for survival 3. Homeostasis – balanced and controlled internal
environment
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ORGANS AND DIVISIONS OF THE NERVOUS SYSTEM
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ORGANS AND DIVISIONS OF THE NERVOUS SYSTEM
1. Central nervous system (CNS) − brain and spinal cord
2. Peripheral nervous system (PNS)
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ORGANS AND DIVISIONS OF THE NERVOUS SYSTEM
1. Central nervous system (CNS) − brain and spinal cord
2. Peripheral nervous system (PNS) A.All nerves of the body (motor and sensory) B.Motor neurons divided into two branches
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Before we go further…. draw what I draw onto dry erase boards (deb)
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ORGANS AND DIVISIONS OF THE NERVOUS SYSTEM
1. Central nervous system (CNS) − brain and spinal cord
2. Peripheral nervous system (PNS) A.All nerves of the body (motor and sensory) B.Motor neurons divided into two branches
a. Somatic nervous system – regulates voluntary muscle movement
b. Autonomic nervous system (ANS) - Regulates automatic or involuntary functions (HR, BP, Digestion)
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ORGANS AND DIVISIONS OF THE NERVOUS SYSTEM
1. Central nervous system (CNS) − brain and spinal cord
2. Peripheral nervous system (PNS) A. All nerves of the body (motor and sensory) B.Motor neurons divided into two branches
a. Somatic nervous system – regulates voluntary muscle movement
b. Autonomic nervous system (ANS) - Regulates automatic or involuntary functions (HR, BP, Digestion)
• Sympathetic - “fight or flight” • Parasympathetic - “rest or digest”
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CELLS OF THE NERVOUS SYSTEMTwo types of cells found in nervous system
A. Neurons – conduct impulses B. Glia – support neurons
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CELLS OF THE NERVOUS SYSTEMA. Neurons
1. Consist of three main parts — dendrites; cell body of neuron; axon
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CELLS OF THE NERVOUS SYSTEMA. Neurons
1. Consist of three main parts — dendrites; cell body of neuron; axon a. Cell body – main part with
nucleus
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CELLS OF THE NERVOUS SYSTEMA. Neurons
1. Consist of three main parts — dendrites; cell body of neuron; axon a. Cell body – main part with
nucleus b. Dendrites—branching
projections that conduct impulses to cell body of neuron
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CELLS OF THE NERVOUS SYSTEMA. Neurons
1. Consist of three main parts — dendrites; cell body of neuron; axon a. Cell body – main part with
nucleus b. Dendrites—branching
projections that conduct impulses to cell body of neuron
c. Axon—elongated projection that conducts impulses away from cell body of neuron
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CELLS OF THE NERVOUS SYSTEMA. Neurons
2. Additional structures— a.Myelin – segmented white wrapping material
around axon
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CELLS OF THE NERVOUS SYSTEMA. Neurons
2. Additional structures— a.Myelin – segmented white wrapping material
around axon b.Schwann cells —individual wrap of myelin
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CELLS OF THE NERVOUS SYSTEMA. Neurons
2. Additional structures— a.Myelin – segmented white wrapping material
around axon b.Schwann cells —individual wrap of myelin c.Nodes of Ranveir (rahn-vee-AY)—indentations between Schwann cells
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CELLS OF THE NERVOUS SYSTEMA. Neurons
2. Additional structures— d. Neurilemma – outer membrane of a
Schwann cell
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CELLS OF THE NERVOUS SYSTEMA. Neurons
2. Additional structures— d. Neurilemma – outer membrane of a
Schwann cell • Play an important role in the
regenration of cut or injured axons.
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CELLS OF THE NERVOUS SYSTEMA. Neurons
2. Additional structures— d. Neurilemma – outer membrane of a
Schwann cell • Play an important role in the
regenration of cut or injured axons.
• Brain and spinal cord have no neurilemma
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CELLS OF THE NERVOUS SYSTEMA. Neurons
2. Additional structures— d. Neurilemma – outer membrane of a
Schwann cell • Play an important role in the
regenration of cut or injured axons.
• Brain and spinal cord have no neurilemma
• Myelinated fibers – axons with Schwann cells; increases speed
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CELLS OF THE NERVOUS SYSTEMA. Neurons
3. Neurons classified according to function (direction they send impulses)
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CELLS OF THE NERVOUS SYSTEMA. Neurons
3. Neurons classified according to function (direction they send impulses) a.Sensory (afferent) neurons — conduct impulses to the spinal cord and brain
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CELLS OF THE NERVOUS SYSTEMA. Neurons
3. Neurons classified according to function (direction they send impulses) a.Sensory (afferent) neurons — conduct impulses to the spinal cord and brain
b.Motor (efferent) neurons — conduct impulses away from brain and spinal cord to muscles and glands
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CELLS OF THE NERVOUS SYSTEMA. Neurons
3. Neurons classified according to function (direction they send impulses) a.Sensory (afferent) neurons — conduct impulses to the spinal cord and brain
b.Motor (efferent) neurons — conduct impulses away from brain and spinal cord to muscles and glands
c.Interneurons — conduct impulses from sensory neurons to motor neurons or among a network of interneurons; also known as central or connecting neurons
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CELLS OF THE NERVOUS SYSTEM
B. Glia (neuroglia) 1. Support cells, bringing the cells of nervous tissue
together structurally and functionally
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CELLS OF THE NERVOUS SYSTEM
C. Glia (neuroglia) 1. Support cells, bringing the cells of nervous tissue
together structurally and functionally 2. Glioma- most common types of brain tumors
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CELLS OF THE NERVOUS SYSTEM
C. Glia (neuroglia) 3. Three main types of glial cells of the CNS
a. Astrocytes —star-shaped cells that anchor small blood vessels to neurons ! Blood-brain barrier – a two-layer structure that protects brain
tissue from harmful chemicals in blood
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CELLS OF THE NERVOUS SYSTEM
C. Glia (neuroglia) 3. Three main types of glial cells of the CNS
b. Microglia —small cells that move in inflamed brain tissue carrying on phagocytosis
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CELLS OF THE NERVOUS SYSTEM
C. Glia (neuroglia) 3. Three main types of glial cells of the CNS
c. Oligodendrocytes —form myelin sheaths on axons in the CNS
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CELLS OF THE NERVOUS SYSTEM
C. Glia (neuroglia) 3. Three main types of glial cells of the CNS
c. Oligodendrocytes —form myelin sheaths on axons in the CNS ! Schwann cells form myelin sheaths on axons of the PNS
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CELLS OF THE NERVOUS SYSTEM
C. Glia (neuroglia) 3. Three main types of glial cells of the CNS
c. Oligodendrocytes —form myelin sheaths on axons in the CNS ! Schwann cells form myelin sheaths on axons of the PNS
FYI - Oligodendrocytes can form myelin sheath around several axons; Schwann cells can only wrap entirely around one axon.