The Nervous System Structures and Processes Central Nervous System Peripheral Nervous System.
The Nervous System
description
Transcript of The Nervous System
![Page 1: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/1.jpg)
The Nervous SystemThe Nervous System
![Page 2: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/2.jpg)
IntroductionIntroduction
Two organ systems, the nervous and endocrine systems, coordinate organ system activity.
The nervous system provides swift but brief responses to stimuli
The endocrine system adjusts metabolic operations and directs long-term changes
Two organ systems, the nervous and endocrine systems, coordinate organ system activity.
The nervous system provides swift but brief responses to stimuli
The endocrine system adjusts metabolic operations and directs long-term changes
![Page 3: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/3.jpg)
The Nervous System
The Nervous System
The nervous system includes al the neural tissue in the body.
Its anatomical divisions include the central nervous system (CNS) (the brain and spinal cord
And the peripheral nervous system (PNS) (all neural tissue outside the CNS)
The nervous system includes al the neural tissue in the body.
Its anatomical divisions include the central nervous system (CNS) (the brain and spinal cord
And the peripheral nervous system (PNS) (all neural tissue outside the CNS)
![Page 4: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/4.jpg)
Functionally it can be divided into an afferent division which brings sensory information to the CNS
And an efferent division which carries motor commands to muscles and glands
Functionally it can be divided into an afferent division which brings sensory information to the CNS
And an efferent division which carries motor commands to muscles and glands
![Page 5: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/5.jpg)
The efferent division includes the somatic nervous system (voluntary control over skeletal muscle contractions
And the autonomic nervous system (involuntary regulation of smooth muscle, cardiac muscle, and glandular activity.
The efferent division includes the somatic nervous system (voluntary control over skeletal muscle contractions
And the autonomic nervous system (involuntary regulation of smooth muscle, cardiac muscle, and glandular activity.
![Page 6: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/6.jpg)
8-18-1
![Page 7: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/7.jpg)
Cellular Organization in
Neural Tissue
Cellular Organization in
Neural TissueThere are two types of cells in neural tissueNeurons, which are responsible for information transfer and processing
Neuroglia, which provide a supporting framework and act as phagocytes.
There are two types of cells in neural tissueNeurons, which are responsible for information transfer and processing
Neuroglia, which provide a supporting framework and act as phagocytes.
![Page 8: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/8.jpg)
NeuronsNeurons
Sensory neurons: form the afferent division of the PNS and deliver information to the CNS
Motor neurons: stimulate or modify the activity of a peripheral tissue, organ or organ system
Sensory neurons: form the afferent division of the PNS and deliver information to the CNS
Motor neurons: stimulate or modify the activity of a peripheral tissue, organ or organ system
![Page 9: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/9.jpg)
Interneurons: may be located between sensory and motor neurons; they analyze sensory inputs and coordinate motor outputs.
Interneurons: may be located between sensory and motor neurons; they analyze sensory inputs and coordinate motor outputs.
![Page 10: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/10.jpg)
A typical neuron has a cell body, an axon, and several branching dendrites and synaptic terminals
A typical neuron has a cell body, an axon, and several branching dendrites and synaptic terminals
![Page 11: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/11.jpg)
8-28-2
![Page 12: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/12.jpg)
Neurons may be described as unipolar, bipolar, or multipolar
Neurons may be described as unipolar, bipolar, or multipolar
8-38-3
![Page 13: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/13.jpg)
NeurogliaNeuroglia
Four typesAstrocytes: largest and most numerous
Oligodendrocytes: myelinate CNS neurons
Microglia: phagocytic white glod cells
Ependymal: produce and help circulate cerebral spinal fluid
Four typesAstrocytes: largest and most numerous
Oligodendrocytes: myelinate CNS neurons
Microglia: phagocytic white glod cells
Ependymal: produce and help circulate cerebral spinal fluid
![Page 14: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/14.jpg)
8-48-4
![Page 15: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/15.jpg)
Nerve cell bodies in the PNS are clustered into ganglia.
Their axons are covered by myelin wrappings of Schwann cells.
Nerve cell bodies in the PNS are clustered into ganglia.
Their axons are covered by myelin wrappings of Schwann cells.
![Page 16: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/16.jpg)
8-58-5
![Page 17: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/17.jpg)
Anatomical organizationAnatomical
organizationIn the CNS, a collection of neuron cell bodies that share a particular function is called a center
A center with a a discrete anatomical boundary is called a nucleus.
Portions of the brain surface are covered by a thick layer of gray matter called the neural cortex
In the CNS, a collection of neuron cell bodies that share a particular function is called a center
A center with a a discrete anatomical boundary is called a nucleus.
Portions of the brain surface are covered by a thick layer of gray matter called the neural cortex
![Page 18: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/18.jpg)
The white matter of the CNS contains bundles of axons, or tracts that share common origins, destinations and functions.
Tract in the spinal cord form larger groups called columns
The white matter of the CNS contains bundles of axons, or tracts that share common origins, destinations and functions.
Tract in the spinal cord form larger groups called columns
![Page 19: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/19.jpg)
8-68-6
![Page 20: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/20.jpg)
Neuron Function: Membrane
Potential
Neuron Function: Membrane
PotentialThe resting potential, or membrane potential of an undisturbed nerve cell, is due to a balance between the rate of sodium ion entry and potassium ion loss and to the sodium-potassium exchange pump
The resting potential, or membrane potential of an undisturbed nerve cell, is due to a balance between the rate of sodium ion entry and potassium ion loss and to the sodium-potassium exchange pump
![Page 21: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/21.jpg)
Any stimulus that affects this balance will alter the resting potential of the cell
Any stimulus that affects this balance will alter the resting potential of the cell
8-78-7
![Page 22: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/22.jpg)
An action potential appears when the membrane depolarizes to a level known as the threshold.
Steps include; opening of sodium channels and opening of potassium channels, return to normal permeability
An action potential appears when the membrane depolarizes to a level known as the threshold.
Steps include; opening of sodium channels and opening of potassium channels, return to normal permeability
![Page 23: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/23.jpg)
8-88-8
![Page 24: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/24.jpg)
Propagation of an Action Potential
Propagation of an Action Potential
In continuous propagation, an action potential spread across the entire excitable membrane surface in a series of small steps.
During saltatory propagation, the action potential appears to leap from node to node.
In continuous propagation, an action potential spread across the entire excitable membrane surface in a series of small steps.
During saltatory propagation, the action potential appears to leap from node to node.
![Page 25: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/25.jpg)
8-98-9
![Page 26: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/26.jpg)
Action potentialAction potential
![Page 27: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/27.jpg)
Neural Communication
Neural Communication
A synapse is a site where intercellular communication occurs through the release of chemicals called neurotransmitters.
A synapse where neurons communicate with other cell types is a neuroeffector junction.
A synapse is a site where intercellular communication occurs through the release of chemicals called neurotransmitters.
A synapse where neurons communicate with other cell types is a neuroeffector junction.
![Page 28: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/28.jpg)
![Page 29: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/29.jpg)
Structure of a Synapse
Structure of a Synapse
Neural communication moves from the presynaptic neuron to the postsynaptic neuron over the synaptic cleft
Neural communication moves from the presynaptic neuron to the postsynaptic neuron over the synaptic cleft
8-108-10
![Page 30: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/30.jpg)
Synaptic function and
Neurotransmitters
Synaptic function and
NeurotransmittersCholinergic synapses release the neurotransmitter acetylcholine (Ach)
Ach is broken down in the synaptic cleft by the enzyme acetylcholinesterase (AChE)
Cholinergic synapses release the neurotransmitter acetylcholine (Ach)
Ach is broken down in the synaptic cleft by the enzyme acetylcholinesterase (AChE)
![Page 31: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/31.jpg)
Other neurotransmitters
Other neurotransmittersNorepinephrine-excitesDopamine-inhibitsGABA -inhibitsSerotonin-inhibits
Norepinephrine-excitesDopamine-inhibitsGABA -inhibitsSerotonin-inhibits
![Page 32: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/32.jpg)
![Page 33: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/33.jpg)
8-11, table 8-18-11, table 8-1
![Page 34: The Nervous System](https://reader035.fdocuments.us/reader035/viewer/2022070413/56814cfd550346895dba1e54/html5/thumbnails/34.jpg)
neurotransmitters neurotransmitters