basic tasks of the nervous system sensation: monitor both external and internal environments....
TRANSCRIPT
Basic Tasks of the Nervous System
Sensation: Monitor both external and internal environments.
Integration: Process the information and often integrate it with stored sensory information.
Regulation and Control: If necessary, signal effector organs to make an appropriate response.
Coordination: of both voluntary and involuntary muscle movements
• Brain
WHAT PARTS DO YOU KNOW THAT ARE IN THE NERVOUS SYSTEM?
• Spinal Cord
• Peripheral Nerves
Structure of a Vertebrate Neuron
Myelinated Neurons
• Many vertebrate peripheral neurons have an insulating sheath around the axon called myelin which is formed by Schwann cells.
• Myelin sheathing allows these neurons to conduct nerve impulses faster than in non-myelinated neurons.
How are neurons connected?
• Synapses!!
Why are neurons connected?
AXON
The synapse - where the action happens
The next cell’s plasma membrane
What is this in the membrane?
Transport protein
Close up look at your synapse
How does the Synapse carry the signal?
1. Action potential travels down the axon until it reaches the synapse. The action potential will NOT move across the synapse.
2. Vesicles with neurotransmitters move toward the membrane3. Chemicals are released into the synaptic cleft and diffuse
toward the next cell’s plasma membrane4. The chemicals open up the transport proteins and allow the
signal to pass to the next cell
Saltatory Conduction in Myelinated Axons
Myelin sheathing has bare patches of axon called nodes of Ranvier
Action potentials jump from node to node
Fig. 48.11
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The synapse carries a signal from cell to cell
REFERENCES• http://faculty.washington.edu/chudler/facts.html• http://occawlonline.pearsoned.com/bookbind/pubbooks/campbell6e_awl/chapt
er0/deluxe.html• JOSHSANESPPT.PPT• www.alfamilyties.org/presentations/The%20Neurobiology%20of%
20Adolescent%20Substance%20Abuse%20II.ppt• http://www.nsbri.org/Education/High_Act.html• http://www.pfizer.com/brain/teachers_html.html• http://www.research.buffalo.edu/quarterly/vol10/num01/n1.shtml• http://www.aim-digest.com/gateway/pages/brain/articles/myths.htm• http://www.nida.nih.gov/pubs/teaching/Teaching5/Teaching3.html• http://www.accessexcellence.com/AE/• http://psych.colorado.edu/~kenth/Image14.gif
• Cell body: functional portion
• Dendrites: short extensions that receive signals
• Axon: long extension that transmits impulses away
Nerve Impulse - The Action PotentialThreshold potential will trigger an action potential or nerve impulse
The action potential is an all-or-none response
Conduction VelocityConduction Velocity
Types of chemical synapse
• Cholinergic Synapses– Acetylcholine– neuromuscular junctions, glands, brain and spinal cord
• Adrenergic ( EPSP)– Norepinepherine– affects brain regions concerned with emotions,
dreaming• Dopamine ( IPSP)
– Inhibits neurotranmission of the nerve impulses
Dura mater is being peeled away in this photo.
Fluid filled cavities, contain CSF
10.VENTRICLES OF THE BRAIN
CEREBRUM - wrinkly large part of the brain, largest area in humans, higher mental function
1. Cerebral Hemispheres - left and right side separated by the ....
2. Corpus Callosum - connects the two hemispheres
Corpus callosum
DiencephalonDiencephalon
CEREBELLUM
• Balance and coordination
Brain Stem - regulates visceral functions (autonomic system)
Figure 13.4
The Cerebral Hemispheres
Figure 13.7b, c
Take the Left Brain – Right Brain Test
3. Convolutions of the Brain - the wrinkles
and grooves of the cerebrum
Fissures = deep groove
Sulcus = shallow groove
Gyrus = bump
4. Fissures – separate lobes
Longitudinal fissure - separate right and left sides
Transverse Fissure - separates cerebrum from cerebellum
Figure 13.7a
LOBES OF THE BRAIN (CEREBRUM)
Sulcus = grooveGyrus = raised bump
Fissure = deep groove
