human body: nervous system brain diencephalon spinal cord nerve
TRANSCRIPT
Human Body: NERVOUS SYSTEM
BrainDiencephalonSpinal CordNerve
BrainDiencephalonSpinal CordNerve
Nervous system = master control and communication
Three functions:
!2. Integration (interpretation
and decision-making about the stimuli).
3. Effects a response – motor output.
RUN AWAY!
1. Gathering Sensory input (information about stimuli).
Organization of the Nervous System
CNS:central nervous systemincludes brain and spinal cord
PNS:peripheral nervous systemincludes nerves
Organization of the Nervous System
Organization of the Nervous System
PNS:peripheral nervous systemincludes nerves
Afferent (Sensory) Division:conveys impulses to the CNSAfferent (Sensory) Division:conveys impulses to the CNS
Efferent (Motor) Division:conveys impulses from the CNSSubdivisions: Somatic/Voluntary NS Autonomic/Involuntary NS
Efferent (Motor) Division:conveys impulses from the CNSSubdivisions: Somatic/Voluntary NS Autonomic/Involuntary NS
Nervous TissueSupporting Cells
Supporting the CNS:
Neuron = nerve cell
Nervous Tissue Supporting the CNS:
Neuroglia (Glia )nerve glue cells
Astrocytes: • type of glial cell• 50% of nerve tissue• protect neurons from harmful substances in blood
Nervous TissueSupporting the CNS:
Ependymal cells on the surface of the choroid plexus secrete cerebrospinal fluid.
Nervous TissueSupporting the CNS:
Microglia found within the central nervous system are similar to macrophages.
Nervous TissueSupporting the CNS:
Extensions from the oligodendrocyte form the myelin sheaths of axons within the central nervous system.
Nervous Tissue
Supporting the CNS:
Extension from the Schwann cell forms a myelin sheath called the neurilemma around each axon within the peripheral nervous system.
Nervous Tissue
Myelin sheath (blue)
No Myelin sheath
Myelin Sheaths and Shingles
Anatomy of a Nerve Cell
prlog.orgemed.com.auherpeszostervirus.comshingleshelpline.com
healthinplainenglish.comb4tea.com
Nervous Tissue
Supporting the CNS:
Neuron cell bodies within ganglia are surrounded by satellite cells. Little is known of their function.
Anatomy of a Nerve Cell
Myelin Sheath
Node of Ranvier
Axons conduct impulses away from the cell body.
Anatomy of a Nerve CellDendrites conduct impulses toward the cell body.
Anatomy of a Nerve Cell
CNS clusters of nerve cells = nucleiPNS clusters of nerve cells = ganglia
nuclei
eftlab.org
ganglion
neuromedia.neurobio.ucla.edu
Anatomy of a Nerve Cell
spiltmartini.com
Tracts = bundles of nerves in CNSNerves = bundles of nerves in the PNSTracts = bundles of nerves in CNSNerves = bundles of nerves in the PNS
Tract
Nerves
Anatomy of a Nerve Cell
Types of Sensory Receptors
1. Naked Nerve Endings = pain & temperature
Types of Sensory Receptors
1. Naked Nerve Endings = pain & temperature
Anatomy of a Nerve Cell
Types of Sensory Receptors
2. Meissner’s corpuscles = touch
Types of Sensory Receptors
2. Meissner’s corpuscles = touch
ttouchnorth.co.uk
kushtush.com
Anatomy of a Nerve Cell
Types of Sensory Receptors
3. Pacinian corpuscle = deep pressure
Types of Sensory Receptors
3. Pacinian corpuscle = deep pressure
responsiblemarketing.com
impactlab.net
russiablog.org
Anatomy of a Nerve Cell
Types of Sensory Receptors
4.Proprioceptors = muscular
stretching or tension
Types of Sensory Receptors
4.Proprioceptors = muscular
stretching or tension
zimbio.comwebmd.com
Anatomy of a Nerve Cell
White matter = myelinated regions of the brainGray matter = unmyelinated regions of the brain
The Human Brain: How We Decide
Anatomy of a Nerve Cell
White matter and gray matter in MRI scans:
wordadaywonder.comradlink.com.sgComparing normal brain (left) with Huntington’s Diseased brain (right).
http://player.discoveryeducation.com/index.cfm?guidAssetId=B1721030-D95E-45BF-B764-D4AC4026D0C0&blnFromSearch=1&productcode=US
The Nerve Impulse
Major functional properties:
1.Irritability
…ability to respond to stimuli
I am irritable! And…You are getting on my very last nerve!
The Nerve Impulse
Conductivity …ability to conduct electrical currentsA. Resting membrane –
Na+ and K+ levels are equal
Na+
K+
Na+Na+Na+Na+Na+
K+K+K+K+K+
Nerve impulses are “all-or-nothing” events.
The Nerve Impulse Conductivity B. Depolarization starts –
Na+ moves into nerve cell.Cell depolarizes (becomes too + inside) Action Potential is generated.
K+
Na+
K+K+K+K+K+
Na+ Na+
K+
ACTION POTENTIAL
Depolarization
Na+ Na+ Na+
De = reversal
The Nerve Impulse Conductivity C. Action potential is propagated.
K+ K+K+K+K+K+ K+
ACTION POTENTIAL
Depolarization K+K+ K+K+ K+K+
Na+ Na+ Na+ Na+ Na+ Na+
The Nerve Impulse Conductivity
C. REpolarization.
K+ K+ K+REpolarization K+ K+ K+Na+ Na+ Na+ Na+ Na+ Na+
Too much + inside!Back to equal!
Nerve Impulsehttp://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter14/animation__the_nerve_impulse.html
Re = again
Nerve to Nerve
Neurotransmitter_Synapse_3D_Animation
Stimulation of Muscles:1. An action potential arrives at
a presynaptic terminal.2. The Calcium ion channel
opens releasing calcium ions into the presynaptic terminal.
3. Calcium ions cause the synaptic vesicle to move to the synaptic cleft.
4. The synaptic vesicle releases ACH neurotransmitter into the cleft.
5. ACH diffuses across the cleft and and binds to ACH receptors on the muscle fiber membrane.
6. Sodium channels open and release sodium into the muscle.
7. The muscle membrane depolarizes and a postsynaptic action potential results.
NA+ACH
Ca+
Ca+
Ca+
Ca+
NA+
NA+
Reflexes
Reflex = rapid, predictable, involuntary responseReflex Arc = neural pathway of a reflex (goes only one way)
Autonomic reflexesregulate smooth muscles
Auto = self
Reflexes
Somatic reflexes stimulates skeletal muscles
http://www.sumanasinc.com/webcontent/animations/content/reflexarcs2.html
Soma = body
Brain Stem
About the size of a thumb in diameter and about 3 inches long.
rainbowrehab.com
Brain Stem
Midbrain = small part that relays impulses and controls reflexes for vision and hearing.
Brain Stem
Pons = rounded structure of mostly fiber tracts involved in the control of breathing.
Pons = bridge
Brain Stem
Medula Oblongata = merges into spinal cord; regulates vital internal activities including heart rate, blood pressure, breathing, swallowing, vomiting, etc.
Brain Stem
Cerebellum = Outer gray matter; inner white matter. Provides timing for skeletal muscle activity, controls balance, and equilibrium. Compared to “autopilot” because it constantly checks and adjusts.
Ataxia = Clumsy and disorganized movements as a result of damage to the cerebellum.
http://www.youtube.com/watch?v=08iZVEa5H9Y&feature=related
Sheep Brain Dissection Lab
THE CNS
http://www.youtube.com/watch?v=UFkSJemE4Pw
Brain Function and Anatomyhttp://www.waiting.com/brainfunction.html
The BRAIN
Brain Explorer
An interactive resource for knowledge about the human brain.
http://www.brainexplorer.org/brain_atlas/brainatlas_index.shtml
Brain Explorer
An interactive resource for knowledge about the human brain.
http://www.brainexplorer.org/brain_atlas/brainatlas_index.shtml
Bon Voyage! Go Explore the Brain.
http://www.wherecreativitygoestoschool.com/vancouver/left_right/rb_test.htm
http://homeworktips.about.com/library/brainquiz/bl_leftrightbrain_quiz.htm
BRAIN FUN!RIGHT BRAIN VS LEFT BRAIN
http://similarminds.com/brain.html
http://frank.mtsu.edu/~studskl/hd/learn.html
What are your results? Are you right or left brained?
What does it mean?
Nervous System
Meninges = three membranes covering the CNS structures (p 211)
Duramater = outermost layer
Dura = hardMater = motherDura = hardMater = mother
netterimages.com
schools-wikipedia.org
Protection of CNSProtection of CNS
Arachnoid Mater = web-like middle layer
Arachno = spiderArachno = spider
commons.wikimedia.org
Pia Mater = innermost layer following folds
pia = gentlepia = gentle
commons.wikimedia.org
Sheep Brain Dissection http://www.youtube.com/watch?v=vE3Yf_xy_mE
Meningitis = inflammation of meninges
http://healthline.healthology.com/hybrid/hybrid-autodetect.aspx?content_id=2582&focus_handle=childrens-diseases&brand_name=healthline
http://www.nmaus.org/programs/getting-it/
http://www.healthline.com/hgy-transcripts/meningitis-overview
http://video.about.com/infectiousdiseases/Meningitis.htm
Cerebrospinal Fluid (CSF) = fluid surrounding the brain and spinal cord
Continually made from blood plasma in choroid plexuses which hang from the “roof” of the brains ventricles.
Circulates continuously by being produced and then drained back into blood plasma to keep a constant volume of about 150 ml.
Function: protection
Spinal Tap = sampling technique to test CSF.Hydrocephalus = “water on the brain”
BLOOD-BRAIN BARRIER Keeps neurons separated from blood-borne substances.
Made of LEAST PERMEABLE capillaries in the body. Can’t keep out
fats, respiratory gases, alcohol, nicotine, or anesthetics.
vandenberg.af.mil
Brain Injuries
Traumatic Brain Injuries and Brain DysfunctionsTraumatic Brain Injuries and Brain Dysfunctions
Head injuries are the leading cause of accidental death in the USA.
Concussion = slight injury, dizziness, brief loss of consciousness.http://www.pennmedicine.org/encyclopedia/em_DisplayAnimation.aspx?gcid=000034&ptid=17
Contusion = marked tissue destruction, coma
Cerebral Edema = swelling of the brain, death
BrainMatters 54:00 http://video.pbs.org/video/1390247671/
Stroke = cerebrovascular accident (CVA) occurs when circulation is cut off to the brain.
http://www.pennmedicine.org/encyclopedia/em_DisplayAnimation.aspx?gcid=000123&ptid=17
Aphasia = result of damage to left cerebral hemisphere, affects speech.
motor aphasia = affects Broca’s area and loss of speechsensory aphasia = loss of understanding of language
TIA = transient ischemic attack (mini-stroke)
Alzheimer’s Disease
• mental deterioration• progressive degenerative disease• originally called “senile dementia”• memory loss, irritability, moodiness, confusion, possibly violent• later stages include hallucinations
Dementia 1:01 http://www.healthscout.com/animation/1/7/main.html
Alzheimer’s Disease 19:10 http://www.alzheimer.ca/english/disease/whatisit-video.htm
articles.mercola.com
topnews.net.nz
Alzheimer’s Disease
Parkinson’s Disease Treatment http://www.edheads.org/activities/brain_stimulation/
Interactive tutorial http://www.nlm.nih.gov/medlineplus/tutorials/parkinsonsdisease/htm/index.htm
Parkinson’s Disease
Spinal Cord
About 17 inches (42 cm) long.31 pairs of nerves arise from it.About 17 inches (42 cm) long.
31 pairs of nerves arise from it.
Association neurons
Sensory neurons
Motor neurons
White matter of the spinal cord
Quadriplegic = damage high in cord
Paraplegic = damage low in cord