Nervous System

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Nervous System

• Biology 1b
• Spring Semester

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Outline of nervous system unit

• Evolution of nervous system
• Basics of the vertebrate nervous system
• How an action potential is transmitted
• Organization of nervous system
• Brain structure function
• Special senses

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Evolution of nervous system

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Sponges-Phylum Porifera

• Do not have a nervous system that allows them to
  respond to change in the environment

http//www.datacomm.ch/renebu/los_roques/los_roque
s.html
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Cnidarians

• Sea jellies
• Neurons form diffuse network nerve net

http//www.world-builders.org/planets2000/Gump/Lim
on/AQAnimal3/Cnidar.html
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Flatworms Phylum Platyhelminthes

• More specialized than the cnidarians
• Increased coordination, for increased motility
• 2 lateral nerve cords nerve ladder with 2
  ganglia at anterior end

publish.uwo.ca/jkiernan/ anfound.htm
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Round worm- Phylum Nematoda

• Simple nervous system, have several ganglia, have
  simple sense organs to detect chemical given off
  by prey or host

http//www.janssenpharmaceutica.be/jah/images/foto
srechts/dogs3.jpg
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Segmented worms-Phylum Annelida

• Earthworm
• Double ventral nerve cord
• 2 cords meet as ganglia for each segment of the
  body

http//cas.bellarmine.edu/tietjen/images/annelids.
htm
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Mollusks-Phylum Mollusca

• Clams, snails, squid
• Nervous system varies in this phylum with the
  activity of the organism. Octopi are capable of
  complex behavior, therefore complex nervous
  system.
• 3 pair of ganglia of equal size 1)cerebral
  2)visceral 3)pedal

http//www.blazemonger.com/GG/albums/octopus.html
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Phylum Echinodermata

• Sea stars
• Nerve ring around mouth

www.usfca.edu/fac-staff/chienp/
phylum20echinodermata.html
http//www.biology.ucsc.edu/classes/bio136/echinod
ermata/asteroidea/asteroidea.html
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Arthropods- Phylum Arthropoda

• Insects, crustaceans, spiders etc.
• Well developed nervous systems, with a brain,
  dorsal nerve cord, sophisticated sense organs

http//lamar.colostate.edu/insects/systems/nervou
s/nervous.html
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Vertebrates- Phylum Chordata

• Increased cephalization
• Dorsal nervous system

http//www.uoguelph.ca/zoology/devobio/210labs/ect
o3.html
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Basics of the vertebrate nervous system
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Basic unit nerve cellNeuronGroup of neuron
ganglia

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Types of neurons

• Motor neuron- (efferent neuron)-
• Transmits away form CNS
• Sensory neuron (afferent neuron)-
• Transmits to CNA
• Interneuron (association neuron)-
• Inside of CNS, connects neurons

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Reflex arc
http//web.ukonline.co.uk/webwise/spinneret/humans
/recodr.htm

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Synapse-gap between neurons

http//images.google.com/images?hlenlrieUTF-8
oeUTF-8qsynapse
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2.   3.   4.   5.   6.  
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•   Resting state
• Depolarization
• A nerve cell is stimulated.
• permeable to Na for an instant and they quickly
  move into the cell.
• inner surface is positive
• Repolarization
• When the cell membrane becomes depolarized, K
  automatically leave the cell until the cell is
  back to its resting state.
• The impulse travels
• Transmission across a synapse
• Refractory period
• A neuron cannot be stimulated during this period.
  This period of time is about 0.0004 of a second.

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Movement of an impulse

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Movement of an impulse

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Movement of an impulse

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http//www.accessexcellence.org/AB/GG/Fig_12.33.jp
g
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Organization of nervous system
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http//www.futuredynamicadvantage.com/research/reg
enerative_neurosciences.html
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CNS structure function

http//serendip.brynmawr.edu/bb/kinser/Home1.html
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The Brain
http//www.dartmouth.edu/artsci/ethics-inst/videos
.html

• Ultimate example of cephalization
• Important so it is covered be the skull, layers
  of protective tissue called meninges, and
  cerebral spinal fluid (CSF)

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http//training.seer.cancer.gov/module_anatomy/uni
t5_3_nerve_org1_cns.html
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cerebrum

• Two parts
• Cerebral cortex- gray matter
• Cerebral medulla white matter-covered with
  myelin

http//www.riken.go.jp/lab-www/frontier-div/PAMPHL
ET/KENKYUJOHO/p33/ep33.html
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Cerebrum- four lobes

http//serendip.brynmawr.edu/bb/kinser/Home1.html
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Cerebrum- four lobesfrontal

• Frontal Lobe- associated with reasoning,
  planning, parts of speech, movement (motor
  control), emotions, and problem solving

http//www.cyberpunks.org/freeside/mab_neuro2.html
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Cerebrum- parietal lobe

• Parietal Lobe- associated with movement,
  orientation, recognition, perception of stimuli
  sensory input

http//www.benbest.com/science/anatmind/anatmd6.ht
ml
http//www.alzheimer-montpellier.org/apraxies.html
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Cerebrum- occipital

• Occipital Lobe- associated with visual processing
  

http//medlib.med.utah.edu/kw/sol/sss/subj2.html
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Cerebrum- temporal

• Temporal Lobe- associated with perception and
  recognition of auditory stimuli, memory, and
  speech

http//www.howe.k12.ok.us/jimaskew/bnerves.htm
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http//www.macalester.edu/psych/whathap/UBNRP/Spl
it_Brain/Corpus20Callosum.html
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Cerebellum-second biggest structure on brain

• Controls muscle coordination and balance "learn"
  and store motor patterns.

http//www.on-with-life.org/WebFrames/Cerebellum.h
tm
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Thalamus Hypothalamusfound between brain stem
cerebrum

• Thalamus- receives messages from the sense
  organs, relays that info to the correct part of
  the cerebrum
• Hypothalamus- control center for recognition and
  analysis of hunger, thirst, fatigue, anger, and
  body temperature. (maintain homeostasis)

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Brainstem (midbrain, pons, medulla oblongata)

• Mid brain- hearing and balance
• Pons- involved in the control of breathing
• Medulla oblongata- regulate visceral activity
  (heart rate, blood pressure, breathing,
  swallowing, vomiting)

http//training.seer.cancer.gov/module_anatomy/uni
t5_3_nerve_org1_cns.html
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Spinal cord

http//www.spinal-cord-injury-resources.com/spinal
-important.html
http//www.bowdoin.edu/jkinsman/PAGES20121201/ve
ntralhornmotorneurons.html
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Special senses
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Eyevision stimuli is processed in occipital lobe

http//whyfiles.org/shorties/098dog_genetherapy/
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Ear-auditory stimuli is processed in parietal lobe

http//pcbunn.cacr.caltech.edu/Cochlea/
http//liftoff.msfc.nasa.gov/news/2002/news-mixup.
asp
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Touch- sense receptor through out your body,
integrated in parietal lobe

http//www.anatomy-resources.com/human-anatomy/sh2
83.htm
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Taste

http//www.udel.edu/Biology/Wags/histopage/colorpa
ge/co/co.htm