Transcript What is the Nervous System?

Biological Perspective
Week 2
Biopsychology
 Definition: branch of psychology dealing with the effects of
biological factors on behavior
 Founder = Descargar
 Pineal gland was point of contact between the mind and body
 Cartesian hydro-mechanics
 people have a soul that allows them to move
 Julien Offrey de la Mettrie
 to understand the mind, you must study the brain
 Luigi Galvani
 muscle movement is due to electricity
 Experiment with frog legs
What is the Nervous System?
 Complex communication network – how your body/brain
communicate
 Regulates bodily functions and activities
 The nervous system tissue falls into two categories:
 Neurons
 Glia = “glue”
 Two major divisions
 The Central Nervous System
 Peripheral Nervous System
The Neuron
 Neurons – individual cells in the nervous system that
receive, integrate, and transmit information.
 Parts of the Neuron:
Dendrites – receive information
Soma – cell body (info flows into this)
Axon – transmits info to other neurons/muscles/glands
Myelin Sheath – insulates the axon, speeds up
transmission
5. Terminal Button – end of axon, secretes neurotransmitters
at the synapse
6. Synapse – junction where info is sent from one neuron to
another
1.
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3.
4.
Label the Neuron!
• Axon
• Axon
Terminal/Terminal
Button
• Soma/Cell Body
• Dendrite
• Myelin Sheath
• Node of Ranvier
• Nucleus
• Schwann Cell
Three Types of Neurons
 1. Sensory Neurons - direct external impulses inward to
the central nervous system to be processed
 2. Motor Neurons - project axons out from the central
nervous system to control muscles
 3. Interneurons - connect the sensory and motor
neurons
 ~100 billion neurons in the human brain
Glia
 Glia are cells found throughout the nervous system that
provide various types of support for neurons
 Outnumber neurons by 10 to 1!
 Glia have many functions
 Supply nourishment to cells
 Help remove neurons’ waste products
 Provide insulation around many axons
Neuron Impulse
 Neural impulses always travel in one direction
 Neurons rely on electrical signals and chemical transfer
to communicate
 Electrical Signals: Action Potentials
 Chemical Signals: Neurotransmitters
Neuron at Rest
 Within the Neuron:
 (+) and (–) charged ions flow back & forth across cell
membrane – but at DIFFERENT rates
 Leads to higher concentration of negatively charged ions
in cell
 Neuron’s resting potential =
 The negative charge when a cell is not active
 (-70 millivolts)
Action Potential
 Action Potential (AP) – Brief shift in a neuron’s electrical
charge
 Stimulation occurs Channels open Positively charged ions
rush in
 Neuron becomes less negative
 Shifts from -70 millivolts to +40 millivolts
 Absolute Refractory Period – length of time after one AP
fires when another AP cannot begin
 “Down time”
 All-or-None Law – AP either fires, or it doesn’t
 No “half-firing”
 APs are always same size (no weak or strong APs)
The Synapse and when a
Neurotransmitter Binds:
 Video clip:
https://www.youtube.com/watch?v=WhowH0kb7n0
Neurotransmitters
 Specific neurotransmitters work at specific sites.
 Acetylcholine (ACh)
 Noradrenaline (NA) – aka Norepinephrine
 Dopamine
 Serotonin
 GABA
Any Questions?
Nervous System
Nervous System
1. Central Nervous System (CNS)


Brain
Spinal Cord
2. Peripheral Nervous System (PNS)

Somatic: voluntary muscles &
sensory receptors
 Autonomic: automatic/involuntary
functions
 Sympathetic – GO (Fight/flight) 

slows digestion, etc
Parasympathetic – STOP (Resting)
 saves & stores energy
CNS: Hindbrain
 Medulla – unconscious, vital
functions
 Circulation, breathing,
sneezing, coughing,
salivating, swallowing,
heartbeat
 Pons – “the bridge” connects
brainstem to cerebellum
 Sleep & arousal
 Cerebellum – “Little brain”
 Coordination, balance
 One of first structures
depressed by alcohol
CNS: Midbrain
 Smallest region of the brain
 Integrates sensory processes
 Reticular formation (also in
hindbrain)
 Reflexes, breathing, pain
perception, sleep & arousal
CNS: Forebrain
1.
Thalamus – sensory relay
station
2.
Hypothalamus – basic
biological drives (hunger,
thirst, sex drive)
3.
Limbic System – emotion
& memory
4.
Cerebrum– complex
mental activities (learning,
remembering,
consciousness and
voluntary movement)
Cerebrum
 Left hemisphere – verbal
processing: language,
speech, reading, writing
 Right hemisphere –
nonverbal processing:
spatial, musical, visual
recognition
 Connected by corpus
callosum
Corpus callosum
Language Processing
 Broca’s area: speech
production
 Video:
https://www.youtube.com/wat
ch?v=f2IiMEbMnPM
 Wernicke’s area: language
comprehension
 Video:
https://www.youtube.com/wat
ch?v=aVhYN7NTIKU
 Located in the left
hemisphere
4 Lobes of the Cerebral Cortex
 Frontal: movement, executive
functions
 Parietal: sensations (touch)
 Occipital: vision
 Temporal: hearing, visual
processing, memory
 Key to remembering:
 F-POT
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CASE STUDIES
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Use your knowledge of the anatomy and workings of the brain to describe what brain areas are particularly
stimulated and how this brain activation relates to the behavior described in the scenarios below. Given that the people
involved are alive, a multitude of brain structures are operating; select the brain areas that are activated more than normal
in these individuals.

1) Anne, the landscape artist, is standing at her easel, painting with her right hand as she looks out the window at her
garden. She’s listening to classical music as she paints.
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2) Crazy Eddie, the professional wrestler, is in the ring wrestling. The crowd is yelling, and his opponent is taunting him.
Eddie yells back at his opponent. The two of them are out of breath and sweating profusely. They continue their wellorchestrated series of wrestling moves.
FOR
NEUROANATOMY ACTIVITY
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3) Jill is a law student studying for her exam. She is reading about violent rape and murder cases. She is snacking on
popcorn and drinking coffee.