ap psych prep 3 - biological psychology (part i)

8/13/2019 AP Psych Prep 3 - Biological Psychology (Part I)

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Part I Overview:Neurons The Cellular basis of behaviour

Neuron Signal Transmission

General Nervous System

Methods of Researching the Brain


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Nervous System Overview:(Green)(Pink)


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Neurons cellular basis of behaviour

Neuron individual nerve cell; the cells thatsend and receive the fast messages that makeup our thoughts, feelings, behaviours, etc.

Neurons are found in your brains, and also inthe rest of your body

Neurons are very specialized cells withimportant parts.


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Neurons / Nerve Cells


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Neurons Components / Parts

Dendrites tree-like parts that stretch outfrom the cell body. These connect to otherneurons, and receive signals from them

Cell Body / Soma round part of the cell thatholds the cell organelles and keeps the cell

alive and operating properly

Axon wire that extends out of the cell body

towards other cells.


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Myelin Sheath oval shaped coverings on theaxon; like the plastic covering on wires. Act tomake the signal transmission faster

Terminal button / synaptic knob theending(s) of the axon, where it meets with

another nerve cell. Contains neurotransmitters


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Neurotransmitters chemicals used byneurons to communicate with each other.They match with receptor sites on the

opposite neuron.

Synapse the space between the terminal

button of one neuron and the dendrites of thenext neuron.


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Neurons Signal Transmission

Nerve signals travel along the axon of theneuron by an electrical signal called a nerveimpulse, or action potential.

It starts from the cell body end of the cell. Ifthe cell is stimulated enough by other

neurons, (threshold level is reached) it will firea signal down the axon to communicate toother cells.


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First Action Potential Videohttp://www.youtube.com/watch?v=U0NpTdge3aw

Second Action Potential Video(file only)
http://www.youtube.com/watch?v=U0NpTdge3awhttp://www.youtube.com/watch?v=U0NpTdge3awhttp://www.youtube.com/watch?v=U0NpTdge3awhttp://www.youtube.com/watch?v=U0NpTdge3aw


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Nerve impulse animation

http://www.youtube.com/watch?v=dSkxlpNs3tU
http://www.youtube.com/watch?v=dSkxlpNs3tUhttp://www.youtube.com/watch?v=dSkxlpNs3tUhttp://www.youtube.com/watch?v=dSkxlpNs3tUhttp://www.youtube.com/watch?v=dSkxlpNs3tUhttp://www.youtube.com/watch?v=dSkxlpNs3tU


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Signals travel 120 meters per second veryfast

Threshold of -55 millivolts is required beforethe neuron will fire (+ All-or-none principle,can only fire, or not fire, no half signals)

When the signal reaches the end of theneuron, it causes CHEMICAL signal to start.Chemicals are how one cell talks to another.Electric signal is just WITHIN one neuron


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Nodes of Ranvier are the gaps between themyelin sheath blobs. These little gaps allowthe signal to jump from one gap to the next,

making the signal much much faster.

(loss of myelin sheath causes problems in

humans; for example, the disease multiplesclerosis)


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After a neuron sends a signal, it will wait for asmall period of time before sending anotherone. This is called the refractory period.

If cells fire signals too quickly and too often,they can die. This can happen if your brain is

injured, and excitatory neurotransmitters arereleased in great numbers.


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Neurons NeurotransmittersBetween cells, chemical signal happens bymovement of neurotransmitters. They travelfrom one nerve cell to the next one across thegap (synapse).

Some neurotransmitters excite the cell theyattach to (make more positive more likely tofire), and some will inhibit (make morenegative, less likely to fire).


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Neurons NeurotransmittersAmount and type of neurotransmitters thatattach to the cell will determine if it fires ornot.


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Neural Synapse Signal Communication

http://www.youtube.com/watch?v=HXx9qlJetSU
http://www.youtube.com/watch?v=HXx9qlJetSUhttp://www.youtube.com/watch?v=HXx9qlJetSUhttp://www.youtube.com/watch?v=HXx9qlJetSUhttp://www.youtube.com/watch?v=HXx9qlJetSU


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A Few Important Neurotransmitters:

Different types of neurotransmitters tend todo different jobs in our brains. Here are a fewexamples. There are many more

SSRIMedications


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General Nervous SystemNervous system is our minds connection tothe outside world. Our nerve cells can only firein ONE direction, so we need two sets of cells;one for signals to the brain, one for signalsfrom the brain.

Sensory Neurons (Afferent) signals from thesenses to the brainMotor Neurons (Efferent) signals from thebrain out to the rest of the body


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General Nervous SystemInterneurons transmits signals betweensensory and motor, or between areas of thebrain.

Nervous system can be divided into differentparts. Central and Peripheral was mentionedbefore.

There are further divisions possible.


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General Nervous System


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Nervous System Central (CNS)Brain and Spinal Cord nerves housed withinbone. Spinal cord large number of nervesthat run out of the brain and send informationto and from the brain and the body.


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Peripheral Nervous System (PNS)The periphery (edges)

Somatic NS controls our voluntarymovements; the movements we choose tomake.

Autonomic NS (think of automatic) controls functions of our body that we dontconsciously control (breathing, heart beat,digestion, etc)


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Autonomic Nervous System:2. Parasympathetic Nervous System changesour bodies actions in the opposite direction.Moves us away from the stressful position to anormal relaxed state.

Slows heartbeat, breathing, lowers bloodpressure, etc.

Speeds up digestion again, etc.


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Peripheral Nervous System OperationBoth sensory and motor neurons are requiredfor normal everyday behaviour.

What parts of your nervous system might beinvolved when you see some candy, and reachout to get it? ______________________________________ ______________________________________ ______________________________________ __________________________________


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ReflexesAutomatic reactions to certain stimuli.

Some of our reflexes happen WITHOUT anyaction by our brains. Spinal cord can initiateaction by itself sometimes.

When doctor hits just below your knee andyour leg jerks up.Touching very hot or cold things pull away

Signal is ALSO sent to


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Spinal Reflexesg

your brain, but decisionto act has alreadyhappened


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The Brain (part of CNS)Hard to study the brain. Its hidden beneathskin and bone, and even if we can see it itshard to tell what its doing.

We use many different technologies to studythe brain.


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Brain Research Methods:Accidents Sometimes a rare accident tosomeones brain will give us some clues. (CaseStudy)E.g. Phineas Gage railway worker hurt on the job behaviour and personality changed


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Brain Research Methods:Lesions removal or destruction of part of thebrian. NEVER done just out of curiosity.Sometimes medically necessary

E.g. H.M. a patient who had brain seizures.Had part of his lateral hippocampus removedto stop the seizures. The surgery probablysaved his life.Hippocampus is very important in memoryformation, and so


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Brain Research Methods:H.M. could not make NEW memories at allafter the surgery happened.

He could remember old memories.He could also learn new motorskills, just couldnt form newdeclarative memories.

This idea explored in thismovie, though its inaccurate


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Brain Research Methods:Electroencephalogram (EEG) measures brainelectrical energy from outside the head;Common in sleep research, but can be used inother areas as well.


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Brain Research Methods:

Computerized Axial Tomography (CAT) multiple angle xray creates a very detailedimage of an internal body area; can not showfunctioning


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Brain Research Methods: CAT


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Brain Research Methods: CAT


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Brain Research Methods:Magnetic Resonance Imaging (MRI) Similarto CAT scan, but uses a large magnet and radiowaves to capture a very detailed internalimage. High resolution, and avoids the

radiation of CAT.See animation.


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Very useful to see where the brain is active


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Very useful to see where the brain is active,not just what it looks like.However, very expensive to make tracers, etc.And not quite as high resolution as othertechniques.


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Brain Research Methods:Functional MRI a new method that combinesaspects of PET and MRI to create very detailedimages of BOTH structure and activity.

Uses the differencein how much bloodis in different areas

of the brain tomeasure activity.

ap psych prep 3 - biological psychology (part i)

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