The document provides an overview of the nervous system and neurons. It discusses that the nervous system controls perceptions, thinking, and actions through neurons. Neurons receive, transmit, and pass on electrochemical signals. The three main types of neurons are sensory, motor, and interneurons. It also describes the basic anatomy and function of neurons, including the cell body, dendrites, axon, myelin sheath, and axon terminals.
Basic principles involved in the traditional systems of medicine PDF.pdf
Understanding the Nervous System and How Neurons Communicate
1. “The Purpose of psychology is to give us a
completely different idea of the things we
know best.”
-Paul Valery, Tel Quel, 1943
MythBusters: Secrets and Lies
2. Nervous System – controls and coordinates our
perceptions, our thinking, our actions.
Neurons- brain cells and nervous
system cells.
Neurons exist to perform three tasks:
◦ 1. to receive information (in the form of electrochemical
impulses) from neurons that feed into it.
◦ 2. to carry this information down its length
◦ 3. to pass the information on to the next
neuron in line.
Every behavior, thought, and emotion
we experience depends on the
neurons ability to process and
move information.
Intro to Nervous System
3. All brain activity hinges on the workings of brain
cells called neurons.
3 Types of Neurons
◦ Sensory – Respond to input from the senses.
◦ Motor – send signals to muscles to control movement
◦ Interneurons – stand b/w the neurons that register what is
out there and those that control movement.
Average human brain- 100 billion neurons.
Neurons either send impulses or they don’t
Neurons value is how they affect other neurons
(How useful would the internet be if only one
computer was connected to it?)
Brain Circuits – sets of neurons that affect one
another. Chain reaction.
4. Cell Body – produces energy that fuels the neuron.
Contains nucleus and cytoplasm.
Dendrites – thin fibers that carry impulses from
other neurons toward the cell body.
Axon- fibers that carry impulses away from the cell
body to other neurons.
Myelin Sheath – a fatty substance that insulates
and protects axon.
Axon Terminals – small fibers branch out
◦ Airport is axon, terminals release planes to other airports
Neurons are the largest cell in the body.
5.
6. Synapse – area in which two nerve cells come into
contact.
◦ Transmission of the nerve impulse across the synapse is
accomplished w/ the help of neurotransmitters-chemicals
that send signals.
Stored in sacs in the axon terminal
Messages only travel in one direction –dominos
New synapses can develop b/w neurons that were
not previously connected, as when we learn
something new.
Neurotransmitters are released into synapse and
converted into an electrical impulse
8. A neuron always fires with the same intensity.
Toilet Analogy
◦ Like a neuron, a toilet has an action potential. When you
flush, an “impulse” is sent down the sewer pipe.
◦ Like a neuron, a toilet has a refractory period. There is a
short period after flushing when the toilet cannot be
flushed again while the tank is being refilled.
◦ Like a neuron, a toilet has a resting potential. The toilet
is “charged” when there is water in the tank and it is
capable of being flushed again.
◦ Like a neuron, a toilet operates on the All –or –None
Principle- it always flushes w/ the same intensity
regardless of how much force
is applied to the handle.
9. Brain and Spinal Cord
◦ Spinal Cord
Main pathway for info b/w brain and Peripheral Nervous
System. (Talk about later)
Vertebrae- protective spine of bones
Brain - Command Center
3 Major parts of Brain
◦ 1. Cerebrum – 7/8 of the Brain, Center of Intelligence
Cerebral Cortex – Gray Matter receives sensory impulses from the
body and coordinates responses.
Thalamus – relay center for impulses
Hypothalamus – controls bodily functions such as thirst, hunger,
body temp. and blood pressure.
◦ 2. Cerebellum – coordination of muscles
◦ 3. Brain Stem – all nerves from spinal cord to cerebrum.
◦ Cerebrum and Hypothalamus
10.
11.
12. Brain Stem Con’t
◦ Parts
◦ Medulla Oblongata – controls involuntary actions –
circulation, digestion, etc.
◦ Pons – Connects 2 Hemispheres of cerebellum and links
cerebellum w/ cerebrum.
◦ Midbrain – controls responses to sight.
2 Hemispheres
◦ Corpus Callosum – connects…What happens if it is cut?
◦ Most functions occur on both sides
◦ Left v. Right
15. Left Brain Right Brain
Uses logic Uses feeling
Detail oriented “big picture” oriented
Facts rule Imagination rules
Words and language Symbols and images
Present and past Present and future
Math and science Philosophy and religion
Can comprehend Can “get it” (i.e. meaning)
Knowing Believes
Acknowledges Appreciates
Order/pattern perception Spatial perception
Knows object names Knows object function
Reality based Fantasy based
Forms strategies Presents possibilities
Practical Impetuous
17. PNS – made up of nerve cells that send messages
b/w the central nervous system and all the parts of
the body.
Somatic NS
◦ Movements
◦ Sensory Neurons- fur of a cat, hot or cold – to CNS
◦ Motor Neurons – balance, posture – Away from CNS
◦ Reflex – doctors check reflexes to tell if there’s nerve
damage.
Autonomic NS – occurring involuntarily or
“automatically”
◦ Regulates blood pressure, digestive system, heart beat
◦ Important to psych b/c involved w/ emotion and stress.
18. Autonomic NS Con’t
◦ Sympathetic – “Fight or Flight”
Prepares body for action
Raises blood pressure
Pupils dialate
Digestive tract slowed
Increased respiration
◦ Parasympathetic
Calms body
Pupils constrict, etc.
What parts of the nervous system was affected when I
blew the airhorn?
What did your neurons do when I fired the horn? What
was the path that followed down the neuron? Think about
when we were in the hall.
Hinweis der Redaktion
Figure 3.4: Temporal and spatial summation.
Figure 4.1: The human nervous system . Both the central nervous system and the peripheral nervous system have major subdivisions. The closeup of the brain shows the right hemisphere as seen from the midline.