Download File - PERSPECTIVE MINDS

Chapter 6
Nathaniel Alnas, Rina Llemit, Kimberly Miniano,
Stephanie Lowe
The Nervous System
How the nervous system works
The Nervous system divided into two parts
-Central Nervous System(brain and spinal cord)
-Peripheral Nervous System(the smaller branches of nerves)
-Nerves from the PNS conducts information from bodily organs
takes it CNS and take information back to the organ
-Nerves branch out from
thick as a pencil
the spinal cord and are about as
How the Nervous System Works
-All parts of the nervous system are protected in some way
-The Brain protected by the skull and several layers of
sheathing
-the spinal protected by the vertebrae and peripheral nervous
system
-The bony protection of the spinal cord is crucial
-Injury to the spinal cord could prevent the transmittal
messages between the brain and the muscles
The Nervous system
-Central Nervous System includes brain and spinal
cord
-Peripheral Nervous system consist of Somatic and
Autonomic muscles
-Somatic:Controls Voluntary Muscles
-Autonomic: Controls Involuntary Muscles
-Sympathetic: expends energy part of Autonomic
-Parasympathetic: Conserves energy part of Autonomic
Neurons
-messages from the brain to the muscles travel along the
nerves which are long thin cells called neurons
-Chemical electrical signals travel down the neurons a
hundred time a minute
-transmissions between neurons occurs whenever the cells are
stimulated past a minimum point and emit signal
-if a neutron is not stimulated past the minimum it is not
transmitted at all
Basic Parts of Neuron
Neurons have three basic parts
The cell body:contains the nucleus and produces the energy
needed to fuel Neuron activity
Dendrites: short thin fibers that stick out from cell body
Axon:long fibers that carry impulses away from the cell
body toward the dendrites of the next Neuron
Other parts of the Neuron
Myelin sheath- insulates and protects the axon for some
neurons. In case of multiple sclerosis, the myelin sheath is
destroyed, and results the behaviour of a person to be
erratic and uncoordinated
Axon terminals- it branches out at the end of the axon. Axon
terminals are positioned opposite the dendrite of another
Neuron
Anatomy of Two Neuron
The Neuron Connection
The synapse is the gap that exits between individual never
cells. A Neuron transmits its impulses or message to another
neuron across the synapse.
Neurotransmitter open chemical locks or excite the receptor.
The neurotransmitter can excite the next Neuron or stop it
from transmitting. They act as a valve in a water system that
allow flow in only one direction
Different type of neurotransmitter
Norepinephrine-involved with memory and learning
Endorphins- inhibits pain
Oversupply or undersupply of certain neurotransmitter causes diseases for
example
Undersupply acetylcholine- involved in movement and memory is associated with
paralysis and Alzheimer's disease
Oversupply of dopamine- involved in learning, emotional arousal, and movement,
and is linked to schizophrenia while undersupply is linked with schizophrenia
Undersupply of norepinephrine and serotonin- may result to depression
Anatomy of the Synapse
Neuron Activity
Intensity of activity in each neuron depends on how many other neurons are
acting on it.
Each individual neuron is either ON or OFF depending on the neurons acting
upon it
Afferent neurons or sensory neurons relay messages from the sense organs to
the brain
Efferent neurons, or motor neurons send siganls from the brain to the gland
and muscles.
The interneurons carry impulses between neurons in the body
Voluntary and Involuntary activities
Somatic Nervous system-refers to the part of the peripheral
nervous system that controls voluntary activities for example
walking, and talking
Autonomic nervous system- refers to the part of the nervous
system that controls involuntary activities, or those that
ordinarily occur automatically, such as heartbeat, and
stomach activity
Studying the brain
Vocabulary
Hindbrain: A part of the brain
located at the rear base of the
skull that is involved in the basic
processes of life
Midbrain: A small part of the brain
above the pons that integrates
sensory information and relays it
upward
Forebrain: A part of the brain that
covers the brain’s central core
Lobes: The different regions into
which cerebral cortex is divided
Electroencephalograph(EEG): A machine used
to record the electrical activity of the
large portions of the brain
Computerized axial tomography(CAT): an
imaging technique used to study the brain to
pinpoint injuries and brain deterioration
Positron emission tomography(PET): An
imaging technique used to see which brain
areas are being activated while performing
tasks.
Magnetic resonance imaging(MRI): An imaging
technique used to study brain structure and
activity.
The three brains
- Composed of three parts:
1) The Hindbrain: Located at the
rear base of the skull, involved in the
most basic processes of life.
2) The Midbrain: A small part of the
brain above the pons that integrates
sensory information and relays it upward
3) The Forebrain: A part of the
brain that covers the brain’s central core
Hindbrain
Cerebellum: behind the
spinal cord, helps
control posture,
balance, and voluntary
movements.
Medulla: controls
breathing, heart rate,
and a variety of
reflexes.
Pons: functions as a
bridge between the
spinal cord and brain.
It’s involved in
producing chemicals the
Midbrain
- Small part of brain above the pons that combine sensory
information and relays it upward.
- The medulla, pons and midbrain contains most of the brain
stem and the reticular activating system (RAS) across all
these structures.
RAS: basic job is to alert the rest of the brain of incoming
signals and is involved in the sleep/wake cycle.
Forebrain
- Include the thalamus, which integrates sensory input.
- The thalamus is a relay station for all the information
that travels to and from the cortex. All sensory
information with the exception of smell enters the
thalamus, then sent to the appropriate areas in the
cortex.
- Hypothalamus just below the thalamus that controls
functions such as thirst, hunger, sexual behavior, and
the body’s reaction to temperature.
- Higher thinking processes are in housed in the forebrain.
Cerebral cortex:
- outer layer
- surrounds hindbrain and
brainstem
- Ability to learn complex
and abstract information,
and to project your
thinking into the future.
- Allows you to see, read
and understand sentences.
- It’s the site of your
conscious thinking
Limbic System:
- Core of the forebrain
- A number of different structures in the brain that regulate
our emotions and motivations.
- Consists of the hypothalamus, amygdala, thalamus, and
hippocampus.
- Amygdala controls violent emotions such as rage and fear.
- Hippocampus:
- Formation of memories
- Would be difficult to form new memories if damaged
The cerebrum covers all these parts.
Lobes of the brain
- The cerebrum is the inner layer of the forebrain.
- Two hemispheres or two sides.
- Left and right hemispheres
- Cerebral hemisphere is connected by a band of fibers
called the corpus callosum.
- Contains different types of lobes (the different regions into which the cerebral
cortex is divided) .
1) Motor cortex
- Sends information
to control body
movement. It’s
divided according
to need.
The Cerebral Cortex
1
4
2
2) Frontal Lobe
- Concerned with
organization,
planning, and
creative thinking.
3) Temporal Lobe
- Concerned with
hearing, memory,
3
emotion, and
speaking.
4) Somatosensory
Cortex
- Receives
information to
control body
movement.
5 5) Parietal Lobe
- Concerned with
information from
the senses from
6
all over the body.
6) Occipital Lobe
- Where the visual
signals are
processed.
LEft and right hemispheres
- Both sides complement and help each other.
- Mirror images of each other.
- Corpus callosum sends messages back and forth between the
hemispheres to control human functions.
Left Hemisphere: Controls the movement of the right side of
the body, speech location, and specialized for mathematical
ability, calculations and logic.
Right Hemisphere: Controls the left side of the body, more
adept at visual and spatial relations, perceptual tasks,
Split-brain operations
- Seizures causes the separation of the two hemispheres.
- As a result, people with seizures have a split brain.
- Two brains that operate independently.
- No communications between the two hemispheres.
- Each hemisphere of the brain is unique with specialized
functions and skills.
- Individuals who have has split-brain operations remained
practically unchanged in intelligence, personality, and
emotions.
How psychologists study the brain
Methods they use to explore the brain are:
1)Recording:
- Electrodes are wires that can be inserted into the brain
to record electrical activity in the brain.
- The electrical activity of whole areas of the brain can
be recorded with an electroencephalograph(EEG). Wires
from the EEG machine are attached to the scalp so that
millions of neurons can be monitored at the same time.
- Overall electrical activity of the brain rises and falls
2) Stimulation:
- Techniques have aroused great
medical interest.
- Used on patients to relieve
them of intolerable pain
without using drugs.
- A current delivered through
electrodes implanted in certain
areas of the brain may provide
a sudden temporary relief.
- Psychiatrists have experimented
on similar methods to control
violent emotional behaviour in
3) Lesions:
- Created by cutting or
destroying part of an
animal’s brain.
- Different behaviour
after operation,
assumption that the
destroyed brain area is
involved with that type
of behaviour.
Ex. Rhesus monkeys. Removed
temporal lobe. Known for
aggression. Became less
fearful and at the same
time less violent.
4) Accidents
- Learn from the tragedies when some people suffer
accidents involving the brain
- Draw connections between the damaged parts of the brain
and a person’s behaviour.
Ex. Phineas Gage (railroad foreman, tamping iron)
Dr. Paul Broca (hand gestures and tan, left side of
the brain was damaged involved with the production of speech)
Images
Computerized axial tomography(CAT): an imaging technique used
to study the brain to pinpoint injuries and brain
deterioration
Positron emission tomography(PET): An imaging technique used
to see which brain areas are being activated while performing
tasks.
Magnetic resonance imaging(MRI): An imaging technique used to
study brain structure and activity. Combines the features of
CAT scans and PET scans.
SECTION 3
THE ENDOCRINE
SYSTEM
WHAT IS THE ENDOCRINE SYSTEM?
- Controls and excites
growth and affects
emotions and behaviour
in people.
- One of two communication
systems for sending
information to and from
the brain
- Sends chemical messages,
called hormones through
the bloodstream
PITUITARY GLAND
- Directed by the
hypothalamus
- Acts as the master gland
- Secretes a large number
of hormones
- Hypothalamus monitors
the amount of hormones
in the blood
- Carry messages to organs
involved in regulating
and storing nutrients
- Control growth and
reproduction
- Ovulation and lactation
THYROID GLAND
- Produces the hormone
thyroxine
- Thyroxine stimulates
certain chemical reactions
that are important for all
tissues of the body
- Too little thyroxine makes
people feel lazy and
lethargic
- hypothyroidism
- Too much may cause people
to lose weight and sleep
- hyperthyroidism
ADRENAL GLANDS
- Become active when a
person is angry or
frightened
- Release epinephrine and
norepinephrine
- Adrenaline and
noradrenaline
- Secretions cause heartbeat
and breathing to increase
- Heighten emotions
- Fear
- anxiety
- Help a person generate the
extra energy he or she
needs to handle a difficult
situation
- Secrete cortical steroids
- Help muscles develop
- Cause liver to release
stored sugar
SEX GLANDS
- Testes in males
- Produce sperm
- Male sex hormone
testosterone
- Important in physical
development
- Prenatal period and
adolescence
- Testosterone helps decide
sex of a fetus
- Growth of muscle and bone
along with growth of male
sex characteristics
- Ovaries in females
- Produce eggs
- Female hormones estrogen
and progesterone
- These are important in the
development
- Hormones regulate the
reproductive cycle of
females
- Levels vary throughout
menstrual cycle
- Can cause premenstrual
syndrome (PMS)
- PMS: fatigue, irritability,
depression
HORMONES VS. NEUROTRANSMITTERS
- Both work to affect the
nervous system
- Same chemical
(norepinephrine) can be
used as hormone and
neurotransmitter
- When chemical used as a
neurotransmitter, it’s
released right beside
the cell that it is to
excite or inhibit
- When used as a hormone,
released in the blood,
- Which diffuses it throughout
the body
- For example, norepinephrine
is a hormone when it is
secreted into the blood by
the adrenal glands
- Norepinephrine is a
neurotransmitter
- When released by the
sympathetic motor neurons of
the peripheral nervous
system
CONTINUATION OF HORMONES VS. NEUROTRANSMITTERS
- Appear to have a common
evolutionary origin
(Snyder, 1985)
- As multicellular
organisms evolved, the
system of communication
among cells coordinated
their actions so that
all cells of the
organism could act as a
unit
- As organisms grew more
complex, this
- Communication system began
to split into two more
specialized communication
systems
- One, nervous system
developed to send rapid
and specific messages,
while the other developed
to send slow and
widespread communication
- Second system, chemical
messengers evolved into
hormones
Continuation of hormones vs. neurotransmitters
- whereas neural messages
can be measured in
thousandths of a second
- Hormone messages may take
minutes to reach their
destination and weeks or
months to have their
total effect
Section 4-Heredity
and environment
Heredity & environment
-Heredity is the genetic
transmission of characteristics
from parents to offspring
-There is lots of controversy about
if human behavior is natural due to
heredity or if it is learned based
on our environment
-Inherited factors and
environmental conditions work
together in difficult ways
nature vs. nurture
-Nature has to do with the
characteristics that a person
inherits from their parents which
would be known as their biological
makeup
-Nurture would be the environmental
factors that you have inherited,
like your family, culture,
education, and individual
experiences
Genes & behavior
-Genes are known as the basic units or
building blocks of heredity that are
reproduced and offspring inherit them
from their parents
-The effects that genes have on behavior
happen through the role that they had on
building and changing the physical
structures of the body
-So if your parents happen to be
musicians, it is possible that a gene was
passed along to you that may have
influenced your musical ability due to
the contribution of brain development
that examines sounds
Twin studies
-An ideal way to find out whether a
trait is inherited; studying twins
-Identical twins come from one
fertilized egg (a.k.a monozygotic)
composed with the same genes
-Fraternal Twins are developed from
two fertilized eggs (a.k.a
dizygotic) and their genes are not
more similar than those of brothers
and sisters
-Twins growing up in the same house
share the same environment, whereas
identical twins also share the same
genes.
-Therefore, identical twins who
grew up together proved to be more
similar on a specific trait than
fraternal twins do, thus it
probably means that genes are more
important to that trait
Fraternal twins
identical twins
Twins studies contd...
-Researchers have studied identical
twins being separated at birth and
being put into different
environments
-The results were that even though
their backgrounds were different
socially, economically and
culturally the twins shared similar
behaviors. Such as excelling at the
same things like math, but not
doing so great in spelling
-Therefore, many researchers have
come to think that many of the
differences can be explained by
thinking of heredity as well as
experience
-This does not mean that you can’t
change the behavior, but it is
correct that it is hard to change
the genetic code, but it is
possible to change the environment
where the genes work
bibliography
-http://1.bp.blogspot.com/-GTN4NUYbqyE/T1p-2QawTLI/AAAAAAAABHk/TJ64LtktgHY/s1600/heredity.gif
-http://www.thoughtpursuits.com/wp-content/uploads/2014/01/dna-activation-meditatoin-720x340.jpg
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-http://www.twin-pregnancy-and-beyond.com/images/xIdentical-Twins-Yellow.jpg.pagespeed.ic.EDz36l5_te.jpg
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