NEURAL SYSTEM
The
neural system of all animals is composed of highly specialized cells called
neurons which can detect, receive and transmit different kinds of stimuli. The
neural organization is very simple in lower invertebrates. For example, in
Hydra it is composed of a network of neurons. The neural system is better organized
in insects, where a brain is present along with a number of ganglia and neural
tissues. The vertebrates have a more developed neural system.
HUMAN NEURAL SYSTEM
The
human neural system is divided into two parts :
(i)
the central neural system (CNS)
(ii)
the peripheral neural system (PNS)
The
CNS includes the brain and the spinal cord and is the site of information
processing and control. The PNS comprises of all the nerves of the body
associated with the CNS (brain and spinal cord). The nerve
fibres
of the PNS are of two types :
(a)
Afferent fibers
(b)
Efferent fibers
The
afferent nerve fibers transmit impulses from tissues/organs to The CNS and the
efferent fibers transmit regulatory impulses from the CNS to the concerned
peripheral tissues/organs. The PNS is divided into two divisions called somatic
neural system and autonomic neural system. The somatic neural system relays impulses
from the CNS to skeletal muscles while the autonomic neural system transmits
impulses from the CNS to the involuntary organs and smooth muscles of the body.
The autonomic neural system is further classified into sympathetic neural system
and parasympathetic neural system.
Brain
structure and function
Forebrain
The
Cerebrum: Also known as the cerebral cortex, the cerebrum is the largest part
of the human brain, and it is associated with higher brain function such as
thought and action. Nerve cells make up the gray surface, which is a little thicker
than our thumb. White nerve fibers beneath the surface carry signals between
nerve cells in other parts of the brain and body. Its wrinkled surface
increases the surface area, and is a six-layered structure found in mammals,
called the neocortex. It is divided into four sections, called “lobes”. They
are; the frontal lobe, the parietal lobe, the occipital lobe and the temporal
lobe.brain lobes
Functions
Of The Lobes:
Frontal
Lobe – The frontal lobe lies just beneath our forehead and is associated with
our brain’s ability to reason, organize, plan, speak, move, make facial
expressions, serial task, problem solve, control inhibition, spontaneity,
initiate and self-regulate behaviors, pay attention, remember and control
emotions.
Parietal
Lobe
– The parietal lobe is located at the upper rear of our brain, and controls our
complex behaviors, including senses such as vision, touch, body awareness and
spatial orientation. It plays important roles in integrating sensory
information from various parts of our body, knowledge of numbers and their
relations, and in the manipulation of objects. Portions are involved with our
visual spatial processing, language comprehension, the ability to construct,
body positioning and movement, neglect/inattention, left-right differentiation
and self-awareness/insight.
Occipital
Lobe – The occipital lobe is located at the back of our brain, and is
associated with our visual processing, such as visual recognition, visual
attention, spatial analysis (moving in a 3-D world) and visual perception of
body language; such as postures, expressions and gestures.
Temporal
Lobe – The temporal lobe is located near our ears, and is associated with
processing our perception and recognition of auditory stimuli (including our
ability to focus on one sound among many, like listening to one voice among
many at a party), comprehending spoken language, verbal memory, visual memory
and language production (including fluency and word-finding), general knowledge
and autobiographical memories.
A
deep furrow divides the cerebrum into two halves, known as the left and right
hemispheres. And, while the two hemispheres look almost symmetrical, each side
seems to function differently. The right hemisphere is considered our creative
side, and the left hemisphere is considered our logical side. A bundle of
axons, called the corpus callosum, connects the two hemispheres.
Midbrain
The
midbrain is located below the cerebral cortex, and above the hindbrain placing
it near the center of the brain. It is comprised of the tectum, tegmentum,
cerebral aqueduct, cerebral peduncles and several nuclei and fasciculi. The
primary role of the midbrain is to act as a sort of relay station for our
visual and auditory systems. Portions of the midbrain called the red nucleus
and the substantia nigra are involved in the control of body movement, and
contain a large number of dopamine-producing neurons. The degeneration of
neurons in the substantia nigra is associated with Parkinson’s disease. The
midbrain is the smallest region of the brain, and is located most centrally
within the cranial cavity.
Limbic
System – the limbic system is often referred to as our “emotional brain”, or
‘childish brain’. It is found buried within the cerebrum and contains the
thalamus, hypothalamus, amygdala and hippocampus.
Thalamus
– the primary role of the thalamus is to relay sensory information from other
parts of the brain to the cerebral cortex
Hypothalamus
– the primary role of the hypothalamus is to regulate various functions of the
pituitary gland and endocrine activity, as well as somatic functions e.g.body
temperature, sleep, appetite.
Amygdala
– the primary role of the amygdala is to be a critical processor for the
senses. Connected to the hippocampus, it plays a role in emotionally laden
memories and contains a huge number of opiate receptor sites that are
implicated in rage, fear and sexual feelings.
Hippocampus
– the primary role of the hippocampus is memory forming, organizing and storing
information. It is particularly important in forming new memories, and
connecting emotions and senses, such as smell and sound, to memories.
Pituitary
Gland – the primary role of the pituitary gland is an important link between
the nervous system and the endocrine system. It releases many hormones which
affect growth, metabolism, sexual development and the reproduction system. It
is connected to the hypothalamus and is about the size of a pea. It is located
in the center of the skull, just behind the bridge of the nose.
Hindbrain
The
Cerebellum – The cerebellum, or “little brain”, is similar to the cerebrum with
its two hemispheres and highly folded surface. It is associated with regulation
and coordination of movement, posture, balance and cardiac, respiratory and
vasomotor centers.
Brain
Stem – The brain stem is located beneath the limbic system. It is responsible
for vital life functions such as breathing, heartbeat, and blood pressure. The
brain stem is made of the midbrain, pons, and medulla.
Pons
– The primary role of the pons is to serve as a bridge between various parts of
the nervous system, including the cerebellum and cerebrum. Many important
nerves that originate in the pons, such as the trigeminal nerve, responsible
for feeling in the face, as well as controlling the muscles that are responsible
for biting, chewing, and swallowing. It also contains the abducens nerve, which
allows us to look from side to side and the vestibularcochlear nerve, which
allows to hear. As part of the brainstem, a section of the lower pons
stimulates and controls the intensity of breathing, while a section of the
upper pons decreases the depth and frequency of breaths. The pons is also
associated with the control of sleep cycles, and controls respiration and
reflexes. It is located above the medulla, below the midbrain, and just in
front of the cerebellum.
Medulla
– The primary role of the medulla is regulating our involuntary life sustaining
functions such as breathing, swallowing and heart rate. As part of the brain
stem, it also helps transfer neural messages to and from the brain and spinal
cord. It is located at the junction of the spinal cord and brain.
Please
support the Northern Brain Injury Association.
Hemisphericity
It referred to the idea that people
rely on a preferred mode of cognitive processing that is linked to predominant
activity of either their left or right cerebral hemisphere. Individual Hemisphericity was erroneously
thought to be located somewhere on a gradient between right and left brain
dominance with most people being intermediate. Left brain controls the right side
of the body and right brain control the left side of the body. There are two hemispheres of the brain including the
“Right Hemisphere” and “Left Hemisphere.” You know the myth that we only
use 10% of our brains but this is simply not true. We do however, have a
dominant hemisphere that we use more often.
Right Brain
The Right
Brain, as it is called, is known as the creative sector of your brain. This
part of your brain is holistic and synthesizing. The Right Brain is the
area of the brain that impacts your ability to collaborate, use your
imagination, use symbols and icons. Interestingly enough, the Right Brain
is used for problem solving, integrating and risk taking!
Left Brain
The Left
Brain is the logical side of the brain. It is the detail and fact oriented area
of the brain. This side dominates memory, the speed in fluency and
completion of tasks especially in math. It is the Left Brain that
controls our focus and keeps us structured and following rules and procedures.
Left
brained people tend to be logical and analytical, with strong mathematical and
verbal skills. Left brained students are usually able to work well on their own
focus in class, although they may prefer a quite class room. In contrast right
brained kids are Imaginative and intuitive .Because they see the whole they
tend to recognize patterns and be good at visual spatial relations.
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Left
brain
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Right
brain
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Sequential
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Wholestics
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Analysis
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Intusion
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Maths
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Creative
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Language
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Art
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Computation
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Feeling
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Logical
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Day dreaming
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Facts
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Imagination
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Here are 8 facts we DO know about the brain and the implications
for teachers.
1.
A teacher has less than 3 minutes to engage a learner at the start of an
activity. A HOOK or great opening to your lesson will help ensure
engagement.
2.
According to earlyintervention.com, an elementary child can only stay
attentive for about 10-15 minutes. “As a guideline some research suggests
using a child’s age as a general starting point for the number of minutes a
child can attend to a single assigned task…so 5 minutes for a 5 year old, 7
minutes for a 7 year old, etc.” which is a reminder that lessons should change
and students should be moving during lessons. For example, you may start a
reading lesson with a picture walk, then students may read–breaking up this
reading with talking, writing, questions etc. help to keep the student engaged
in learning.
3.
The cerebellum which is only 1/10 of your brain has the most neurons
(40 million nerve fibers) which is 40 times more than your optic trac and
associated with your motor control. It is also a path to the section of
the brain which controls memory and attention. When you are using the
cerebellum (moving) then you are stimulating your memory!
4.
When a student (or adult) is stressed the hippocampus (the brain’s
structure for memory) is negatively affected. When in an overly stressed
state the brain in unable to identify and store information into short or long
term memory. Now with this being said, a small bit of stress can stimulate
learning by engaging the learner so the teacher must know her/his students to
ensure there is balance. A good example to remember is: When you are in a
competition–you are alert and engaged but if you are so scared that you are
crying or consumed with anxiety–you will not perform well and most likely
forget anything you were wanting to say.
5.
Students learn information more easily in small chunks. We used to think
7-8 but now researchers believe it is 2-4. Breaks and process time are
very important when learning new information.
6.
Your brain learns the circle as the first shape. When creating
flashcards–using a circle will help students focus on the content more easily
because the brain is not focused on the outline of the card itself.
7.
Colors affect our brain so therefore it affects learning. Blue and
green are calming where yellow causes more excitement. Red can help hold the
attention of our ADHD students. We have used colored overlays for
students in reading for years–here is another reason to think about our decor.
8.
Waelti, Dickinson and Schultz (2001), found in brain studies that there
is a benefit “associating rewarding, positive social experiences with the
learning process” which is called dopamine-based reward stimulated learning.
This basically means that students are more comfortable and engaged when
talking with their peers so collaborative learning helps to stimulate learning.
