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Nervous System & Endrocine Glands
Our brain:
Now,
lets continue our journey of self discovery and lets take a look
at our very important physical body, lets begin with our brain
which is part of our central nervous system, then we will get to
the Endocrines glands, soon you will see that the physical and
the subtle or etheric body function as one, they are
interdependent, as everything in nature is. The next few pages
talks about anatomy, so I have taken what is relevant to
Kundalini From Wikipedia, the free encyclopedia which I consider
to be common knowledge but for a detailed study of this section
you can refer to any book on anatomy.
The human brain is vast and complex. It contains some one
hundred billion neurons, which are capable of electrical and
chemical communication with tens of thousands of other nerve
cells. Nerve cells in turn rely on some million billion
connections for their communications. For the sake of study and
related to our path, we can divide the brain into four sections.
The telencephalon is the name for a large
region within the brain that is attributed to many functions.
Many people refer to it as the cerebrum; however, it is
technically referred to as the telencephalon.
A more technical definition: the telencephalon refers to the
cerebral hemispheres and other smaller structures within the
brain, although the telencephalon is one of the larger divisions
(in terms of number). It is the anterior-most embryological
division of the brain that develops from the prosencephalon;
the pineal gland which plays a very important role
in Samadhi and psychic phenomena is situated here.

The cerebellum (Latin: "little brain") is a
region of the brain that plays an important role in the
integration of sensory perception and motor output.
Master Sivananda say that the Mind rests here during dreams.
The medulla oblongata is the lower portion
of the brainstem. It controls autonomic functions and relays
nerve signals between the brain and spinal cord.
The Medulla oblongata is responsible for controlling several
major autonomic functions of the body, such as:
- respiration (via dorsal respiratory group and ventral
respiratory group)
- blood pressure
- heart rate
- reflex arcs
- vomiting
The medulla ablongata is important to us because its plays a
very important role in Asanas and Pranayama, which are essential
practice on the path of Enlightenment and Self -Realization.

The Pons Varolli are a band of nerve fibers
on the ventral surface of the brainstem that links the medulla
oblongata and the cerebellum with upper portions of the brain.
There are five ventricles of the brain. The fourth it is the
one important to us. It is situated in the Medulla
Oblongata. The fourth ventricle is the
central canal of the spinal cord, this canal is known as
“ Canalis Centralis” when it enters the
cranial cavity this tiny canal becomes bigger in size.
Canalis Centralis is Sushuma, the central Nadi which is the
traveling path of Kundalini where it enters the brain.
At this point Kundalini energy, energizes and
rewires Neuron pathways, giving a new perception of life, here
Enlightenment begins. Sushuma goes out piercing the head through
the fontanelle; the portion that is very soft in babies, as the
child grows the bones harden and close to form the sutures of
the neurocranium to protect the brain. When Kundalini pierces
the fontanelle it reaches the Crown Chakra, Sahasrara, eight
inches above the head. At this point it is said “that one has
attained immortality.” It is also through the fontanelle that
the soul leaves the physical body at the moment of death.
 
(1)This image is a work of the National
Institutes of Health, part of the United States Department of
Health and Human Services. As a work of the U.S. federal
government, the image is in the public domain.
(2) I, the creator of this work, hereby
release it into the public domain. This applies worldwide.
In case this is not legally possible,
I grant any entity the right to use this work for any
purpose, without any conditions, unless such conditions are
required by law.
Endocrines glands: ( internally secreting glands)
These glands are also called ductless glands, since they lack
excretory ducts. Instead, the secretors cells release their
products, hormones, into the extra cellular space. From
the extra cellular space, the hormones may enter the blood
stream, by which they reach their target organs. Alternatively,
the hormones may affect nearby cells (paracrine acting
hormones).

(Illu_endocrine_system.jpg from the Wikimedia
Commons.)
The pituitary gland, or hypophysis, is an
endocrine gland about the size of a pea that sits in a small,
bony cavity (pituitary fossa) covered by a membrane. The
pituitary fossa, in which the pituitary gland sits, is situated
in the sphenoid bone at the base of the brain.
The pituitary gland secretes hormones regulating
homeostasis,( Homeostasis is the property of an open system,
especially living organisms, to regulate its internal
environment to maintain a stable, constant condition, by means
of multiple dynamic equilibrium adjustments, controlled by
interrelated regulation mechanisms) including trophic hormones
that stimulate other endocrine glands. The Pituitary gland it is
also called the master gland because of its homeostatic role.

The pineal gland (also called the pineal
body or epiphysis) is a small endocrine gland in the brain. It
is located near the center of the brain, between the two
hemispheres, tucked in a groove where the two rounded thalamic
bodies join. The pineal gland was originally believed to be a
"vestigial remnant" of a larger organ (much as the appendix was
thought to be a vestigial digestive organ). It was only after
the 1960s that scientists discovered that the pineal gland is
responsible for the production of melatonin, which is regulated
in a circadian rhythm. Melatonin is a derivative of the amino
acid tryptophan, which also has other functions in the Central
Nervous System. The production of melatonin by the pineal gland
is stimulated by darkness and inhibited by light. The retina
detects the light, and directly signals and entrains the
suprachiasmatic nucleus (SCN). Fibers project from the SCN to
the paraventricular nuclei (PVN), which relay the circadian
signals to the spinal cord and out via the sympathetic system to
superior cervical ganglia (SCG), and from there into the pineal
gland. The pineal gland is large in children, but shrinks at
puberty. It appears to play a major role in sexual development,
hibernation in animals, metabolism, and seasonal breeding. The
abundant melatonin levels in children is believed to inhibit
sexual development, and pineal tumors have been linked with
precocious puberty. When puberty arrives, melatonin production
is reduced. -Calcification of the pineal gland is typical in
adults.
Normally, the production of melatonin by the pineal gland is
inhibited by light and permitted by darkness. For this reason
melatonin has been called "the hormone of darkness". The
secretion of melatonin peaks in the middle of the night, and
gradually falls during the second half of the night. Until
recent history, humans in temperate climates were exposed to up
to eighteen hours of darkness in the winter. In this modern
world, artificial lighting typically reduces this to eight hours
or less per day all year round. Even low light levels inhibit
melatonin production to some extent, but over-illumination can
create significant reduction in melatonin production. Reduced
melatonin production has been proposed as a likely factor in the
significantly higher cancer rates in night workers,
and the effect of modern lighting practice on endogenous
melatonin has been proposed as a contributory factor to the
larger overall incidence of some cancers in the developed world.
As inadequate as blood concentrations may be in brightly-lit
environments, some scientists now believe that people's
overnight output of melatonin can be further jeopardized each
time they interrupt their sleep and turn on a bright light
(suggesting that the lower brightness level of a nightlight
would be safer). Others suggest that such short exposures do no
harm. Melatonin is a powerful antioxidant that can easily cross
cell membranes and the blood-brain barrier. Unlike other
antioxidants, melatonin does not undergo redox cycling, the
ability of a molecule to undergo reduction and oxidation
repeatedly. Redox cycling may allow other antioxidants (such as
vitamin C) to act as pro-oxidants, counterintuitively promoting
free radical formation. Melatonin, once oxidized, cannot be
reduced to its former state because it forms several stable
end-products upon reacting with free radicals.
The pineal gland is associated with the Sixth
Chakra called Ajna, or sometimes is associated with the Seventh
(Crown) Chakra, this is because the two glands are very very
close to each other and it is difficult to distinguish which
Chakra energize which gland, but is very easy to detect. The
master gland Pituitary is energized by the master Chakra
Sahasrara, also call the Crown Chakra; the Pineal gland it is
energize by Ajna, also call the Third Eye.
The
thyroid (from the Greek word for "shield",
after its shape) is one of the larger endocrine glands in the
body. It is a double-lobed structure located in the neck and
produces hormones, principally thyroxine and triiodothyronine,
that regulate the rate of metabolism and affect the growth and
rate of function of many other systems in the body. The
parathyroid glands are small endocrine glands in the neck,
usually located behind the thyroid gland, which produce
parathyroid hormone. In rare cases the parathyroid glands are
located within the thyroid glands. Most often there are four
parathyroid glands but some people have six or even eight. The
sole purpose of the parathyroid glands is to regulate the
calcium level in our bodies within a very narrow range so that
the nervous and muscular systems can function properly.
The thyroid and parathyroid glands are associated with the
Fifth Chakra call Vishuda.
The
thymus is an organ located in the upper
anterior portion of the chest cavity. It is of central
importance in the maturation of T cells. The thymus plays an
important role in the development of the immune system, being
the primary site of T cell maturation. The organ is most active
between the late stages of gestation and early puberty, when
most of the T cells an individual will carry for their lifetime
are formed. With the onset of puberty the organ atrophies,
gradually shrinking in size and function. The atrophy is due to
the increased circulating level of sex hormones, and chemical or
physical castration of an adult results in the thymus increasing
in size and activity. In the two thymic lobes, lymphocyte
precursors from the bone-marrow become thymocytes, and
subsequently mature into T cells. Once mature, T cells emigrate
from the thymus and constitute the peripheral T cell repertoire
responsible for directing many facets of the adaptive immune
system. Loss of the thymus at an early age through genetic
mutation or surgical removal results in severe immunodeficiency
and a high susceptibility to infection. The Chakra
that energize the thymus is the Forth Chakra called Anahata.
Healthy Chakra = strong inmune ssystem.
The
adrenal glands (also known as suprarenal
glands) are the triangle-shaped endocrine glands that sit atop
the kidneys; their name indicates that position (ad,
"near" or "at" + renes, "kidneys"). They are chiefly
responsible for regulating the stress response through the
synthesis of corticosteroids and catecholamines, including
cortisol and adrenaline. Anatomically, the adrenal glands are
located in the abdomen, situated on the anteriosuperior aspect
of the kidneys. In humans, the adrenal glands are found at the
level of the 12th thoracic vertebra and receive their blood
supply from the adrenal arteries. It is separated into two
distinct structures, both of which receive regulatory input from
the nervous system. As its name suggests, the adrenal medulla is
at the center of the adrenal gland surrounded by the adrenal
cortex. The adrenal medulla is the body's main source of the
catecholamine hormones adrenaline (epinephrine) and
noradrenaline (norepinephrine). By contrast, some cells of the
adrenal cortex belong to the hypothalamic-pituitary-adrenal axis
and are the source of cortisol synthesis. Other cortical cells
produce androgens such as testosterone, while some regulate
water and electrolyte concentrations by secreting aldosterone.
The adrenal glands secrete steroids, including some sex
hormones, and catecholamines. Steroids are synthesized and
secreted by the adrenal cortex, while catecholamines are
synthesized and secreted by chromaffin cells of the adrenal
medulla. The principal steroids are aldosterone (a
mineralocorticoid) and cortisol (a glucocorticoid). Aldosterone
promotes sodium retention and potassium excretion and is
therefore important in maintaining fluid balance and blood
pressure. Cortisol on the other hand has a wide range of
metabolic effects such as protein and fat breakdown that aim to
elevate blood glucose levels. Many sex hormones are secreted
including testosterone and oestrogen. The sex hormone that is
secreted by the adrenals that has the most influence is
dehydroepiandrosterone (DHEA). It has virilising effects and is
important in development and maintenance of pubic hair, axillary
hair, pubertal growth spurts, and sex drive. The effects are
only significant in females as the effects are masked by high
testosterone levels in males. Catecholamines that the adrenal
glands secrete are adrenaline and noradrenaline. Adrenaline has
the more influential effects. The effects of adrenaline and
noradrenaline are wide ranging; adrenaline has a more marked
effect on the heart and metabolic activities while noradrenaline
is involved more in peripheral vasoconstriction. Adrenaline and
noradrenaline secretion is stimulated directly by sympathetic
neurons in response to stressors. The adrenal glands secrete
other hormones as well. This tiny but very important
glands are energize by Manipura, the Third Chakra call by some
the solar plexus.
The
pancreas is an organ in the digestive and
endocrine system (of vertebrate) that serves two major
functions: exocrine (producing pancreatic juice containing
digestive enzymes) and endocrine (producing several important
hormones, including insulin). In humans, the pancreas is a 15-25
cm (6-10 inch) elongated organ in the abdomen located
retroperitoneal. It is located posterior to the stomach and in
close association with the duodenum. It is often described as
having three regions: a head, body and tail. The body of the
pancreas lies at the level of L2 on the spine. The pancreatic
head abuts the second part of the duodenum. The tail of the
pancreas extends towards the spleen. Under a microscope, when
properly stained, it is easy to distinguish two different tissue
types in the pancreas; These regions correspond to the main
pancreatic functions: Endocrine pancreas, secretes hormones that
regulate blood glucose levels. Exocrine pancreas, produces
enzymes that break down digestible foods. The
Pancreas as the Adrenals is energize by the Third Chakra
Manipura.
Ovaries
are egg-producing reproductive organs found in female
organisms. They are part of the vertebrate female reproductive
system. Ovaries in females are homologous to testes in males.
The term gonads refers to the ovaries in females and testes in
males. Normally, a female will have two ovaries, each performing
two major functions: producing eggs, or (exocrine function) and
secreting hormones, or (endocrine function). For our study we
are interested in the endocrine function of the ovaries. Ovaries
produce various steroid and peptide hormones. Estrogen and
progesterone are the most important ,these hormones serve many
functions: They induce and maintain the physical changes of
puberty and the secondary sex characteristics; They support
maturation of the uterine endometrium in preparation of
implantation of a fertilized egg; They provide signals to the
hypothalamus and pituitary that help maintain the menstrual
cycle; Estrogen plays an important role in maintaining
subcutaneous fat, bone strength, and some aspects of brain
function.
The
testicles, or testes (singular
testis), are the male generative glands in animals. Male mammals
have two testicles, which are often contained within an
extension of the abdomen called the scrotum. In land mammals,
with the exception of the elephant, the testes are located
outside of the body, as they are suspended by the spermatic cord
and within the scrotum. This is due to the fact that fertile
spermatogenesis in mammals is more efficient at a temperature
somewhat less than the core body temperature (37 °C or 98.6 °F
for humans). The cremasteric muscle is part of the spermatic
cord. When this muscle contracts, the cord is shortened and the
testicle is moved closer up toward the body, which provides
slightly more warmth to maintain optimal testicular temperature.
When cooling is required, the cremasteric muscle relaxes and the
testicle is lowered away from the warm body and are able to
cool. This phenomenon is known as the cremasteric reflex. It
also occurs in response to stress (the testicles rise up toward
the body in an effort to protect them in a fight), and there are
persistent reports that relaxation indicates approach of orgasm.
There is a noticeable tendency to also retract during orgasm.
Like the ovaries (to which they are homologous), testicles are
components of both the reproductive system (being gonads) and
the endocrine system (being endocrine glands). The respective
functions of the testicles are: Producing sperm (spermatozoa),
producing male sex hormones, of which testosterone is the
best-known; Both functions of the testicle, sperm-forming and
endocrine, are under control of gonadotropic hormones produced
by the anterior pituitary. The Svadishtana Chakra
(Second Chakra) energize the ovaries in women and the testicles
in men, that is why this is call the sexual chakra.
The First Chakra Muladara translates to "root" and is one's
connection to the entire physical body, here within the Kunda
lies Kundalini, our divine life force, it is the root that feeds
all other Chakras, making life possible. For men, Muladara is
located inside the perineum at the prostate gland. For women, it
is located behind the cervix on the back wall of the vagina.
Nervous System:
Now, our very important Nervous system which coordinates the
activity of the muscles, monitors the organs, constructs and
also stops input from the senses, and initiates actions.
Prominent participants in a nervous system include neurons and
nerves, which play roles in such coordination. All parts of
nervous system are made of nervous tissue. The nervous system of
vertebrate animals is often divided into the central
nervous system (CNS) and the peripheral nervous
system (PNS). The CNS consists of the
brain and spinal cord. The PNS consists of all
other nerves and neurons that do not lie within the CNS. The
large majority of what are commonly called nerves (which are
actually axonal processes of nerve cells) are considered to be
PNS. The peripheral nervous system is divided into the somatic
nervous system and the autonomic nervous system.
The somatic nervous system is responsible
for coordinating the body's movements, and also for receiving
external stimuli. It is the system that regulates activities
that are under conscious control. The autonomic nervous
system is then split into the sympathetic division,
parasympathetic division, and enteric division. The
sympathetic nervous system responds to impending danger
or stress, and is responsible for the increase of one's
heartbeat and blood pressure, among other physiological changes,
along with the sense of excitement one feels due to the increase
of adrenaline in the system. The parasympathetic
nervous system, on the other hand, is evident when a person is
resting and feels relaxed, and is responsible for such things as
the constriction of the pupil, the slowing of the heart, the
dilation of the blood vessels, and the stimulation of the
digestive and genitourinary systems. The role of the enteric
nervous system is to manage every aspect of digestion, from the
esophagus to the stomach, small intestine and colon .
The spinal cord is a thin, tubular structure
that is an extension of the central nervous system from the
brain and is enclosed in and protected by the bony vertebral
column. The main function of the spinal cord is transmission of
neural inputs from the periphery to the brain and vice versa and
is a vital structure in our survival and functional capacity.
The spinal cord extends from the medulla oblongata in the brain
and continues to the conus medullaris near the lumbar level at
L1-2, terminating in a fibrous extension known as the filum
terminale. The adult spinal cord is approximately 18 inches
long, ovoid-shaped, and is enlarged in the cervical and lumbar
regions. The peripheral regions of the cord contains neuronal
white matter tracts containing sensory and motor neurons. The
central region is four-leaf clover shaped that surrounds the
central canal (an anatomic extension of the fourth ventricle)
and contains nerve cell bodies. The three meninges that cover
the spinal cord -- the outer dura mater, the arachnoid membrane,
and the innermost pia mater -- are continuous with that in the
brainstem and cerebral hemispheres, with cerebrospinal fluid
found in the subarachnoid space. The cord within the pia mater
is stabilized within the dura mater by the connecting
denticulate ligaments which extends from the pia mater laterally
between the dorsal and ventral roots. The spinal cord is divided
into 31 different segments, with motor nerve roots exiting in
the ventral aspects and sensory nerve roots entering in the
dorsal aspects. The ventral and dorsal roots later join to form
paired spinal nerves, one on each side of the spinal cord.

(This is a file (Picture
Illu_vertebral_column.jpg) from the Wikimedia Commons.)
There are 31 spinal cord nerve segments: 8 cervical segments,
12 thoracic segments, 5 lumbar segments, 5 sacral segments, 1
coccygeal segment.
Because the vertebral column grows longer than the spinal
cord, spinal cord segments become higher than the corresponding
vertebra, especially in the lower spinal cord segments in
adults. In a fetus, the vertebral levels originally correspond
with the spinal cord segments. In the adult, the cord ends
around the L1/L2 vertebral level at the conus medullaris, with
all of the spinal cord segments located superiorly to this. For
example, the segments for the lumbar and sacral regions are
found between the vertebral levels of T9 and L2. The S4 spinal
nerve roots arise from the cord around the upper lumbar/lower
thoracic vertebral region, and descend downward in the vertebral
canal. After they pass the end of the spinal cord, they are
considered to be part of the cauda equina. The roots for S4
finally leave the vertebral canal in the sacrum.
The picture below shows the aproximative location
of the major Chakras in relation to the spine. A Chakra is like
a miniature sun or a miniature energetic planet about the size
of a Canadian 2 dollar coin almost 2 inches in diameter. The
First Chakra Muladara in the centre has another litlle planet
halve the size, call the Kunda, and it is here that lies our
divine Kundalini, called by some” The Fire Serpent;” so now you
can imagine the miniscule size of it. When Kundalini energy
rises throuht the Nadis the stream of energy is no thicker than
a human hair. Can you imagine such a miniscule bit of energy
with the power of an atomic bomb, that is God! The Chakras spin
and draw in the Universal Life Force Energy (Prana) to keep the
spiritual, mental, emotional and physical health of the body in
balance.

(This is a file: Picture ChakraDiag.jpg) from the Wikimedia
Commons.Kim.Diagram of the location of chakras as described by
some writers on the subject. (Not everybody agrees in regard to
all details).
This Diagram shows only seven major Chakras, but
gives you a visual on the location of the main Chakras.

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