The Nervous And Endocrine Systems

The Nervous And Endocrine Systems
Introduction The nervous and endocrine systems both function to maintain the stability of the internal environment. While both systems may work
together as a single Neuroendocrine system, the systems may also work alone performing communications, integration and control within the body.
(Patton and Thibodeau, 2010) The endocrine system consists of eight major glands; the hypothalamus, pituitary, thyroid, adrenals, pineal body,
reproductive organs and the pancreas. These glands are widely separated from each other with no physical connections. Endocrine glands are groups
of secretory cells surrounded by an extensive network of capillaries that facilitate diffusion of hormones from the secretory cells into the bloodstream.
Hormones are then carried in the bloodstream too target tissues and organs that may be quite distant, where they influence cellular growth and
metabolism. (Waugh, Grant and Ross, 2010) Hormones Hormones are important when gradual changes in the body are needed, such as; puberty and
growth hormones that are used during this process. They are gradual because the messages are sent through the blood system. Hormones are
controlled by glands, they decide how much, if any, are secreted. Some key examples of hormones in the body are as follows... HormoneSecreted
fromFunction Adrenalin Adrenal medulla Affects muscle and liver cells, adrenalin increases heart and metabolism rates. Released to prepare the body
for 'fight or flight' response. InsulinBeta cells
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NERVOUS SYSTEM
The nervous system consists of the brain, spinal cord, and a complex network of neurons. This system is responsible for sending, receiving, and
interpreting information from all parts of the body. The nervous system monitors and coordinates internal organ function and responds to changes in
the external environment. This system can be divided into two parts: the central nervous system and the peripheral nervous system. Let 's take a look at
the central nervous system.
Central Nervous System
The central nervous system (CNS) is the processing center for the nervous system. It receives information from and sends information to the peripheral
nervous system. The two main organs of the CNS are the brain and spinal cord. The brain processes ... Show more content on Helpwriting.net ...
The parietal lobes are located behind the frontal lobes and in front of theoccipital lobes. They process sensory information such as temperature,
pain,taste, and touch. In addition, the processing includes information about numbers, attentiveness to the position of one 's body parts, the space
around one 's body, and one 's relationship to this space.
The temporal lobes are located on each side of the brain. They process memory and auditory (hearing) information and speech and language functions.
The occipital lobes are located at the back of the brain. They receive and process visual information.
The cortex, also called gray matter, is the most external layer of the brain and predominantly contains neuronal bodies (the part of the neurons where
the DNA–containing cell nucleus is located). The gray matter participates actively in the storage and processing of information. An isolated clump of
nerve cell bodies in the gray matter is termed a nucleus (to be differentiated from a cell nucleus). The cells in the gray matter extend their projections,
called axons, to other areas of the brain.
Fibers that leave the cortex to conduct impulses toward other areas are termedefferent fibers, and fibers that approach the cortex from other areas of
the nervous system are termed afferent (nerves or pathways). Fibers that go from the motor cortex to the brainstem (for example, the pons) or the spinal

The Central Nervous System
The central nervous system is composed of our spinal cord and brain which consistently controls our mind and behavior. The complexity of our brain
is not entirely deciphered, but with extensive scientific research it can be concluded that each specific section has its own specialized function. In
reference to eating pizza, socializing, and playing a game of cards, it can be deduced that our central nervous system is always critically analyzing data
using our Broca's area for speech, hippocampus for memories, hypothalamus controlling internal body, and occipital lobe organizing visual stimuli. The
Broca's area lies within the frontal lobe of our brain. With the assistance of motor neurons, we are able to comprehend language and control our
speech when information is present. The flow of sensory stimuli is evaluated, allowing this multiplex network to create a plan for communication.
When conversing with friends over a game of cards, your Broca's area will interpret the situation. If you are being strategic, your brain may withhold
certain information that may expose your unique gaming tactics leaving you prone to losing. When you're engaged in a conversation with your peers,
the Broca's area then deciphers the language, allowing you to comprehend it so you understand what is being said. The motor neurons are used for
facial movements specifically in the mouth to produce the desired speech. Since the Broca's area works specifically with our mouth and face, when
you eat a

THE CENTRAL NERVOUS SYSTEM
Every behavior begins with biology. Our behaviors, as well as our thoughts and feelings, are produced by the actions of our brains, nerves, muscles,
and glands. In this chapter we will begin our journey into the world of psychology by considering the biological makeup of the human being, including
the most remarkable of human organs–the brain. We'll consider the structure of the brain and also the methods that psychologists use to study the brain
and to understand how it works.
We will see that the body is controlled by an information highway known as the nervous system. A collection of hundreds of billions of specialized cells
that transmit information between different parts of the body, a collection of... Show more content on Helpwriting.net ...
To improve the speed of their communication, and to keep their electrical charges from shorting out with other neurons, axons are often surrounded by
a myelin sheath. The myelin sheathmyelin sheathA layer of fatty tissue surrounding the axon of a neuron that acts as an insulator and allows faster
transmission of the electrical signal. is a layer of fatty tissue surrounding the axon of a neuron that both acts as an insulator and allows faster
transmission of the electrical signal. Axons branch out toward their ends, and at the tip of each branch is a terminal button.
Neurons Communicate Using Electricity and Chemicals
The nervous system operates using an electrochemical process (see Video Clip: The Electrochemical Action of the Neuron). An electrical charge moves
through the neuron itself and chemicals are used to transmit information between neurons. Within the neuron, when a signal is received by the
dendrites, is it transmitted to the soma in the form of an electrical signal, and, if the signal is strong enough, it may then be passed on to the axon and
then to the terminal buttons. If the signal reaches the terminal buttons, they are signaled to emit chemicals known as neurotransmitters, which
communicate with other neurons across the spaces between the cells, known as synapses.
Video Clip: The Electrochemical Action of the Neuron
This video clip

Nervous Systems And The Nervous System
Nervous System The human body is one of the most complex structures known to mankind. To this day, we still do not have all the answers to how our
body functions. One of the most complex structures in the human body is the nervous system, which controls the voluntary and involuntary actions, as
well as send signals throughout the body. The nervous system is split up into two parts; the peripheral (PNS) and central (CNS) nervous systems. The
central nervous system consists of two main parts; the brain and spinal cord. The brain receives and processes information as well as deal with
memories, thoughts, emotion, and much more. The spinal cord mainly deals with sending out signals from the brain to the rest of the body, as well as
control ... Show more content on Helpwriting.net ...
During this time our muscles change and blood vessels dilate or constrict without us consciously telling them to do so. This is an involuntary function
from autonomic system. On the other hand, while we rest, we have this system controlling our resting and digestion state. Again, these are involuntary
actions that go on all the time without us knowing or giving any thought to. Some of the important muscles the autonomic system deals with are
muscles in the stomach and intestine, muscles in the eye, cardiac muscles, smooth muscle around the blood vessels, and more. Not only does the ANS
deal with muscles, but it also plays a key role in regulation of the glands. The ANS is divided into three different parts; the sympathetic nervous system,
the parasympathetic nervous system, and the enteric nervous system. The sympathetic nervous system is the part that is related to the "fight or flight"
as discussed earlier. The sympathetic nervous system operates through neurons that originate in the spinal cord. Some of the main functions the
sympathetic system deals with are; increasing heart rate, pupil dilation, secretion of epinephrine and norepinephrine, mucus and saliva production,
bronchial dilation, and much more. The parasympathetic system is the part that is related to the "rest and digest" situations. This system deals with
conserving energy as well as dealing with digestion. In this system, there

Central Nervous And Peripheral Nervous System
Slide #1
The nervous system
The nervous system is a network of nerves and neurons that transmit signals from the brain to different parts of the body. This system is broken into
two main divisions the central nervous system and the peripheral nervous system (Victoria, 2013).
–The central nervous system consists of the brain and spinal cord. Here information is stored and necessary instructions or an output response is given.
–The peripheral nervous system consists of nerves and clusters of ganglion (ganglia). This division of the nervous system is split into two branches; the
somatic and the autonomic nervous system. The autonomic branch is known as the involuntary nervous system which controls the heart rate,
digestion, respiratory rate, swallowing and pupil dilation just to name a few. The somatic nervous system however is generally associated with
voluntary movement of the skeletal muscle allowing control of some body movements. ... Show more content on Helpwriting.net ...
Slide #2
Also known as the cardiovascular system, the circulatory system is responsible for the transportation of oxygen, nutrients and hormones around the
body, the regulation of blood flow and heart rate in order for the body to maintain homeostasis and the body's response to injury (Taylor, 2014).
Arteries carry oxygenated blood away from the heart to supply all bodily tissue with oxygenated blood. Stroke and myocardial infarction are generally
caused by deterioration of the arterial division of the circulatory system.
Veins carry deoxygenated blood back to the heart in order to be oxygenated. There are two different venous systems the systemic and the pulmonary.
–the circulatory system also works to maintain the body's optimal PH level which is vital in order for the body to reach homeostasis.
Slide

The Nervous And Endocrine Systems
The nervous and endocrine systems are arguably two of the most important systems in any form of complex organism. They are particularly complex
and important in humans. Both systems, especially in their cooperation, are essential for our bodies to function properly. Any simple fault or damage
to any aspects of these systems that goes untreated could mean at best chronic disease, or at worst death. This is because both systems together
maintain homeostasis in our bodies. Homeostasis in the meticulous control of bodily processes to maintain a stable internal environment that allows us
to function adequately. This essay will describe and explain how these systems work both separately and together to maintain homeostasis in the human
body.
The nervous system is the first port of call in our body's reception and response to both internal and external stimuli. Its many components enable us to
see, hear, smell, taste and feel the many aspects of touch, such as pressure and pain, along with many more physical senses such as heat, hunger, thirst
and balance. This system is also wholly responsible for our control of movement.
It is made up of many branches that coordinate different nervous activities in our bodies. The two main parts are the central nervous system (CNS),
which is composed of the brain and spinal chord (Fig. 1), and the peripheral nervous system (PNS), which has several more extensions. The PNS
consists of the nerves that radiate from the CNS; this includes the 12

Our nervous system and brain interact as we cope with our immediate environment. Thus, it transmits and receives our sensory inputs such as sounds,
sight, smells and feelings. One end of each neuron on the nerve endings are enclosed in a structure created to sense a specific stimulus. Sending sensory
information to the brain or spinal cord is performed by the nervous system. Nervous system is divided into two main systems: Central nervous system
and Peripheral nervous system (Saladin, 2014). The central nervous system consists of the spinal cord and brain, the brain which is divided into four
lobes (parietal, frontal, temporal and occipital). Spinal cord and brain work together even though there are some occasions when the spinal cord acts
earlier before the brain gets the information.
THE 3 BASIC FUNCTION OF THE NERVOUS SYSTEM
Sensory neurons or afferent: carry signals to the central nervous system from the outer parts of the body. Receptors within and near body surface,
Respond to stimuli .Send nerve impulses to CNS neurons are nerve cells that transmit sensory ... Show more content on Helpwriting.net ...
It is associated with our perception and recognition of auditory stimuli, memory skills, and speech. The right side lesions result in recall of non
verbal material such as music and drawing, while the left side temporal lesion result in impaired memory for verbal material (Blumer and Benson,
1975) The Temporal Lobe is basically all about our hearing and selective listening. It receives sensory information from our ears such as sounds and
speech, it is very important in comprehending any meaningful sound or speech. Temporal lobe made it possible for us to understand when we are been
talked to, it basically transmit different sound and even pitches into our ears from the sensory receptors. Any damage to the temporal lobe will cause
language comprehension disturbance, memory to be impaired and altered

The Nervous System And Nervous Systems
Every move that our bodies make, thinking about a film you saw last night or an essay you need to write for school, shaking off a little bug from the
leg, deciding between two things or drinking tea after it cools a bit, every action, reaction is driven by our nervous system. All the information taken
in is processed and executed by electrical and chemical signals to and from nervous cells. The nervous system controls all our physiological and
psychological reactions. All animals have nervous system, except for very simple ones like sponges (The Nervous System, 2015). Human's nervous
system is probably the most complex one, all of our thoughts, emotions and actions are based on the three principle functions: sensory input, integration,
... Show more content on Helpwriting.net ...
Efferent divisions includes also the somatic nervous system that controls skeletal muscle movements. And the autonomic nervous system that controls
inner organs such as heart, lungs etc. In the autonomic nervous system there are two divisions: sympathetic, that triggers an action and parasympathetic
that relaxes the body. The whole nervous system is made up by nervous cells– neurons, which respond to stimuli and transmit signals along. There are
many different types of neurons and different sizes of neurons.
Human's moods, impulses that flash through the mind or ideas are spurred by the biological condition. Which means that how you think, sense, feel
and see the world around you is influenced by chemicals in the brain (The chemical mind, 2014). Every neuron is made up of the cell body, where the
DNA information and the mitochondria are stored. Dendrites receive messages, they pick up the electric impulses and activate the action potential that
passes the impulses along to the cell body and the axon, which transmits the electrical impulses from the cell body out to other neurons or muscles and
so on. The axon is sometimes protected by myelin sheath, which helps speed up the transmission of messages. It shoots the electrical charge to its
terminals and toward the neighbouring neuron. The place where one neuron almost touches the other is called synapse, the little gap between two
neurons is called the synaptic gap. When the actual potential runs

The Body System : The Nervous System
The body systems: The Nervous system
Samantha P. Little
MA111
Jacquelyn Barrett
02/22/2016
Miller–Motte College Online Programs
Page Break The Body Systems: The Nervous System The nervous system is divided into two major sections: There is the central nervous system and the
peripheral nervous system. The central nervous system and the peripheral nervous system work together to collect information from within the body
and from the environment outside it. The systems process all the collected information and send instructions to the body; to obtain an appropriate
response. Once the data arrives, the brain will sort and file it before sending out any commands on what to do. The central system is the main
command center of the body that contains the brain as well as the spinal cord. The peripheral nervous system contains a network of nerves that
connect the rest of the body to the central nervous system. Even though the brain is the major control center if the body, its job would not be possible
without the spinal cord. The spinal cord is the major organ that helps information travel between the body and the brain. Nerves branch in the
peripheral system from, either the brain stem or spinal cord, each nerve attaches to a specific area of the torso and limbs it 's responsible for
communication to and from those regions. There are three very important

The Importance Of The Nervous System
During development, neurons extend their axons and dendrites to establish proper connections in the central and peripheral nervous system (CNS and
PNS). This wiring process is largely controlled by extracellular cues, which activate receptors on the responding neurons. In turn, these receptors initiate
signaling cascades that ultimately alter actin and microtubule dynamics, and these changes are translated into diverse cellular responses (1,2). Multiple
studies have demonstrated that guidance cues are multi–functional, where the same pairs of cues and their neuronal receptors induce diverse, and in
many cases opposite, cellular responses in different neuronal subtypes (3–5). For instance, Semaphorin3A (Sema3A) signaling through the same... Show
more content on Helpwriting.net ...
Therefore, here we aim to determine the underlying mechanisms of how the same guidance cue complex (Semaphorin–Plexin) promotes diverse
neuronal structure morphogenesis in different neuronal populations. Findings from this study are expected to provide a model for understanding how
one ligand–receptor complex can exhibit multiple phenotypes through the recruitment of distinct intracellular signaling pathways. We also anticipate
that the results of this study will have a significant impact on the field of developmental neurobiology, and bring us closer to our long–term goal in
elucidating the molecular mechanisms of neural circuit formation, organization and function.
Our central hypothesis is that Sema3A/PlexinA4, controls the distinct developmental neuronal processes, axon guidance and dendrite morphogenesis in
both the CNS and PNS through the recruitment of distinct PlexinA4 signaling cytoplasmic domains and their downstream effectors. Our initial
findings showed that the H/RBD or C2 domain of PlexA4 is equally capable of restoring the growth cone collapse process in PlexA4 knockout
sensory DRG axons, while the combination of the H/RBD and C1 domains are necessary for promoting dendritic elaboration in PlexA4 knockout
cortical neurons (9).
To address this further, we aim to achieve the following aims:
Aim 1: Investigate the structure–function

The Human Nervous System
The Human Nervous system is the most complex of the body, it is our essential controller; this system is independent and governs our cerebrations,
emotions, and functions. It additionally avails with sending, receiving, and transforming nerve impulses. The sensory system incorporates nerves,
tactile organs, the mind, and muscles. This system is furthermore classified as the visceral motor system separating it from the somatic motor system.
The most essential organs of the ANS are named the viscera of the Thoracic and abdominopelvic cavities. With this association we are incapable of
determining or feeling its existence in our bodies as it works unwillingly. This system explains our flight or battle reaction, watching our body amid
rest and reclamation, and observing our heart rate and body temperatures on a steady premise.
The ANS has two subsystems, known as the Sympathetic and Parasympathetic; these two systems vary somehow, the sympatheticnervous system
increments vigilantness, heart rate, blood glucose focus, circulatory strain, and blood stream to cardiovascular and skeletal muscle, and additionally
lessening blood stream to skin and digestive tract. Then again, the Parasympathetic division has a cooling, impact on a large portion of the body 's
capacities. This is kenned as the resting, and processing state. Both frameworks are constantly dynamic, and working. The thoughtful division speeds
up pulse and the parasympathetic division decelerates it. Each of these

The Nervous System ( Cns )
Introduction
The nervous system coordinates voluntary and involuntary actions of animal bodies and is in charge of transmitting signal from one part of the body
to another part. It is divided into two main systems, the Central Nervous System (CNS) that contains the brain and the spinal cord, and the Peripheral
Nervous System (PNS) that includes mostly all nerves connecting the CNS to every part of the body (Martini et al., 2005). The entire nervous system
relies on the good functioning of specialized cells: the neurons that convey electrical signals; and the neuroglia that is composed of several types of
specialized cells with different functions either involved in the structure of the nervous system, the enhancement of the signal transmission or even in
the defense mechanism.
Although the nervous system is an extraordinary machine that allows living organisms to respond to varying environmental conditions, physical
shocks may damage the structure itself and external chemical agents may compromise its good functioning by altering the basic mechanisms of the
electrical signal transmission or, in the worst case by initiating the death of neuronal cells. To counter such random risks, the nervous system has
developed multiple protections that can deal with most of major issues. However, in some cases, acute or chronic exposures to high concentrations of
neurotoxic chemicals may break through these protective barriers and induce irreversible effects or damages.
Anatomy and

Autonomic Nervous System
Organs of the body, such as the heart, intestines, and stomach, are regulated by the autonomic nervous system. The autonomic nervous system is
known as the involuntary division of the nervous system which consists of autonomic neurons that innervates cardiac muscle, smooth muscles, and
exocrine glands. The autonomic nervous system plays an essential role to keep the internal environment of the body in proper balance, known as
homeostasis. Regulation of blood pressure, gastrointestinal responses to food, contraction of the urinary bladder, focusing of the eyes, and
thermoregulation are just a few homeostatic functions that are regulated by the autonomic nervous system There are two divisions: the sympathetic
and parasympathetic nervous

Functions Of The Nervous System
Overtime, organisms have been able to adapt and develop in a range of diverse environments as a result of their ability to maintain homeostasis.
Homeostasis is the tendency of anatomical, behavioural and physiological systems to maintain internal stability, owing to the coordinated response of
its parts to any situation or stimulus that would tend to disturb its normal condition or function. (1) A major physiological system that works in
maintaining homeostasis in animals, specifically humans, is the nervous system. The nervous system consists of a vast network of interconnecting
neurons which transmit electronic signals throughout the body. All neurons relay information to each other through a complex electrochemical
process, making ... Show more content on Helpwriting.net ...
Neurons are the functional unit of the nervous system and thus are very complicated structures that play dynamic roles in performing vital bodily
functions. (4) As the information–processing units of the nervous system, neurons acquire information from sensory receptors, pass the information on
to other neurons, and make muscles move to produce behaviours. They encode memories and produce our thoughts and emotions. There are three
general classifications of neurons; these are sensory neurons, interneurons and motor neurons. They differ significantly in function and slightly in
structure, all having the same basic configuration. (6) Figure 1: Neuron shape and function (5)
In basic form, sensory neurons get information about what is happening in the body internally and externally and is responsible for transporting it to
the CNS to be processed. Motor neurons get information from other neurons and send commands to ones muscles, organs and glands. Interneurons are
neurons that are connected to one another, and are responsible for receiving information from other neurons and transmitting the information to other
neural connections. The basic structure of the neuron can be seen in the appendix below. (27) Figure 2: Neuron structure (3) Figure 3: Axons and
Node of Ranvier (3)
The junction between two neurons or a neuron and a muscle or gland is called the synapse. This is where

Controversy Of The Nervous System
The Nervous System and Controversy in Research The nervous system is a network of nerves and specialized cells that act as transmitters sending and
receiving signals through the human body. As science progresses research involving the nervous system stands in controversy. Just as the nature verses
nurture debate explaining the nervous system involves researcher investigate the areas of the brain and spinal cord affected by disorders ,as well as the
genetic factors, and environment factors involved in order to synthesize an understanding of the nervous system 's function (Gilbert, 2002).
Construction of the Nervous System and Its Role in Shaping Behaviors There are two main divisions that comprise the nervous system: the central
nervous system consisting of the brain and the spinal cord and the peripheral nervous system consisting of somatic and autonomic nervous systems
(Kalat, 2013). The brain and the spinal cord make up the central nervous system and is responsible for the transmission of nervous impulses as well as
receiving sensory information (Siegal, 1999). The peripheral nervous system, consisting of cranial nerves, spinal nerves, and peripheral ganglia, is
responsible for transmitting information to the central nervous system as well as the rest of the body (Hubbard, 2013). The formation of attitudes and
behaviors occur within the central nervous system (Koch, Cipolletta, & Gebbaro, 2014). A person's reaction to the environment in which they

The Parasympathetic Nervous System
The aim of the current study was to assess the ANS changes associated with RA from the clinical and electrophysiological point of view.
In the present study, both components of the ANS were assessed including the sympathetic and the parasympathetic nervous systems. The sympathetic
nervous system was assessed by using the BP changes in response to postural changes and SSR. The parasympathetic nervous system was assessed by
HR changes in response to postural changes [18].
Orthostatic stress test assesses the BP and HR changes associated postural changes in the body position from supine to standing. These changes are
mediated by sympathetic and parasympathetic nerve fibers. During standing from supine position (actively or passively), there

The Nervous Systems Essay
The processes of communication between distinct tissues and organs
Among various types of organ systems, the nervous system is one of the most important one in human body. It is responsible for producing, controlling
and guiding our thoughts and responses to the world around us according to James W. Pennebaker (2012). During embryological development, the cells
that form nervous system are incredibly specialised and work complexly than the cells that form skin or other body parts. Neurosecretory cells are one
of the examples of specialised nervous system cells that produce neurosecretions. Neurosecretions are hormones which carry information from sensor
cells to target cells and they can be released directly into the bloodstream ... Show more content on Helpwriting.net ...
Each individual nerve is made up of: afferent nerves and efferent nerves where afferent nerves transmit impulses towards the nervous system from
different parts of the body and efferent nerves transmit impulses away from the nervous system to the different parts of the body. The autonomic
nervous system is another type of PNS responsible for involuntary actions like movement of heart, lungs, etc.
The nervous system is made up of basic units called neurons. The main role of the neurons is to receive, integrate and transmit information
throughout the body. There are some neuroglial cells found in nervous system aswell which provide support to the neurons by giving protection and
nourishment Neurons have nerve processes that looks like finger like projections extended from the nerve cell body. They also contain axons and
dendrites which enable them to transmit signals throughout the body. Normally, axon carry signals away from the cell body and dendrites carry
signals toward the cell body according to Regina Bailey (2013). Neurons have three different shapes: bipolar, unipolar and multipolar where bipolar
has two neuronal processes coming out of the cell body, unipolar has only one neuronal process coming out of the cell body and multipolar has many
neuronal processes coming out of the cell body.
Source: http://www.studyblue.com/notes/note/n/nerve–cell–physiology–part–1/deck/1225587

The Development Of The Nervous System
Greetings class. I am Professor Valle and today we will discuss the development of the nervous system. Before we begin with the subject, I would
like to share a small clip. Please focus on the signs and symptoms seen on the clip. (At this point I will show the clip on https://www.youtube.com
/watch?v=b9R4cjdCGoY, it will last no more than 3 minutes). Did you see anything wrong between the couple? If so who was it? What were
some of the signs and symptoms that you noticed throughout the clip? Yes, you are all correct. This was a day to day life of someone living with
Alzheimer's disease. Notice how the wife was not able to do basic survival task. She was not able to put her shoes on, hygiene, eat, sleep, or
exercise without assistance. She had also lost her memory, she kept asking her husband who are you? Even though he was constantly taking care of
her on the daily basis. This type of mental illness affects 10% of people over the age of 65 (Turner, 2006). I did not show you guys the clip to be scared
of what the future might hold, I showed you the clip to demonstrate an example of a disorder caused by a disturbance in brain cell growth.
This class will focus on the importance of how the brain cells grow and how they degenerate. We will also address the following questions:
What facilitates the growth process?
What happens when brain cells die?
What is the impact of brain cell growth and degeneration on the brain and on human functioning?
What are some disorders

Nervous System
The Nervous System
The nervous system is the most complex part of the body, as they govern our thoughts, feelings, and bodily functions. It is an important factor in
science because it can lead to new discoveries for cures or diseases. The studies of the nervous system helped lower death rates from heart disease,
stroke, accidents, etc. The nervous system is a network of neurons (nerve cells) that that sends information to the brain to be analyzed. Neurons live both
in and outside the central nervous system. Understanding how the neurons work is vital to understanding the nervous system. Neurons The neuron has
two important structures called the dendrite and axon, also called nerve fibers. The dendrites are like tentacles that sprout from ... Show more content on
Helpwriting.net ...
Central Nervous System The brain and spinal cord forms the Central Nervous System. The spinal cord gathers information from the neurons and
sends it to the brain, but not all nerve impulses get sent to the brain. Only a few impulses reach the brain, and an even smaller number reaches the
part of the brain where they cause awareness. The brain and spinal cord is made up of gray and white matter, as well as the various nerve cells. The
brain is divided into three parts: the forebrain, midbrain, and hindbrain. The forebrain is called the cerebrum, the largest and most developed part of the
human brain. It is divided by the longitudinal sulcus, a deep crevice that separates the forebrain into the left and right cerebral hemispheres. Each
hemispheres control the motor (movement) and sensory (sight, smell, hearing, taste, and touch) functions of the other side of the body. The two
hemispheres are divided into four lobes: the frontal, parietal, occipital, and temporal lobe. The frontal lobe is involved with muscle control from head
to toe. The parietal lobe obtains sensory information from the skin and muscles. The occipital lobe receives information from vision, and the temporal
lobe controls speech. Although the four lobes do different jobs, they communicate with each other to allow the brain to coordinate a response. The
cerebrum combines the mixtures of sight, sound, smell, and

The Neuron The central nervous system is one of the most important systems in the human body, and at its core is the neuron. Neurons are cells that
facilitate the transmission of electrical signals throughout the body. They allow the nervous system to act as a communication network that runs
throughout the entire body. Without neurons, the brain could not tell the rest of the body what to do. Neurons come in various shapes and sizes;
however, they all share the same basic structure. Additionally, there are several different types of neurons that perform a variety of functions.
Structure of the Neuron As shown in Figure 1 (Barker 1991), the neuron is composed of three parts: the dendrite, the cell body, and theaxon. The
dendrites are structures resembling tree branches that receive signals from other neurons and send them to the cell body. The cell body determines
which signals among the many that it gets from the dendrites to send to the axon, which sends signals away from the cell body to other neurons
(Herlihy, 2000). The axons are sheathed by a layer of fat known as myelin, which protects the axon and increases the speed at which impulses are
carried out. However, myelin is formed differently in the central nervous and peripheral systems. In the central nervous system myelin is created by a
type of cell known as oligodendrocytes, while in the peripheral system they are formed by Schwann cells (Hall 1991). Figure 1 – Body of Neuron
Functions of Neurons

The Positive Nervous System
Given
In his book, The Sensitive Nervous System, Butler1 describes the complexity and connectedness of the nervous system. He describes how unique the
nervous system is, in that a change in one part will have effects on other parts, whether those changes be electrical, chemical, or mechanical.1 This
means, theoretically, producing an effect in the nervous system of the lower quadrant should produce an effect in an upper quadrant nervous system.
In a study performed on 60 healthy university students with no musculoskeletal conditions, Hyong and Kang2 found that passive hamstring stretching
had a statistically significant increase in the participant cervical flexion and extension range of motion (ROM). The participants had measurements taken
... Show more content on Helpwriting.net ...
Butler, D. S. (2000). The sensitive nervous system. Noigroup publications.
2.Hyong, I. H., & Kang, J. H. (2013). The immediate effects of passive hamstring stretching exercises on the cervical spine range of motion and
balance. Journal of Physical Therapy Science, 25(1), 113–116.Lohkamp M, Small K. Normal response to upper limb neurodynamic test 1 and 2a.
Manual Therapy [serial online]. April 2011; 16(2): 125–130. Available from: CINAHL Complete, Ipswich, MA. Accessed July 12, 2015.
3.Shacklock, M. O. (1996). Positive upper limb tension test in a case of surgically proven neuropathy: analysis and validity. Manual Therapy, 1(3),
154–161.
4.Oliver, G. S., & Rushton, A. (2011). A study to explore the reliability and precision of intra and inter
–rater measures of ULNT1 on an asymptomatic
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5.Lai, W. H., Shih, Y. F., Lin, P. L., Chen, W. Y., & Ma, H. L. (2012). Normal neurodynamic responses of the femoral slump test. Manual therapy, 17(2),
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6.Coppieters, M. W., & Butler, D. S. (2008). Do 'sliders' slide and 'tensioners' tension? An analysis of neurodynamic techniques and considerations
regarding their application. Manual therapy, 13(3),

Nervous System Analysis
As we do simple actions in our life we start to do them so often that we don't even realize how and when we are doing them. For example when we
get ready to ride a bike we just get on the bike and go, because we have done it so many times that it just comes naturally to us. Another example is
watching a scary movie and putting popcorn in our mouth at the same time. Well it is our nervous system that helps us to do these simple actions
because it handles information. When our phone rings there are a number of functions that go on in our brain. The first thing would be our neurons in
the auditory cortex which picks up the sound of the ringing phone, neuron functions are then going to relay the information to higher areas to process
what's going ... Show more content on Helpwriting.net ...
They supply nourishment to neurons, help remove neurons' waste products, and provide insulation around many axons. The primary role is to shield
synapses from the chatter of surrounding neuronal activity, enhancing the signal to noise ratio in the nervous system. The Neural Impulse uses energy
to send information. The resting potential of a neuron is its stable, negative charge when the cell is inactive Anaction potential is a very brief shift in a
neurons electrical charge that travels along the axon. After firing the action potential the channels in the cell membrane that opened now close up.
Some time is needed before they are ready to open and fire again. The absolute refractory period is the minimum length of time after an action potential,
during which another action potential cannot begin. Special junctions called synapses which depend on chemical messengers. A synaptic cleft is a
microscopic gap between the terminal button of 1 neuron and the cell membrane of another neuron. The neuron that sends a signal across the gap is
called the presynaptic neuron, and the neuron that receives the signal is called the postsynaptic neuron. The arrival of an action potential at an axon's
terminal buttons triggers the release of neurotransmitters chemicals that transmit information from 1 neuron to another. Most of these chemicals are
stored in small sacs called synaptic vesicles. Receptor sites are tuned to recognize and respond to some neurotransmitters but not to others. When a
neurotransmitter and a receptor molecule combine, reactions in the cell membrane cause a postsynaptic potential, a voltage change at a receptor site
on a postsynaptic cell membrane. They are graded which means that they vary in size and that they increase or decrease the probability of a neural
impulse in the receiving cell in proportion to the amount of voltage change. An excitatory PSP is a

Postnatal Nervous System
Introduction:
The nervous system is a complex body system that takes years to fully develop and changes main functions throughout one's life. (Enter Fetal
Development Structure Here). Postnatal nervous system development is a mix of fully developing parts of the brain, learning motor skills and natural
responses to outer stimuli. By puberty, all parts of the brain and spinal cord are almost fully growth, and the pituitary gland starts releasing FSH and LH
to begin the development of the body. After the frontal lobe is at its full maturity level, the brain begins to lose grey matter and white matter, this causes
the nervous system to focus on maintaining homeostasis and make decisions based on what is being lost and how do deal with it. Disorders are very
prevalent with the nervous system, such as Autism and Epilepsy, and they also occur due to... Show more content on Helpwriting.net ...
Fetal Development:
Changes Through the Lifespan:
After birth, the nervous system works to develop the rest of the system and for the child to have core motor skills by the age of three. By the age
of six, the brain will almost be to its full size, and the system is functioning for the child to have their personality, emotional responses, and reflexes
to begin to finalize what they will be for a majority of the life span. Puberty begins around 11 for girls and 12 for boys, thus the anterior pituitary
gland begins to release the hormones needed to let the body develop. The frontal lobe is still not fully developed at this age, which allows for poor
judgement and loss of control of emotions as a high amount of hormones are now pumping through the body. The nervous system works to balance out
any discrepancies in emotional balance, bodily growth, and personality developments in this stage of life. Adulthood occurs when puberty is over
between age 17 and 22, and the brain reaches

The Nervous System And Peripheral Nervous Systems
The nervous system has three general functions: a sensory function, an interpretative function and a motor function. Sensory nerves gather information
from inside the body and the outside environment. The nerves then carry the information to central nervous system (CNS). Nervous tissue consists of
two main types of cells: neurons and neuroglia. Neurons also so known as nerve cells ") transmit nerve impulses that move information around the
body. Central Nervous System and Peripheral Nervous System are Identified as the two major groups of nervous system organs while CNS = brain &
spinal cord and PNS nerves that extend from the brain (cranial nerves) and spinal cord (spinal nerves). Sensory receptors respond to stimuli and
transmit data about them to the brain. In the skin, receptors detect touch, pressure, vibration, temperature, and pain. Elsewhere in the body, more
specialized receptors detect light (see How the eye works), sound (see The mechanism of hearing), smell, and taste. The body nervous system detects
the changes affecting the body, make decisions, and stimulate muscles or glands to respond. The responses counteract the effects of the changes, where
the nervous system helps maintain homeostasis. Neurons vary in size and shape and also differ in the lengths and sizes because of their axons and
dendrites. Aneuron has 4 basic parts: the dendrites, the cell body which is also called the soma, the axon and the axon terminal. Dendrites – Extensions
from the neuron

Central Nervous And Peripheral Nervous System
My most interested system is the nervous system. The nervous system is made up of the brain, the spinal cord, and nerves. One of the most important
systems in your body, the nervous system is your body's control system. It sends, receives, and processes nerve impulses throughout the body. Together,
these organs are responsible for the control of the body and communication among its parts. The nervous system has two major parts: the central
nervous system (CNS) and the peripheral nervous system (PNS).
The central nervous system is the primary center of the body. It is composed of the brain, nerves, and spinal cord. It processes, guide movement and
send out sensations throughout the body. The brain sits right in the skull and have four parts to it, the brain stem, cerebrum, cerebellum, and the
diencephalon. The spinal cord is a long tube that connects to the brain and down the back of the body. It has 31 segments and there are pair of spinal
nerves in each segment. Both motor and sensory nerves are in the spinal cord. ... Show more content on Helpwriting.net ...
Such as eyes, ears, skin, and other "sensory receptors". The peripheral nervous system is made up of two parts, somatic nervous system and autonomic
nervous system. The somatic system picks up sensory information and its carried to the central nervous system. They also consist of the motor nerve
fibers. It sends messages for movement and acts to the skeletal muscle. It sends messages to the brain to give the muscle to give action. The autonomic
nervous system is made up of three parts; sympathetic nervous system, parasympathetic nervous system, and enteric nervous system. System controls
organs in the body where humans cannot. Like, heartbeat, digestion, and

The Nervous System Of The Brain
Introduction
The nervous system serves the purposes of communication inside of the body, coordination, movement, and sensation. The primary components that
make the nervous system carry out its functions include the brain, spinal cord, nerves, and ganglia (Saladin 2011 p. 10). Each component carries out its
specific function through electrical and chemicals messages (Saladin 2011 p. 352). The cerebral cortex of the brain is made up of neurons that make
connections with other parts of the brain. Different types of brain rhythms occur under different conditions. Alpha waves occur when an individual is
relaxed with their eyes closed. Relaxed means that the individual is not focused on external stimuli or performing mental operations. Beta ... Show more
content on Helpwriting.net ...
The CNS is made up of the brain and the spinal cord. The PNS is made up of the nerves and the ganglia (Saladin 2011 p. 352). Nerves are neural fibers
that are traveling together (Widmaier et al. 2014 p. G–16). Ganglia are spots were nerve cell bodies are bundled together (Saladin 2011 p. G–6). The
PNS can also be divided up into afferent and efferent. The afferent division is the sensory portion of thenervous system. Afferent is further broken
down into somatic and visceral. The somatic sensory portion receives signals from the muscles, skin, bones, and joints, and the visceral sensory
receives information from objects in the viscera, and they both carry the signals to the CNS (Saladin 2011 pp. 352–353). The efferent division is the
motor part of the nervous system, and unlike the afferent division, the efferent is carrying signals away from the CNS to deliver responses to muscles
and glands (Widmaier et al. 2014 p.179). Responses are triggered through preganglionic neurons that go from the CNS to the ganglia, and the
postganglionic neurons that go from the ganglia to what the neurons are targeting (Widmaier et al. 2014 p. 180). Just like the afferent division, the
efferent division can be divided into somatic and visceral. The somatic motor division goes from the CNS to skeletal muscles and is

Nervous Systems And The Nervous System
The nervous system is made up of tissues, cells and organs which regulate the body's responses to stimuli. The nervous system consists of the central
nervous system and the peripheral nervous system. It also consists of brain, spinal chord, facial nerves, body nerves, sensory neurone and motor
neurones, somatic and autonomic nervous systems, parasympathetic and sympathetic.
Central nervous system– The CNS is made up of the brain and spinal chord.
Peripheral nervous system– The PNS is made up of many sense organs, sensory neurons and ganglia. This allows communication between the body and
the CNS.
Somatic nervous system– The somatic nervous system controls places in the body such as the bones, skeletal muscles, skin and joints.
The somatic nervous system keeps the body and coordinated, both through reflexes and voluntary action.
Autonomic nervous system– The autonomic nervous system in the body regulates involuntary actions for example the beating of the heart, breathing,
digestion and organ function. The autonomic system is divided into sympathetic and parasympathetic.
.
Sympathetic– The sympathetic nervous system causes a fight or flight responses that speeds the body up in stressful or sudden circumstances. This
causes an increase in the heart rate, breathing rate and causes pupils to dilate whilst preparing the body to run or for danger.
Parasympathetic– The parasympathetic nervous system causes a rest or digest responses to slow the body down after stressful

Neuroscience Of The Nervous System
Vigen Karchyan
Neuroscience Neuroscience, commonly referred to as Neural Science, is the study of the way the nervous system develops, how it is structured and the
functions of it. Scientists put emphasis on the brain and the impact it has on behavior and cognitive functions. These scientists approach a closer look
on the reactions the nervous system has when humans have neurological, psychiatric and neurodevelopmental disorders. The entire concept of
neuroscience is addressed as a subdivision of biology. It is applied to chemistry, cognitive science, engineering, mathematics, linguistics and more.
Scientists say that neuroscience is identical as neurobiology but there is a difference between the two conceptions. Neurobiology focuses mainly on the
biology of the nervous system and neuroscience emphasizes on any portion of the nervous system. Neuroscientists have various fields of study that
include cellular, functional, computational and medical aspects of the nervous system. The history of neuroscience dates back and the Ancient
Egyptians believed that intelligence rooted from the heart. Throughout the process of mummification, they detached the brain but left the heart inside
of the body. Herodotus, a Greek historian that lived up until 425BC, claimed "the most perfect practice is to extract as much of the brain as possible
with an iron hook, and what the hook cannot reach is mixed with drugs." There were scripts focused on the brain that were first found in 1700BC in

Peripheral Nervous System
The nervous system comprise of the CNS and peripheral nervous system. The brain and spinal cord make up the CNS, while the autonomic nervous
system and somatic nervous system makes up the peripheral nervous system illustrated in figure 1 below. Figure 1. structure of the nervous system The
bone shelters the structures in the CNS and the cerebrospinal fliud mitigates them from injury. Shaped like a mushroom and lying within the skull, the
brain weighs around 1.35kg and has two types of matter. The impluses are recived and stoted in the grey while white matter trasmits impulses to and
from the grey matter. There are three main parts of the brain which are forebrain, midbrain and hindbrain. The brain stem is one inch long and located...
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More so, the impulse passes to the motor area and then down the spinal cord with the voluntary action, while on the other hand for the reflex
action, impulse passes up the dendrite and axon of the sensory neurone. The reflex action impulse passes on to relay neurone in the grey matter
near to the centre of the spinal cord. A voluntary action's impulse passes over to opposite side of the body, while a reflex action controls the same
side of the body. A voluntary action is controlled by the forebrain while the reflex action is controlled by the hindbrain. During a voluntary action,
the cerebrum coordinates incoming information and initiate impulses sent to the effectors. A voluntary action has a lot of cells and synapses and
long pathway leading to the slower reaction, while reflex only has 3 cells and 2 synapses leading to the quicker reaction. An example of a voluntary
action is that of when we want to answer a question we raise our hands while reflex is a knee jerk. A voluntary action may result in various responses
while the reflex always results in the same response.
In conclusion, the nervous system tells the body when something occurs. A change in temperature or light, pain, or pleasure, tension

A Study Of The Nervous System
All feelings and emotions that people experience are produced through chemical changes in the brain. A lack of certain chemicals or an abundance of
chemicals can lead individuals to have emotional imbalances often classifying them as more commonly and more seriously known as mental disorders.
Specific chemicals cause certain moods in individuals, often times substances containing these chemicals influence the way a person may feel.
Discussing what happens in the brain as it reacts to different chemical build ups will help us as individuals better understand our body and
communicate and respond to these experiences in a healthier way. The study of the nervous system is known as Neurochemistry. It 's the practice of
observing ... Show more content on Helpwriting.net ...
To get a sense of how activity takes place in an event of experience a feeling, any one neuron may be receiving many chemical messages both positive
and negative from surrounding neurons. Neurotransmitters may be "competing" to get the neuron to respond in different ways or they may work
together to produce a certain effect, when a neurotransmitter fails to affect a neuron it ceases to exist by returning back into separate chemicals.
When succeeding, you begin to have an emotional response. Every day we experience different combinations of emotions being exposed to
different events in our lives. If you were to search a list of feelings, you'd find lists that are longer than you'd think. Chemical build up for these
feelings are easier to classify. "Feel good" chemicals are chemicals that activate responses of well, feeling good. These include Oxytocin
(C43H66N12O12S2), Serotonin (C10H12N2O), and Dopamine (C8H11NO2). Depression linked chemicals are Norepinephrine (C8H11NO3), and
lack of Dopamine and Serotonin. Noteworthy, Dopamine controls arousal levels and motor control in many parts of the brain. Serotonin is the
neurotransmitter enhanced by many antidepressants and has a profound effect on mood, anxiety, and aggression. These chemical formulas are
compounds of simpler chemicals (example of Dopamine Synthesis provided on page 6). When is it classified as having too much or too little of

The Peripheral Nervous System
The peripheral nervous system made up of sensory and motor neurons that transmit messages to and from the central nervous system. The main
functions connect to the CNS as well. The PNS is not protected by the bone of the spine and the skull. Which leaves it's open to the exposed of toxins
and mechanical injuries. The PNS is divided into two man parts, which are the somatic and autonomic nervous system. The somatic nervous system is
there to transmit messages through the body. It transmits messages to the CNS like sight, sound, smell, temperature and body positions. When the
message is transmitted to the CNS, that's how a human is able to raise a hand, walk, wink or even run. The somatic system is even able to make a
human keep its

Anatomy Of The Nervous System
Emma Fletcher 013729779
Brain Functions Assignment 1. Anatomical Position – Human
The main anatomical position of the human is where the human is standing straight, facing forwards, with the arms down the sides of the body with
the palms facing outwards and the feet pointing outwards. The human is positioned this way so no bones crossover. 2. Central Nervous System
The part of the nervous system encompasses the brain and spinal cord. There is both white and grey matter in the central nervous system (CNS). Its
main function is to send, receive and interpret motor, sensory and cognitive information around the entire body. 3. Peripheral Nervous System
This part of the nervous system encompasses all of the ganglia and nerves ... Show more content on Helpwriting.net ...
Its main function is to control vomiting in the body by being able to detect toxins in the blood. It also participates in autonomic control in the body, due
to it being located outside the blood brain barrier. In autonomic control it helps control many systems in the body including both cardiovascular, feeding
and metabolism. 6. Cauda Equina
The cauda equina is a part of the external anatomy of the spinal cord consisting of a bunch of spinal nerves and their roots. It encompasses some
lumbar nerve pairs, sacral nerve pairs and the coccygeal nerve. The nerves within the cauda equina excite both the pelvic organs and lower limbs. Its
function also includes innervating the perineum in men and the bladder in both sexes.
7. Choroid Plexus
There are 4 sections of the brain where the choroid plexus is present, one located in each brain ventricle. They are all a plexus consisting of
specialized ependymal cells, the epithelial layer of the choroid plexus has very tight gap junctions which ensure substances are not crossing the layer of
cells into the cerebrospinal fluid. Its primary function is to manufacture cerebrospinal fluid, but it also acts as a filter. It helps to remove metabolic
waste, excess neurotransmitters and foreign substances, helping the brain to perform its functions well.
8. Dorsal root ganglion
The ganglia of the dorsal root are nodules on a dorsal root located next to vertebral column which run

The central nervous system can be compared to the air traffic control tower of a large international airport. Just as this main tower directs and controls
all incoming and outgoing flights. The central nervous system is the control center of our body, it sends information out and interprets things our body
senses. Regulating, controlling and coordinating incoming and outgoing impulses, thoughts, and feelings via nerves. Functionally, the nervous system
can be divided into the central nervous system (controls in–bound and out–bound neural impulses), and peripheral nervous system (connects the CNS
with the peripheral parts of the body). The PNS can be divided into subdivisions of the somatic nervous system (deals with the parts of the ... Show
more content on Helpwriting.net ...
The structure of the brain can be divided into three parts; cerebrum (the brain divided into two parts called the "cerebral hemispheres", cerebellum
(occupies the posterior fossa and separated by fissures), and the brainstem (a vertical stalk that ends at the opening of the foramen magnum and
continues as the spinal cord). Brain functions or activity is how a doctor can determine clinically one's death or ability to perform daily tasks based on
sensory and reflex testing. (Saladin, K. p. 512–514). Some diseases or disorders associated with the brain can range from infections, trauma, or
degenerative occurrences'. One of the most serious disease of infancy and childhood is Meningitis that is caused by infection. Meningitis invades the
CNS via the eyes, ears, nose, or throat causing swelling of the brain, hemorrhage, and sometimes death. Symptoms include high fevers, stiff neck,
intense headaches, drowsiness, and vomiting. Depending on the severity of diagnosis of meningitis by evaluation of CSF fluid is how treatment is
determined. Mild viral meningitis can be resolved with hydration, rest, and pain medications. More severe cases of viral or bacterial meningitis may
require hospitalization with antibiotics and oxygen treatments with close supervision of medical staff. Traumatic injuries of the brain include vascular
disorders. A stroke (CVA), transient ischemic attack (TIA),

Generation of pattern and diversity in Central Nervous System Central nervous system (CNS) is composed of brain and the spinal cord. Neurons
constitute a major part of the developing CNS. An axon is an extension of a neuron. The brain grows as a swelling at the front (rostal) end of the
neural tube and later leads to become a spinal cord (1,2). Development of the CNS involves many complex mechanisms beginning at the onset of
transformation of a single layer of ectodermal cells, the neuroectoderm until the end of the differentiation process resulting into highly complex
structure involving variety of neural cell types (1,2). A large number of cell types need to be arranged spatially and temporally to form a complex
structure during an... Show more content on Helpwriting.net ...
A distinct subset of cells (roof–plate) can be identified on the dorsal midline along the entire anterior– posterior axis of the CNS. Roof–plate acts as an
organizing center that control mechanisms of dorsal CNS development. With the closure of dorsal end (caudal) of neural tube, arise the interneuron
progenitors with non–overlapping expression of Basic helix–loop–helix (bHLH) Transcription factors (TFs) including Math1, Ngn1/2 and Mash1 in the
ventricular region of the developing dorsal spinal cord. (6) Mediators of roof–plate patterning activity in a developing spinal cord include secretory
factors of BMP and Wnt signaling cascades. (6,7) It has been documented that there is a mutual antagonistic effect between Wnt and BMP signaling
pathways in regulation of differentiation and proliferation of neuroepithelial cells in the dorsal spinal cord. (8). Several other signaling pathways like
the retinoic acid signaling and homeodomain TF– Lbx1expression in a group of interneurons is found to be crucial for dorsal spinal cord development.
However, there are evidences that had shown roof plate dependent patterning in the rostral (anterior) CNS. It is also hypothesized to influence the
development of dorsal hindbrain and forebrain. (6) The vertebrate CNS is a very

The Nervous System
The nervous system is made up of 2 main parts – the spinal cord and the brain. These two parts combine to make the central nervous system and the
sensory and motor nerves which form the peripheral nervous system. Neurons process information in the form of electrical signals, namely nerve
impulses, which travel along the axon. Charged ions are not able to enter plasma membranes which make neurons have a difference in ion
concentration between the inside and the outside of a neuron. This prevents the passive diffusion of Potassium and Sodium ions from areas of high
concentration to areas of low concentration. Proteins which act as ion channels and ion pumps are attached to plasma membranes. This allows the ions
to be transported across ... Show more content on Helpwriting.net ...
Voltage–gated ion channels maintain the concentrations of different ions inside and outside of the neuron cell.
An action potential takes place when a neuron sends information through an axon, away from the cell body. The transmission of the information flows
through a synapse. At the synaptic terminal, an electrical impulse causes the movement of vesicles containing neurotransmitters towards the
pre–synaptic membrane. The vesicle membrane merges with the pre–synaptic membrane releasing the neurotransmitters into the synaptic cleft, a space
which is between the pre–synaptic and post–synaptic endings. When a neurotransmitter binds to a receptor, the post–synaptic cell 's likelihood of firing
an action potential can be increased or decreased.
When neurotransmitter molecules are stuck to receptors located on a neuron 's dendrites, the part of a neuron which receives signals from other
neurons, ion channels are opened. At an excitatory synapse, the opening of ion channels enable positive ions to enter the neuron and results in the loss
of difference in the charge between the inside and the outside of the membrane, this is called depolarization. Sodium channels open first and sodium
ions rush into the neuron. When potassium channels open, potassium ions rush out of the cell and the depolarization is reversed. Sodium ion channels
begin to close which results in the action potential to go past –70 mV because the

The Nervous System
In the nervous system there are two main parts that it can be broken down into. The central nervous system (CNS) and peripheral nervous system
(PNS). The CNS controls the brain and spinal cord. The PNS's main job is to connect the CNS to the brain and spinal cord to the rest of the body e.g.
the organs so that they can communicate/ relay information to each other. How does this work?
The nervous system is a complex network of cells called neurons. The average brain has around 100 billion neurons communicating and relaying
information to around thousands of other neurons. Each neuron had a cell body and multiple extensions.
Just to make it even more complicated the PNS and the CNS also have systems of their own. Which are named the voluntary

Autonomic Nervous System
The two divisions of the autonomic nervous system (ANS), sympathetic (SNS) and parasympathetic (PNS), function in a complementary and
integrated manner to maintain homeostasis. The output of the autonomic nervous system is quick in comparison to the endocrine system functions. In
most cases, these systems have opposite effects, where one initiates a physiological response and the other inhibits. The nerves of this system regulate
vital internal functions which are generally performed without conscious control (Khan Academy, 2014).
The output of the ANS effects smooth, cardiac muscle and glandular tissue (Betts et al, 2013)
The sympathetic division is associated with the "fight or flight" response, dominating in stressful situations ... Show more content on Helpwriting.net ...
The synapse at the axon terminal of the postganglionic neuron and the target effector cell (in the form of muscle or gland) uses epinephrine
/norepinephrine (adrenaline/noradrenaline) (AK Lectures, 2014)
The parasympathetic division however, is concerned with "rest and digest" responses and when active, reverses the effects of the SNS. The PNS
system increases blood flow to digestive organs and excretory system and decreases the blood flow to skeletal tissue (an opposite effect to the SNS)
(AK Lectures, 2014) Salivary secretion is increased and gastric motility is stimulated to facilitate digestion (McCorry, 2007). The PNS either originates
at the start of the spinal cord or at the end (Khan Academy, 2014). The preganglionic neuron is of long structure and uses acetylcholine to transmit
signals to the shorter postganglionic neuron. The postganglionic neuron continues to use acetylcholine to transmit to the target effector cell (AK
Lectures, 2014)
Question 2 (1.3)
Using Illustrations, and a short commentary, describe the sensory and motor neuron.
Figure 1– A Motor Neuron (Biologymad, n.d.)
Figure 2– A Sensory Neuron (Biologymad, n.d.)
(200)
Sensory neurons are unipolar (Betts et al, 2013) Sensory (afferent) neurons transmit impulses from sensory receptors to the CNS and Motor (efferent)

neurons transmit impulses from the CNS to effector muscle and

The Nervous Systems ( Cns ) And The Peripheral Nervous System
The nervous system is the part of the human body in charge of coordinating the reception of external stimuli and the response the body gives to them. It
is equipped with sense organs called receptors, which are in charge of transforming the stimuli's energy into nerve impulses [1]. To emit an external
response, the nervous system uses effectors that can be either muscles or glands.
We can divide the nervous system into two separate systems: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS
consists of the brain and the spinal cord and is protected by the cranium and the vertebral column, respectively. The PNS is in charge of connecting the
CNS with the receptors and the effectors. To transfer the information from one part of the body to another, a specialized type of cells called neurons is
used.
Neurons are in charge of a communicative function. They perform two different types of activities. The first one consists in helping the conduction of a
signal from one part of the cell to another. The second activity they perform is synaptic transmission, which means communication between adjacent
cells.
Figure 1.1 – Neuron structure. Source: http://webspace.ship.edu
Neurons are composed of a cell body called soma, dendrites and axon. There is a single axon while there are multiple dendrites per each neuron.
Dendrites are used to conduct the received signals to cell body. The axon conducts nerve impulses to other neurons or muscle cells. It is

The Nervous And Endocrine Systems

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