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Unit 9
- Module
- Biology Applied Science
- Institution
- PEARSON (PEARSON)
An in depth essay on the human regulation and reproductive system that got a distinction.
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Introduction:This assignment is on the Nervous System
and how diseases can affect the normal
functioning of the Nervous system. The
nervous system is a network of nerve cells
and fibres that transmits nerve impulses
between different parts of the body, it is the
main controlling system, regulatory system
and communicating system in our body. It is
the centre of all mental activity such as our
thoughts, learning and memory. Alongside
the endocrine system the nervous system is
responsible for regulating and maintaining
homeostasis. The nervous system consists
of the brain, spinal cord, and a network of
neurons; it sends, receives, and processes
information from all parts of the body
(Pearson, 2016). The functional organisation
of the nervous system is the CNS, it has two
main organs: the brain and the spinal cord.
Whilst the peripheral nervous system has
sensory nervous cells that send info to the
central nervous system from exterior stimuli
or inner organs, & motor nervous system
cells that carry info to organs, muscles along
with glands from the central nervous
system. The nervous system is made up of
two types of cells. Neurons are cells that
transmit electrical impulses to and from the
brain and nervous system. There are two
types of neuron-myelinated and
unmyelinated. Myelinated neurons conduct
electrical impulses much faster than unmyelinated neurons; myelinated neurons carry impulses from
sensory receptors to the central nervous system, or from the central nervous system to the effectors.
Neurons are an essential functional unit of the nervous system (Pearson, 2016).
Autonomic & Somatic Nervous System:
Being able to respond to changes in our environment is key to our safety & survival. It is the function of the
nervous system to allow us to identify changes & direct actions in response to these changes. The nervous
system enables us to respond to these changes with the somatic system. The somatic system is
sometimes referred to as the voluntary nervous system because many of its actions are under conscious
control. The voluntary system includes neurons that transmit impulses to the central nervous system from
receptors all over the body, it also includes motor neurons which transmit impulses to the muscles
(Pearson, 2016).
The autonomic nervous system is sometimes referred to as the involuntary nervous system because it
enables functioning of internal organs. The neural pathway to the heart involves the two branches of the
autonomic nervous system, this being the sympathetic and parasympathetic branches. When the
sympathetic nerves are activated, your heart rate accelerates, and your arteries and heart constrict to
increase blood pressure, or your pupils dilate to increase sensory input from the eyes. This prepares the
body to react in emerging situations. Whilst when the parasympathetic nerves are activated it does the
opposite, so the heart decelerates, and the lungs constricts to slow breathing. This is to bring the body back
to equilibrium as it calms the body after a predicament & brings back homeostasis. Furthermore, the
regulation of the heart & peripheral circulation by the nervous system is achieved by the control centres in
, the medulla that receive feedback from higher neural areas in the brain and afferent input from
mechanically sensitive receptors located throughout the body.
Central & Peripheral Nervous System:
The central nervous system aka CNS is the coordination centre that contains the brain and the spinal cord
This system helps the human body in terms of coordinating their behaviours and reacting to the
environment. The central nervous system receives information from the peripheral nervous system. Your
circulatory system carries oxygen, water, and nutrients to cells throughout your body. Wastes from the cells
are eliminated by your respiratory system, your excretory system, and your skin. Your nervous system
controls all these activities with electrical impulses through the CNS.
Different diseases can affect the CNS and because of that your cognitive or thought-process changes
including decreased memory, problems with balance, dizziness, nausea, feeling like the room is spinning,
coordination problems and Seizures. This affecting the sympathetic and parasympathetic pathways as they
rely on the CNS to send nerve impulses.
The peripheral nervous system is made up of nerves, and ganglia. Ganglia is a network of cells, conjoined
by synapses, found outside the brain and the spinal cord. Additionally, it includes the autonomic nervous
system and the sensory-somatic system. The Peripheral nervous system collects all vital information that
has been obtained from the environment and sends it to the central nervous system which processes the
information and gathers a response.
Reflex Arc:
The reflex arc is a passageway
that regulates the reflex action.
An example being if an individual
touched a hot object. We would
identify the hot object as the
stimulus as it is an object or
substance that causes and
encourages a response. This
can be both internal and
external. In this given case it is
an external stimulus which can
produce a fight or flight
response. Receptors in the skin
detect stimuli. The skin contains
a receptor known as a
mechanoreceptor. They enable
us to detect touch, so when the
individuals hand touches the hot
object, this would stimulate the mechanoreceptor, due to sudden pressure. The type of receptors that
would detect heat from the object are thermoreceptors and cutaneous mechanoreceptors which are also
located in the skin.
Nervous impulses are sent to the sensory neurons. Sensory neurons are found outside the CNS, and the
impulses are from the receptors. Electrical signals are fast and immediate. They are formed by the
movement of positively charged metal ions in and out of nerve cells. Sensory neurons then reconstruct the
external stimuli into an electrical impulse, and travels to the relay neuron, located in the CNS through the
synapse. The CNS acquires and absorbs the info from the sensory neurons and determines the necessary
steps needed to deal with the matter. The CNS dispatches the info to the muscles onwards to the motor
neurons. The motor neurons carry electrical signals to the muscles, which is the effector. Effectors consist
of muscles and glands; they respond to impulses and bring about change; the muscles in the palm and
forearm then contract in response to the nervous impulse. The hand flinches away.
How Impulses are generated:
Neurons conduct electrical impulses by using the Action Potential. This is generated through the flow of
positively charged ions across the neuronal membrane (Webmaster, 2011). Neurons, like all cells, maintain
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